Proposal of snowfall prediction method using single-shot polarized lidar

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K22030
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 25:Social systems engineering, safety engineering, disaster prevention engineering, and related fields
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: Shibata Yasukuni 東京都立大学, システムデザイン研究科, 准教授 (10305419)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: ライダー / 降水粒子 / 雨 / 雪 / 判別 / 偏光 / パーティクル

Outline of Final Research Achievements

The purpose of this study is to provide information on snow disasters and to establish a new method for directly measuring the altitude distribution of snowfall areas with a lidar. We have developed a single-shot polarized lidar system that measures the polarization component of individual precipitation particles and a dedicated app that acquires observation data. Using these systems, continuous observations were carried out for 17 hours during the snowfall on January 23-24, 2021. Individual precipitation particles falling from the clouds were detected, and the degree of depolarization was measured. Clouds at an altitude of around 300 m fell to an altitude of around 100 m in two hours, and the rain turned into snow on the ground. At this time, the surface temperature of 3℃ plummeted to the 0℃. These observations suggest that snowfall started due to the fall of cold air.

Free Research Field

リモートセンシング

Academic Significance and Societal Importance of the Research Achievements

シングルショットでリアルタイム信号処理する高速処理装置および雨雪判別アルゴリズムという、ライダー信号処理分野における新たな挑戦の有用性が実証された。将来計画として、本研究で開発する降雪検知シングルショット・ライダーを他点配置し、立体的な降雪情報を取得することにより、大雪時の交通障害の回避や物流の確保、雪氷災害軽減の実現につなげる。さらに、上空の雨雪状況、特に2重偏波レーダーでは取得が難しい降水粒子種の組成率の取得を実現することで、気象学的、特に数値モデル分野へのインパクトが大きいと思われる。