@Article{VasconcellosDengZhanMart:2020:AuSuPr,
author = "Vasconcellos, Fernanda Cerqueira and Deng, Yi and Zhang, Henian
and Martins, Guilherme",
affiliation = "{Universidade Federal do Rio de Janeiro (UFRJ)} and {Georgia
Institute of Technology} and {Georgia Institute of Technology} and
{Instituto Nacional de Pesquisas Espaciais (INPE)}",
title = "Austral summer precipitation biases over tropical South America in
five CMIP5 earth system models",
journal = "International Journal of Climatology",
year = "2020",
volume = "40",
pages = "6506--6525",
month = "Dec.",
keywords = "earth system models, precipitation bias, surface energy budget,
tropical South America, WES feedback.",
abstract = "This study examined the historical (19802005) austral summer
precipitation in Tropical South America (SA) simulated by five
Earth System Models (ESM) from the Coupled Model Intercomparison
Project Phase 5 (CMIP5). All simulations show a band of maximum
precipitation eastward of the observed one and without typical
NW-SE orientation. This displacement suggests models have trouble
in reproducing the South Atlantic Convergence Zone (SACZ). Due to
this and additional model problems in simulating the Atlantic
Intertropical Convergence Zone (ITCZ), all models exhibit negative
precipitation biases at the extreme northern SA, including
Guianas, Suriname, and north of Brazil and positive precipitation
biases at part of northeastern Brazil. For extreme northern SA,
models, in general, underestimate intense precipitation and
overestimate weak rainfall. Analysis of the moisture flux
divergence over the northern coast of SA in models suggested that
the precipitation bias could primarily stem from model
misrepresentations of moisture availability for convection.
Further analyses indicate that the moisture flux biases are, in
turn, tied to a negative sea surface temperature (SST) bias in the
tropical North Atlantic, inducing stronger northeasterly trade
winds. Thus, more intense moisture flux goes to the inner
continent. Consequently, an anomalous divergence of moisture flux
and less precipitation occur near the coast. Despite some
differences in energy budget and cloudiness, models results for
wind, precipitation, SST, and latent heat flux suggest problems at
WES feedback. In the GFDL-ESM and MIROC-ESM models, the negative
SST bias was also partly associated with a lower incident
shortwave (SW) radiation over the tropical North Atlantic. This SW
bias was tied to a positive bias of cloud cover over tropical
North Atlantic, at least in the GFDL-ESM.",
doi = "10.1002/joc.6595",
url = "http://dx.doi.org/10.1002/joc.6595",
issn = "0899-8418",
language = "en",
targetfile = "vasconcellos_austral.pdf",
urlaccessdate = "29 mar. 2024"
}