| Summary: | 碩士 === 中華科技大學 === 土木防災工程研究所在職專班 === 107 === Taiwan is located in a subtropical region with versatile weather systems by the special geography; this paper explores the thunderstorms on April 23, 2018 as a case to check the severe convection development affected by offshore sea wind field in Eastern Taiwan. Seizing the atmospheric environment per case, this paper analyzes the overall atmospheric environment through NCEP observation grid, Wind Profiler by Laser, and meteorological data of the Central Meteorological Bureau; then applying mesoscale weather numerical model for simulating values with comparative analysis approach by satellite, radar and other data for understanding the mechanism and structural characteristics of the system's self-generation development.
Thunderstorms and the accompanying weather phenomena obviously threaten security of flight, and public lives and properties; yet, the short-term thunderstorm is unable to interpret real-time development and evolution trend of the phenomenon by the most meteorological observation system. The severe weather forecast and timely detection of risky factors, therefore, harden aviation meteorological and disaster prevention personnel as challenge; the sophisticated geography of Eastern Taiwan even deepens the difficulty of risky elements to weather prediction.
The results signify that on April 23, 2018, the Eastern Taiwan and coast belong to a weak synoptic weather pattern; however, the space below 850hPa, a south-eastern wind farm, generates accumulation of steam in the Eastern Taiwan and coast with lifting effect, resulting in the evident convection system in Eastern Taiwan. While with intense rainfall, 850hPa to 700hPa frontogenesis function and Q-Vector value show that 850hPa frontogenesis function is between 0.5-1, 700hPa is between -0.5-0; 850hPa Q-Vector is between 0-1, 700hPa is less than 0. The frontogenesis function and Q-Vector value are high in this case; Q-Vector, influenced by wind farm and terrain interaction, activates steam in Eastern Taiwan and coast. In additional, this is a South-eastern wind farm case, except the impact of terrain, lifting effect favors accumulation and conducts to the development of convection system.
Keywords: severe convection, thunderstorms, weak synoptical environment,
Wind Profiler by Laser
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