Development of a rainfall prediction method by combined use of geostationary satellite and ground-based radar observations

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K05026
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 25030:Disaster prevention engineering-related
• Research Institution: University of Toyama
• Principal Investigator: Hamada Atsushi 富山大学, 学術研究部都市デザイン学系, 准教授 (30550008)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 極端降雨 / 降雨予測 / 静止気象衛星 / 高頻度観測

Outline of Final Research Achievements

Utilizing so-called "rapid-scan" measurements by the geostationary satellite Himawari-8, we studied a method for predicting the rainfall onset based on the statistical characteristics of the development of cumulonimbus clouds. After being defined the onset time of rainfall at each location using meteorological radar measurements, we examined the relationship between the temporal variation of brightness temperature before the rainfall onset, and found that the brightness temperature decreased about 15 minutes before the rainfall onset. The results demonstrate that rapid-scan measurements from geostationary satellite can predict the rainfall onset more than 15 minutes earlier than meteorological radar measurements. The relationship between rainfall intensity and the decrease rate of brightness temperature before the rainfall onset was examined, and it was found that the stronger the rainfall intensity at the rainfall onset, the greater the decrease rate of brightness temperature.

Free Research Field

衛星気象学

Academic Significance and Societal Importance of the Research Achievements

強い降雨は積乱雲からもたらされる周知の事実をもとに、雲の発達を適切に捉えることで降雨開始を予測しようとした着眼点、および最新の静止気象衛観測を用いればその予測が可能であることを示した点において、学術的意義が大きい。予測手法の開発および実装には至らなかったものの、降雨レーダよりも早く降雨開始を国民に伝えられる可能性は示されており、一定の社会的意義もあると考える。