10:45 AM - 11:00 AM
[ACG38-07] Algorithm updates and validation results of GSMaP realtime version (GSMaP_NOW)
Keywords:precipitation, GPM, GSMaP, Satellite
Precipitation is one of the most essential parameters in the Earth system. In order to address water issues like water shortage or floods, JAXA has developed Global Satellite Mapping of Precipitation (GSMaP) under the Global Precipitation Measurement (GPM) mission, which is hourly global precipitation dataset. GSMaP allows us to capture the hourly horizontal distribution of global precipitation with good latency after observation. The spatial resolution is 0.1 x 0.1 degrees latitude/longitude. It has been used for various kinds of utilization purposes.
In particular, GSMaP real-time version with a latency of only a few minutes called “GSMaP_NOW” has been widely used for real-time rainfall monitoring by operational meteorological agencies or disaster management offices in the Asia-Pacific countries. GSMaP_NOW was firstly available only within the domain of Himawari-8 by Japan Meteorological Agency (JMA) in November 2015. The domain of GSMaP_NOW was expanded to the domain of Meteosat by European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) in November 2018, and of Geostationary Operational Environmental Satellite (GOES) by National Oceanic and Atmospheric Administration (NOAA) in June 2019.
The algorithm of GSMaP_NOW to estimate precipitation has been maintained with minor updates since 2015, but it was majorly updated in December 2021. In this study, verification results of GSMaP_NOW product are reported to show the quantitative improvement of GSMaP NOW. The radar/raingauge analysed precipitation data by the JMA, which is an hourly rainfall analysis generated from ground-based precipitation radars corrected by automated rain gauges, are used as the reference data. As for daily precipitation validation, the root mean square error of the new GSMaP_NOW is decreased and the spatial correlation coefficient is increased compared to the previous version of GSMaP_NOW.
In particular, GSMaP real-time version with a latency of only a few minutes called “GSMaP_NOW” has been widely used for real-time rainfall monitoring by operational meteorological agencies or disaster management offices in the Asia-Pacific countries. GSMaP_NOW was firstly available only within the domain of Himawari-8 by Japan Meteorological Agency (JMA) in November 2015. The domain of GSMaP_NOW was expanded to the domain of Meteosat by European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) in November 2018, and of Geostationary Operational Environmental Satellite (GOES) by National Oceanic and Atmospheric Administration (NOAA) in June 2019.
The algorithm of GSMaP_NOW to estimate precipitation has been maintained with minor updates since 2015, but it was majorly updated in December 2021. In this study, verification results of GSMaP_NOW product are reported to show the quantitative improvement of GSMaP NOW. The radar/raingauge analysed precipitation data by the JMA, which is an hourly rainfall analysis generated from ground-based precipitation radars corrected by automated rain gauges, are used as the reference data. As for daily precipitation validation, the root mean square error of the new GSMaP_NOW is decreased and the spatial correlation coefficient is increased compared to the previous version of GSMaP_NOW.