Coul air outbreaks over southeastern South America in the winter season in scenarios of climate change.

MULLER GABRIELA V; ANDRADE KELEN; CAVALCANTI IRACEMA F.A

São Paulo, Brasil

Workshop; 1st Ibero-American Workshop on Climate Dynamics, Climate Change and Regional Climate Modeling; 2007

Frequency of extreme cold air outbreak cases over southern/southeastern South America (SESA) in global circulation model results and in reanalysis data are compared in the present climate and also analyzed in simulations of the future climate. The analyses were performed for 3 areas within the region to identify cases in different temperature intervals.  In the lower latitudes the majority of cases occur in the interval 2.5 to 5.5 in the reanalyses and model results. In the intermediate area of SESA, the largest number of extreme cases occurs in the interval 0 to 2.5, which is also reproduced by the models. In the higher latitudes of the region there is a large occurrence of cases with temperature lower than 0, also reproduced by the models. In the three regions, the models overestimate the frequency of cases identified in the reanalyses. Results for the future climate indicate lower frequency than for the present climate in the three analyzed areas.