Evolution of the tropical atmosphere radiative budget as seen from observations and AR4 model simulations

A transient change in the balance between the incoming and outgoing radiation is an important indicator of the changing Earth's climate. In this paper we use available data from satellites (1980 to present) and ground measurements (1995 to present) to reconstruct the long-term evolution of the energy budget of the tropical atmosphere (20S-20N). We compare the estimate of the radiative budget with the corresponding estimates obtained from model simulations from the AR4 database. We show that in spite of the dramatic increase in the model's ability to simulate past and recent temperature change, the models show different sensitivities to the Mt. Pinatubo eruption and do not agree with observations of the overall radiative balance tendencies over 1980-2000.