Seasonal Climate Prediction for Amazonia

.The Brazilian Center for Weather Forecasting and Climate Studies (CPTEC) has been issuing experimental seasonal climate forecasts for a number of years. It uses a medium-resolution GCM and specified SST for the global oceans. Experimental forecasts are obtained as the average of an ensemble of individual numerical forecasts (usually an ensemble with 25 members). Inter-run spread provides a measure of reliability of forecasts. Examples of the use of seasonal forecasts will be shown.

Seasonal predictions over Amazonia exhibit high skill. The reasons for such skill are studied. Seasonal climate variability over Amazonia is affected both by the Tropical Pacific and Atlantic Oceans. There may be local sources of seasonal climate variability, such as soil moisture memory or the potencial influence of the Andes Mountains, but their role and mechanisms are uncertain. Understanding the role of local forcing versus remote forcing in determining seasonal climate variability in Amazonia is one of the research questions of the LBA Experiment