학술논문

Climate change impact on precipitation for the Amazon and La Plata basins
Document Type
Author abstract
Report
Source
Climatic Change. July, 2014, Vol. 125 Issue 1, p111, 15 p.
Subject
Brazil
Italy
Language
English
ISSN
0165-0009
Abstract
Byline: Marta Llopart (1), Erika Coppola (2), Filippo Giorgi (2), Rosmeri P. Rocha (1), Santiago V. Cuadra (3) Abstract: 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. Author Affiliation: (1) Department of Atmospheric Sciences, University of Sao Paulo, Sao Paulo, Brazil (2) Earth System Physics, Abdus Salam International Centre for Theoretical Physics, Trieste, Italy (3) Brazilian Agricultural Research Corporation--Embrapa, National Temperate Agriculture Research Centre, Pelotas, Brazil Article History: Registration Date: 21/04/2014 Received Date: 31/05/2013 Accepted Date: 20/04/2014 Online Date: 22/05/2014 Article note: This article is part of a Special Issue on 'The Phase I CORDEX RegCM4 Experiment MAtrix (CREMA)' edited by Filippo Giorgi, William Gutowski, and Ray W. Arritt. Electronic supplementary material The online version of this article (doi: 10.1007/s10584-014-1140-1) contains supplementary material, which is available to authorized users.