Diurnal Variation of Precipitation in the Eastern Tropical Atlantic

Abstract

Summaries of ship observations for four marine areas off the west coast of Africa have been used to describe the diurnal variation of precipitation in the eastern tropical Atlantic. These long-term means show a definitive early morning maximum in precipitation frequency throughout the year, in agreement with findings in most tropical ocean areas. In contrast, data for the nearby GATE area, which are limited to summer months, show late afternoon-early evening maxima in precipitation frequency and amount. Support for differences of this type is offered by the patterns of convective activity over the tropical Atlantic shown by satellite IR data during GATE as presented by Murakami (1979).