Adequacy of the daily TMPA 3B42 high-resolution satellite precipitation product for monitoring hydrometeorological hazards in the Southeast Sahel of Africa

作者：Hermance John F^*; Sulieman Hussein M

来源：International Journal of Remote Sensing, 2018, 39(8): 2579-2596.

DOI：10.1080/01431161.2018.1430405

• TRMM
• Sahel
• meteorology
• hazard monitoring

Rural hamlets in the Southeast Sahel, because of their pastoral setting and dependence on local agricultural production, are particularly vulnerable to flash flooding, loss of soil and the inundation of arable land caused by sudden storm events. High resolution satellite precipitation estimates (SPEs) could prove essential for detecting, monitoring, predicting and mitigating the effects of such hydrometeorological extremes. The focus of this report is on assessing - in the context of the needs of the local community - the effectiveness of what has become the gold standard for such applications in Africa and elsewhere since 1998: Tropical Rainfall Monitoring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA)program's 0.25 degrees x 0.25 degrees, daily 3B42 Version 7 satellite-gauge merged product. The scientific community now has almost 20years of TMPA data that will likely play a significant role well into the future for retrospective studies in conjunction with the next generation (post-2014) Global Precipitation Mission (GPM) products. To assess the 3B42 product for the purposes of this report, we employ a pixel-to-point comparison of 3B42 daily time series with synchronous gauge data at four well-separated gauge sites. While others have found notable agreement between 3B42 and gauge observations aggregated over large areas and seasonal to annual time periods, it is a different matter downscaling to daily values at local sites, where we find a disturbing number of false alarms' and missed events'. More than 90% of the total annual rainfall estimated by the 3B42 is contributed by daily events that are misaligned in time or intensity with gauge events. This largely concurs with the findings of our prior reports based on CPC-RFE2 0.1 degrees x 0.1 degrees daily values. Thus, users might be cautious in using the TMPA 3B42, CPC-RFE2 or, by inference, any SPE, as deterministic metrics for detecting and monitoring short term (i.e. 1 day), extreme storm events in this area of the Sahel.

• 出版日期2018