Page 137 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

LONGWAVE ENERGY BUDGET
Radiative transfer
Ozone layer −3 Gases and dust −18 Clouds −3 Direct from surface −8 Through greenhouse effect
Nonradiative transfer
–69 Longwave energy radiated to space (surface losses + atmospheric losses)
–24 Energy loss from atmosphere
(= shortwave radiation absorbed)
–37
Energy lost from Earth's surface and gained by the atmosphere, and then eventually lost to space.
−19 Convection −4 Total longwave −69 [Total initially reflected] −31
Latent heat transfer
−14
Total energy output
–100 units
–3
Stratospheric ozone
–3
Clouds
–18
Atmospheric gases and dust
Explain: Greenhouse gases emit longwave radiation toward the surface and into space. Explain the net effect of this process.
Greenhouse effect
–8
–19
–4
–14
Net loss of energy from
surface and gain to atmosphere through greenhouse effect
GEOquiz
23 units lost from surface and temporarily gained by atmosphere
+110
Absorbed by atmosphere
Latent heat transfer Convection (evaporation)
Nonradiative transfer
+96
Surface warming
Direct heat loss from surface
Longwave energy emitted by land, water, atmosphere, and cloud surfaces back to space. [NASA, CERES.]
Outgoing longwave radiation (W·m–2)
Radiative transfer
–96
Transfer from atmosphere
–110
Transfer to atmosphere
4.2 OUTGOING LONGWAVE RADIATION
Over time, Earth emits, on average, 69% of incoming energy to space. When added to the amount of energy reflected (31%), this equals the total energy input from the Sun (100%). Outgoing energy transfers from the surface are both radiative (consisting of longwave radiation directly to space) and non-radiative (involving convection and the energy released by latent heat transfer).
100 210 320
1. Infer: Which is more important in heating Earth’s atmosphere: incoming shortwave radiation or outgoing longwave radiation? Explain.
2. Predict: Suppose that latent heat energy is released into the atmosphere as water evaporates from a lake. How is this energy involved in the atmosphere’s energy balance and what eventually happens to it?
101
geosystems in action 4 EARTH–ATMOSPHERE EnERGy BALAnCE