摘要
对1959～2009年吉安气象观测站逐日、逐月、逐年雷暴的观测资料进行数理统计,分析了吉安雷暴发生的特征。结果表明:吉安年平均雷暴日为63.0d,属于强雷区;雷暴日数的年际变化幅度大,最多年份102d(1983年)与最少年份41d(2000年和2001年)相差61d,接近年平均日数;年雷暴日数以5a左右为一个周期,10年左右出现一个峰值,目前年雷暴日数正处于减少期内;初(终)雷暴日及雷暴持续期年际间振荡的幅度较为剧烈,最早初雷日与最晚初雷日相差90d,最早终雷日与最晚终雷日相差108d,最长雷暴持续期310d与最短雷暴持续期186d相差124d;51年来吉安雷暴日数线性减少趋势明显,减小幅度为4.0d/10年;雷暴日季节分布以夏季最多,占全年的50.2%,冬季最少,只有全年的4.3%;月分布呈单峰型,雷暴多集中在3～9月份,8月最多,12月最少;日分布呈单峰型,以14～20时频数最大,最低值在7～12时;单个雷暴持续时间最长达7小时23分钟,出现在1962年3月20日;雷暴出现频率最多为SW(西南)方向,占38.4%,为吉安雷暴的主导方向。
Based on the statistics of the 1959~2009 thunderstorms meteorological data of Ji’an observed day by day,month by month,year by year,the characteristics of Jian thunderstorm was analyzed.The results showed that Ji’an had 63.0 thunderstorm days per year,belonged to strong thunderstorm area.Thunderstorm days of annual changes in amplitude,with 61d disparity between the most year 102 d （1983 years） and the least year 41d （2000 and 2001）,close to the average days.annual thunderstorm days in 5a or so was for a period,a peak appeared every 10a or so,the current annual number of thunderstorm days is in the reductive period.Initial （final） thunderstorm and thunderstorm duration of the interannual oscillation amplitude is more severe,the first beginning of thunder date had the difference of 90 d compared with the latest,the earliest end thunder date had the difference of 108 d compared with the latest,the longest duration of thunderstorms had the difference of 124 d compared with the shortest.In the past 51a,Jian thunderstorm days had the trend of linear decrease,with reducing small amplitude of 4.0 d/10a.Seasonal distribution of thunderstorm days in summer was the most,accounting for 50.2% of the whole year,the least in winter,only 4.3% of the year.Month distribution appeared single peak type,thunderstorm most centralized in March to September,the most in August,the least in December.Day distribution appeared single peak type,with the maximum frequency of 14：00 to 20：00,the minimum frequency of 7：00 to 12：00.The longest single thunderstorm duration was up to 7 hours and 23 minutes,appeared in the March 20,1962.Thunderstorm most appeared in SW （southwest） direction,accounting for 38.4%,the dominant direction for the Jian thunderstorms.
出处
《井冈山大学学报（自然科学版）》
2010年第6期53-56,共4页
Journal of Jinggangshan University (Natural Science)
关键词
雷暴日
定义
统计
特征
分析
thunderstorm day
definition
statistics
characteristic
analysis
