TRMM遥感降水低估还是高估中国大陆地区的降水?

Does TRMM Precipitation Underestimate or Overestimate in China's Mainland?

卫星降水产品在一定程度上为地表观测稀疏地区的降水提供了参照值,但在具体应用时仍需进行适用性和精度评价。为降低不确定性,通行做法是利用地面观测数据对卫星产品进行融合校正,评价和修正卫星降水产品。以TRMM为例,对研究中国大陆范围的融合TRMM降水的公开成果进行了检视,发现不同研究成果结论之间存在不可忽视的方向性相背情况,极大地影响着生产实践应用中对融合产品的可靠性判断。研究认为,这种融合结果相背的现象与融合校正方法关系不大,而与地面降水参照站点选取的范围有密切关系。研究表明,仅靠TRMM卫星降水自身及与地面融合方法的创新,尚不能降低卫星降水产品的不确定性。目前仍需加强对卫星降水融合中地面观测数据的完整性要求,采用多种独立检验方法验证融合结果的一致性和可靠性。

Although satellite precipitation has provided a valuable reference for the precipitation estimation in the sparse region,its uncertainties in the practical application are still challenging. Researchers tried to fuse ground observation and satellite precipitation to evaluate and modify satellite precipitation products for uncertainty reduction. Unfortunately,this paper examined many publications of fusion TRMM precipitation products in China's Mainland and found a non-negligible directional contradiction between the approaches. The findings will significantly affect the reliability of satellite precipitation in practical applications. It was found that the contradiction has not related to the satellite precipitation products and fusion methods but significantly related to the selection of precipitation observation stations. It was also found that the uncertainty is hard to be reduced only by innovating the fusing methods of TRMM precipitation with ground observation data. Therefore,it is necessary to strengthen the integrity of ground observation and adopt independent practices to verify consistency and reliability.