广州白云机场雷暴大风的气候特征和环境参数

Climatological Characteristics and Environmental Parameters of the Thunderstorms and Gales at Baiyun Airport,Guangzhou

基于2005—2021年广州白云机场气象观测报文数据和清远探空站探空数据,采用线性趋势分析、合成分析等方法,分析广州白云机场雷暴大风的气候特征及环境参数。结果表明:广州白云机场年平均雷暴大风日数为10.43 d,并呈缓慢增加的趋势,季节分布呈单波峰型,主要分布在3—9月,占雷暴大风日数总数的97.6%。历史风速极大值为42 m/s,大风的风速强度主要在15~19 m/s区间内,雷暴大风主要出现在午后至前半夜的时段。影响雷暴大风的主要天气系统为低压槽和切变线;其次是气旋型、西太副热带高压型和锋面型。最大抬升指数介于-1至-4.5℃;湿对流有效位能中位值介于1130~1395 J/kg;850与500 hPa温度差介于21.2~23.7℃;对流抑制能量值介于0.875~69.15 J/kg;0~3 km风矢量差介于0.3~3.1 m/s;湿层厚度介于2302.3~5250.5 m,易发生雷暴大风天气。

Based on the message data of meteorological observation at the Baiyun Airport,Guangzhou and the sounding data from a radiosonde station in Qingyuan for the years 2005-2021,this paper analyzed the climatological characteristics and environmental parameters for the thunderstorms and gales observed at the airport in the study years using the methods of linear tendency analysis and composite analysis.The results are shown as follows.For the airport of interest,the annual average number of days with thunderstorms and gales was 10.43 d,which shows a slowly increasing tendency.Its seasonal distribution is unimodal.Thunderstorms and gales were mainly recorded from March to September,which accounts for 97.6% of the annual total.The historical wind speed extreme was 42 m/s and the intensity of gale was mainly in the interval of 15-19 m/s.At the airport,thunderstorms and gales mainly took place between post-midday and the first half of the night.Their governing synoptic systems were mostly low-pressure troughs and shears,followed in turn by cyclones,subtropical highs in the western North Pacific and fronts.When the maximum lift-ing index was between -1 and -4.5℃,the medium value of moist convective available potential energy ranged from 1130 to 1395 J/kg,the temperature difference between 850 and 500 hPa was from 21.2 to 23.7℃,the convective inhibitive energy was from 0.875 to 69.15 J/kg,the 0-3 km wind vector difference was from 0.3 to 3.1 m/s,and the thickness of a moist layer was between 2302.3 and 5250.5 m,it was likely for thunderstorms and gales to take place.