EXPLORING SOIL MOISTURE - PRECIPITATION FEEDBACKS IN SOUTHEASTERN SOUTH AMERICA USING A RCM

RUSCICA ROMINA; SÖRENSSON ANNA AMELIA; MENÉNDEZ CLAUDIO GUILLERMO

Petropolis, Brazil

Workshop; CLIVAR VAMOS Workshop on Modeling and Predicting Climate in the Americas; 2012

Laboratorio Nacional de Computação Cientifica (LNCC)

A regional climate model was implemented to study soil moisture - atmosphere interactions. We found that in the summer 92-93 a high soil moisture-evapotranspiration coupling exists in the La Plata Basin region. Different precipitation indeces were defined and their changes due to full or not full interaction between soil moisture and different variables were analized. We found that on the west of the region (Argentina and Paraguay) changes in precipitation indices were more sensitive to dry conditions of soil moisture fields and consequent modifications in the general circulation than on high coupling with the surface. However the east of the region (Uruguay and South of Brazil) was less affected by changes in the circulation and therefore could be more appropriate to study land-atmosphere feedbacks. So the "hot spot" and the extreme events of precipitation that were enhanced with a full interaction, leads to the question if a positive feedback between soil moisture and precipitation had existed in that region of Southeast South America.