【摘要】 利用1965-2016年上海虹桥机场中有关雷暴的观测资料,进行了雷暴发生频次统计特征分析。研究表明,以雷暴日数、初/终雷日、雷暴小时数表征的雷暴发生频次特征有明显的季节、年和年代际变化特征。上海虹桥机场年平均雷暴日数为28.7 d,各月雷暴日数呈明显的单峰型特征,其中雷暴发生日数最多的是7月,具有季节性强、高度集中的特征。虹桥机场初雷日发生在1-4月,终雷日则发生在8-12月间。近52年来,年雷暴日数呈现缓慢震荡向下的趋势。从1960年代-1990年代,雷暴日数减少趋势非常明显。但进入21世纪后,年雷暴日数出现明显的回升。1986-2015年间,雷暴小时数及雷暴日数趋势一致,都是呈现增加的趋势,但雷暴小时数的增长趋势比雷暴日数更显著。最近30年来,6-9月较其他月份,雷暴小时数的增加远大于雷暴日数。雷暴日数和雷暴小时数都具有明显的年代际变化特征。虹桥机场初雷的发生日期在逐渐提前,而发生终雷的日期较明显地推迟。更多还原

【Abstract】 Using the observation data of Shanghai Hongqiao Airport from 1965 to 2016, the characteristics of thunderstorm frequency are analyzed. The results show that number of thunderstorm day, early/final thunderstorm day, and thunderstorm hours have obvious seasonal, inter annual and decadal variances. Shanghai Hongqiao Airport has an average annual thunderstorm of 28.7 d.The number of thunderstorm days at Hongqiao Airport has obvious monthly unimodal distribution,characterized by strong seasonality and high concentration with peak in July. The early thunderstorms were between January and April, while the final thunderstorms were between August and December.Over the past 52 years, the annual thunderstorm day has shown a slow downward trend, especially,from the 1960 s to the 1990 s, has seen a rapid decline, but the number of thunderstorms has rebounded significantly in the 21 st century. The thunderstorm hours were increased as same as the number of thunderstorm day, but with a more obvious increase trend. Within the latest 30 years, the increase rate of the thunderstorm hours is large than that of the number of thunderstorm day. The numbers of thunderstorm day and thunderstorm hours have obvious decadal variance. The date of the early thunder was gradually earlier, and the date of the final thunder was significantly delayed.更多还原