Assimilating the Global Precipitation Measurement (GPM) Estimates in the Canadian Precipitation Analysis (CaPA) Over North America.

Abstract:

The importance of precipitation measurement using estimates from satellite products cannot be over emphasized. Observations from space using sensors mounted on satellites cover wider areas and provide high spatial and temporal resolution. The estimates derived from this process are very useful in integrated hydrologic modeling, weather forecasting and monitoring landslides, droughts and floods, etc. Example of a satellite precipitation product is the Tropical Rainfall Measurement Mission (TRMM) and Global Precipitation Mission (GPM). TRMM was primarily designed to measure heavy-to-moderate rainfall over tropical and subtropical regions. GPM was designed to extend, enhance, and improve TRMM precipitation data. The primary objective of this study is the assimilation GPM satellite based precipitation estimates into the Canadian Precipitation Analysis (CaPA). CaPA combines the Global Environmental Multi-Scale model (GEM) dataset and observed precipitation from monitoring stations to provide precipitation estimates at 6hr and 24hr time steps and spatial resolution of 10km covering North America. In the result, we used the Equitable Threat Score (ETS) as performance evaluation. GPM assimilation provides higher skill (ETS) at precipitation values below 3mm while being used as additional data source. GPM has better skill as background field at precipitation value above 3mm.