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CHAPTER 17
HEAT AND THE
ATMOSPHERE 17.2
HEATING THE ATMOSPHERE
• ENERGY FOR METEOROLOGY
ORIGINATES IN THE SUN
• EARTH RECIEVES ONE 2 BILLIONTH
OF SUNS ENERGY
INFRARED
LONGWAVE
UV LIGHT
SHORTWAVE
HOW HEAT ENERGY MOVES
1. RADIATION
 TRANSFER OF ENERGY THROUGH
EMPTY SPACE BY VISIBLE LIGHT, UV
AND OTHER ELECTROMAGNETIC
ENERGY
 THE WAY ENERGY FROM THE SUN
GETS HERE
– RADIANT ENERGY IS ABSORBED BY
EARTH AND CHANGED TO HEAT!
2. CONDUCTION
 DIRECT TRANSFER
OF HEAT ENERGY
FROM ONE OBJECT
TO ANOTHER BY
COLLISIONS OF
ATOMS AND
MOLECULES
3. CONVECTION
 HEAT ENERGY TRANSFERED THROUGH
A LIQUID OR GAS BY MOTION DUE TO
DENSITY
TEMPERATURE
 ATOMS AND MOLECULES ARE IN
CONSTANT MOTION
 FASTER = MORE K.E
 TEMPERATURE IS THE MEASURE OF
THE AVERAGE KINECTIC ENERGY IN A
SUBSTANCE
HEAT
 HEAT – MEASURE OF THE TOTAL KINECTIC ENERGY
OF A SUBSTANCE
 EX TWO CUPS OF COFFEE, ONE LARGE ONE SMALL
AT THE SAME TEMP OR ICECUBE MELTING
 THERMOMETER – MEASURES TEMP NOT HEAT
(CELCIUS)
 TEMPERATURE GRADIENT
HOT
COLD
STRUCTURE OF ATMOSPHERE
120
110
100
THERMOSPHERE
90
Height above ground (kilometers)
The atmosphere
is divided into
layers based
on temperature.
Mesopause
80
70
MESOPHERE
60
50
Stratopause
40
30
STRATOSPHERE
20
Tropopause
10
TROPOSPHERE
0
-120
COLDER
-100
-80
-60
-40
-20
0
20
40
60
WARMER
TROPOSPHERE
 This is the layer
that is closest to
the surface of the
earth
 Where most
weather occurs
 It’s elevation
ranges from 0 to
10 km
STRATOSPHERE
• This layer sits on top of
the troposphere
• It’s elevation ranges
from 10 km to around 25
km
• This layer contains the
ozone layer, which
absorbs UV light
Mesosphere
 This layer is above the
stratosphere
 It’s elevation ranges
from 25 to 100 km
Thermosphere
 This is the highest
layer of the
atmosphere
 It’s height ranges from
100 to 400 km
 This is where most
small meteorites burn
up and is also the
location in the
atmosphere that the
northern lights occur
(aurora borealis)
IONOSPHERE
 IONS ARE FORMED WHEN ULTRAVIOLET
RAYS FROM THE SUN STRIPS ELECTRONS
FROM ATOMS OF 0XYGEN AND NITROGEN
 IONS FROM SOLAR FLARES GET DEFLECTED
BY EARTHS MAGNETIC FIELD TO THE N AND S
POLES AND INTERACT WITH AIR MOLECULES.
 PRODUCES THE AURORA BOREALIS
NORTHERN LIGHTS
INSOLATION AND THE
ATMOSPHERE
 INSOLATION – INCOMING SOLAR
RADIATION
 GLOBAL ENERGY BUDGET IN BALANCE
– 100 UNITS FROM SUN
– 30 REFLECTED BACK TO SPACE
– 70 UNITS ABSORBED AND 70 RADIATED
BACK TO SPACE
– MORE OR LESS RADIATED MEANS RISE OR
FALL IN GLOBAL TEMP
100 units of
insolation
30 units reflected
or scattered back
to space
6 units radiate
to space from
Earth’s surface
A total of 64 units
radiated back into
space via the
atmosphere
Atmosphere
absorbs 19
units
Earth’s surface
absorbs 51
units
15 units
radiate from
surface to
atmosphere
Evaporation
transfers
23 units to
atmosphere
Conduction and convection
transfer 7 units to atmosphere
HEAT BUDGET OF EARTH AND
THE ATMOSPHERE
 MOST OF THE ATMOSPHERE’S ENERGY IS
TRANSFERRED FROM THE EARTH’S SURFACE BY
RADIATION, CONDUCTION, CONVECTION,
EVAPORATION AND CONDENSATION – ONE OF THE
MAJOR CAUSES OF WEATHER
 ENERGY TRANSFERRED BACK TO ATMOSPHERE AS
INFRARED RADIATION
 CO2 AND H2O IN ATMOSPHERE ABSORBS MOST OF
THE IR RADIATION – GREENHOUSE EFFECT
 WITHOUT ATMOSPHERE 330C COLDER