Testing Energy Balance Climate Models

Abstract

Adopting procedures often applied to model the earth's climate, we use zonal fields from the control run of a general circulation climate model (GCM) (Wetherald and Manabe, 1975) to construct parameterizations of the energy budget components for use in. a simple Budyko-Sellers energy balance climate model (EBM) (North, 1975). Comparing the results of the GCM and the EBM for changes in solar constant, we find that with these parameterizations changes in the surface temperature calculated with the EBM are substantially larger than those calculated with the GCM. Furthermore, when the meridional energy transport in the EBM is held constant so that it simulates the transport in the GCM, the results of the two models diverge hopelessly. On the other hand, with the parameterizations of the EBM modified to simulate the behavior of the GCM fields, the results of the two models agree fairly well. This exercise illustrates the weakness of current methods used to extract parameterizations for EBMs from observations of the present climate.