Theory of EnergyBalance Climate Models.
Abstract
A class of mean annual, zonally averaged energybalance climate models of the BudykoSellers type are studied by a spectral (expansion in Legendre polynomials) method. Models with constant thermal diffusion coefficient can be solved exactly, The solution is approached by a rapidly converging sequence with each succeeding approximant taking into account information from ever smaller space and time scales. The first two modes represent a good approximation to the exact solution as well as to the present climate. The twomode approximation to a number of more general models are shown to be either formally or approximately equivalent to the same truncation in the constant diffusion case. In particular, the transport parameterization used by Budyko is precisely equivalent to the twomode truncation of thermal diffusion. Details of the dynamics do not influence the first two modes which fortunately seem adequate for the study of global climate change. Estimated ice age temperatures and ice line latitude agree well with the model if the solar constant is reduced by 1.3%.
 Publication:

Journal of Atmospheric Sciences
 Pub Date:
 November 1975
 DOI:
 10.1175/15200469(1975)032<2033:TOEBCM>2.0.CO;2
 Bibcode:
 1975JAtS...32.2033N