Fenômenos luminosos estratosféricos e mesosféricos associados a nuvens de tempestades

Abstract

AN OBSERVATIONAL STUDY ABOUT THE SEA SURFACE TEMPERATURE ANOMALIES DIPOLE PATTERN OVER THE TROPICAL ATLANTIC OCEAN-This work presents an observational analysis ofthe large scale atmospheric circulation domain at the surface and high levels of the troposphere, during the periods in wich dipole events were observed over the Tropical Atlantic Ocean. The dipole events were selected looking the SST Southern Brazil. Simulations have been done with 24 and 48 hours preceding the first day of frost, for 14 cases of severe frosts occurred at decade of 80. The model performance was evaluated considering four variables (temperature near the surface, sea level pressure, 200-hPa winds and geopotential height) and comparing simulated fields with those from the analysis of the model, as well as with the corresponding analyzed fields of the ECMWF. Comparisons between simulated and analyzed fields show that the model, in general reproduces the variable patterns and their values mainly for simulations with 24 hours of antecedence. For simulations with 48 hours of antecedence although the simulated and analyzed patterns are similar, the values of low level variables, in some cases have not been well reproduced.