中国中东部区域TRMM降水产品降尺度研究及其时空特征分析

Spatial downscaling of TRMM precipitation product in mid-eastern region of China and analysis of its temporal and spatial features

该研究以中国中东部区域(17°~50°N,98°~135°E)为研究范围,在前人研究基础上,根据水汽与降水之间的关系,基于MOD05水汽产品,采用偏最小二乘法,对中国中东部区域2001—2010年10a平均TRMM3B43_V7月降水产品进行降尺度,旨在得到空间分辨率为1km×1km的月降水空间分布。通过比较分析,发现该降尺度模型能大幅提高TRMM产品空间分辨率,估算结果平均相对误差为15.35%,与地面观测较接近,能体现中国中东部区域降水宏观分布趋势,且估算结果精度高于前人基于归一化植被指数(NDVI)的降尺度模型,能满足降水产品的精细化需求。

Based on previous studies,according to the relationship between water vapor and precipitation,the MOD05 water vapor product was used in mid-eastern region of China(17°-50°N,98°-135°E)to downscale the average TRMM3B43 monthly precipitation products from 2001 to 2010 by the partial least squares.The TRMM monthly precipitation product with spatial resolution of 1 km×1 km was obtained.The comparative analysis shows that the downscaling model can greatly improve the spatial resolution of TRMM products.The average relative error of the estimation results is 15.35%,which is close to the ground observations.It can reflect the macroscopic distribution trend of precipitation in mid-eastern region of China,and the accuracy of the estimation results is higher than that of NDVI.The method can meet the refined demand for precipitation products.