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基于雷达和微波辐射计的湖北省冷季“高架雷暴”特征分析
引用本文:苟阿宁,高正旭,侯 静,韩芳蓉,刘文婷,张文言,张文刚.基于雷达和微波辐射计的湖北省冷季“高架雷暴”特征分析[J].热带气象学报,2020,36(4):528-541.
作者姓名:苟阿宁  高正旭  侯 静  韩芳蓉  刘文婷  张文言  张文刚
作者单位:1.武汉中心气象台,湖北 武汉 430074
基金项目:湖北省雷电灾害防御科研专项FL-Z-201401中国气象局预报员专项CMAYBY2020-081
摘    要:利用常规观测、加密自动气象站、三维闪电定位仪、天气雷达和地基微波辐射计资料等,对湖北冷季(2014年11月)发生的3次高架雷暴过程进行了分析。(1)3次过程发生在地面冷锋后部地面冷气团中,主要以短时强降水和频繁的雷电活动为主,是典型的冷季“高架雷暴”,对流区位于地面冷锋后部500 km左右。(2)地面到925 hPa的冷垫,迫使暖湿气流爬升,在925 hPa逆温层附近触发对流,冷垫之上西南暖湿气流越强,对流越旺盛,雷达径向速度剖面可以明显看到1 km之下的冷垫。(3)冷季高架雷暴雷电活动剧烈,CG(地闪)占总闪比例60%以上,而+CG则占CG的40%左右,闪电频次和降水有很好的时空对应关系,CG出现在较强降水中心附近及周围,IC和CG突增对降水均有一定的时间提前量。CG更靠近强回波中心,且和≥30 dBZ的回波位置对应较好,IC则分布在雷暴单体外侧回波强度≥15 dBZ的区域。0 ℃等温线以上的(最大)回波强度达到43 dBZ以上或者18 dBZ回波顶高超过7.5 km是湖北冷季高架雷暴是否发生雷电的重要预警因子。(4)地基微波辐射计温度、湿度廓线和探空曲线基本吻合,可以看到明显的冷垫、逆温层及西南急流。基于微波辐射计资料计算的不稳定指数变化特征对冷季高架雷暴的短临预报有重要的实际应用价值。当A指数、TT指数、K指数和T850-500出现快变抖动时,伴随抖动加剧可以判断将会有雷暴天气发生,当波动曲线开始下降并变得平稳,表示雷暴减弱消亡;θse 850在雷暴出现后跃增并在320 K附近抖动,雷暴结束后下落到290 K的平稳状态;Td850在雷暴活跃阶段近乎为0 ℃;T850-500在雷暴发生前是一个缓慢下降的过程,雷暴结束后大气趋于稳定。 

关 键 词:冷季    高架雷暴    三维闪电定位仪    地基微波辐射计
收稿时间:2020-03-20

ANALYSIS OF LIGHTNING AND PRECIPITATION ACTIVITIES IN THREE ELEVATED CONVECTIVE EVENTS BASED ON DOPPLER RADAR AND MICROWAVE RADIOMETER IN HUBEI PROVINCE
GOU A-ning,GAO Zheng-xu,HOU Jing,HAN Fang-rong,LIU Wen-ting,ZHANG Wen-yan,ZHANG Wen-gang.ANALYSIS OF LIGHTNING AND PRECIPITATION ACTIVITIES IN THREE ELEVATED CONVECTIVE EVENTS BASED ON DOPPLER RADAR AND MICROWAVE RADIOMETER IN HUBEI PROVINCE[J].Journal of Tropical Meteorology,2020,36(4):528-541.
Authors:GOU A-ning  GAO Zheng-xu  HOU Jing  HAN Fang-rong  LIU Wen-ting  ZHANG Wen-yan  ZHANG Wen-gang
Institution:1.Wuhan Central Meteorological Observatory, Wuhan 430074, China2.Wuhan Regional Climate Centre, Wuhan 430074, China3.Wuhan national basic meteorological observation station, Wuhan 430040, China4.Institute of Heavy Rain, CMA, Wuhan 430074, China
Abstract:Based on conventional observation, encrypted automatic station observation, three-dimensional lightning locator, Doppler weather radar of Wuhan and ground-based microwave radiometer data, the characteristics of three Convective Events in cold season (November 2014) were analyzed in Hubei Province. The results shows: (1) three cases produced short-term precipitation and lightning activities, and the convection area was located on the cold side 500 kilometers away from the surface front. (2) the warm and humid air flow are forced climbing by the cold pad from the ground to 925 hPa, while convection was triggered by convergence on 925 hPa. the cold pad below 1km can be seen clearly in the radar radial velocity profile. (3) cloud to ground lighting(CG) accounts for more than 60% of the total lightning, while positive cloud to ground lighting(+CG) accounts for about 40% of CG. The lightning frequency has a good time-space correspondence with precipitation, CG appeared near the center of strong precipitation, and the sudden increase of IC and CG has a certain time advance to precipitation. CG is closer to the center of strong echo(≥30 dBZ). IC is distributed in the area outside the thunderstorm cell, which with the echo ≥15 dBZ. The reflectivity of 43 dBZ above 0 ℃ isotherm or the ET height of 7.5 km, which are important indicators for the monitoring and early warning of lightning in cold season. (4) the temperature and humidity profiles of the ground-based microwave radiometer are consistent with the sounding curves, and cold pad, inversion layer and southwest jet can be seen obviously. The variation characteristics of instability index was calculated from the microwave radiometer data, which have important value for monitoring and early warning of elevated thunderstorm in cold season. While the index of A, TT, K and T850-500 changed rapidly, it can be judged that there will be thunderstorms. When the fluctuation curve begins to decline and become stable, it means that the thunderstorm will weaken and died out, when θse 850 jumped to 320 K after the thunderstorm occuring, which falled to a stable state of 290 K while the thunderstorm ending, when Td850 is nearly 0 ℃ during the life of thunderstorm, the water vapor in the lower layer was almost saturated, T850-500 was a slow decline process before thunderstorm, T850-500 maintained at 18~22 ℃ after thunderstorm appeared. 
Keywords:cold season  elevated thunderstorm  three-dimensional lightning locator  ground-based microwave radiometer
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