Multiscale Comparative Evaluation of the GPM IMERG v5 and TRMM 3B42 v7 Precipitation Products from 2015 to 2017 over a Climate Transition Area of China
Multiscale Comparative Evaluation of the GPM IMERG v5 and TRMM 3B42 v7 Precipitation Products from 2015 to 2017 over a Climate Transition Area of China
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中国气候转型区2015-2017年GPM IMERG v5和TRMM 3B42 v7降水产品多尺度对比评价
DOI：
10.3390/rs10060944
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发表时间：
2018-06-01
期刊：
影响因子：
5
通讯作者：
Tang, Guoqiang
中科院分区：
文献类型：
--
作者：
Chen, Cheng;Chen, Qiuwen;Tang, Guoqiang
在2015 - 2017年半湿润-湿润气候过渡区（淮河流域），对最新发布的GPM使命综合多卫星反演（IMERG）第5版（IMERG v5）和TRMM多卫星降水分析3B 42第7版（3B 42 v7）的性能进行了评估和比较。降雨率，纬度和海拔对降水探测技术的影响也进行了研究。结果表明，这两个卫星估计显示出较高的皮尔逊相关系数（r，0.89以上）与仪表观测，并高估了降水量在月和年尺度。IMERG v5和3B 42 v7的平均日降水量显示出一致的空间格局，并且都很好地表征了观测到的降水分布，但3B 42 v7倾向于明显高估水体降水量。两种卫星降水产品都高估了强度范围为0.5至25毫米/天的暴雨，但往往低估了轻（0-0.5毫米/天）和重（>25毫米/天）暴雨，特别是暴雨（超过100毫米/天）。对于每个测量站，IMERG v5的平均r（GPM为0.36，TRMM为0.33）和平均相对均方根误差（RRMSE，GPM为1.73，TRMM为1.88）均大于3B 42 v7。在不同降雨率下，IMERGv 5的探测概率（POD）、临界成功指数（CSI）和虚警率（FAR）均高于3B 42 v7，表明IMERGv 5总体上具有较好的降水探测能力。该研究有助于更好地了解IMERG v5和3B 42 v7降水精度的时空分布及其影响因素，对水文应用具有重要意义。
The performance of the latest released Integrated Multi-satellitE Retrievals for GPM mission (IMERG) version 5 (IMERG v5) and the TRMM Multisatellite Precipitation Analysis 3B42 version 7 (3B42 v7) are evaluated and compared at multiple temporal scales over a semi-humid to humid climate transition area (Huaihe River basin) from 2015 to 2017. The impacts of rainfall rate, latitude and elevation on precipitation detection skills are also investigated. Results indicate that both satellite estimates showed a high Pearson correlation coefficient (r, above 0.89) with gauge observations, and an overestimation of precipitation at monthly and annual scales. Mean daily precipitation of IMERG v5 and 3B42 v7 display a consistent spatial pattern, and both characterize the observed precipitation distribution well, but 3B42 v7 tends to markedly overestimate precipitation over water bodies. Both satellite precipitation products overestimate rainfalls with intensity ranging from 0.5 to 25 mm/day, but tend to underestimate light (0-0.5 mm/day) and heavy (>25 mm/day) rainfalls, especially for torrential rains (above 100 mm/day). Regarding each gauge station, the IMERG v5 has larger mean r (0.36 for GPM, 0.33 for TRMM) and lower mean relative root mean square error (RRMSE, 1.73 for GPM, 1.88 for TRMM) than those of 3B42 v7. The higher probability of detection (POD), critical success index (CSI) and lower false alarm ratio (FAR) of IMERG v5 than those of 3B42 v7 at different rainfall rates indicates that IMERG v5 in general performs better in detecting the observed precipitations. This study provides a better understanding of the spatiotemporal distribution of accuracy of IMERG v5 and 3B42 v7 precipitation and the influencing factors, which is of great significance to hydrological applications.