OBSERVATION AND NUMERICAL EXPERIMENTS OF PRECIPITATION IN A TROPICAL MOUNTAIN IN SOUTHEAST ASIA

Abstract

Since 1997, rainfall has been measured by using tipping-bucket rain gauges in a mountainous area as a part of GAME-Tropics (the Global Energy and Water Cycle Experiment (GEWEX) Asian Monsoon Experiment (GAME)). Orographic precipitation tends to occur when easterly or southeasterly wind is predominated, wind speed is relatively strong (Average: 4.6m/s, S. D.: 2.1m/s), and the lifted condensation level is low. By investigating orographic precipitation using a regional atmospheric model under various atmospheric conditions, 1) comparatively strong monsoon westerly in the lower troposphere and complex terrain and 2) moist condition in the lower atmosphere including evapotranspiration from the wet ground are significant factors to the spatial pattern of precipitation in the mountainous region.