Vórtices ciclônicos da alta troposfera: dois estudos de caso para o Nordeste do Brasil.

Abstract

The formation and development of high troposphere cyclonic vortices in northeastern Brazil were diagnosed for two periods: December 15 to 30, 1980 and December 9 to 20, 1989. Charts of current lines, vorticity, advection of vorticity, advection of Temperature, mass divergence and humidity divergence were analyzed for both periods. Intense convection in Bolivia's anticyclone area and the penetration of a frontal system in the Northeast have been found to be fundamental for vortex formation. The position and intensity of the jet stream over South America also influences system formation and maintenance. The results suggest that advection of cyclonic vorticity and cold advection in the medium and high troposphere over NEB contribute to the existence of the vortices. Moisture and mass divergence fields converge in the lower troposphere over the Region over the lifetime of the cyclones. A synoptic model proposed for the development of the upper atmosphere cyclonic vortex.