Understanding and improving convective-scale predictability

2021 Fiscal Year Final Research Report

• Project/Area Number: 16K17807
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Otsuka Shigenori 国立研究開発法人理化学研究所, 計算科学研究センター, 研究員 (40585022)
• Project Period (FY): 2016-04-01 – 2022-03-31
• Keywords: 積雲対流 / 予測可能性 / 降水ナウキャスト

Outline of Final Research Achievements

This project investigated 1) chaotic error growth at the scale of cumulus convection, 2) effectiveness of prediction by linear spatiotemporal extrapolation, and 3) development of methods to improve practical predictability of cumulus convection. It was found that the prediction error grew associated with convective cores at the time scale of 30 seconds. Using observations by the Phased Array Weather Radar, a 10-minute-lead precipitation prediction system that refreshes every 30 seconds was developed, and the system was successfully operated in real time. To evaluate prediction accuracy, a method to compute statistics on the area of cumulus convection and a method to evaluate shapes of convective areas were developed.

Free Research Field

気象学

Academic Significance and Societal Importance of the Research Achievements

ゲリラ豪雨や線状降水帯に代表されるように、積雲対流は私たちの社会生活に大きな影響をもたらす。本研究では積雲対流がどこまで予測可能であるかという点について理解を深めた。また、降水予測の精度評価は従来の手法では問題があったが、本研究では新しい指標を提案した。これらの点で学術的な意義がある。さらに、実際に積雲対流の予測を行う新たな手法を開発し、リアルタイム運用を実現したという点で社会的意義がある。