Post on 11-Feb-2016
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Discussion 3
Wednesday 2/13Quiz review + lectures 4-6
Quiz multiple choice
Most common gas?• O2
• Ar• N2
• CO2
• He
Closest to the Earth?• Thermosphere
– Mesopause• Mesosphere
– Stratopause• Stratosphere
– Tropopause• Troposphere• Earth
Quiz multiple choice
Stratospheric warming?• Density increases• Captures heat radiated from
Earth• Borders thermosphere• Contains ozone
• Thermosphere– Mesopause
• Mesosphere– Stratopause
• Stratosphere– Tropopause
• Troposphere• Earth
Essay redux – most common errors
Carbon cycle• Ocean both sink and source• Carbonates are a sink• Sinks and sources are NOT
in equilibrium– e.g. Keeling curve
Water cycle• Transpiration (or at least
one of the –ation’s)• Groundwater• Glaciers/ice caps• Biosphere
Lecture 4: Insolation
• Earth’s tilt & the seasons• Angle of incidence & solar zenith angle• Earth’s energy budget– Insolation and re-radiation– Latitudinal heat balance– The greenhouse effect
Fig. 2-12, p. 42
HEATING OF THE EARTH’S SURFACE DEPENDS ON THE AMOUNT OF SOLAR RADIATION PER UNIT AREA.SAME AMOUNT OF RADIATION IS DISTRIBUTED OVER A LARGER AREA IN A THAN IN B.RADIATION PER UNIT AREA IS LESS IN A THAN IN B. LESS HEATING IN A THAN IN B.
Latitudinal Heat Balance
20 )1( eA RQE
Simple Greenhouse Model
24 4 eeR RTE
4)1(
04
Q
Te
But this doesn’t factor in the atmosphere! 254K vs 288K
Lecture 5+6: Temperature controls
• Diurnal cycle• Geographic controls– Latitude– Surface type– Elevation– Aspect
• Long-term control
– Cloud cover– Albedo– Ocean currents– Differential heating of
land and water
Miami
NYCChicago
STLDenver
Santa FeLA
Lecture 6: Heating, cooling,and stability
• Adiabatic processes• Equilibrium and lapse rates• Temperature Inversions• Wind Chill
• Ideal gas law: P=dR’T :: PV=nRT• Adiabatic process: no heat added or removed– P(Vγ)=const., T(Vγ-1)=const.
• Adiabatic lapse rate (T change with height)– Dry: ≈10oC / km (really 9.8)
– Wet: depends on water content, always less than dry rate; ≈6oC / km
Adiabatic Expansion and Compression
Equilibrium inthe atmosphere
Fig. 3-19, p. 75
Lifecycle of a nocturnal (radiative) temperature inversion
(A)Mid-afternoon(B)Evening(C)Sunrise(D)Mid-morning
Fig. 3.12
Wind Chill Factor
• The wind chill factor describes the increased loss of heat by the body due to the movement of air.
• The wind causes an increased rate of evaporation of perspiration from the skin..
• It cannot be measured, so it is calculated• Wind chill equivalent temperature