Climate change impact on precipitation for the Amazon and La Plata basins

Autor(es)

Llopart, Marta ^[1] ; Coppola, Erika ^[2] ; Giorgi, Filippo ^[2] ; da Rocha, Rosmeri P. ^[1] ; Cuadra, Santiago V. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Atmospher Sci, Sao Paulo - Brazil

^[2] Abdus Salam Int Ctr Theoret Phys, Trieste - Italy

^[3] Brazilian Agr Res Corp Embrapa, Natl Temperate Agr Res Ctr, Pelotas - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Climatic Change; v. 125, n. 1, p. 111-125, JUL 2014.
• Citações Web of Science: 26

Resumo

We analyze the local and remote impacts of climate change on the hydroclimate of the Amazon and La Plata basins of South America (SA) in an ensemble of four 21st century projections (1970-2100, RCP8.5 scenario) with the regional climate model RegCM4 driven by the HadGEM, GFDL and MPI global climate models (GCMs) over the SA CORDEX domain. Two RegCM4 configurations are used, one employing the CLM land surface and the Emanuel convective schemes, and one using the BATS land surface and Grell (over land) convection schemes. First, we find considerable sensitivity of the precipitation change signal to both the driving GCM and the RegCM4 physics schemes (with the latter even greater than the first), highlighting the pronounced uncertainty of regional projections over the region. However, some improvements in the simulation of the annual cycle of precipitation over the Amazon and La Plata basins is found when using RegCM4, and some consistent change signals across the experiments are found. One is a tendency towards an extension of the dry season over central SA deriving from a late onset and an early retreat of the SA monsoon. The second is a dipolar response consisting of reduced precipitation over the broad Amazon and Central Brazil region and increased precipitation over the La Plata basin and central Argentina. An analysis of the relative influence on the change signal of local soil-moisture feedbacks and remote effects of Sea Surface Temperature (SST) over the Nino 3.4 region indicates that the former is prevalent over the Amazon basin while the latter dominates over the La Plata Basin. Also, the soil moisture feedback has a larger role in RegCM4 than in the GCMs. (AU)

• Processo FAPESP: 13/50521-7 - Processos de multi-escala que atuam na convecção tropical e a influência de aerossóis
• Beneficiário: Tercio Ambrizzi
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Regular