WORLD DISTRIBUTION OF MEAN MONTHLY AND ANNUAL PRECIPITABLE WATER

Abstract

Mean values of precipitable water are determined for 182 stations throughout the world using a 3-yr. period and evaluation methods developed by Peterson and Showalter. The resulting distribution is presented on a series of monthly maps and a map of the annual mean value. A general latitudinal pattern is present, especially over the oceans, with Highs near the Equator and Lows at the Poles. The continents show the effects of elevation and distance from the sea. The highest yearly mean is found in the Bay of Bengal in the summer. Other areas of high precipitable water are the tropical lowlands. Lowest values are in the high latitudes, continental interiors, and at high elevations in winter. Annual ranges are greatest in the Bay of Bengal and interior Asia and lowest over the equatorial oceans.