Energy Balance Climate Models

This model, written by Dr. Steve Vavrus, integrates a simple form of the surface energy equation to generate average monthly latitudinal temperatures for an assumed hemispherically symmetric Earth.  In words, the governing equation states:

Rate of Surface Temperature Change = 1/(Heat Capacity) x (Incoming Solar Radiation - Net Outgoing Longwave Radiation + Meridional and Zonal Heat Transports)

The user can then change boundary conditions known to be important, such as carbon dioxide concentration, date of perihelion, and Earth's eccentricity and tilt to estimate the sensitivity of the climate to various combinations. In addition, because land and ocean have very different heat capacities and albedoes, the surface temperature is strongly affected by the presence and latitudinal distribution of land and sea.

There are two versions of the Energy Balance Climate Model:

  • EBCM1 allows the user to alter the Earth's fraction of land and sea; the chosen fraction is assigned to all latitudes.
  • EBCM2 allows the user to vary the location of continental land mass (taken to occupy about 1/3 of the planet, as at present) among the tropics, mid latitudes, and high latitudes to explore how continental drift may have altered Earth's climate over millions of years.