Comparative Analysis of CHIRPS, TRMM, and GSMaP Rainfall Data on Pari Island

Abstract Studies on climatic conditions, especially rainfall on small islands were very necessary for the conservation of fresh water resources. However, Pari Island, as a small island, has limited rainfall observation data. Use of satellite rainfall data was one of the ways to overcome the problem. This study aims to determine the performance of rainfall satellite data, namely CHIRPS, TRMM, IMERG, and GSMaP on small islands, especially Pari Island. The satellite data period used in this study followed observational data from 2000 to 2002 both daily and monthly data. The best satellite data is determined based on the Taylor Diagram. Furthermore, in this study, satellite data performance was calculated based on statistical values. The result showed that CHIRPS had the closest match to the observational data for average daily rainfall, with GSMaP coming in second. The climatology and monthly rainfall patterns were generally consistent between observational data and satellite rainfall data, except for IMERG. Satellite data tended to overestimated than observational data. CHIRPS data has the best performances, on the contrary, IMERG is the least capable. Bias values required treatment such as bias correction before further impact analysis.