Evaluation of IMERG and TRMM 3B43 Monthly Precipitation Products over Mainland China

Fengrui Chen,Xi Li

doi:10.3390/rs8060472

Abstract

As the successor of the Tropical Rainfall Measuring Mission (TRMM), the Global Precipitation Measurement (GPM) mission significantly improves the spatial resolution of precipitation estimates from 0.25° to 0.1°. The present study analyzed the error structures of Integrated Multisatellite Retrievals for GPM (IMERG) monthly precipitation products over Mainland China from March 2014 to February 2015 using gauge measurements at multiple spatiotemporal scales. Moreover, IMERG products were also compared with TRMM 3B43 products. The results show that: (1) overall, IMERG can capture the spatial patterns of precipitation over China well. It performs a little better than TRMM 3B43 at seasonal and monthly scales; (2) the performance of IMERG varies greatly spatially and temporally. IMERG performs better at low latitudes than at middle latitudes, and shows worse performance in winter than at other times; (3) compared with TRMM 3B43, IMERG significantly improves the estimation accuracy of precipitation over the Xinjiang region and the Qinghai-Tibetan Plateau, especially over the former where IMERG increases Pearson correlation coefficient by 0.18 and decreases root-mean-square error by 54.47 mm for annual precipitation estimates. However, most IMERG products over these areas are unreliable; and (4) IMERG shows poor performance in winter as TRMM 3B43 even if GPM improved its ability to sense frozen precipitation. Most of them over North China are unreliable during this period.

Highlights

The availability of reliable and accurate precipitation data at regional and global scales is critical to the applications of meteorology, hydrology, and water resources management [1,2,3]
Integrated Multisatellite Retrievals for GPM (IMERG) products can provide many more spatial details related to precipitation than
As the interval of observation improved from 3 h for Tropical Rainfall Measuring Mission (TRMM) to 30 min for Global Precipitation Measurement (GPM), many more samples of precipitation were attained by IMERG, so many data can efficiently decrease the power of certain anomalous value

Summary

Introduction

The availability of reliable and accurate precipitation data at regional and global scales is critical to the applications of meteorology, hydrology, and water resources management [1,2,3]. The rapid development of remote sensing technology has brought an unprecedented opportunity for better estimating precipitation than before. Center morphing method [4], Precipitation Estimation from Remotely Sensed Information using. Multi-Satellite Precipitation Analysis (TMPA) [7] products. Among these datasets, TMPA products, which have a relatively high level of accuracy, have been used widely [8,9,10,11,12,13,14,15]

Methods

Results

Conclusion