Global Energy Balance
The surface energy balance is the resultant of radiative components such as incoming
and outgoing short-wave and long-wave radiation, and also non-radiative components such as
sensible heating, latent heating, and the change in energy storage in water or substrate
on land. The following animations show radiative and non-radiative components which
emphasize the latitudinal and seasonal variations of solar input and surface-atmosphere
- Net short-wave radiation = short-wave down - short-wave up.
- Net long-wave radiation = long-wave down - long-wave up.
- Net radiation = net short-wave radiation + net long-wave radiation.
Positive values represent energy moving towards the surface, negative values represent
energy moving away from the surface.
- Sensible heat flux = direct heating, a function of surface and air temperature.
- Latent heat flux = energy that is stored in water vapor as it evaporates, a function of
surface wetness and relative humidity.
- Change in heat storage = net radiation - latent heat flux - sensible heat flux.
Positive values for sensible and latent heat flux represent energy moving towards the
atmosphere, negative values represent energy moving away from the atmosphere.
Positive values for change in heat storage represent energy moving out of storage,
negative values represent energy moving into storage.
Seasonal temperature variations can be explained in terms of the latitudinal and
seasonal variations in the surface energy balance. The pattern of temperatures are a
function of net short-wave radiation, net long-wave radiation, sensible heat flux, latent
heat flux and change in heat storage.
||Seasonal variations in surface temperature.
Global Water Balance
The water balance is the inflow, outflow, and storage of moisture on the earth's
surface. The source of inflow is precipitation, outflow is evaporation and runoff,
and an example of storage is soil moisture. The following animations are examples of
the seasonal cycle for inflow, outflow and storage of moisture as part of the global water
- Precipitable water vapor is a measure of available moisture in the atmosphere.
- Precipitation rate is the actual measurement of precipitation at the surface.
- Precipitation-Evaporation (P-E) represents the difference between precipitation and
- Runoff/Water surplus are measurements of outflow of moisture.
- Soil moisture represents the pattern of storage of moisture at the surface.
Atmospheric Circulation and Winds
Atmospheric circulation and winds are generated by the pole-equator-pole variation in
the energy balance and in turn, redistribute energy and moisture around the globe.
Animations of the seasonal cycle of circulation and winds show the pattern of mean
sea-level pressure and 500 mb heights with wind speed and direction. Animations of
wind vectors for January and July months are shown to emphasize the actual pattern of air
Research was supported by the National Science
Foundation, for TEMPO (Testing Earth System Models with Paleoenvironmental
2000 AAG-Cartography Specialty Group First Place
Award for Best Student Paper
1999 NACIS Student Web
Map Contest Award for Best Animation
1999 APCG President's Award for Outstanding Paper by a Ph.D. Student
1999 National Geographic Cartography Award
Contact: Jacqueline J. Shinker
Created by the Climate Lab section of the Environmental Change Research Group
© Department of Geography, University of Oregon
Last updated: 02/13/03