GMS-5卫星估计中国西部地区月降水

Monthly Precipitation Estimation over Western China Using GMS Satellite Data

在气候降水数据集中,中国西部地区的降水数据精度一直偏低,如全球降水气候项目数据集(GPCP)数据1998年年平均相对误差在100°E以西达到100%以上,由于这一地区人烟稀少,缺少足够的地面雨量站,极轨卫星时间覆盖率低,GMS静止卫星高度角偏低,给这一地区的降水测量和估计带来困难。本文尝试将GOES卫星降水指数(GPI)算法拓展应用到这一区域,同时,为了消除卫星高度角偏低造成的影响,利用当地气候资料,引入相对湿度修正因子。结果表明,用GMS静止卫星云图结合气候资料,可以有效估计中国西部地区的月降水。

Among common climate precipitation data sets, the accuracy over the western part of China is not high enough, for example, the annual average relative error (uncertainty) is above 100% to the west of 100°E in China. Most part of this area is desert, so few weather stations are located in this area and the amount of annual precipitation is no more than 100 mm. It is more difficult to measure and estimate precipitation when the GMS satellite is positioned outside the suitable domain for GOES Precipitation Index (GPI). This paper presents a new method (WGPI) to estimate the monthly precipitation over the western part of China by modifying GPI with climate precipitation and humidity data. Results show that WGPI has the similar accuracy to Global Precipitation Climate Preject (GPCP) data set.