COPPOLA, E.

CUADRA, S. V.

GIORGI, F.

LLOPART, M.

ROCHA, R. P. da

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Geophysical Research AbstractsVol. 15, EGU2013-10761-1, 2013EGU General Assembly 2013© Author(s) 2013. CC Attribution 3.0 License.Land surface feedbacks and climate change over South America asprojected by RegCM4Marta Llopart (1), Rosmeri da Rocha (1), Erika Coppola (2), Filippo Giorgi (2), and Santiago Cuadra (3)(1) Department of Atmospheric Sciences – University of Sao Paulo (IAG-USP), Sao Paulo, Brazil , (2) Earth System Physics,Abdus Salam International Centre for Theoretical Physics, Trieste, Italy, (3) Brazilian Agricultural Research Corporation -Embrapa, Pelotas, BrazilThe hydroclimatic regime variability over the Amazon and La Plata Basin, the two main basins of South America(SA), are affect by local climate feedbacks and climate patterns associated with SST anomalies. The local andremote impacts of climate change over SA are evaluated using the regional model RegCM4 driven by HadGEM,GFDL and MPI global climate models (RegHad_CLM, RegGFDL, and RegMPI, respectively).All simulations used CLM (Community Land Model) land surface scheme and Emanuel convective scheme, with50 km of horizontal resolution; except for one simulation driven by HadGEM that used the BATS (RegHad_BATS)as a land surface scheme and a mixed convection scheme (Grell over land and Emanuel over ocean). Climatechanges were evaluated by comparing the future (2070-2098) with the present climate (1975-2004) during therainy season (December to April).For the present day climate, the regional simulations reproduce reasonably well the precipitation annual cycle overAmazon and La Plata Basin. In particular the RegCM4 runs driven by MPI and GFDL are quite good over theAmazon and RegCM4 runs driven by HadGEM for La Plata Basin.For the future climate projections, all the global models show a precipitation decrease over the central AmazonBasin, northeast Brazil, and northern of SA (ranging from -5 to -25%) for the end of century, except the GFDL.Over the La Plata Basin, mainly over northern Argentina, and western of Amazon Basin simulations indicatean increase of precipitation (ranging from 25 to 50%). These patterns are intensified in the RegCM4-CLMsimulations. The exceptions are the RegHad_BATS results that shows a general precipitation reduction overalmost all Amazon basin. Over the La Plata Basin all regional models presented a positive coupling between seasurface temperature (SST) in Niño 3.4 region and precipitation. With exception of RegHad_CLM, all simulationsshow a negative SST/Precipitation regression over the central and northeastern Brazil.The soil moisture feedback on precipitation is evaluated too by mean of a statistical approach. The RegCM-CLMsimulations have a common feature and they show a similar behavior when the future changes are investigated.The RegCM-BATS shows a different soil moisture feedback picture. Of course this can be explained by thedifferences in the two land-surface schemes and in the precipitation change signal that comes out from the twosets of simulations.

Land surface feedbacks and climate change over South America as projected by RegCM4.

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