Cold Air Intrusions over Southeastern South America Models Behavior and Changes from Climate Simulations of 20th Century to Future Projections using A2 IPCC Scenario

GABRIELA V. MÜLLER; KELEN M. ANDRADE; IRACEMA F.A CAVALCANTI

São Paulo

Workshop; Regional Outreach Meeting IPCC SREX; 2012

Cold air intrusions in three areas of South America which are frequently affected by frosts are analyzed in results of two Global Circulation Models (atmospheric and coupled ocean-atmosphere). The general objective was to investigate the models ability in simulating the frequency of cases in the present climate as well as the changes in the frequency of occurrence and atmospheric characteristics in a future climate scenario.   In order to investigate the frequency of these cold air incursions in southern Brazil and  the eastern region of Paraguay (area 1), in the central-northern region of Uruguay (area 2) and in the argentine Pampa Húmeda region (area 3) reanalysis data from NCEP/ NCAR are used, as well as the GFDL model in the coupled ocean-atmosphere version. The cold period (May to September) is analyzed for the control period 1961 to 1990 and for the period of 2081 to 2100 from the IPCC A2 scenario, which reflects the extreme global warming. The mean spatial temperature for each area (considering the stations or the grid points inside a 5º lat x 5º long area at 925 hPa) should be in the intervals: T< 0ºC; 0ºC