甘肃庆阳近30年雷暴气候特征分析  

Analysis of the Climatic Characteristics of Thunderstorms in Qingyang,Gansu Province in Recent 30 Years

作　　者：曹彦超 韩晶 张秉政 Cao Yanchao;Han Jing;Zhang Bingzheng(Qingyang Meteorological Bureau,Qingyang 745000,China)

机构地区：[1]庆阳市气象局,甘肃庆阳745000

出　　处：《甘肃科学学报》2020年第5期50-55,共6页Journal of Gansu Sciences

基　　金：甘肃省气象局气象科研项目(Ms2019-12);庆阳市气象局项目(QY2019-2)。

摘　　要：利用1980—2018年雷暴观测资料,结合地形地貌和气候特点对庆阳市雷暴的空间分布、月分布及年际分布进行分析。结果表明,气候特点和地形地貌的差异使正宁县、庆城县和环县成为雷暴频发区域,但正宁县伴随的降水更明显;6—8月是雷暴发生频率最高的时段,春季需要更有利的天气系统才能产生雷暴天气,夏季高温高湿,较弱的抬升条件,甚至局地的地形抬升都可以产生雷暴天气;1995年以前雷暴发生频率较高,之后波动减少,其中环县减少速度最快,其原因可能是绝对不稳定条件下的干雷暴较多,气温对雷暴潜势的影响更大,近年来环县夏季气温持续升高,冷空气活动不频繁,因此下降速度最快。夏半年冷空气活动频率对年雷暴日数的贡献大于对流层低层持久而稳定的暖湿平流。The spatial distribution,monthly distribution and annual variation of thunderstorm distribution in Qingyang city from 1980 to 2018 were statistically analyzed.The results show that the differences in climate and landform make Zhengning County,Qingcheng County and Huan County have frequent thunderstorms,which accompanying precipitation in Zhengning County is more obvious.Thunderstorms occur most frequently from June to August in a year.In spring,a feasible weather system is needed to produce thunderstorms.In summer,high temperature and humidity with poor lifting conditions contribute to the development of thunderstorms.Before 1995,thunderstorms frequency was higher,and then decreased with fluctuations,of which Huan County thunderstorms decreased dramatically because dry storms produced under absolutely unstable conditions accounted for larger proportion.Temperature was highly related to the frequency of thunderstorms.In recent years,the summer temperatures in Huan County continues to rise and cold air is inactive,so the frequency of thunderstorms drops dramatically.The contribution of the cold air activity frequency in summer to the annual thunderstorm days is greater than to the persistent and stable warm and wet advective flow in the lower troposphere.

关 键 词：雷暴 气候特征 时空分布 地理地形 天气形势 

分 类 号：P466[天文地球—大气科学及气象学]