CLIMATIC EFFECTS OF AMAZONIAN DEFORESTATION - SOME RESULTS FROM ABRACOS

This paper reviews the climatological measurements and some of the mod eling in the Anglo-Brazilian Amazonian Climate Observational Study (AB RACOS) project. The local-scale, mesoscale, and large-scale climatic i mpacts of Amazonian deforestation are demonstrated. The difference in radiation and energy balance between forest and clearing gives higher air temperatures in the clearings, particularly in the dry season. In areas of substantial deforestation, higher sensible heat fluxes from t he cleared forest produce deeper convective boundary layers, with diff erences in cloud cover being observed and mesoscale circulations being predicted. The use of the ABRACOS data for calibrating general circul ation model land surface schemes is discussed.