A COMPARISON OF AMAZONIAN CLIMATE DATA WITH GENERAL-CIRCULATION MODELSIMULATIONS

Climate data from the Anglo-Brazilian Amazonian Climate Observation St udy have been compared with the simulations of three general circulati on models with prognostic cloud schemes. Monthly averages of net all w ave radiation. incoming solar radiation, net longwave radiation, and p recipitation obtained from automatic weather stations sited in three a reas of Amazonia are compared with the output from the unified model o f the Hadley Centre for Climate Prediction and Research, the operation al forecasting model of the European Centre for Medium-Range Weather F orecasts (ECMWF), and the model of the Laboratoire dr Meteorologie Dyn amique (LMD). The performance of the models is much improved when comp ared to comparisons of observations with the output from earlier, less sophisticated models. However. the Hadley Centre and LMD models tend to overpredict net and solar radiation, and the ECMWF model underpredi cts net and solar radiation at two of the sites, but performs very wel l in Manaus. it is shown that the errors are mainly linked to the amou nt of cloud cover produced by the models. but also to the incoming cle ar sky solar radiation.