A Technique for Estimating Tropical Open-Ocean Rainfall from Satellite Observations

Abstract

A procedure has been devised for extracting the frequency of highly reflective clouds from visual satellite picture mosaics of the tropical Pacific Ocean. Over the period May 1971 through April 1973 monthly frequencies of highly reflective clouds were statistically tested for a regression relationship with 820 station-months of coral island rainfall. The correlation coefficient was +0.75 while the line of regression passed near the origin and was equidistant from the abscissa and ordinate. The F calculated from an analysis of variance table was highly significant at the 1% level. The rainfall estimated from highly reflective cloud frequencies was then compared to other tropical Pacific Ocean climatological rainfall estimates.