Comparisons of rainrates from IMERG (V05) and Korean QPE
IMERGIntegrated Multi-Satellite Retrievals for GPM (IMERG) Algorithm is intended to intercalibrate, merge, and interpolate "all" satellite microwave precipitation estimates, together with microwave-calibrated infrared (IR) satellite estimates, precipitation gauge analyses, and potentially other precipitation estimators at fine time and space scales for the TRMM and GPM eras over the entire globe. The system is run several times for each observation time, first giving a quick estimate and successively providing better estimates as more data arrive. The final step uses monthly gauge data to create research-level products. Background information and references are provided to describe the context and the relation to other similar missions. Issues involved in understanding the accuracies obtained from the calculations are discussed. Throughout, a baseline Day-1 product is described, together with options and planned improvements that might be instituted before or after launch depending on maturity and project constraints. The IMERG gridded estimates are on a 30-minute temporal resolution and a 0.1o by 0.1o spatial resolution extending from 180W to 180E and 60S to 60N. For more information about IMERG, read IMERG_ATBD_V5.2_0.pdf Thanks to George Huffman and David T. Bolvin for providing IMERG Early-Run, Late-Run, and Final-Run products.
Korean QPEKorea Meteorological Administration(KMA) has developed a Real-time ADjusted Radar-AWS (Automatic Weather Station) Rainrate (RAD-RAR) system using eleven radars over South Korea. The Korean QPE data are on a 1-hour temporal resolution and a 1-km by 1-km spatial resolution extending from 119.883E to 136.316E and 29.1906N to 45.7572N. Thanks to Geunhyoerk Ryu at KMA for providing Korean QPE data for this study.
Comparisons between IMERG and Korean QPEThe comparisons are conducted over the area (125E-129.5E, 34N-38N) during Mar 2014- Aug (May) 2018 between Korean QPE and Version-05 IMERG (Early, Late and Final Runs). Note IMERG Final Run files are available to May 2018 as of this update in Sep 2018. Validations for other versions of IMERG products are listed below:
V03 comparisons among Korean QPE, TMPA 3B42 and Version-03D IMERG products.
V04 comparisons between Korean QPE and Version-04 IMERG products.
The number listed in the upper left panel is the total rain occurrence in all bins for each product.
Rain/no-rain threshold is set to 0.1 mm/h.