Um estudo sobre a influencia do Albedo diferencial e da Orografia na circulacao atmosferica: uma aplicacao para o Nordeste Brasileiro / A study over influence of differential Albedo and Orography in the atmosphere circulation: a aplication to the Brazilian Northeast

AUTOR(ES)
DATA DE PUBLICAÇÃO

1979

RESUMO

A study of the influence of orography and differential albedo on the mean vertical motion in the atmosphere over Northeast Brazil is presented. The vertical velocity is calculated at the top of the planetary boundary layer, using a vertically integrated atmospheric model, in which the zonal flow is laterally limited by rigid walls in the north and south and vertically limited by a fixed lid. The mathematical model is similar to that of Berkofsky (1976) except that equations are in the sigma coordinate system. The linearized equations are numerically resolved using a grid in which the variables are staggered in space and an Euler-backward time integration scheme. Considering the orography alone, sinking motions are induced over the region where the mean annual precipitation is a minimum. The same distribution of vertical motion results when the albedo alone is considered, which is in accord with the hypothesis of Charney (1975). When both the orography and the albedo are incorportated in the model, the descending motion is found to be a greater intensity. As a result, it appears that the orography and the albedo together contribute to the low rainfall and arid conditions over Northeast Brazil. This conclusion, however, needs to be confirmed by a more realistic mathematical model followed by a test of statistical significance.

ASSUNTO(S)

estudos do tempo e do clima camada limite meteorologia dinamica regiao nordeste - brasil albedo precipitacao pluvial seca

ACESSO AO ARTIGO

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