5:15 PM - 6:30 PM
[ACG10-P04] Additional information of precipitating cloud life stages for Improvement of rain rate data estimated from Himawari-8
Keywords:Himawari-8, GPM, precipitation, GSMaP
For verification of the above product, the threat score of the rain area estimated from Himawari-8 was calculated by comparing with rain observed by ground-based radar in near Japan region as the truth. As a result, the threat score in daytime is very high value more than 0.5, and that in night time is more than 0.42, which are conditionally comparable to microwave rain estimation. Next we verified effectiveness of Himawari-8 new additional channels to rain estimation. Then in rain area classification, a visible blue channel (0.46μm) is most effective and in rain type classification a near Infrared channel (1.6μm) is most effective. Route mean square error of rain rate is about 1.3 mm par hour but strong rain greater than 8.0 mm par hour is tend to be underestimated. This is partly because that it is difficult to distinguish thick convective cloud from thin cirrus since the rain rate estimated by RF method is mainly based on cloud top temperature (height) information obtained from Himawari-8 observation of brightness temperature. To overcome this problem, we tried to improve an accuracy of estimating convective rain rate by using temporal variation information of rainy cloud. First a moving vector of rainy cloud is calculated from every 10 minutes global observation of Himawari-8. Next we added temporal variation information of rainy cloud brightness temperature obtained by tracing rainy cloud with the moving vector into the RF method. As a result the Himwari-8 rain rate product is improved with life stage information of rainy cloud. We intend to show example analysis of the improved Himawari-8 rain product in near Japan region.
Himawari-8 GMS data is released from the Center for Environmental Remote Sensing, Chiba University. We used near surface rain observed by GPM (Ku PR) and rain intensity observed by ground-based radar in the Japan Meteorological Agency as the truth of Rain