Space weather

Mladen MartinisTheoretical Physics Division

Rudjer Boskovic InstituteZagreb Croatia

1st International Congress of CAPNIR-Opatija 2006

Space weather refers to the phenomena taking place in the Sun-Earth environment It is connected with the violent transfers of matter and electromagnetic energy from the Sun to the Earth

Basically all the energy that reaches the Earth comes from the Sun The Sun provide all the energy needed to maintain life on EarthThis huge nuclear engine drives also the Earthsweather

Outline

Solar activitySolar spectrumUV radiationEarths atmosphereOzone

Activity of the SunActivity of the Sun

E = mc2

Eλ = hcλ

Plancks lawWiens law

The solar cycleThe solar cycle

The Sun follows an 11-year activity cycle One indicator of solar activity is the number of sunspots This chart shows that the Sun was near its peak level or ldquosolar maximumrdquo at late 2000 or early 2001

FilamentsProminencesFilamentsProminences

This image is taken through a filter This image is taken through a filter centered on a spectral line of Hydrogen centered on a spectral line of Hydrogen that forms above the surface of the Sunthat forms above the surface of the Sun

Interesting new features seen on this Interesting new features seen on this image are filaments dark string-like image are filaments dark string-like structures visible on the disk and structures visible on the disk and prominences bright structures extending prominences bright structures extending outward over the limboutward over the limb

Physically filaments and prominences are Physically filaments and prominences are one and the same namely condensations one and the same namely condensations of cooler gas high up in the solar of cooler gas high up in the solar atmosphereatmosphere

Filament Prominences

ProminencesProminences

Some filaments and prominences Some filaments and prominences

can reachcan reach impressive sizes and impressive sizes and

remain visible very far above the remain visible very far above the

solar disk Thsolar disk Thee prominence prominence on theon the

picture picture extends some 200000 km extends some 200000 km

above the solar surfaceabove the solar surface

The Solar CoronaThe Solar Corona

The corona is the area The corona is the area just above the surface just above the surface While the surface is While the surface is about about 50005000o o CelsiusCelsius the temperature in the the temperature in the corona reaches about corona reaches about 2 million degrees 2 million degrees CelsiusCelsius

What causes this rapid What causes this rapid increase in tempera-increase in tempera-ture is still one of the ture is still one of the big mysteries in solar big mysteries in solar physicsphysics

Surface 5000 o C

Corona2000000 o C

The black circle divides two images

The Sunrsquos Magnetic FieldThe Sunrsquos Magnetic Field

The Sun is strongly affected The Sun is strongly affected by magnetic forces by magnetic forces The The redred arrowsarrows show open show open

magnetic field lines emerging magnetic field lines emerging from the poles from the poles

The The graygray arrowsarrows represent represent solar wind particles which solar wind particles which carry field lines with it carry field lines with it

The bright active regions The bright active regions have closed magnetic field have closed magnetic field lines lines (orange)(orange)

Solar spectrumSolar spectrum

The solar spectrumBy and large the spectrum of theSun resembles closely a blackbody

Why measure solar UV lightWhy measure solar UV light

Solar PhysicsSolar Physics ie the mechanisms responsible for the workings of ie the mechanisms responsible for the workings of and changes in the Sun and changes in the Sun The Earths Upper AtmosphereThe Earths Upper Atmosphere ie changes resulting from the UV ie changes resulting from the UV light absorption in the stratosphere mesosphere and thermosphere light absorption in the stratosphere mesosphere and thermosphere The Earths ClimateThe Earths Climate eg changes in tropospheric temperatures eg changes in tropospheric temperatures

The sun is the primary driving force behind the Earths climate The sun is the primary driving force behind the Earths climate

Both the sun itself and the climate are changing and evolving Both the sun itself and the climate are changing and evolving consistent with known physical laws However due to the veryconsistent with known physical laws However due to the verycomplicated nature of these laws predictions of their overall effectscomplicated nature of these laws predictions of their overall effectsare uncertain To understand and properly model the evolution of theare uncertain To understand and properly model the evolution of thestate of the upper atmosphere or climate systems it is necessary tostate of the upper atmosphere or climate systems it is necessary toknow the spectral distribution of solar light and the energies and fluxesknow the spectral distribution of solar light and the energies and fluxesof incoming particles of incoming particles

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

Space weather refers to the phenomena taking place in the Sun-Earth environment It is connected with the violent transfers of matter and electromagnetic energy from the Sun to the Earth

Basically all the energy that reaches the Earth comes from the Sun The Sun provide all the energy needed to maintain life on EarthThis huge nuclear engine drives also the Earthsweather

Outline

Solar activitySolar spectrumUV radiationEarths atmosphereOzone

Activity of the SunActivity of the Sun

E = mc2

Eλ = hcλ

Plancks lawWiens law

The solar cycleThe solar cycle

The Sun follows an 11-year activity cycle One indicator of solar activity is the number of sunspots This chart shows that the Sun was near its peak level or ldquosolar maximumrdquo at late 2000 or early 2001

FilamentsProminencesFilamentsProminences

This image is taken through a filter This image is taken through a filter centered on a spectral line of Hydrogen centered on a spectral line of Hydrogen that forms above the surface of the Sunthat forms above the surface of the Sun

Interesting new features seen on this Interesting new features seen on this image are filaments dark string-like image are filaments dark string-like structures visible on the disk and structures visible on the disk and prominences bright structures extending prominences bright structures extending outward over the limboutward over the limb

Physically filaments and prominences are Physically filaments and prominences are one and the same namely condensations one and the same namely condensations of cooler gas high up in the solar of cooler gas high up in the solar atmosphereatmosphere

Filament Prominences

ProminencesProminences

Some filaments and prominences Some filaments and prominences

can reachcan reach impressive sizes and impressive sizes and

remain visible very far above the remain visible very far above the

solar disk Thsolar disk Thee prominence prominence on theon the

picture picture extends some 200000 km extends some 200000 km

above the solar surfaceabove the solar surface

The Solar CoronaThe Solar Corona

The corona is the area The corona is the area just above the surface just above the surface While the surface is While the surface is about about 50005000o o CelsiusCelsius the temperature in the the temperature in the corona reaches about corona reaches about 2 million degrees 2 million degrees CelsiusCelsius

What causes this rapid What causes this rapid increase in tempera-increase in tempera-ture is still one of the ture is still one of the big mysteries in solar big mysteries in solar physicsphysics

Surface 5000 o C

Corona2000000 o C

The black circle divides two images

The Sunrsquos Magnetic FieldThe Sunrsquos Magnetic Field

The Sun is strongly affected The Sun is strongly affected by magnetic forces by magnetic forces The The redred arrowsarrows show open show open

magnetic field lines emerging magnetic field lines emerging from the poles from the poles

The The graygray arrowsarrows represent represent solar wind particles which solar wind particles which carry field lines with it carry field lines with it

The bright active regions The bright active regions have closed magnetic field have closed magnetic field lines lines (orange)(orange)

Solar spectrumSolar spectrum

The solar spectrumBy and large the spectrum of theSun resembles closely a blackbody

Why measure solar UV lightWhy measure solar UV light

Solar PhysicsSolar Physics ie the mechanisms responsible for the workings of ie the mechanisms responsible for the workings of and changes in the Sun and changes in the Sun The Earths Upper AtmosphereThe Earths Upper Atmosphere ie changes resulting from the UV ie changes resulting from the UV light absorption in the stratosphere mesosphere and thermosphere light absorption in the stratosphere mesosphere and thermosphere The Earths ClimateThe Earths Climate eg changes in tropospheric temperatures eg changes in tropospheric temperatures

The sun is the primary driving force behind the Earths climate The sun is the primary driving force behind the Earths climate

Both the sun itself and the climate are changing and evolving Both the sun itself and the climate are changing and evolving consistent with known physical laws However due to the veryconsistent with known physical laws However due to the verycomplicated nature of these laws predictions of their overall effectscomplicated nature of these laws predictions of their overall effectsare uncertain To understand and properly model the evolution of theare uncertain To understand and properly model the evolution of thestate of the upper atmosphere or climate systems it is necessary tostate of the upper atmosphere or climate systems it is necessary toknow the spectral distribution of solar light and the energies and fluxesknow the spectral distribution of solar light and the energies and fluxesof incoming particles of incoming particles

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

Outline

Solar activitySolar spectrumUV radiationEarths atmosphereOzone

Activity of the SunActivity of the Sun

E = mc2

Eλ = hcλ

Plancks lawWiens law

The solar cycleThe solar cycle

The Sun follows an 11-year activity cycle One indicator of solar activity is the number of sunspots This chart shows that the Sun was near its peak level or ldquosolar maximumrdquo at late 2000 or early 2001

FilamentsProminencesFilamentsProminences

This image is taken through a filter This image is taken through a filter centered on a spectral line of Hydrogen centered on a spectral line of Hydrogen that forms above the surface of the Sunthat forms above the surface of the Sun

Interesting new features seen on this Interesting new features seen on this image are filaments dark string-like image are filaments dark string-like structures visible on the disk and structures visible on the disk and prominences bright structures extending prominences bright structures extending outward over the limboutward over the limb

Physically filaments and prominences are Physically filaments and prominences are one and the same namely condensations one and the same namely condensations of cooler gas high up in the solar of cooler gas high up in the solar atmosphereatmosphere

Filament Prominences

ProminencesProminences

Some filaments and prominences Some filaments and prominences

can reachcan reach impressive sizes and impressive sizes and

remain visible very far above the remain visible very far above the

solar disk Thsolar disk Thee prominence prominence on theon the

picture picture extends some 200000 km extends some 200000 km

above the solar surfaceabove the solar surface

The Solar CoronaThe Solar Corona

The corona is the area The corona is the area just above the surface just above the surface While the surface is While the surface is about about 50005000o o CelsiusCelsius the temperature in the the temperature in the corona reaches about corona reaches about 2 million degrees 2 million degrees CelsiusCelsius

What causes this rapid What causes this rapid increase in tempera-increase in tempera-ture is still one of the ture is still one of the big mysteries in solar big mysteries in solar physicsphysics

Surface 5000 o C

Corona2000000 o C

The black circle divides two images

The Sunrsquos Magnetic FieldThe Sunrsquos Magnetic Field

The Sun is strongly affected The Sun is strongly affected by magnetic forces by magnetic forces The The redred arrowsarrows show open show open

magnetic field lines emerging magnetic field lines emerging from the poles from the poles

The The graygray arrowsarrows represent represent solar wind particles which solar wind particles which carry field lines with it carry field lines with it

The bright active regions The bright active regions have closed magnetic field have closed magnetic field lines lines (orange)(orange)

Solar spectrumSolar spectrum

The solar spectrumBy and large the spectrum of theSun resembles closely a blackbody

Why measure solar UV lightWhy measure solar UV light

Solar PhysicsSolar Physics ie the mechanisms responsible for the workings of ie the mechanisms responsible for the workings of and changes in the Sun and changes in the Sun The Earths Upper AtmosphereThe Earths Upper Atmosphere ie changes resulting from the UV ie changes resulting from the UV light absorption in the stratosphere mesosphere and thermosphere light absorption in the stratosphere mesosphere and thermosphere The Earths ClimateThe Earths Climate eg changes in tropospheric temperatures eg changes in tropospheric temperatures

The sun is the primary driving force behind the Earths climate The sun is the primary driving force behind the Earths climate

Both the sun itself and the climate are changing and evolving Both the sun itself and the climate are changing and evolving consistent with known physical laws However due to the veryconsistent with known physical laws However due to the verycomplicated nature of these laws predictions of their overall effectscomplicated nature of these laws predictions of their overall effectsare uncertain To understand and properly model the evolution of theare uncertain To understand and properly model the evolution of thestate of the upper atmosphere or climate systems it is necessary tostate of the upper atmosphere or climate systems it is necessary toknow the spectral distribution of solar light and the energies and fluxesknow the spectral distribution of solar light and the energies and fluxesof incoming particles of incoming particles

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

Activity of the SunActivity of the Sun

E = mc2

Eλ = hcλ

Plancks lawWiens law

The solar cycleThe solar cycle

The Sun follows an 11-year activity cycle One indicator of solar activity is the number of sunspots This chart shows that the Sun was near its peak level or ldquosolar maximumrdquo at late 2000 or early 2001

FilamentsProminencesFilamentsProminences

This image is taken through a filter This image is taken through a filter centered on a spectral line of Hydrogen centered on a spectral line of Hydrogen that forms above the surface of the Sunthat forms above the surface of the Sun

Interesting new features seen on this Interesting new features seen on this image are filaments dark string-like image are filaments dark string-like structures visible on the disk and structures visible on the disk and prominences bright structures extending prominences bright structures extending outward over the limboutward over the limb

Physically filaments and prominences are Physically filaments and prominences are one and the same namely condensations one and the same namely condensations of cooler gas high up in the solar of cooler gas high up in the solar atmosphereatmosphere

Filament Prominences

ProminencesProminences

Some filaments and prominences Some filaments and prominences

can reachcan reach impressive sizes and impressive sizes and

remain visible very far above the remain visible very far above the

solar disk Thsolar disk Thee prominence prominence on theon the

picture picture extends some 200000 km extends some 200000 km

above the solar surfaceabove the solar surface

The Solar CoronaThe Solar Corona

The corona is the area The corona is the area just above the surface just above the surface While the surface is While the surface is about about 50005000o o CelsiusCelsius the temperature in the the temperature in the corona reaches about corona reaches about 2 million degrees 2 million degrees CelsiusCelsius

What causes this rapid What causes this rapid increase in tempera-increase in tempera-ture is still one of the ture is still one of the big mysteries in solar big mysteries in solar physicsphysics

Surface 5000 o C

Corona2000000 o C

The black circle divides two images

The Sunrsquos Magnetic FieldThe Sunrsquos Magnetic Field

The Sun is strongly affected The Sun is strongly affected by magnetic forces by magnetic forces The The redred arrowsarrows show open show open

magnetic field lines emerging magnetic field lines emerging from the poles from the poles

The The graygray arrowsarrows represent represent solar wind particles which solar wind particles which carry field lines with it carry field lines with it

The bright active regions The bright active regions have closed magnetic field have closed magnetic field lines lines (orange)(orange)

Solar spectrumSolar spectrum

The solar spectrumBy and large the spectrum of theSun resembles closely a blackbody

Why measure solar UV lightWhy measure solar UV light

Solar PhysicsSolar Physics ie the mechanisms responsible for the workings of ie the mechanisms responsible for the workings of and changes in the Sun and changes in the Sun The Earths Upper AtmosphereThe Earths Upper Atmosphere ie changes resulting from the UV ie changes resulting from the UV light absorption in the stratosphere mesosphere and thermosphere light absorption in the stratosphere mesosphere and thermosphere The Earths ClimateThe Earths Climate eg changes in tropospheric temperatures eg changes in tropospheric temperatures

The sun is the primary driving force behind the Earths climate The sun is the primary driving force behind the Earths climate

Both the sun itself and the climate are changing and evolving Both the sun itself and the climate are changing and evolving consistent with known physical laws However due to the veryconsistent with known physical laws However due to the verycomplicated nature of these laws predictions of their overall effectscomplicated nature of these laws predictions of their overall effectsare uncertain To understand and properly model the evolution of theare uncertain To understand and properly model the evolution of thestate of the upper atmosphere or climate systems it is necessary tostate of the upper atmosphere or climate systems it is necessary toknow the spectral distribution of solar light and the energies and fluxesknow the spectral distribution of solar light and the energies and fluxesof incoming particles of incoming particles

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

The solar cycleThe solar cycle

The Sun follows an 11-year activity cycle One indicator of solar activity is the number of sunspots This chart shows that the Sun was near its peak level or ldquosolar maximumrdquo at late 2000 or early 2001

FilamentsProminencesFilamentsProminences

This image is taken through a filter This image is taken through a filter centered on a spectral line of Hydrogen centered on a spectral line of Hydrogen that forms above the surface of the Sunthat forms above the surface of the Sun

Interesting new features seen on this Interesting new features seen on this image are filaments dark string-like image are filaments dark string-like structures visible on the disk and structures visible on the disk and prominences bright structures extending prominences bright structures extending outward over the limboutward over the limb

Physically filaments and prominences are Physically filaments and prominences are one and the same namely condensations one and the same namely condensations of cooler gas high up in the solar of cooler gas high up in the solar atmosphereatmosphere

Filament Prominences

ProminencesProminences

Some filaments and prominences Some filaments and prominences

can reachcan reach impressive sizes and impressive sizes and

remain visible very far above the remain visible very far above the

solar disk Thsolar disk Thee prominence prominence on theon the

picture picture extends some 200000 km extends some 200000 km

above the solar surfaceabove the solar surface

The Solar CoronaThe Solar Corona

The corona is the area The corona is the area just above the surface just above the surface While the surface is While the surface is about about 50005000o o CelsiusCelsius the temperature in the the temperature in the corona reaches about corona reaches about 2 million degrees 2 million degrees CelsiusCelsius

What causes this rapid What causes this rapid increase in tempera-increase in tempera-ture is still one of the ture is still one of the big mysteries in solar big mysteries in solar physicsphysics

Surface 5000 o C

Corona2000000 o C

The black circle divides two images

The Sunrsquos Magnetic FieldThe Sunrsquos Magnetic Field

The Sun is strongly affected The Sun is strongly affected by magnetic forces by magnetic forces The The redred arrowsarrows show open show open

magnetic field lines emerging magnetic field lines emerging from the poles from the poles

The The graygray arrowsarrows represent represent solar wind particles which solar wind particles which carry field lines with it carry field lines with it

The bright active regions The bright active regions have closed magnetic field have closed magnetic field lines lines (orange)(orange)

Solar spectrumSolar spectrum

The solar spectrumBy and large the spectrum of theSun resembles closely a blackbody

Why measure solar UV lightWhy measure solar UV light

Solar PhysicsSolar Physics ie the mechanisms responsible for the workings of ie the mechanisms responsible for the workings of and changes in the Sun and changes in the Sun The Earths Upper AtmosphereThe Earths Upper Atmosphere ie changes resulting from the UV ie changes resulting from the UV light absorption in the stratosphere mesosphere and thermosphere light absorption in the stratosphere mesosphere and thermosphere The Earths ClimateThe Earths Climate eg changes in tropospheric temperatures eg changes in tropospheric temperatures

The sun is the primary driving force behind the Earths climate The sun is the primary driving force behind the Earths climate

Both the sun itself and the climate are changing and evolving Both the sun itself and the climate are changing and evolving consistent with known physical laws However due to the veryconsistent with known physical laws However due to the verycomplicated nature of these laws predictions of their overall effectscomplicated nature of these laws predictions of their overall effectsare uncertain To understand and properly model the evolution of theare uncertain To understand and properly model the evolution of thestate of the upper atmosphere or climate systems it is necessary tostate of the upper atmosphere or climate systems it is necessary toknow the spectral distribution of solar light and the energies and fluxesknow the spectral distribution of solar light and the energies and fluxesof incoming particles of incoming particles

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

FilamentsProminencesFilamentsProminences

This image is taken through a filter This image is taken through a filter centered on a spectral line of Hydrogen centered on a spectral line of Hydrogen that forms above the surface of the Sunthat forms above the surface of the Sun

Interesting new features seen on this Interesting new features seen on this image are filaments dark string-like image are filaments dark string-like structures visible on the disk and structures visible on the disk and prominences bright structures extending prominences bright structures extending outward over the limboutward over the limb

Physically filaments and prominences are Physically filaments and prominences are one and the same namely condensations one and the same namely condensations of cooler gas high up in the solar of cooler gas high up in the solar atmosphereatmosphere

Filament Prominences

ProminencesProminences

Some filaments and prominences Some filaments and prominences

can reachcan reach impressive sizes and impressive sizes and

remain visible very far above the remain visible very far above the

solar disk Thsolar disk Thee prominence prominence on theon the

picture picture extends some 200000 km extends some 200000 km

above the solar surfaceabove the solar surface

The Solar CoronaThe Solar Corona

The corona is the area The corona is the area just above the surface just above the surface While the surface is While the surface is about about 50005000o o CelsiusCelsius the temperature in the the temperature in the corona reaches about corona reaches about 2 million degrees 2 million degrees CelsiusCelsius

What causes this rapid What causes this rapid increase in tempera-increase in tempera-ture is still one of the ture is still one of the big mysteries in solar big mysteries in solar physicsphysics

Surface 5000 o C

Corona2000000 o C

The black circle divides two images

The Sunrsquos Magnetic FieldThe Sunrsquos Magnetic Field

The Sun is strongly affected The Sun is strongly affected by magnetic forces by magnetic forces The The redred arrowsarrows show open show open

magnetic field lines emerging magnetic field lines emerging from the poles from the poles

The The graygray arrowsarrows represent represent solar wind particles which solar wind particles which carry field lines with it carry field lines with it

The bright active regions The bright active regions have closed magnetic field have closed magnetic field lines lines (orange)(orange)

Solar spectrumSolar spectrum

The solar spectrumBy and large the spectrum of theSun resembles closely a blackbody

Why measure solar UV lightWhy measure solar UV light

Solar PhysicsSolar Physics ie the mechanisms responsible for the workings of ie the mechanisms responsible for the workings of and changes in the Sun and changes in the Sun The Earths Upper AtmosphereThe Earths Upper Atmosphere ie changes resulting from the UV ie changes resulting from the UV light absorption in the stratosphere mesosphere and thermosphere light absorption in the stratosphere mesosphere and thermosphere The Earths ClimateThe Earths Climate eg changes in tropospheric temperatures eg changes in tropospheric temperatures

The sun is the primary driving force behind the Earths climate The sun is the primary driving force behind the Earths climate

Both the sun itself and the climate are changing and evolving Both the sun itself and the climate are changing and evolving consistent with known physical laws However due to the veryconsistent with known physical laws However due to the verycomplicated nature of these laws predictions of their overall effectscomplicated nature of these laws predictions of their overall effectsare uncertain To understand and properly model the evolution of theare uncertain To understand and properly model the evolution of thestate of the upper atmosphere or climate systems it is necessary tostate of the upper atmosphere or climate systems it is necessary toknow the spectral distribution of solar light and the energies and fluxesknow the spectral distribution of solar light and the energies and fluxesof incoming particles of incoming particles

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

ProminencesProminences

Some filaments and prominences Some filaments and prominences

can reachcan reach impressive sizes and impressive sizes and

remain visible very far above the remain visible very far above the

solar disk Thsolar disk Thee prominence prominence on theon the

picture picture extends some 200000 km extends some 200000 km

above the solar surfaceabove the solar surface

The Solar CoronaThe Solar Corona

The corona is the area The corona is the area just above the surface just above the surface While the surface is While the surface is about about 50005000o o CelsiusCelsius the temperature in the the temperature in the corona reaches about corona reaches about 2 million degrees 2 million degrees CelsiusCelsius

What causes this rapid What causes this rapid increase in tempera-increase in tempera-ture is still one of the ture is still one of the big mysteries in solar big mysteries in solar physicsphysics

Surface 5000 o C

Corona2000000 o C

The black circle divides two images

The Sunrsquos Magnetic FieldThe Sunrsquos Magnetic Field

The Sun is strongly affected The Sun is strongly affected by magnetic forces by magnetic forces The The redred arrowsarrows show open show open

magnetic field lines emerging magnetic field lines emerging from the poles from the poles

The The graygray arrowsarrows represent represent solar wind particles which solar wind particles which carry field lines with it carry field lines with it

The bright active regions The bright active regions have closed magnetic field have closed magnetic field lines lines (orange)(orange)

Solar spectrumSolar spectrum

The solar spectrumBy and large the spectrum of theSun resembles closely a blackbody

Why measure solar UV lightWhy measure solar UV light

Solar PhysicsSolar Physics ie the mechanisms responsible for the workings of ie the mechanisms responsible for the workings of and changes in the Sun and changes in the Sun The Earths Upper AtmosphereThe Earths Upper Atmosphere ie changes resulting from the UV ie changes resulting from the UV light absorption in the stratosphere mesosphere and thermosphere light absorption in the stratosphere mesosphere and thermosphere The Earths ClimateThe Earths Climate eg changes in tropospheric temperatures eg changes in tropospheric temperatures

The sun is the primary driving force behind the Earths climate The sun is the primary driving force behind the Earths climate

Both the sun itself and the climate are changing and evolving Both the sun itself and the climate are changing and evolving consistent with known physical laws However due to the veryconsistent with known physical laws However due to the verycomplicated nature of these laws predictions of their overall effectscomplicated nature of these laws predictions of their overall effectsare uncertain To understand and properly model the evolution of theare uncertain To understand and properly model the evolution of thestate of the upper atmosphere or climate systems it is necessary tostate of the upper atmosphere or climate systems it is necessary toknow the spectral distribution of solar light and the energies and fluxesknow the spectral distribution of solar light and the energies and fluxesof incoming particles of incoming particles

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

The Solar CoronaThe Solar Corona

The corona is the area The corona is the area just above the surface just above the surface While the surface is While the surface is about about 50005000o o CelsiusCelsius the temperature in the the temperature in the corona reaches about corona reaches about 2 million degrees 2 million degrees CelsiusCelsius

What causes this rapid What causes this rapid increase in tempera-increase in tempera-ture is still one of the ture is still one of the big mysteries in solar big mysteries in solar physicsphysics

Surface 5000 o C

Corona2000000 o C

The black circle divides two images

The Sunrsquos Magnetic FieldThe Sunrsquos Magnetic Field

The Sun is strongly affected The Sun is strongly affected by magnetic forces by magnetic forces The The redred arrowsarrows show open show open

magnetic field lines emerging magnetic field lines emerging from the poles from the poles

The The graygray arrowsarrows represent represent solar wind particles which solar wind particles which carry field lines with it carry field lines with it

The bright active regions The bright active regions have closed magnetic field have closed magnetic field lines lines (orange)(orange)

Solar spectrumSolar spectrum

The solar spectrumBy and large the spectrum of theSun resembles closely a blackbody

Why measure solar UV lightWhy measure solar UV light

Solar PhysicsSolar Physics ie the mechanisms responsible for the workings of ie the mechanisms responsible for the workings of and changes in the Sun and changes in the Sun The Earths Upper AtmosphereThe Earths Upper Atmosphere ie changes resulting from the UV ie changes resulting from the UV light absorption in the stratosphere mesosphere and thermosphere light absorption in the stratosphere mesosphere and thermosphere The Earths ClimateThe Earths Climate eg changes in tropospheric temperatures eg changes in tropospheric temperatures

The sun is the primary driving force behind the Earths climate The sun is the primary driving force behind the Earths climate

Both the sun itself and the climate are changing and evolving Both the sun itself and the climate are changing and evolving consistent with known physical laws However due to the veryconsistent with known physical laws However due to the verycomplicated nature of these laws predictions of their overall effectscomplicated nature of these laws predictions of their overall effectsare uncertain To understand and properly model the evolution of theare uncertain To understand and properly model the evolution of thestate of the upper atmosphere or climate systems it is necessary tostate of the upper atmosphere or climate systems it is necessary toknow the spectral distribution of solar light and the energies and fluxesknow the spectral distribution of solar light and the energies and fluxesof incoming particles of incoming particles

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

The Sunrsquos Magnetic FieldThe Sunrsquos Magnetic Field

The Sun is strongly affected The Sun is strongly affected by magnetic forces by magnetic forces The The redred arrowsarrows show open show open

magnetic field lines emerging magnetic field lines emerging from the poles from the poles

The The graygray arrowsarrows represent represent solar wind particles which solar wind particles which carry field lines with it carry field lines with it

The bright active regions The bright active regions have closed magnetic field have closed magnetic field lines lines (orange)(orange)

Solar spectrumSolar spectrum

The solar spectrumBy and large the spectrum of theSun resembles closely a blackbody

Why measure solar UV lightWhy measure solar UV light

Solar PhysicsSolar Physics ie the mechanisms responsible for the workings of ie the mechanisms responsible for the workings of and changes in the Sun and changes in the Sun The Earths Upper AtmosphereThe Earths Upper Atmosphere ie changes resulting from the UV ie changes resulting from the UV light absorption in the stratosphere mesosphere and thermosphere light absorption in the stratosphere mesosphere and thermosphere The Earths ClimateThe Earths Climate eg changes in tropospheric temperatures eg changes in tropospheric temperatures

The sun is the primary driving force behind the Earths climate The sun is the primary driving force behind the Earths climate

Both the sun itself and the climate are changing and evolving Both the sun itself and the climate are changing and evolving consistent with known physical laws However due to the veryconsistent with known physical laws However due to the verycomplicated nature of these laws predictions of their overall effectscomplicated nature of these laws predictions of their overall effectsare uncertain To understand and properly model the evolution of theare uncertain To understand and properly model the evolution of thestate of the upper atmosphere or climate systems it is necessary tostate of the upper atmosphere or climate systems it is necessary toknow the spectral distribution of solar light and the energies and fluxesknow the spectral distribution of solar light and the energies and fluxesof incoming particles of incoming particles

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

Solar spectrumSolar spectrum

The solar spectrumBy and large the spectrum of theSun resembles closely a blackbody

Why measure solar UV lightWhy measure solar UV light

Solar PhysicsSolar Physics ie the mechanisms responsible for the workings of ie the mechanisms responsible for the workings of and changes in the Sun and changes in the Sun The Earths Upper AtmosphereThe Earths Upper Atmosphere ie changes resulting from the UV ie changes resulting from the UV light absorption in the stratosphere mesosphere and thermosphere light absorption in the stratosphere mesosphere and thermosphere The Earths ClimateThe Earths Climate eg changes in tropospheric temperatures eg changes in tropospheric temperatures

The sun is the primary driving force behind the Earths climate The sun is the primary driving force behind the Earths climate

Both the sun itself and the climate are changing and evolving Both the sun itself and the climate are changing and evolving consistent with known physical laws However due to the veryconsistent with known physical laws However due to the verycomplicated nature of these laws predictions of their overall effectscomplicated nature of these laws predictions of their overall effectsare uncertain To understand and properly model the evolution of theare uncertain To understand and properly model the evolution of thestate of the upper atmosphere or climate systems it is necessary tostate of the upper atmosphere or climate systems it is necessary toknow the spectral distribution of solar light and the energies and fluxesknow the spectral distribution of solar light and the energies and fluxesof incoming particles of incoming particles

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

The solar spectrumBy and large the spectrum of theSun resembles closely a blackbody

Why measure solar UV lightWhy measure solar UV light

Solar PhysicsSolar Physics ie the mechanisms responsible for the workings of ie the mechanisms responsible for the workings of and changes in the Sun and changes in the Sun The Earths Upper AtmosphereThe Earths Upper Atmosphere ie changes resulting from the UV ie changes resulting from the UV light absorption in the stratosphere mesosphere and thermosphere light absorption in the stratosphere mesosphere and thermosphere The Earths ClimateThe Earths Climate eg changes in tropospheric temperatures eg changes in tropospheric temperatures

The sun is the primary driving force behind the Earths climate The sun is the primary driving force behind the Earths climate

Both the sun itself and the climate are changing and evolving Both the sun itself and the climate are changing and evolving consistent with known physical laws However due to the veryconsistent with known physical laws However due to the verycomplicated nature of these laws predictions of their overall effectscomplicated nature of these laws predictions of their overall effectsare uncertain To understand and properly model the evolution of theare uncertain To understand and properly model the evolution of thestate of the upper atmosphere or climate systems it is necessary tostate of the upper atmosphere or climate systems it is necessary toknow the spectral distribution of solar light and the energies and fluxesknow the spectral distribution of solar light and the energies and fluxesof incoming particles of incoming particles

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

Why measure solar UV lightWhy measure solar UV light

Solar PhysicsSolar Physics ie the mechanisms responsible for the workings of ie the mechanisms responsible for the workings of and changes in the Sun and changes in the Sun The Earths Upper AtmosphereThe Earths Upper Atmosphere ie changes resulting from the UV ie changes resulting from the UV light absorption in the stratosphere mesosphere and thermosphere light absorption in the stratosphere mesosphere and thermosphere The Earths ClimateThe Earths Climate eg changes in tropospheric temperatures eg changes in tropospheric temperatures

The sun is the primary driving force behind the Earths climate The sun is the primary driving force behind the Earths climate

Both the sun itself and the climate are changing and evolving Both the sun itself and the climate are changing and evolving consistent with known physical laws However due to the veryconsistent with known physical laws However due to the verycomplicated nature of these laws predictions of their overall effectscomplicated nature of these laws predictions of their overall effectsare uncertain To understand and properly model the evolution of theare uncertain To understand and properly model the evolution of thestate of the upper atmosphere or climate systems it is necessary tostate of the upper atmosphere or climate systems it is necessary toknow the spectral distribution of solar light and the energies and fluxesknow the spectral distribution of solar light and the energies and fluxesof incoming particles of incoming particles

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

Earths upperEarths upper atmosphereatmosphere

Solar UV light is primarily responsible for both creation Solar UV light is primarily responsible for both creation and destruction of ozone in the earths stratosphere and and destruction of ozone in the earths stratosphere and mesosphere mesosphere

Ozone is the molecular form of oxygen which shields the Ozone is the molecular form of oxygen which shields the Earths surface from solar UVB radiation through their Earths surface from solar UVB radiation through their absorption absorption

The same process also causes the temperature in the The same process also causes the temperature in the stratosphere to be higher than in the upper tropospherestratosphere to be higher than in the upper troposphere

Stratospheric ozone densities are known to vary with Stratospheric ozone densities are known to vary with the 11 year solar cycle Solar variability over the solar the 11 year solar cycle Solar variability over the solar cycle causes expansion and contraction of the outward cycle causes expansion and contraction of the outward extension of the Earths atmosphere into space extension of the Earths atmosphere into space

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

EarthsEarths climateclimate

The connection of solar UV light and its variability to climate change is controversial The connection of solar UV light and its variability to climate change is controversial among scientists Recent measurements of the suns total irradiance show that it among scientists Recent measurements of the suns total irradiance show that it varied by about varied by about 0101 during the recent 11 year solar cycle during the recent 11 year solar cycle

Computational models indicate that this level of variation is insufficient to significantly Computational models indicate that this level of variation is insufficient to significantly modulate the climate modulate the climate

However the models do not include subtle feedback mechanisms (eg enhanced However the models do not include subtle feedback mechanisms (eg enhanced cloud formation) which could magnify the impact of this tiny variation It is also cloud formation) which could magnify the impact of this tiny variation It is also possible that changes in the Earths upper atmosphere induced by solar UV light possible that changes in the Earths upper atmosphere induced by solar UV light could similarly affect the surface climate could similarly affect the surface climate

Yet skeptics point out that the energy per unit volume stored in the tropopause (the Yet skeptics point out that the energy per unit volume stored in the tropopause (the boundary between the troposphere and the stratosphere) is 100 times greater than in boundary between the troposphere and the stratosphere) is 100 times greater than in the upper atmosphere indicating that such causality is unlikely the upper atmosphere indicating that such causality is unlikely

Numerous correlations between solar activity and climatic events have been claimed Numerous correlations between solar activity and climatic events have been claimed in the past many of which were abandoned when their statistical significance could in the past many of which were abandoned when their statistical significance could not be convincingly established not be convincingly established

A dramatic example of a connection which remains credible occurred during the A dramatic example of a connection which remains credible occurred during the extended seventeenth century period known as the extended seventeenth century period known as the Little Ice AgeLittle Ice Age which was which was characterized by Earth surface temperatures much colder than normal and which characterized by Earth surface temperatures much colder than normal and which coincided with a very unusual period of low solar activity and no sunspots known as coincided with a very unusual period of low solar activity and no sunspots known as the the Maunder MinimumMaunder Minimum

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

Variations in the solar EUV (10-120 nm) andVariations in the solar EUV (10-120 nm) and

UV (120-400 nm) spectral irradiance is UV (120-400 nm) spectral irradiance is

known to affect Earths atmosphereespeciallyknown to affect Earths atmosphereespecially

its upper layers its upper layers

Longertermthey also may influence terrestrialLongertermthey also may influence terrestrial

climateclimate

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

The ozone layer is located 50 kilometers above the ground

Most of the solar ultraviolet light is absorbed by the ozone molecules which temporarily break up when the ultraviolet light photons collide with them

O2UV

UV

O3

O2

O

O2 + UV rarr O + O

O3 + UV rarr O2 + O

+ IR

O O2 O3

O + O2 rarr O3 + IR

Ozone layer formation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

Changes in the suns ultraviolet light affects the ozone layer and the energy input into the upper atmosphere As the upper atmosphere is heated it expands into space causing increased friction for satellites

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

UV and sunspot cyclesUV and sunspot cycles The amount of UV from the Sun ( specifically UVB) The amount of UV from the Sun ( specifically UVB)

changes during the sunspot cycle changes during the sunspot cycle At sunspot maximum there is 01 more UV-B At sunspot maximum there is 01 more UV-B

radiation than at minimum Scientists have detected this radiation than at minimum Scientists have detected this sunspot cycle-effect in a 2 change in ozone sunspot cycle-effect in a 2 change in ozone concentrations concentrations

The difference in total ozone between maximum and The difference in total ozone between maximum and minimum conditions during the sunspot cycle were minimum conditions during the sunspot cycle were estimated using yearly averages of total ozone estimated using yearly averages of total ozone

For solar cycle 21 116 and 126 for solar cycle 22 For solar cycle 21 116 and 126 for solar cycle 22 a larger difference of 38 and 41 were found a larger difference of 38 and 41 were found

The corresponding variation in UVB at 300 nm using The corresponding variation in UVB at 300 nm using Beers law is 4-10 with maxima occurring during the Beers law is 4-10 with maxima occurring during the minimum of the solar cycle minimum of the solar cycle

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

11-yr sunspot cycles

Little ice age

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

Solar activity and climate changeSolar activity and climate change

The most well-documented connection between The most well-documented connection between solar activity and climate change is the solar activity and climate change is the Maunder Maunder MinimumMinimum This was a 40-year period when This was a 40-year period when extreme cold weather prevailed in Europe It extreme cold weather prevailed in Europe It also coincided with astronomers watching the also coincided with astronomers watching the sun and not seeing many sunspots sun and not seeing many sunspots

Scientists have examined the climate record for Scientists have examined the climate record for other signs of the connection between space other signs of the connection between space weather and climate-weather changes with weather and climate-weather changes with many surprising results many surprising results

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

Radiation is a common word but in space weather studies there are two types that differ in important ways

Matter - in the form of electrons protons and the ions of various atoms which travel much slower than the speed of light

Electromagnetic - In the form of X-rays visible light gamma rays and other forms of energy that travel at the speed of light

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

Plagesbull This solar image isbull taken through a bull 10Aring wide filter bull centered on the Kbull line of Calcium ( Aring) bull Bright filamentary bull structures most

easilybull seen near the limb

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

The shortwave radiation from the Sun The shortwave radiation from the Sun and the Earth energy balanceand the Earth energy balance

Energy balanceEnergy balance

Incoming solar insolation Incoming solar insolation and outgoing radiation and outgoing radiation are equal in quantityare equal in quantity

Shortwave radiationShortwave radiation from from the Sun enters the the Sun enters the surface-atmosphere surface-atmosphere system of the Earth and system of the Earth and is ultimately returned to is ultimately returned to space as space as longwave radiationlongwave radiation

The longwave radiation of the EarthThe longwave radiation of the Earth

The surface of the Earth emits The surface of the Earth emits 117 units117 units of of longwave radiationlongwave radiation

The atmosphere emits The atmosphere emits 160 160 unitsunits of of longwave energylongwave energy

The total amount of energy lost The total amount of energy lost to space in the to space in the global global longwave radiationlongwave radiation cascade cascade is is 7070 units units (surface emission (surface emission 66 unitsunits + atmospheric emission + atmospheric emission 6464 units units) )

This is the same amount of This is the same amount of energy that was added to the energy that was added to the Earths atmosphere and Earths atmosphere and surface by the surface by the shortwave shortwave radiationradiation of the Sunof the Sun

bull Sun Facts bull Solar radius = 695990 km = 432470 mi = 109 Earth radii bull Solar mass = 1989 1030 kg = 4376 1030 lb = 333000 Earth masses bull Solar luminosity (energy output of the Sun) = 3846 1033 ergs

bull Surface temperature = 5770 K = 9930ordm F bull Surface density = 207 10-7 gcm3 = 16 10-4 Air density bull Surface composition = 70 H 28 He 2 (C N O ) by mass

bull Central temperature = 15600000 K = 28000000ordm F bull Central density = 150 gcm3 = 8 times Gold density bull Central composition = 35 H 63 He 2 (C N O ) by mass

bull Solar age = 457 109 yr

Energy and the sun1048713 Hydrostatic equilibrium and ideal-gas behaviour ensurethat the center of the Sun is very hot and energy (in theform of light) is radiated from the center1048713 The high opacity of the Sun to light determines the rate atwhich the energy leaks out As we have seen it takes along time for photons to diffuse from center to surface1048713 This cannot go on forever without the Sun cooling downor replacement for the energy that leaks away1048713 We know that the solar system is about 45x109 years old(from many radioisotope abundance measurements onmeteorites) and that life has existed here for at least 3x109years Thus the Sun must have had close to its presentluminosity for billions of years

How could the Sun convert mass-energy to radiation1048713 Nuclear fusion basically the liberation of mass energystored as potential energy of the strong nuclearinteractionWould this work under the conditions known to prevail atthe center of the Sun1048713 Yes Requires such conditions in factTo demonstrate these answers we need to talk a bit about thefundamental interactions of matterρC = 150 g cm-3 PC = 21 1017 dyne cm-2

T = 157 106 K Mostly hydrogen

TThe Solar Windhe Solar Wind

A constant stream A constant stream

of particles flows of particles flows

from the Sunrsquos from the Sunrsquos

corona with a corona with a

temperature of temperature of

about a million about a million

degrees and withdegrees and with

a velocity of abouta velocity of about

450 kms 450 kms

The solar wind reaches out beyond Plutos orbit (about 5900 million kilometers)

Solar magnetic field

Although sunspots themselves produce only minor effects on solar emissions the magnetic activity that accompanies the sunspots can produce dramatic changes in the ultraviolet and soft x-ray emission levels These changes over the solar cycle have important consequences for the Earths upper atmosphere

bull Ultraviolet 1-400 nm Most blocked by Earthrsquos atmosphere (O3 absorption)

bull except from 300-400 nm

bull The atmosphere is a gaseous envelope thatbull surrounds the earthbull Electromagnetic energy from the Sun must passbull through the Earths atmosphere to the surfacebull and then back through the atmosphere to thebull remote sensing instrumentbull During this process the atmospherebull ndashabsorbsbull ndashscattersbull ndashand transmitsbull electromagnetic energy

bull ABSORBTIONbull The blocking characteristics of the atmosphere protect living things frombull the damaging high-energy radiation from the sunbull Without the atmosphere to block most of the ultraviolet radiation humanbull skin exposed to sunlight would quickly be sunburned and develop skinbull cancer For remote sensing these blocking characteristics arebull problematicbull The transmission characteristics of the earths atmosphere vary withbull wavelength Some wavelengths are transmitted almost perfectly whilebull others are completely blockedbull Ranges of wavelengths transmitted well by the atmospherebull Ranges of wavelengths transmitted well by the atmospherebull are termed atmospheric windows

bull Atmospheric absorption occurs when energy is lost tobull constituents of the atmospherebull bull Energy absorbed by the atmosphere is subsequentlybull reradiated at longer wavelengths When it is radiated atbull infrared wavelengths we sense it as heatbull bull Three atmospheric gases account for most of thebull atmospheric absorption of solar radiation water vaporbull carbon dioxide and ozonebull Of the three water vapor is capable of the most absorptionbull Water vapor absorbs electromagnetic radiation two to threebull times more strongly than ozone or carbon dioxide

Rayleigh (or molecular) Scattering which occurs whenthe size of the particles is smaller than the wavelength oflight Amount of scattering is inversely proportional towavelength ^ 4bull Mie (or non-molecular) scattering occurs when there issufficient quantity of materials with diameters 1 to 10times the wavelength of light under considerationbull Non selective Scattering is the most problematic of thescattering processes and is found only in the lowestportions of the atmosphere

Blue light is caused by Rayleigh scattering where the shorterwavelengths are scattered by the atomic particles in the atmospheric(typically molecular gases and water vapour) In the absence ofscattering the sky would be black However the particles in theatmosphere cause the shorter wavelengths to scatter thus a blueskyIt is the scattered blue wavelengths that givethe sky a blue color as well as an overallbrightness or skylight

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Slide 50
• Slide 51
• Slide 52
• Slide 53
• Slide 54
• Slide 55

Energy and the sun1048713 Hydrostatic equilibrium and ideal-gas behaviour ensurethat the center of the Sun is very hot and energy (in theform of light) is radiated from the center1048713 The high opacity of the Sun to light determines the rate atwhich the energy leaks out As we have seen it takes along time for photons to diffuse from center to surface1048713 This cannot go on forever without the Sun cooling downor replacement for the energy that leaks away1048713 We know that the solar system is about 45x109 years old(from many radioisotope abundance measurements onmeteorites) and that life has existed here for at least 3x109years Thus the Sun must have had close to its presentluminosity for billions of years

How could the Sun convert mass-energy to radiation1048713 Nuclear fusion basically the liberation of mass energystored as potential energy of the strong nuclearinteractionWould this work under the conditions known to prevail atthe center of the Sun1048713 Yes Requires such conditions in factTo demonstrate these answers we need to talk a bit about thefundamental interactions of matterρC = 150 g cm-3 PC = 21 1017 dyne cm-2

T = 157 106 K Mostly hydrogen

TThe Solar Windhe Solar Wind

A constant stream A constant stream

of particles flows of particles flows

from the Sunrsquos from the Sunrsquos

corona with a corona with a

temperature of temperature of

about a million about a million

degrees and withdegrees and with

a velocity of abouta velocity of about

450 kms 450 kms

The solar wind reaches out beyond Plutos orbit (about 5900 million kilometers)

Solar magnetic field

Although sunspots themselves produce only minor effects on solar emissions the magnetic activity that accompanies the sunspots can produce dramatic changes in the ultraviolet and soft x-ray emission levels These changes over the solar cycle have important consequences for the Earths upper atmosphere

bull Ultraviolet 1-400 nm Most blocked by Earthrsquos atmosphere (O3 absorption)

bull except from 300-400 nm

bull The atmosphere is a gaseous envelope thatbull surrounds the earthbull Electromagnetic energy from the Sun must passbull through the Earths atmosphere to the surfacebull and then back through the atmosphere to thebull remote sensing instrumentbull During this process the atmospherebull ndashabsorbsbull ndashscattersbull ndashand transmitsbull electromagnetic energy

bull ABSORBTIONbull The blocking characteristics of the atmosphere protect living things frombull the damaging high-energy radiation from the sunbull Without the atmosphere to block most of the ultraviolet radiation humanbull skin exposed to sunlight would quickly be sunburned and develop skinbull cancer For remote sensing these blocking characteristics arebull problematicbull The transmission characteristics of the earths atmosphere vary withbull wavelength Some wavelengths are transmitted almost perfectly whilebull others are completely blockedbull Ranges of wavelengths transmitted well by the atmospherebull Ranges of wavelengths transmitted well by the atmospherebull are termed atmospheric windows

bull Atmospheric absorption occurs when energy is lost tobull constituents of the atmospherebull bull Energy absorbed by the atmosphere is subsequentlybull reradiated at longer wavelengths When it is radiated atbull infrared wavelengths we sense it as heatbull bull Three atmospheric gases account for most of thebull atmospheric absorption of solar radiation water vaporbull carbon dioxide and ozonebull Of the three water vapor is capable of the most absorptionbull Water vapor absorbs electromagnetic radiation two to threebull times more strongly than ozone or carbon dioxide

Rayleigh (or molecular) Scattering which occurs whenthe size of the particles is smaller than the wavelength oflight Amount of scattering is inversely proportional towavelength ^ 4bull Mie (or non-molecular) scattering occurs when there issufficient quantity of materials with diameters 1 to 10times the wavelength of light under considerationbull Non selective Scattering is the most problematic of thescattering processes and is found only in the lowestportions of the atmosphere

Blue light is caused by Rayleigh scattering where the shorterwavelengths are scattered by the atomic particles in the atmospheric(typically molecular gases and water vapour) In the absence ofscattering the sky would be black However the particles in theatmosphere cause the shorter wavelengths to scatter thus a blueskyIt is the scattered blue wavelengths that givethe sky a blue color as well as an overallbrightness or skylight

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Slide 50
• Slide 51
• Slide 52
• Slide 53
• Slide 54
• Slide 55

How could the Sun convert mass-energy to radiation1048713 Nuclear fusion basically the liberation of mass energystored as potential energy of the strong nuclearinteractionWould this work under the conditions known to prevail atthe center of the Sun1048713 Yes Requires such conditions in factTo demonstrate these answers we need to talk a bit about thefundamental interactions of matterρC = 150 g cm-3 PC = 21 1017 dyne cm-2

T = 157 106 K Mostly hydrogen

TThe Solar Windhe Solar Wind

A constant stream A constant stream

of particles flows of particles flows

from the Sunrsquos from the Sunrsquos

corona with a corona with a

temperature of temperature of

about a million about a million

degrees and withdegrees and with

a velocity of abouta velocity of about

450 kms 450 kms

The solar wind reaches out beyond Plutos orbit (about 5900 million kilometers)

Solar magnetic field

Although sunspots themselves produce only minor effects on solar emissions the magnetic activity that accompanies the sunspots can produce dramatic changes in the ultraviolet and soft x-ray emission levels These changes over the solar cycle have important consequences for the Earths upper atmosphere

bull Ultraviolet 1-400 nm Most blocked by Earthrsquos atmosphere (O3 absorption)

bull except from 300-400 nm

bull The atmosphere is a gaseous envelope thatbull surrounds the earthbull Electromagnetic energy from the Sun must passbull through the Earths atmosphere to the surfacebull and then back through the atmosphere to thebull remote sensing instrumentbull During this process the atmospherebull ndashabsorbsbull ndashscattersbull ndashand transmitsbull electromagnetic energy

bull ABSORBTIONbull The blocking characteristics of the atmosphere protect living things frombull the damaging high-energy radiation from the sunbull Without the atmosphere to block most of the ultraviolet radiation humanbull skin exposed to sunlight would quickly be sunburned and develop skinbull cancer For remote sensing these blocking characteristics arebull problematicbull The transmission characteristics of the earths atmosphere vary withbull wavelength Some wavelengths are transmitted almost perfectly whilebull others are completely blockedbull Ranges of wavelengths transmitted well by the atmospherebull Ranges of wavelengths transmitted well by the atmospherebull are termed atmospheric windows

bull Atmospheric absorption occurs when energy is lost tobull constituents of the atmospherebull bull Energy absorbed by the atmosphere is subsequentlybull reradiated at longer wavelengths When it is radiated atbull infrared wavelengths we sense it as heatbull bull Three atmospheric gases account for most of thebull atmospheric absorption of solar radiation water vaporbull carbon dioxide and ozonebull Of the three water vapor is capable of the most absorptionbull Water vapor absorbs electromagnetic radiation two to threebull times more strongly than ozone or carbon dioxide

Rayleigh (or molecular) Scattering which occurs whenthe size of the particles is smaller than the wavelength oflight Amount of scattering is inversely proportional towavelength ^ 4bull Mie (or non-molecular) scattering occurs when there issufficient quantity of materials with diameters 1 to 10times the wavelength of light under considerationbull Non selective Scattering is the most problematic of thescattering processes and is found only in the lowestportions of the atmosphere

Blue light is caused by Rayleigh scattering where the shorterwavelengths are scattered by the atomic particles in the atmospheric(typically molecular gases and water vapour) In the absence ofscattering the sky would be black However the particles in theatmosphere cause the shorter wavelengths to scatter thus a blueskyIt is the scattered blue wavelengths that givethe sky a blue color as well as an overallbrightness or skylight

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Slide 50
• Slide 51
• Slide 52
• Slide 53
• Slide 54
• Slide 55

TThe Solar Windhe Solar Wind

A constant stream A constant stream

of particles flows of particles flows

from the Sunrsquos from the Sunrsquos

corona with a corona with a

temperature of temperature of

about a million about a million

degrees and withdegrees and with

a velocity of abouta velocity of about

450 kms 450 kms

The solar wind reaches out beyond Plutos orbit (about 5900 million kilometers)

Solar magnetic field

Although sunspots themselves produce only minor effects on solar emissions the magnetic activity that accompanies the sunspots can produce dramatic changes in the ultraviolet and soft x-ray emission levels These changes over the solar cycle have important consequences for the Earths upper atmosphere

bull Ultraviolet 1-400 nm Most blocked by Earthrsquos atmosphere (O3 absorption)

bull except from 300-400 nm

bull The atmosphere is a gaseous envelope thatbull surrounds the earthbull Electromagnetic energy from the Sun must passbull through the Earths atmosphere to the surfacebull and then back through the atmosphere to thebull remote sensing instrumentbull During this process the atmospherebull ndashabsorbsbull ndashscattersbull ndashand transmitsbull electromagnetic energy

bull ABSORBTIONbull The blocking characteristics of the atmosphere protect living things frombull the damaging high-energy radiation from the sunbull Without the atmosphere to block most of the ultraviolet radiation humanbull skin exposed to sunlight would quickly be sunburned and develop skinbull cancer For remote sensing these blocking characteristics arebull problematicbull The transmission characteristics of the earths atmosphere vary withbull wavelength Some wavelengths are transmitted almost perfectly whilebull others are completely blockedbull Ranges of wavelengths transmitted well by the atmospherebull Ranges of wavelengths transmitted well by the atmospherebull are termed atmospheric windows

bull Atmospheric absorption occurs when energy is lost tobull constituents of the atmospherebull bull Energy absorbed by the atmosphere is subsequentlybull reradiated at longer wavelengths When it is radiated atbull infrared wavelengths we sense it as heatbull bull Three atmospheric gases account for most of thebull atmospheric absorption of solar radiation water vaporbull carbon dioxide and ozonebull Of the three water vapor is capable of the most absorptionbull Water vapor absorbs electromagnetic radiation two to threebull times more strongly than ozone or carbon dioxide

Rayleigh (or molecular) Scattering which occurs whenthe size of the particles is smaller than the wavelength oflight Amount of scattering is inversely proportional towavelength ^ 4bull Mie (or non-molecular) scattering occurs when there issufficient quantity of materials with diameters 1 to 10times the wavelength of light under considerationbull Non selective Scattering is the most problematic of thescattering processes and is found only in the lowestportions of the atmosphere

Blue light is caused by Rayleigh scattering where the shorterwavelengths are scattered by the atomic particles in the atmospheric(typically molecular gases and water vapour) In the absence ofscattering the sky would be black However the particles in theatmosphere cause the shorter wavelengths to scatter thus a blueskyIt is the scattered blue wavelengths that givethe sky a blue color as well as an overallbrightness or skylight

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Slide 50
• Slide 51
• Slide 52
• Slide 53
• Slide 54
• Slide 55

Solar magnetic field

Although sunspots themselves produce only minor effects on solar emissions the magnetic activity that accompanies the sunspots can produce dramatic changes in the ultraviolet and soft x-ray emission levels These changes over the solar cycle have important consequences for the Earths upper atmosphere

bull Ultraviolet 1-400 nm Most blocked by Earthrsquos atmosphere (O3 absorption)

bull except from 300-400 nm

bull The atmosphere is a gaseous envelope thatbull surrounds the earthbull Electromagnetic energy from the Sun must passbull through the Earths atmosphere to the surfacebull and then back through the atmosphere to thebull remote sensing instrumentbull During this process the atmospherebull ndashabsorbsbull ndashscattersbull ndashand transmitsbull electromagnetic energy

bull ABSORBTIONbull The blocking characteristics of the atmosphere protect living things frombull the damaging high-energy radiation from the sunbull Without the atmosphere to block most of the ultraviolet radiation humanbull skin exposed to sunlight would quickly be sunburned and develop skinbull cancer For remote sensing these blocking characteristics arebull problematicbull The transmission characteristics of the earths atmosphere vary withbull wavelength Some wavelengths are transmitted almost perfectly whilebull others are completely blockedbull Ranges of wavelengths transmitted well by the atmospherebull Ranges of wavelengths transmitted well by the atmospherebull are termed atmospheric windows

bull Atmospheric absorption occurs when energy is lost tobull constituents of the atmospherebull bull Energy absorbed by the atmosphere is subsequentlybull reradiated at longer wavelengths When it is radiated atbull infrared wavelengths we sense it as heatbull bull Three atmospheric gases account for most of thebull atmospheric absorption of solar radiation water vaporbull carbon dioxide and ozonebull Of the three water vapor is capable of the most absorptionbull Water vapor absorbs electromagnetic radiation two to threebull times more strongly than ozone or carbon dioxide

Rayleigh (or molecular) Scattering which occurs whenthe size of the particles is smaller than the wavelength oflight Amount of scattering is inversely proportional towavelength ^ 4bull Mie (or non-molecular) scattering occurs when there issufficient quantity of materials with diameters 1 to 10times the wavelength of light under considerationbull Non selective Scattering is the most problematic of thescattering processes and is found only in the lowestportions of the atmosphere

Blue light is caused by Rayleigh scattering where the shorterwavelengths are scattered by the atomic particles in the atmospheric(typically molecular gases and water vapour) In the absence ofscattering the sky would be black However the particles in theatmosphere cause the shorter wavelengths to scatter thus a blueskyIt is the scattered blue wavelengths that givethe sky a blue color as well as an overallbrightness or skylight

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
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Although sunspots themselves produce only minor effects on solar emissions the magnetic activity that accompanies the sunspots can produce dramatic changes in the ultraviolet and soft x-ray emission levels These changes over the solar cycle have important consequences for the Earths upper atmosphere

bull Ultraviolet 1-400 nm Most blocked by Earthrsquos atmosphere (O3 absorption)

bull except from 300-400 nm

bull The atmosphere is a gaseous envelope thatbull surrounds the earthbull Electromagnetic energy from the Sun must passbull through the Earths atmosphere to the surfacebull and then back through the atmosphere to thebull remote sensing instrumentbull During this process the atmospherebull ndashabsorbsbull ndashscattersbull ndashand transmitsbull electromagnetic energy

bull ABSORBTIONbull The blocking characteristics of the atmosphere protect living things frombull the damaging high-energy radiation from the sunbull Without the atmosphere to block most of the ultraviolet radiation humanbull skin exposed to sunlight would quickly be sunburned and develop skinbull cancer For remote sensing these blocking characteristics arebull problematicbull The transmission characteristics of the earths atmosphere vary withbull wavelength Some wavelengths are transmitted almost perfectly whilebull others are completely blockedbull Ranges of wavelengths transmitted well by the atmospherebull Ranges of wavelengths transmitted well by the atmospherebull are termed atmospheric windows

bull Atmospheric absorption occurs when energy is lost tobull constituents of the atmospherebull bull Energy absorbed by the atmosphere is subsequentlybull reradiated at longer wavelengths When it is radiated atbull infrared wavelengths we sense it as heatbull bull Three atmospheric gases account for most of thebull atmospheric absorption of solar radiation water vaporbull carbon dioxide and ozonebull Of the three water vapor is capable of the most absorptionbull Water vapor absorbs electromagnetic radiation two to threebull times more strongly than ozone or carbon dioxide

Rayleigh (or molecular) Scattering which occurs whenthe size of the particles is smaller than the wavelength oflight Amount of scattering is inversely proportional towavelength ^ 4bull Mie (or non-molecular) scattering occurs when there issufficient quantity of materials with diameters 1 to 10times the wavelength of light under considerationbull Non selective Scattering is the most problematic of thescattering processes and is found only in the lowestportions of the atmosphere

Blue light is caused by Rayleigh scattering where the shorterwavelengths are scattered by the atomic particles in the atmospheric(typically molecular gases and water vapour) In the absence ofscattering the sky would be black However the particles in theatmosphere cause the shorter wavelengths to scatter thus a blueskyIt is the scattered blue wavelengths that givethe sky a blue color as well as an overallbrightness or skylight

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
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• Slide 55

bull Ultraviolet 1-400 nm Most blocked by Earthrsquos atmosphere (O3 absorption)

bull except from 300-400 nm

bull The atmosphere is a gaseous envelope thatbull surrounds the earthbull Electromagnetic energy from the Sun must passbull through the Earths atmosphere to the surfacebull and then back through the atmosphere to thebull remote sensing instrumentbull During this process the atmospherebull ndashabsorbsbull ndashscattersbull ndashand transmitsbull electromagnetic energy

bull ABSORBTIONbull The blocking characteristics of the atmosphere protect living things frombull the damaging high-energy radiation from the sunbull Without the atmosphere to block most of the ultraviolet radiation humanbull skin exposed to sunlight would quickly be sunburned and develop skinbull cancer For remote sensing these blocking characteristics arebull problematicbull The transmission characteristics of the earths atmosphere vary withbull wavelength Some wavelengths are transmitted almost perfectly whilebull others are completely blockedbull Ranges of wavelengths transmitted well by the atmospherebull Ranges of wavelengths transmitted well by the atmospherebull are termed atmospheric windows

bull Atmospheric absorption occurs when energy is lost tobull constituents of the atmospherebull bull Energy absorbed by the atmosphere is subsequentlybull reradiated at longer wavelengths When it is radiated atbull infrared wavelengths we sense it as heatbull bull Three atmospheric gases account for most of thebull atmospheric absorption of solar radiation water vaporbull carbon dioxide and ozonebull Of the three water vapor is capable of the most absorptionbull Water vapor absorbs electromagnetic radiation two to threebull times more strongly than ozone or carbon dioxide

Rayleigh (or molecular) Scattering which occurs whenthe size of the particles is smaller than the wavelength oflight Amount of scattering is inversely proportional towavelength ^ 4bull Mie (or non-molecular) scattering occurs when there issufficient quantity of materials with diameters 1 to 10times the wavelength of light under considerationbull Non selective Scattering is the most problematic of thescattering processes and is found only in the lowestportions of the atmosphere

Blue light is caused by Rayleigh scattering where the shorterwavelengths are scattered by the atomic particles in the atmospheric(typically molecular gases and water vapour) In the absence ofscattering the sky would be black However the particles in theatmosphere cause the shorter wavelengths to scatter thus a blueskyIt is the scattered blue wavelengths that givethe sky a blue color as well as an overallbrightness or skylight

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
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• Slide 48
• Slide 49
• Slide 50
• Slide 51
• Slide 52
• Slide 53
• Slide 54
• Slide 55

bull The atmosphere is a gaseous envelope thatbull surrounds the earthbull Electromagnetic energy from the Sun must passbull through the Earths atmosphere to the surfacebull and then back through the atmosphere to thebull remote sensing instrumentbull During this process the atmospherebull ndashabsorbsbull ndashscattersbull ndashand transmitsbull electromagnetic energy

bull ABSORBTIONbull The blocking characteristics of the atmosphere protect living things frombull the damaging high-energy radiation from the sunbull Without the atmosphere to block most of the ultraviolet radiation humanbull skin exposed to sunlight would quickly be sunburned and develop skinbull cancer For remote sensing these blocking characteristics arebull problematicbull The transmission characteristics of the earths atmosphere vary withbull wavelength Some wavelengths are transmitted almost perfectly whilebull others are completely blockedbull Ranges of wavelengths transmitted well by the atmospherebull Ranges of wavelengths transmitted well by the atmospherebull are termed atmospheric windows

bull Atmospheric absorption occurs when energy is lost tobull constituents of the atmospherebull bull Energy absorbed by the atmosphere is subsequentlybull reradiated at longer wavelengths When it is radiated atbull infrared wavelengths we sense it as heatbull bull Three atmospheric gases account for most of thebull atmospheric absorption of solar radiation water vaporbull carbon dioxide and ozonebull Of the three water vapor is capable of the most absorptionbull Water vapor absorbs electromagnetic radiation two to threebull times more strongly than ozone or carbon dioxide

Rayleigh (or molecular) Scattering which occurs whenthe size of the particles is smaller than the wavelength oflight Amount of scattering is inversely proportional towavelength ^ 4bull Mie (or non-molecular) scattering occurs when there issufficient quantity of materials with diameters 1 to 10times the wavelength of light under considerationbull Non selective Scattering is the most problematic of thescattering processes and is found only in the lowestportions of the atmosphere

Blue light is caused by Rayleigh scattering where the shorterwavelengths are scattered by the atomic particles in the atmospheric(typically molecular gases and water vapour) In the absence ofscattering the sky would be black However the particles in theatmosphere cause the shorter wavelengths to scatter thus a blueskyIt is the scattered blue wavelengths that givethe sky a blue color as well as an overallbrightness or skylight

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
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• Slide 49
• Slide 50
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• Slide 52
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• Slide 54
• Slide 55

bull ABSORBTIONbull The blocking characteristics of the atmosphere protect living things frombull the damaging high-energy radiation from the sunbull Without the atmosphere to block most of the ultraviolet radiation humanbull skin exposed to sunlight would quickly be sunburned and develop skinbull cancer For remote sensing these blocking characteristics arebull problematicbull The transmission characteristics of the earths atmosphere vary withbull wavelength Some wavelengths are transmitted almost perfectly whilebull others are completely blockedbull Ranges of wavelengths transmitted well by the atmospherebull Ranges of wavelengths transmitted well by the atmospherebull are termed atmospheric windows

bull Atmospheric absorption occurs when energy is lost tobull constituents of the atmospherebull bull Energy absorbed by the atmosphere is subsequentlybull reradiated at longer wavelengths When it is radiated atbull infrared wavelengths we sense it as heatbull bull Three atmospheric gases account for most of thebull atmospheric absorption of solar radiation water vaporbull carbon dioxide and ozonebull Of the three water vapor is capable of the most absorptionbull Water vapor absorbs electromagnetic radiation two to threebull times more strongly than ozone or carbon dioxide

Rayleigh (or molecular) Scattering which occurs whenthe size of the particles is smaller than the wavelength oflight Amount of scattering is inversely proportional towavelength ^ 4bull Mie (or non-molecular) scattering occurs when there issufficient quantity of materials with diameters 1 to 10times the wavelength of light under considerationbull Non selective Scattering is the most problematic of thescattering processes and is found only in the lowestportions of the atmosphere

Blue light is caused by Rayleigh scattering where the shorterwavelengths are scattered by the atomic particles in the atmospheric(typically molecular gases and water vapour) In the absence ofscattering the sky would be black However the particles in theatmosphere cause the shorter wavelengths to scatter thus a blueskyIt is the scattered blue wavelengths that givethe sky a blue color as well as an overallbrightness or skylight

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
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• Slide 48
• Slide 49
• Slide 50
• Slide 51
• Slide 52
• Slide 53
• Slide 54
• Slide 55

bull Atmospheric absorption occurs when energy is lost tobull constituents of the atmospherebull bull Energy absorbed by the atmosphere is subsequentlybull reradiated at longer wavelengths When it is radiated atbull infrared wavelengths we sense it as heatbull bull Three atmospheric gases account for most of thebull atmospheric absorption of solar radiation water vaporbull carbon dioxide and ozonebull Of the three water vapor is capable of the most absorptionbull Water vapor absorbs electromagnetic radiation two to threebull times more strongly than ozone or carbon dioxide

Rayleigh (or molecular) Scattering which occurs whenthe size of the particles is smaller than the wavelength oflight Amount of scattering is inversely proportional towavelength ^ 4bull Mie (or non-molecular) scattering occurs when there issufficient quantity of materials with diameters 1 to 10times the wavelength of light under considerationbull Non selective Scattering is the most problematic of thescattering processes and is found only in the lowestportions of the atmosphere

Blue light is caused by Rayleigh scattering where the shorterwavelengths are scattered by the atomic particles in the atmospheric(typically molecular gases and water vapour) In the absence ofscattering the sky would be black However the particles in theatmosphere cause the shorter wavelengths to scatter thus a blueskyIt is the scattered blue wavelengths that givethe sky a blue color as well as an overallbrightness or skylight

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Slide 50
• Slide 51
• Slide 52
• Slide 53
• Slide 54
• Slide 55

Rayleigh (or molecular) Scattering which occurs whenthe size of the particles is smaller than the wavelength oflight Amount of scattering is inversely proportional towavelength ^ 4bull Mie (or non-molecular) scattering occurs when there issufficient quantity of materials with diameters 1 to 10times the wavelength of light under considerationbull Non selective Scattering is the most problematic of thescattering processes and is found only in the lowestportions of the atmosphere

Blue light is caused by Rayleigh scattering where the shorterwavelengths are scattered by the atomic particles in the atmospheric(typically molecular gases and water vapour) In the absence ofscattering the sky would be black However the particles in theatmosphere cause the shorter wavelengths to scatter thus a blueskyIt is the scattered blue wavelengths that givethe sky a blue color as well as an overallbrightness or skylight

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Slide 50
• Slide 51
• Slide 52
• Slide 53
• Slide 54
• Slide 55

Blue light is caused by Rayleigh scattering where the shorterwavelengths are scattered by the atomic particles in the atmospheric(typically molecular gases and water vapour) In the absence ofscattering the sky would be black However the particles in theatmosphere cause the shorter wavelengths to scatter thus a blueskyIt is the scattered blue wavelengths that givethe sky a blue color as well as an overallbrightness or skylight

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Slide 50
• Slide 51
• Slide 52
• Slide 53
• Slide 54
• Slide 55

Electromagnetic radiation interacts with feature on the Earthssurface the same way as it does with the airIt can beraquoabsorbedraquoreflectedraquoand transmitted

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Slide 50
• Slide 51
• Slide 52
• Slide 53
• Slide 54
• Slide 55

Solar eruptive prominence seen in He II 304 nm from the EIT instrument on the NASAESA SOHO satellite (NASAGSFC)

• Slide 1
• Slide 4
• Slide 11
• Slide 15
• Slide 24
• Slide 25
• Slide 26
• Slide 28
• Slide 29
• Plages
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 39
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Slide 50
• Slide 51
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• Slide 53
• Slide 54
• Slide 55