Southwest Monsoon Experiment/Terrain-influenced Monsoon Rainfall Experiment (SoWMEX/TiMREX)
Ben Jong-Dao Jou, Professor, Department of Atmospheric Science, National Taiwan University
A Taiwan and United States joint field program in studying the heavy rain events associated with Asia Summer Monsoon (Meiyu frontal system) has been conducted in May and June 2008. The field experiment was conducted at the western plain and mountain slope region of southern Taiwan and it is called Southwest Monsoon Experiment/Terrain-influenced Monsoon Rainfall Experiment (SoWMEX/TiMREX). The goal of the program is to improve the capability of quantitative precipitation estimation and forecasting (QPE/QPF) during the Asian Summer Monsoon season. The localized heavy rainfall events frequently lead to floods and landslides resulted in casualty and heavy property damage in the Taiwan area. SoWMEX/TiMREX provides an unique opportunity to advance our basic understanding of physical processes leading to development of heavy orographic precipitation through intensive field observation campaign. SoWMEX/TiMREX provides an unprecedented opportunity for complementing the science of previous investigations in the general area of orographic precipitation.
The primary observational facilities been deployed at southern Taiwan include: NCAR SPOL (S-band polarimetric Doppler radar system), TEAM-Radar (X-band mobile polarimetric Doppler radar system), and MRR (Micro rain radar systems). In addition to advanced radar systems, upstream soundings by operating airborne dropsondes and ship soundings over the northern boundary of South China Sea has been conducted.
The major scientific outcomes from SoWMEX/TiMREX including a better understanding of the kinematic and thermodynamic characteristics of the southwesterly monsoonal flows over the ocean upstream of Taiwan. It is demonstrated that rainfall prediction has been greatly improved with this extensive observation campaign. The rainfall products will be valuable not only for early warning of flood and landslide but also for regional water resource management. The primary funding supports are from National Science Foundation of USA and National Science Council (Ministry of Science and Technology) and Central Weather Bureau of Taiwan.