衛星降水資料於臺灣與鄰近地區之適用性評估與應用(子計畫八)(II)

This is the second year final report of the three-year plan, entitled “the assessment and application of satellite precipitation observations on Taiwan and surrounding areas”. In the first year, we focused on "evaluating the applicability of international satellite precipitation products in Taiwan". We analyzed the characteristics of Taiwan precipitation on different time scales (including Year, season, day, and diurnal), and compared the performance of various satellite products. Based on the experience of the first year, the main research axis of the second year focused on the assessment of "extreme precipitation" and explored the characterization capabilities of multiple sets of satellite data for extreme rainfall events. With the support of the second year plan, we have published 3 international SCI papers and one TSSCI paper. The performance of the satellite precipitation products (including Early, Late and Final runs) of the latest version of IMERG (V06B) and TRMM 3B42 v7 (TRMM7) for the 2000-2018 Taiwan typhoon season (July-October) rainfall is evaluated. Our analysis focused on the seasonal average, daily variation and inter-annual variation of typhoon rainfall (denoted as TC) and non-typhoon rainfall (denoted as non-TC).Our results show that all IMERG products capture the spatio-temporal variations of TC rainfall better than those of non-TC rainfall. Among SPPs, the final run performs better than the late run, which is slightly better than the early run for most of the features assessed for both TC and non-TC rainfall. Despite these differences, all IMERG products outperform the frequently used TRMM7 for the illustration of the spatio-temporal characteristics of TC rainfall in Taiwan. In contrast, for the non-TC rainfall, the final run performs notably better relative to TRMM7, while the early and late runs showed only slight improvement. These findings highlight the advantages and disadvantages of using IMERG products for studying or monitoring typhoon season rainfall in Taiwan.