訊息公告

同化福衛三號及七號掩星觀測對熱帶氣旋旋生預報的影響

Understanding the impact of assimilating FORMOSAT-7/COSMIC-2 radio occultation refractivity on tropical cyclone genesis: Observing system simulation experiments using Hurricane Gordon (2006) as a case study
Yang, Shu-Chih, Shu-Hua Chen and Chih-Chien Chang


本篇研究利用理想觀測同化系統探討同化福衛三號及七號掩星觀測對熱帶氣旋旋生預報的影響,並針對大西洋低可預報度之颶風Gordon(2006)進行討論。研究結果顯示同化更密集的福衛七號掩星觀測可提供水氣、中層重力位高度及渦度場之修正,有助改進旋生預報。研究首次利用同化福衛三號及七號掩星觀測所產生分析場顯示,模式初始場在氣旋核區須滿足最小總可降水量才可發展為熱帶氣旋,且若能掌握氣旋生成則有更可進一步改善降雨預報。

Hurricane Gordon (2006) has a low predictability of its genesis forecast, which can be greatly improved through the corrections of moisture and mid-level geopotential and vorticity fields in initial conditions by assimilating high-density radio occultation observations from FORMOSAT-7/COSMIC-2. A minimum total precipitable water of 54 mm at the storm core region in the initial condition is found to be required for forecasting Gordon’s genesis. The ensemble that better reproduces Gordon’s formation also has higher probabilistic quantitative precipitation forecast.