14.7
Evaluation of Eta Model Seasonal Forecasts over South America
PAPER WITHDRAWN
Sin Chan Chou, Centro de Previsao de Tempo e Estudos Climaticos, Cachoeira Paulista, SP, Brazil; and J. L. Gomes and J. F. Bustamante
Seasonal forecasts of precipitation produced from the CPTEC global model have been providing some guidance in the planing of agriculture activities or use of water resources in Brazil. However, the resolution of this model, about 200 km, limits the use of these forecasts. The regional model, generally has higher horizontal resolution which makes these models more attractive for detailed forecasts. The Eta model was configured to run with 40km resolution and 38 layers over most of South America domain including parts of adjacent oceans. The model was setup to perform 4-month forecasts. The sea surface temperature was daily updated during the integration with the persisted anomaly. The initial soil moisture used climatological value whereas the albedo used seasonal values. The lateral boundary conditions were provided by the CPTEC global model forecasts at T62L28 resolution, and updated every 6 hours. Verification of the 2002 summer season is showed. The frequency of frontal passages over the domain was generally well forecast by the model. An excess of precipitation along the coast of Northeastern Brazil was removed by replacing the lateral boundary conditions by the NCEP analysis. It seems that the global model winds produce stronger sea-breeze than the analyses which causes more moisture brought into the continent.
Session 14, Model Improvements
Friday, 16 August 2002, 8:00 AM-9:44 AM
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