An evaluation of high resolution precipitation products at low resolution

摘要

The large-scale homogeneity of several high-resolution satellite-based estimates of precipitation is assessed against the Global Precipitation Climatology Project (GPCP) between January 2003 and December 2006. The highresolution estimates are aggregated to match the resolution of GPCP (monthly, 2.5°) and an Empirical Orthogonal Functions (EOF) analysis is conducted on each product along with an analysis of the slope from a linear regression with time. The results show that some of the datasets have significant artefacts and that none of the high-resolution products give a good depiction of precipitation above 50°N. The two datasets which are most consistent with GPCP are the Tropical Rainfall Monitoring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) and the Global Satellite Mapping Project (GSMaP) both of which have undergone recent re-processing which is an important quality for dataset homogeneity.