TITLE:
Downscaling Climate Projections over La Plata Basin
AUTHORS:
Caroline Mourão, Sin Chan Chou, José Marengo
KEYWORDS:
Regional Climate Model, Climate Downscaling, Climate Change Assessment, La Plata Basin
JOURNAL NAME:
Atmospheric and Climate Sciences,
Vol.6 No.1,
December
31,
2015
ABSTRACT: Regional
Climate Models are important tools, which are increasingly being used in
studies of impacts and adaptation to climate change at local scale. The goal of
this work is to assess the climate change over the La Plata Basin, using the
Eta Regional model with a resolution of 10 km. Initial and boundary conditions
used by the model are provided by the Eta-20 km model and the HadGEM2-ES
Global model. The RCP 4.5 scenario was used for simulations of the future
climate. The evaluation of the present climate (1961-1990) shows that the model
represents well the spatial and temporal distribution of precipitation and
temperature in the region. The model underestimates precipitation over large
areas in summer, and overestimates in Southern Brazil in winter. Simulated
temperature shows a good correlation with CRU data, with bias less than 1°C. The
bias of temperature and precipitation in this simulation setup for the La Plata
Basin is substantially reduced in comparison with previous literature using
regional models. The climatic projections are shown in timeslices:
2011-2040, 2041-2070, and 2071-2099. In the three timeslices, the simulation
project has a trend for an increase in precipitation during summer in
Argentina, Uruguay, and southernmost Brazil. This increase is only projected in
Southern Brazil during winter. The negative anomaly of precipitation appears in
a large portion of the model domain during summer and is limited to some states
in Southeast and Central-West Brazil in winter. The area with largest warming
is projected in the northern portion of the domain. The projected increase in
temperature reaches about 4°C in 2071-2099.