上海金山地区近50a雷暴气候特征分析

使用1959～2008年上海金山地区站点观测资料,分析近50a该地区雷暴的气候特征。结果表明:上海金山地区年雷暴日数年际变化大,平均27.8d,最多52d,最少12d;每10a减少1d,呈逐渐减少的趋势;该区雷暴季节性强,集中出现在3～10月,夏季雷暴发生次数占7成以上。雷暴初始日在3月中旬,终日在10月上旬,雷暴初(终)日年际间差异大。雷暴日数存在1～2a左右、准3a和准6a的年际尺度显著变化周期。候平均气温上升稳定通过6℃,是初雷暴日的温度阈值,候平均气温下降稳定通过18℃,是终雷暴日的温度阈值。

Climatological Characteristics of Thunderstorms in Shanghai Jinshan in Past 50 Years

In this paper,the 5-day average critical air temperature on the first and last thunderstorm days is computed based on observations of the first and the last thunderstorm days in Jinshan from 1959 to 2008.The Results indicate that: the mean annual number of thunderstorm days is comparatively large,and intramural thunderstorm variability is great,the annual number of thunderstorm days has a decreasing trend,the average tendency rate is 1.2 days per 10 years.The obvious seasonal variation of thunderstorm can a...