Influências de zonas de convergência na organização da convecção tropical sobre o Nordeste do Brasil.

Abstract

This paper investigates the performance of organized convective cloudiness bands (FxNC) associated with low level convergence zones over the Northeast Region of Brazil (NE). The study was divided into two parts: a) event climatology using six years of meteorological satellite images; and (b) case studies using conventional weather data and European numerical analysis. Center for Medium Range and Weather Forecasts "(ECMWF). The climatological study reveals two main types of FxNC configuration; the first, classified as Type A, is associated with convergence zones formed by the actuation of cyclonic vortices or frontal systems that reach the south. The second pattern (type S) is formed by the interaction between frontal systems and high-level cyclonic vortices over the Atlantic Ocean east of the NE The results obtained from the case studies reveal that: (i) there are patterns low and high levels of circulation associated with each type of FxNC configuration, (ii) significant precipitation observed when such events occur, (iii) the Second Type Conditional Instability (CISK) mechanism, assessed from of the fields of divergence of moisture flow and equivalent potential temperature, contributes to the maintenance of FxNC.