Evaluation of GSMaP Satellite Precipitation Over Central VietNam in 2000-2010 Period and Correction Ability

Abstract

Abstract: Daily/Monthly precipitation of GSMaP is compared with observation at 10 stations over Central VietNam in 2000-2010 period. Evaluation indices used in this study include correlation coefficient (r), relative bias (B), probability of detection (POD) and false alarm ratio (FAR). The results show that the agreement of the first rainy month over 100mm and the maximum rainy month between GSMaP and observation, however, the duration of rainy months over 100mm of GSMaP is shorter than that of observation. GSMaP precipitationoften underestimates compared to observation in October-December at almost stations.It can be seen that monthly correlation coefficients are often positive at almost stations when evaluating daily precipitation, the lower values normally are found in January and February. Positive relative biases are observed in April-September at most of North Central stations, while those often occur in July-September at South Central stations. Negative relative biases can be found in October until March of next year at almost stations. The good POD and FAR values are given at 0-6mm/day threshold and the worse values are found at 6-16mm/day threshold. After applying correction methods, the GSMaP precipitation is much better agreement with observation, especially in underestimated rainy months.
 Key words:Precipitation, GSMaP, evaluation, correction.