近54年四川雷暴气候特征分析
Climate Characteristics of Thunderstorm in Sichuan in Recent 54 Years
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摘要: 利用四川省154个国家级地面观测站1960~2013年的整编观测资料,采用合成分析、小波分析、线性趋势分析等方法,对雷暴日数和初、终雷暴日的时空分布及气候变化特征进行了定量分析。结果表明,四川地区年雷暴日数呈“西多东少”型分布,且存在准11周年的变化特征。雷暴日数总体呈减少趋势,甘孜州西北部、阿坝州北部和攀西地区西部减少较明显。各市州的雷暴集中出现在6月下旬至8月下旬,但川西高原要略早于盆地南部和盆地中部。盆地和攀西地区的雷暴多出现于午后、消失于凌晨,而川西高原的雷暴多开始于14~20时。另外,初、终雷暴日分别存在延后和提前的趋势,但川西南山地地区和理塘等地的初雷暴日是提前的,而巴中、达州、南充、广安、广元、绵阳大部的终雷暴日存在明显的延后趋势。综合来看,广元、巴中、达州、泸州和凉山州地区的雷暴期有较明显的变长趋势,而其它地区的雷暴期有变短趋势。Abstract: With composition analysis,wavelets analysis and trend analysis methods adopted,the spatial and temporal variation,initial and ending dates of thunderstorms was analyzed for 154 stations in Sichuan region during the period 1960-2013.The research results show that the annual thunderstorm day is much more in the west of Sichuan region than in the east,and has a quasi-periodic oscillation of 11 years.It also displays a decrease situation,remarkable decrease in the northwest of Ganzi,north of Aba,west of Panzhihua and Liangshan.Overall,the highest proportion of thunder occurrence occurs from the last tenday of June to the last ten-day of August,but it's earlier in western Sichuan Plateau and later in the south and midland Sichuan basin.Meanwhile thunderstorm appears more in the time from the afternoon to wee hours,but thunderstorm events peak from 14:00 to 20:00 in western Sichuan Plateau and southwest Sichuan mountain region.In addition,the initial(or ending) dates of thunderstorms became earlier obviously in southwest Sichuan mountain region and Litang(or in Bazhong,Dazhou,Nanchong,Guang'an,Guangyuan,Mianyang) .As a whole,the period of annual thunderstorm is shortened in Guangyuan,Bazhong,Dazhou,Luzhou and Liangshan.