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Lecture 5Atmospheric structure

TemperatureSolar and earth radiation

Stable?

Brick

Stable?

How can the atmosphere be made more stable? More unstable?

Cold

Warm

Warm

Cold

Stable Unstable

night day

Inversion layer

Inversion layerTemperature increases with height

Stable

Cold

Warm

Why does the smoke stay all the valley?

Cold

WarmInversion layer

The Stratosphere inversion layer, stable?

Q: Why does the temperature increase with height in the stratosphere?

contains ozone layer peak concentrations are at about 20-30 km

Ozone absorbs ultraviolet radiation (UV)

The ozone then reemits this energy in the form of heat into the stratosphere, warming it up in the mid-upper parts of the layer

97% of atmospheric ozone is in the stratosphere

Ozone maximum

The Mesosphere

Bounded by the stratopause from below and the mesopause from above

99.9 % of air is below this level

The Thermosphere The layer above the mesosphere

Temperature increases with height

What are weather

elements?

NYC daily Weather

Temperaturedew point temperature

Relative humidity

Wind

Rain

Weather Elements

“Climate is what you expect, weather is what you get.”

– Robert Heinlein

Climate is the long-term average

of weather

What is Climate?

Is Weather or Climate ?

Today’s Temperature in NYC?

Winter temperature?

Tornado?

Ice Age?

Annual variability of precipitation in NYC?

Climate

Weather

Weather

Climate

Climate

Climate change usually refers to temperature change

Temperature

Energy

is defined as the ability to do work

kinetic energy is the energy of motion

Kinetic Energy = 21

mass velocity2mv m v

kinetic energy is large when velocity is large

Temperature

21 1 1

1

2e m v

1

m = mass

v = velocity

2

energy

1

2kinetic

e mv22 2 2

1

2e m v

221

2i i ie m v

i

2 2 2 2 21 1 2 2 3 3

2

1 1 1 1 1... ...1 2 2 2 2 2

2 2

i i N NB

m v m v m v m v m vk Tmv

N

kB is the Boltzmann constant

is the average kinetic energy of its constitute atoms and molecules

Temperature and Heat

Heat energy exchange from one object to another

Absolute temperature is proportional to the average kinetic energy of its constitute atoms and molecules

What is difference between temperature and heat?

Object 1 Object 2

FasterSlower

Heat = an exchange of kinetic energy

Equilibrium = Both objects have the same temperature

Heat

Latent Heat

is energy exchange from one object to another

energy required for a substance (i. e. water) to change from one state to another at constant temperature

Sensible Heatheat added or taken from a gas, liquid or solid that

causes a change in temperature

Lecture 4- 20

Need energy

release energy

Need energy

release energy

Latent Heat energy required for water to change from one state to another at constant temperature

scale melting point of ice

boiling point of water

Fahrenheit (oF)

32 212

Celsius(oC)

0 100

Kelvin (K)

273 373

• Relative size of a degree F vs. a degree C--compare the number of degrees between freezing and boiling:

100oC = 180oF 1oC = 1.8oF

Temperature Scales:

Fahrenheit and Celsius

(oC x 1.8) + 32 = oF

(oF - 32) / 1.8 = oC

Why Kelvin temperature is also called absolute temperature?

Third Law of Thermodynamics

It is impossible to cool a body to absolute zero by any finite

process.

Although one can approach absolute zero as closely as one desires, one cannot actually reach this limit.

There are three ways of heat transfer in the atmosphereConduction

ConvectionRadiation

Heat Transfer

Heat Transfer

Conduction

from warm to cold from molecular motions

Air is a poor conductor of heat Basically insignificant

Lecture 4- 26

Convectiontransfer energy through mass movement of a substance

Q: what are examples of atmospheric convection?

consider a hot parcel of air near the ground

what is the parcel going to do?

It’s going to rise, why?

a thermal is formed

Q: By which mechanism is the heat transferred from ground to the air adjacent to the ground?

Thermals