1989年6月の日本周辺の梅雨の雨量分布について

Abstract

The method developed for estimating rainfall over several sample areas over the main islands of Japan from IR imagery data of GMS is extended to estimate rainfall over a wider region including the Japanese islands and their adjacent ocean.In extended method, the proportional coefficients between rainfall and cold cloud fractional coverage, FC are assumed to be linear functions of latitudes and calculated for the 3 types of rainy clouds by using IR and rainfall data of AIP/1. The extended method gives a relatively good estimation of rainfall in applying to the whole AIP/1 data, with relative errors of 73% and 17% for daily and monthly estimation, respectively. Rainfall features of the Baiu season are then investigated through IR estimation for June 1989.The total monthly rainfall for the period is distributed in a band-like shape exteding from west to east, showing its maximum on 35ﾟN in the latitudinal section and a sudden decrease to the west of 130ﾟE in the longitudinal section. The latitudinal distributions of rainfall relative to the Baiu front show almost the same shape with their maximam at 1.25ﾟ north of the front at the surface over both land and ocean, but the peak amount is larger over the island than that over the ocean.