TRMM降水数据在东北地区的精度验证与应用

利用东北地区2000-2007 年的APHRODITE降水数据,基于GWR方法对TRMM降水数据进行修正,分析新的TRMM降水数据精度,并基于修正的TRMM降水数据对东北地区降水进行时空分布特征分析.结果表明:①APHRODITE降水数据与观测数据之间的线性相关性更高、均方根误差RMSE更小,数据具有较高的精度;②修正后的TRMM降水数据相关系数R有所提高,且RMSE值均有降低.整体来看,TRMM降水数据的降水量数值偏大于观测值;③修正TRMM降水数据在5-10 月的误差相对较小,整体来看,在大部分区域的误差在0~30%之间;④东北地区降水分布极不均匀,整体呈从东南向西北减少趋势.11 月到翌年3 月的降水稀少,降水主要集中在夏季,其中7月降水量最大.

Accuracy Validation and Application of TRMM Precipitation Data in Northeast China

As the important component of the global water cycle, precipitation is the key parameter in hydrology, meteorology and climate. Conventional interpolated observed precipitation data cannot reflect the spatial variation due to the limitation of the number of stations. In recent decades, with the development of remote sensing and meteorological satellite technology, satellite remote sensing images has become an important source of spatial precipitation data to detect rainfall information. In this study, APHRODITE precipitation data in Northeast China from 2000 to 2007 are used. We adjust the TRMM precipitation data based on GWR method, validate the accuracy of the adjusted data, and analyze the spatial and temporal distribution characteristics of precipitation in Northeast China based on the adjusted TRMM precipitation data. The conclusions are: 1) Correlation coefficient between APHRODITE and observed data is higher, and the root mean square error is smaller, so APHRODITE data have a higher accuracy. 2) The adjusted TRMM precipitation data have a higher correlation coefficient and a smaller RMSE value. Overall, the TRMM precipitation is higher than that of observed data. 3) High value of R mainly exists in the northern, eastern and southeastern regions, low-values mainly exist in the western and central regions. 4) The BIAS of adjusted TRMM precipitation data is relatively small from May to October. Overall, the BIAS of most areas ranges in 0-30%. 5) The distribution of precipitation is uneven in Northeast China, which reduces from the southeast to the northwest. The rainfall mostly happens in summer while less happens from November to the following March. The largest rainfall happens in July.