贵州高原地带TRMM 3B42卫星降水数据的精度评价

在下垫面相对复杂,位于高原地带的贵州,利用19个气象站点实测数据分别从年、季度、月和天时间尺度对TRMM 3B42卫星降水数据进行精度检验,并讨论TRMM 3B42卫星对不同降水强度的探测能力,以此来分析其在贵州的适用性。结果表明,TRMM 3B42降水数据在年尺度上拟合优度较好(R=0.82)。研究区内19个站点年均相对误差为-2.39%,其中将近70%的站点数据表现TRMM 3B42降水量低于地面气象站点。月尺度上整体相关系数很好,R达到0.89。但是TRMM 3B42卫星数据对不同季节的探测能力存在差异,其中,冬季相关系数最低。在日尺度上TRMM 3B42降水数据与实际降水偏差大,对降水强度过大或过小的降水情况均不能准确地探测。对于单个站点而言,海拔较低的站点TRMM卫星探测出的降水与实测降水偏差小。

Evaluation of TRMM 3B42 Satellite Precipitation Data Accuracy of Guizhou Plateau

In this paper, the accuracy of the TRMM 3B42 satellite precipitation data was tested in the annual, quarterly, monthly and daily timescales using the observed data from the 19 meteorological stations, and the ability of TRMM 3B42 to detect different levels of precipitation wasdiscussed, so as to analyze the applicability of the TRMM data for Guizhou. The results show that TRMM 3B42 precipitation data are better in theannual scale (R = 0.82). The average relative error of the 19 stations in the study area is -2.39%, of which nearly 70% of the site data show that theTRMM 3B42 precipitation is lower than that from the ground meteorological stations. The overall correlation coefficient is very good in the monthscale (R = 0.89). However, the TRMM 3B42 satellite data have different detection capabilities for different seasons. Among them, the winter fittingcoefficient is the lowest. In the daily scale, the precipitation data of TRMM 3B42 are different from the actual precipitation, and the precipitationintensity is too large or too small to detect accurately. For a single site, the low-altitude site TRMM satellites detect a small deviation from the observedprecipitation.