Characteristics of Low-Level Jets over Northern Taiwan in Mei-Yu Season and Their Relationship to Heavy Rain Events
Characteristics of Low-Level Jets over Northern Taiwan in Mei-Yu Season and Their Relationship to Heavy Rain Events
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DOI：
10.1175/mwr-2813.1
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发表时间：
2005
影响因子：
3.2
通讯作者：
G. T. Chen;Chung‐Chieh Wang;D. Lin
中科院分区：
文献类型：
--
作者：
G. T. Chen;Chung‐Chieh Wang;D. Lin
摘要本文研究了低空急流的特性。梅雨期台湾北方600 hPa以下（≥12.5 m s-1）降水及其与暴雨的关系（24小时内≥50毫米），方法是利用12小时的探空数据、850和700百帕的天气图，和1985- 1994年5 - 6月期间6个地面站的每小时降雨量资料。所有LLJ根据其高度，外观（单射流或双射流）和运动（迁移和非迁移）进行分类。讨论了与强降水发生有关的低空急流的频率、垂直结构和时空分布。LLJ的一般特征表明，它们大约有15%的时间发生在台湾北方，最高速度低于40 m s-1。最大风场主要出现在850 ~ 700 hPa之间，出现频率最高的是825-850 hPa。单射流（76%）比双射流（24%）更常见，而在后一种情况下，屏障射流通常是一种非对称射流。
Abstract The present study investigates the characteristics of low-level jets (LLJs) (≥12.5 m s−1) below 600 hPa over northern Taiwan in the mei-yu season and their relationship to heavy rainfall events (≥50 mm in 24 h) through the use of 12-h sounding data, weather maps at 850 and 700 hPa, and hourly rainfall data at six surface stations during the period of May–June 1985–94. All LLJs are classified based on their height, appearance (single jet or double jet), and movement (migratory and nonmigratory). The frequency, vertical structure, and spatial and temporal distribution of LLJs relative to the onset of heavy precipitation are discussed. Results on the general characteristics of LLJs suggest that they occurred about 15% of the time in northern Taiwan, with a top speed below 40 m s−1. The level of maximum wind appeared mostly between 850 and 700 hPa, with highest frequency at 825–850 hPa. A single jet was observed more often (76%) than a double jet (24%), while in the latter case a barrier jet usually ...