中国西部及邻区现代年降水时空分布初步研究

Modern Spatial and Seasonal Distribution of Precipitation in Western China and Its Adjacent Areas

传统上认为中国东部、西南以及青藏高原南部的降水主要受亚洲夏季风的控制,以夏季降水为主;而青藏高原北部以及新疆受西风带的影响,以冬、春季降水为主。最近一些地质记录和数值模拟结果显示,在万年时间尺度上新疆降水在地质历史时期的间冰期增加,和亚洲季风区类似。用TRMM 3B43降雨数据和气象台站观测降水数据,研究了中国西部及邻区现代年降水的时空分布。研究结果显示现代中国西部地区以夏季降水为主,中国边境线以西的中亚干旱区（介于25°-45°N,58°-70°E之间）以冬、春季降水为主。中国新疆的降水模式不同于西风带影响区,但其降水也不全是亚洲夏季风带来的。

The precipitation of eastern,southwestern China,and south Qinghai-Tibetan Plateau（QTP） is traditionally considered brought by Asian summer monsoon（ASM）,while the northern QTP and Xinjiang Uygur Autonomous Region is influenced by Westerlies with predominant winter and spring precipitation.However,recent geological evidence and model simulation results indicated that the precipitation pattern of Xinjiang Region was similar to the ASM area during the past interglacial stages.In this study,the precipitation data of TRMM 3B43 and meteorological station observed were used to investigate modern precipitation distribution pattern in western China and its adjacent areas.We concluded that：（1） Most of the annual precipitation occurred during the summer time in western China.（2） The annual rainfall in eastern and central area west of China boundary（within the area of 25°-45° N and 58°-70° E） was dominated by winter and spring precipitation.（3） Most of annual precipitation in Xinjiang Region falls between April and August,accompanied with risen temperature.The precipitation pattern of Xinjiang Region is neither similar to the Westerlies influenced areas nor to the ASM area.