Moisture in the Atmosphere Moisture in the Atmosphere and the Results of Energy and the Results of Energy
InputsInputs
Created By:Created By:
Mr. KreegerMr. Kreeger
Homework and Page Homework and Page ReferencesReferences
Review Book- Page 574, 579-584Review Book- Page 574, 579-584 Textbook-Pages 485-493Textbook-Pages 485-493
HW#1-1-3 on page 488 of textbook HW#1-1-3 on page 488 of textbook HW#2-1-4 on page 493 HW#2-1-4 on page 493 HW #3-Explain why condensation is a HW #3-Explain why condensation is a
heating process and evaporation is a heating process and evaporation is a cooling process, how do these processes cooling process, how do these processes affect storm formationaffect storm formation
Table of ContentsTable of Contents
1.1. Moisture and Energy InputMoisture and Energy Input2.2. Air movementAir movement
a)a) Breezes and currentsBreezes and currentsb)b) WindsWinds
1.1. Pressure GradientsPressure Gradients2.2. Local BreezesLocal Breezes3.3. Planetary Convection CellsPlanetary Convection Cells4.4. Planetary WindsPlanetary Winds5.5. Jet StreamsJet Streams
3.3. Clouds Clouds a)a) Formation/Rising and Subsiding airFormation/Rising and Subsiding airb)b) Why they formWhy they formc)c) How are they classifiedHow are they classified
4.4. PrecipitationPrecipitation
1. Moisture and Energy 1. Moisture and Energy Input Input
Moisture in atm Moisture in atm depends ondepends on Evaporation-(LEvaporation-(LG)G) Transpiration- Water Transpiration- Water
released by plantsreleased by plants Evapotranspiration- Evapotranspiration-
All water vapor All water vapor released, large released, large amounts of energy amounts of energy (540cal/gm)(540cal/gm)
2. Air Movement2. Air Movement
a) a) Breezes and Breezes and Currents-Currents- A A breezebreeze is a small local is a small local movement of air movement of air while a while a currentcurrent is a is a vertical movement vertical movement of air (T-of air (T-Storms)Storms)
2b. Winds2b. Winds
A wind is a large A wind is a large horizontal movement horizontal movement of air near the Earth’s of air near the Earth’s surface (named for surface (named for direction from which it direction from which it comes), Ex. SW wind comes), Ex. SW wind means it came from means it came from SW and is moving NE.SW and is moving NE.
1.1. Pressure gradient-The Pressure gradient-The rate of change in rate of change in pressure between 2 pressure between 2 locations (ESRT), closer locations (ESRT), closer the isobars, stronger the isobars, stronger gradient, stronger wind, gradient, stronger wind, further, less gradient, further, less gradient, less wind.less wind.
Activity on WindsActivity on Winds
Determine which scenario world Determine which scenario world have greater winds.have greater winds.
a.a. HP=1025mb, LP=990mb, Dist=5kmHP=1025mb, LP=990mb, Dist=5km
b.b. HP=1030mb, LP=996mb, HP=1030mb, LP=996mb, Dist=7.5kmDist=7.5km
c.c. HP=1022mb, LP=998mb, HP=1022mb, LP=998mb, Dist=10kmDist=10km
2b2. Local Breezes2b2. Local Breezes
DayDay-Land heats faster -Land heats faster than water than water (LP-Land, HP-Water)-(LP-Land, HP-Water)-Air flows from sea to Air flows from sea to land. (Sea breeze)land. (Sea breeze)
NightNight-Land cools -Land cools faster than water faster than water (HP-Land, LP-Water)-(HP-Land, LP-Water)-Air flows from land to Air flows from land to sea. (Land breeze)sea. (Land breeze)
2b3. Planetary Convection 2b3. Planetary Convection Cells (ESRT Page 14)Cells (ESRT Page 14)
Convection Cell- Cyclic Convection Cell- Cyclic movement due to density movement due to density difference and effects of difference and effects of gravity.gravity.
Variations in Variations in insolation(Why?) result in insolation(Why?) result in unequal heating of earth’s unequal heating of earth’s surface and atm.surface and atm.
Air moves Air moves verticallyverticallypressure belts pressure belts producedproduced Rising air (LP)-Zones of Rising air (LP)-Zones of
convergence (Moist)convergence (Moist) Sinking air (HP)-Zones of Sinking air (HP)-Zones of
divergence (Dry)divergence (Dry)
2b4. Planetary Winds2b4. Planetary Winds(ESRT Page 14)(ESRT Page 14)
If earth did not rotate and If earth did not rotate and was equally heatedwas equally heated 1 1 convection cell would be convection cell would be produced from NP to produced from NP to equator.equator.
BUT>>>>> it is modified BUT>>>>> it is modified by Corilois effect which by Corilois effect which aid in creating a aid in creating a planetary wind system.planetary wind system. At equator-At equator- Wind moves Wind moves
due to trade windsdue to trade winds At mid latitudes-At mid latitudes- move due move due
to prevailing westerliesto prevailing westerlies At high latitudes-At high latitudes- move due move due
to polar easterliesto polar easterlies
2b5. Jet Streams2b5. Jet Streams
Winds at high Winds at high altitudes that control altitudes that control movements of air movements of air masses.masses. Travel at 7-8 miles Travel at 7-8 miles
high( travels at 200 high( travels at 200 kph, travels faster in kph, travels faster in winter)winter)
Migrates from 31N in Migrates from 31N in winter to 50 N in winter to 50 N in summer Why?summer Why?
3. Clouds 3. Clouds
a)a) Formation-Condensation, need a Formation-Condensation, need a surface called cloud condensation surface called cloud condensation nuclei (CCN), can only occur when nuclei (CCN), can only occur when saturation happens (Dewpoint=Air saturation happens (Dewpoint=Air Temp) and a CCN is present i.e. Temp) and a CCN is present i.e. dust, saltdust, salt
• Condensation is a heating process- fuel Condensation is a heating process- fuel for storms (540 cal)for storms (540 cal)
Rising and Subsiding AirRising and Subsiding Air
1. RISING AIR EXPANDS AND COOLS
Higher P
Lower P
High P
High P
2. SUBSIDING AIR IS COMPRESSED AND WARMSLower P
Lower P
Higher P (surface)Low P
3b. Why do clouds form3b. Why do clouds form
LiftingLifting Cloud TypeCloud Type
Localized convective Localized convective lifting lifting
CumulusCumulus
Topography (orographic Topography (orographic lifting)lifting)
Nimbostratus / lenticularNimbostratus / lenticular
ConvergenceConvergence Cumulus / cumulonimbusCumulus / cumulonimbus
Uplift along weather Uplift along weather fronts (frontal wedging)fronts (frontal wedging)
Nimbostratus/stratus, Nimbostratus/stratus, cumulonimbuscumulonimbus
3b. Why do clouds form 3b. Why do clouds form Cont..Cont..
3c. How are clouds 3c. How are clouds classifiedclassified
Divided into groups Divided into groups based on the based on the height in which height in which they form.they form.
High CloudsHigh Clouds > 6000 m> 6000 m Cold and “dry” - thinCold and “dry” - thin Almost exclusively ice crystalsAlmost exclusively ice crystals
mares’ tails mackerel sky halo
Cirrocumulus
Middle CloudsMiddle Clouds
2000 – 7000 m2000 – 7000 m Mostly water droplets, some ice crystalsMostly water droplets, some ice crystals
No halo, associated with warm fronts, form before storms
Morning Ac means afternoon thunderstorms in summer
Low CloudsLow Clouds <2000 m<2000 m Almost always water droplets (ice and Almost always water droplets (ice and
snow in winter)snow in winter)
Light-moderate rainFor long duration
High pressure,Stabile weather
Fog that doesn’t reach the ground,drizzle
Clouds with Vertical DevelopmentClouds with Vertical Development
Cumulonimbus – unstable atmosphereCumulonimbus – unstable atmosphere Rapid convection brings tops to 12 kmRapid convection brings tops to 12 km Form thunderstorms / lightningForm thunderstorms / lightning
Fair weather Thunderstorms
Summary of cloud typesSummary of cloud types
4. Precipitation4. Precipitation
When water droplets or ice crystals When water droplets or ice crystals grow large enough to fall.grow large enough to fall.
TypesTypes Rain Rain SnowSnow SleetSleet Freezing rainFreezing rain HailHail
Diagrams explaining Diagrams explaining precipitationprecipitation
TypeType DiameteDiameter (mm)r (mm)
Fall Fall Velocity Velocity (km/hr)(km/hr)
Small cloud Small cloud dropletsdroplets
0.010.01 0.010.01
Typical cloud Typical cloud dropletsdroplets
0.020.02 0.040.04
Large cloud Large cloud dropletsdroplets
0.050.05 0.30.3
Drizzle dropsDrizzle drops 0.50.5 77
Typical rain dropsTypical rain drops 2.02.0 2323
Large rain dropsLarge rain drops 5.05.0 3333
0
5
10
15
20
25
30
35
0 1 2 3 4 5
drop diameter (mm)
fall
velo
cit
y (
km
/hr)
Fall Velocity
RainRain
Drops of water that Drops of water that fall from a cloud with fall from a cloud with a diameter of a diameter of >0.5mm>0.5mm
Originates from Originates from nimbostratus or nimbostratus or cumulonimbus cloudscumulonimbus clouds
Begins often as snow Begins often as snow crystals, but also as crystals, but also as raindropsraindrops
SnowSnow
Packets of ice Packets of ice crystalscrystals
Low temps Low temps light light fluffly snow or fluffly snow or “powder”“powder”
Warm temps (-5C) Warm temps (-5C) heavy moist heavy moist snowsnow
SleetSleet
Sleet = small, Sleet = small, translucent translucent particles of iceparticles of ice
Formed as ice, Formed as ice, melted, refrozen as melted, refrozen as ice pelletsice pellets
Freezing RainFreezing Rain
Subfreezing air Subfreezing air near ground is not near ground is not thick enough to thick enough to allow raindrops to allow raindrops to freezefreeze
Raindrops Raindrops supercooledsupercooled
Summary of PrecipitationSummary of Precipitation
HailHail
Hard round pelletsHard round pellets Concentric shells of Concentric shells of
ice from traveling ice from traveling up and down a up and down a convective cloudconvective cloud
Produced in large Produced in large cumulonimbus cumulonimbus clouds, speeds = clouds, speeds = 160km/hr160km/hr
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