Variações interanuais da circulação geral de inverno no Hemisfério Norte e da oscilação sul (Meridional) e suas possíveis conexões com o clima do nordeste Brasileiro / Interannual variations of winter general circulation in the North Hemisphere and South oscillation (Meridional) and its possible connections with the Northeast Brazilian

AUTOR(ES)
DATA DE PUBLICAÇÃO

1984

RESUMO

Interannual variations of the winter circulation in the Northern Hemisphere (NH) and their possible connections with the interannual variation of the precipitation in Northeast (NE) Brazil are studied. The data set used for the NH circulation are the winter grid point geopotential height of the 700mb for the period 1964-82 (19 years). These grid point data are subjected to harmonic analysis yielding amplitudes and phases of zonal harmonics. Using the amplitudes and phases of different harmonics, dynamical quantities such as kinetic energy and momentum transport. are calculated. Examination of these quantities did not show any systematic interannual variation, although some interesting connections between them are detected. The connection between NH circulation and NE Brazil .rainfall is examined calculating correlation coefficients between rainfall and grid point data of geopotential height field. Significant correlations are found in the region of Siberia, Arctic and Southern Europe. Correlation coefficients are calculated between the Southern Oscillation index during the summer of Southern Hemisphere (SH) and the rainfall during the rainy season in NE Brazil. The highest significant correlation is found with SO index preceding rainfall by about two months. The rainfall distribution in NE Brazil during the 1983 drought year is analyzed. It is found that this is the worst drought that occurred during the last twenty years.

ASSUNTO(S)

seca ciencias meteorológicas hemisfério sul momentum climatologia dinâmica precipitação (meteorologia)

ACESSO AO ARTIGO

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