A Decade of Progress in Modeling the Hydroclimatology of the Amazon System Marcos Heil Costa Universidade Federal de Viçosa III LBA Scientific Conference Brasília – July 2004

Overview Review studies on large-scale hydrological modeling Review studies on climate modeling, including the biosphere-atmosphere interaction Future trends

Large-Scale Hydrological Systems 1994: –A few basin/continental-scale routing-scheme- based large-scale hydrological studies performed –Mainly water transport models –Basic flooding scheme

Large-Scale Hydrological Systems Since 1994: –Increased model resolution –New input and validation products New remote sensing products Basin-wide water chemistry measurements (HIBAM) –Improved validation (many discharge stations, water height, flooded area) –Focus on land use/land cover change

Large-Scale Hydrological Systems Current research efforts –New validation efforts, specially with respect to flooded area, soil moisture –Water chemistry (carbon) Tapley et al. (2004) – Geoid height estimates from the GRACE mission

Large-Scale Hydrological Systems Future research efforts –Not much room for large-scale water balance/ water transport simulations – just refinements –Plenty of room for large-scale hydrochemical/ water quality studies

Climate System 1994: –Several climate studies demonstrating the role of local vegetation on the local climate –ABRACOS field observations completed, but climate experiments did not benefit from such measurements yet

Climate System Since 1994: –Post-ABRACOS studies indicate climate change after a deforestation may not be as strong as initially thought Post-ABRACOS studies ABRACOS recommendation

Climate System Since 1994: –Combined effects of deforestation and rising CO 2 –Dynamic/equilibrium vegetation studies for present climate, LGM and 2xCO 2 scenarios –Role of Amazonia in the global carbon cycle –Debate between regional- and global-scale modellers –Evidence that small-scale deforestation would lead to increasing precipitation large-scale deforestation would lead to decreasing precipitation

Climate System Current research efforts: –Search for confirmation/ explanation of the small/large-scale dichotomy –Focus on current levels of deforestation/ near future (~10-40 years) scenarios

Climate System Future research efforts: –Will we be able to forecast the Amazon climate? –Or are we still studying scenarios?

Climate System Future research efforts: –At the multi-decadal time scales, we must consider: interdecadal variability of climate (NAO, PDO) rising CO 2 effects of deforestation –In the years scale, the interdecadal variability of climate may be stronger than the effects of partial deforestation, which may be stronger than the effects of rising CO 2 –for multi-decadal climate forecasts, we should include modes of climate variability that depend on the ocean

Thank you!