摘要: |
利用常规观测资料、ERA5再分析资料、闪电定位仪资料、福建龙岩双偏振多普勒天气雷达资料,分析了2020年春季闽西南地区的一次强对流过程。结果表明,此次过程发生在地面锋线北侧冷区内,属于典型的高架雷暴过程,产生的灾害性天气包括冰雹、短时强降水、高山站雷雨大风。500 hPa冷平流、850 hPa暖湿平流、925 hPa闽西南地区的假相当位温高能舌为高架雷暴的发生发展提供了有利的环境条件。探空显示逆温层深厚且逆温层顶温度高,暖湿气流沿着锋面被强迫抬升,至逆温层之上饱和假相当位温随高度递减,存在显著的条件不稳定,对流得到快速发展。雷达分析表明,本次高架雷暴冰雹回波自低层快速倾斜向上发展,具有发展快、强度强、降雹时间长的特征。其双偏振参数演变特征与基于地面抬升的雷暴基本一致,降雹阶段表现为CC谷、ZDR接近零、KDP小于零。降雹前回波单体中存在强ZDR和KDP柱,可以作为冰雹预报的参考,提前量达到半小时。 |
关键词: 高架雷暴 条件不稳定 列车效应 双偏参数 |
DOI:10.16032/j.issn.1004-4965.2023.006 |
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MESO-SCALE STRUCTURE ANALYSIS OF AN ELEVATED THUNDERSTORM IN SOUTHWEST FUJIAN |
ZHANG Wei1,2, CHEN Lin3, HUANG Huirong1,4, HUANG Xin1,2, HU Yajun4, CHEN Dehua1,2
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1. Laboratory of Straits Meteorology, Xiamen, Fujian 361012, China;2. Xiamen Meteorological Observatory, Xiamen, Fujian 361012, China;3. Xiamen Meteorological Disaster Prevention Technology Center, Xiamen, Fujian 361012, China;4. Xiangan Meteorological Bureau, Xiamen, Fujian 361103, China
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Abstract: |
Using the data of automatic weather stations, ERA5 reanalysis, and a polarized doppler in Longyan, we investigated a severe convective process that happened in southwest Fujian in the spring of 2020. The results are shown as follows. This event occurred inside the cold zone north of a surface cold front, which was a typical elevated thunderstorm process, with small hail, short-duration precipitation and high-altitude gust. 500 hPa cold advection, 850 hPa warm moisture advection, and a 925 hPa high-energy tongue of pseudo-equivalent potential temperature provided favorable large-scale circulation conditions for the thunderstorm. As shown in radiosonde curves, the inversion layer was deep with a warm layer top. Warm air was forced to lift along the cold front. Saturated pseudo-equivalent potential temperature decreased with altitude, causing conditional instability above the inversion layer and fast development of convection. Radar analysis indicated that hail cells developed from the low level, characterized by fast enhancement, strong strength and sustained hail. Polarized parameters of hail echoes showed basically the same characteristics with those of the ground-based thunderstorm, with a CC trough, a ZDR close to zero, and a KDP smaller than zero. About 30 minutes prior to hail precipitation, there were intense columns of ZDR and KDP in the echo cells, which could be an important reference to hail forecast. |
Key words: elevated thunderstorm conditional instability train effect polarization parameter |