甘肃中部雷暴天气变化的气候特征分析  

Climatic Characteristic of Thunderstorm Weather Variations in the Middle Part of Gansu Province

作　　者：景怀玺 石圆圆[1] 白虎志[2] 

机构地区：[1]甘肃省白银市气象局,甘肃白银730900 [2]中国气象局兰州干旱气象研究所,甘肃兰州730020

出　　处：《干旱气象》2007年第1期53-57,共5页Journal of Arid Meteorology

基　　金：白银市科学技术局"白银市地质气象灾害预报预警系统"(GK20062-3-011A)资助

摘　　要：利用1958-2005年白银地区4测站观测资料,采用线性趋势估计、子波分析等数理统计方法,对白银地区雷暴初、终日及雷暴出现日数气候变化特征进行分析。结果表明:雷暴初日北部平原呈推迟的趋势(2.7 d/10 a),南部山区在其平均期(4月20日)附近上下摆动。雷暴终日北部平原呈提前趋势(-2.6 d/10 a),南部山区呈抛物线变化趋势,先升后降;雷暴初日变化北部平原较南部山区稳定,雷暴终日变化南部山区较北部平原区稳定,雷暴初日较终日稳定;雷暴初、终日北部平原对应的候平均气温阈值分别为9℃、11℃,南部山区对应的候平均气温阈值皆为6℃;雷暴日数“南多北少,”20世纪80年代中期以前8-10 a的周期显著,其总趋势是减少的。The climatic variation feature of the first and the last dates for thunderstorm occurring and thunderstorm days in the middle part of Gansu province was analyzed by using observations of 4 stations in Baiyin from 1958 to 2005 based on statistics methods of linear tendency estimate and wavelet analysis. Results show that the first dates of thunderstorm presented a delay trend （2.7 d/10 a） in the north plain; the last dates were ahead （ -2.6 d/10 a） in the north plain and presented parabola change in the south mountain area. The first date variation of thunderstorm in the north plain was steadier than that in the south mountain area, whereas the last date variation of thunderstorm in the south mountain area was steadier than that in the north plain, and the first date change was steadier than that of the last date of thunderstorm. The corresponding threshold of 5 - day average temperature was 9 ℃ and 11 ℃ in the north plain for the first and last dates, respectively, and 6 ℃ in the south mountain area. Thunderstorm days were more in the south and less in the north, the period of 8 - 10 years was remarkable before the middle of the 1980s and the general trend of thunderstorm days was decreasing.

关 键 词：雷暴天气 气候特征 候平均气温阈值 

分 类 号：P467[天文地球—大气科学及气象学]