Transcript Energy Transport in the Atmosphere

Energy in the OceanAtmosphere Climate System
SOEE3410 : Lecture 2
Dr Ian Brooks
[email protected]
Room 1.64a Environment Building
http://homepages.see.leeds.ac.uk/~ibrooks
• The atmosphere-ocean system acts as a
heat engine
Energy IN
(solar radiation)
Work done
Energy OUT
(heat lost to space
as infra-red radiation)
• Energy OUT = Energy IN
• Work done  moving atmosphere and
ocean around
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Contributions to global oceanatmosphere energy budget
Energy Flux (W m-2)
Solar radiation
340
Latent heat
70
Rate of kinetic energy dissipation
~2
Photosynthesis
~0.1
Geothermal heat flux
0.06
World energy production (fossil fuels)
0.02
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reflected solar
radiation
107 W m2
Incoming solar radiation
342 W m2
Outgoing
longwave
radiation
235 W m2
40
30
Reflected by clouds,
aerosol & atmosphere
77
Absorbed by
atmosphere
165
emitted by
atmosphere
67
24
78
350
back radiation
324
Reflected
by surface
30
40
168
24
Absorbed by surface
390
324
Surface radiation
Absorbed by
surface
78
thermals Evapotranspiration
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IPCC : http://www.ipcc.ch/present/graphics.htm
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0
2
4
6
8
10
12
16
14
18
14.5
0.9
Heat absorbed by the continents (Beltrami et al. 2002)
Heat absorbed by
the oceans
0.8
Heat required to melt continental glaciers at estimated maximum melting
rate (Houghton et al. 2001)
0.7
Heat absorbed by the atmosphere during 1955-96 (Levitus et al. 2001)
0.3
Heat required to reduce Antarctic sea-ice extent (de la Mare, 1997)
0.1
Heat required to melt mountain glaciers at estimated maximum melting
rate (Houghton et al. 2001)
0.005
Heat require to melt northern hemisphere sea-ice (Parkinson et al. 1999)
0.002
Heat require to melt Arctic perennial sea-ice volume (Rotherock et al.
1999)
Estimate of Earth’s heat balance components (1022 J) for the
period 1955-1988
(after Levitus et al, 2005, GRL, VOL. 32, L02604, doi:10.1029/2004GL021592)
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No Atmosphere
SWi = Solar (shortwave) radiation
SWr = shortwave reflected
LWe = Infra red (longwave) emitted
radiation
SWi
SWr
Ts
= Ts4
LWe
Ts
= surface temperature

= Stefan-Boltzman constant
(5.67 x 10-8 Watts m-2 K-4 )
At equilibrium… SWi = SWr + LWe
In the absence of an atmosphere the surface temperature of earth would be
approximately 255K (-18ºC). It’s actual mean temperature is 288K (+15ºC)
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Some radiation
passes through
atmosphere
CO2
Some radiation absorbed
by gas molecules
Radiation absorbed from ONE direction, heating gas, is re-emitted in ALL directions
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90
Ferrel Cell
60
Polar Cell
0
Heat Transport
Net Radiation
30
30
60
90
Idealized model of atmospheric circulation.
N.B. actual circulations are not continuous in space or time.
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Mid-latitude
Jet Stream
60°
Polar Front
Tropical
jet
30°
0°
Deep convection
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IPCC : http://www.ipcc.ch/present/graphics.htm
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Animation of monthly net Short-Wave (solar) radiation (W/m2)
From http://geography.uoregon.edu/envchange/clim_animations/index.html
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Animation of monthly net Long-Wave (infra-red) radiation (W/m2)
From http://geography.uoregon.edu/envchange/clim_animations/index.html
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Animation of monthly net radiation (W/m2)
From http://geography.uoregon.edu/envchange/clim_animations/index.html
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Animation of monthly sensible heat flux (W/m2)
From http://geography.uoregon.edu/envchange/clim_animations/index.html
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Animation of monthly latent heat flux (W/m2)
From http://geography.uoregon.edu/envchange/clim_animations/index.html
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Animation of monthly change in heat storage (W/m2)
From http://geography.uoregon.edu/envchange/clim_animations/index.html
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From http://geography.uoregon.edu/envchange/clim_animations/index.html
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Animation of monthly surface temperature (ºC)
From http://geography.uoregon.edu/envchange/clim_animations/index.html
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Animation of monthly sea-level pressure (mb) and surface winds
From http://geography.uoregon.edu/envchange/clim_animations/index.html
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Suphate aerosols deposited in
Greenland ice
Concentrations of 3 well-mixed greenhouse gases
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• Increases in greenhouse gas concentrations
change the radiative balance of the earth by
reducing the outgoing longwave radiation.
• The climate system must adjust to a new
equilibrium.
• The nature of the change in climate state is
complicated by the large number of interacting
processes.
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Online Resources
• The animations shown in this lecture have been made available at
http://homepages.see.leeds.ac.uk/~ibrooks/envi3410
• The were produced by the Department of Geography at the
University of Oregon. These and some additional animations can be
found at :
http://geography.uoregon.edu/envchange/clim_animations/index.html
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