Evaluation of Extreme Rain Estimates in the TRMM/PR Standard Product Version 7 Using High-Temporal-Resolution Rain Gauge Datasets over Japan

Shinta Seto, Toshio Iguchi, Nobuyuki Utsumi, Masashi Kiguchi, Taikan Oki
2013 SOLA : Scientific Online Letters on the Atmosphere  
The Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) standard product version 7 (V7) is evaluated, particularly in terms of extreme event estimation, using rain gauge data of high-temporal-resolution over southern Japan. A 1-minute rain gauge dataset within PR's field-of-view (FOV) is desirable for the evaluation. However, such dataset included only one data match with near-surface rain rate estimates (NSR) higher than 50 mm h −1 (extreme NSR). By relaxing the spatial and
more » ... oral matchup conditions, several tens of matches with extreme NSR are obtained, and the bias ratio of extreme NSR to corresponding gauge value is calculated to range from +41% to +94%. Considering that the relaxed matchup conditions may exaggerate the positive bias, the conclusion can be made that extreme NSR has a positive bias of less than +50% in V7 and that estimates are largely reliable. A similar evaluation is performed for extreme NSR in the TRMM PR standard product version 6 (V6), which showed a bias ratio of greater than +100%. Many false extreme NSR are estimated in V6, but a large part of them are diminished in V7. (Citation: Seto, S., T. Iguchi, N. Utsumi, M. Kiguchi, and T. Oki, 2013: Evaluation of extreme rain estimates in the TRMM/PR standard product version 7 using high-temporal-resolution rain gauge datasets over Japan. SOLA, 9, 98−101,
doi:10.2151/sola.2013-022 fatcat:25pujunvu5hlhc236e53bfo2uu