利用50年人工观测资料分析河南省末雷暴日特征

Analysis of Characteristics of the Last Thunderstorm Days of Henan Province Based on 50 Years Observation Data

利用河南省1957-2005年121个有效气象台站雷暴观测资料,对河南省末雷暴日进行初步分析。结果表明,全省末雷暴日有明显的年际变化特征,末雷暴日随着年份的增加有推迟的趋势,统计发现1977-2005年平均末雷暴日比1957-1976年平均末雷暴日推迟6 d,末雷暴日的推迟可能是由温度升高引起的。统计末雷暴日的雷暴天气发生时段发现,12:00-16:00时段发生的雷暴最多,占到全部雷暴次数的43.4%,其次是16:00-20:00,占到总时段的24.0%,雷暴次数最少的时段是00:00-04:00和20:00-24:00,这与全省雷暴日的日变化特征存在较大差异。全省末雷暴日的空间分布大概分3个区域:西南及南部区域末雷暴日结束最迟,其次是北部区域,中部末雷暴日结束较早,末雷暴日较迟的区域多分布在山区或气温较高的南部,这些分布特征与雷暴日数的空间分布比较一致。

Using the thunderstorm observation data of 121 effective meteorological stations in Henan Province from1957 to 2005,the last thunderstorm days in Henan Province were preliminarily analyzed. The analysis showed that the last thunderstorm days in Henan had obvious interannual variation characteristics,and the last thunderstorm days tended to be delayed with the increase of years. Statistics showed that the average last thunderstorm days in 1977-2005 were six days later than that in 1957-1976. The delay of the last thunderstorm days in 1977-2005 may be caused by the increase of temperature. It was found that the thunderstorms occurred at 12:00-16:00,accounting for 43.4% of the total thunderstorms,followed by 16:00-20:00,accounting for 24.0% of the total thunderstorms,and the minimum thunderstorms occurred at 00:00-04:00 and20:00-24:00,which were quite different from the daily variation characteristics of thunderstorms in the whole province. The spatial distribution of the last thunderstorm days in the whole province could be divided into three regions:the end of the last thunderstorm days in the southwest and southern regions was the latest,followed by the northern region,the end of the last thunderstorm days in the central region was earlier,and the late last thunderstorm days were mostly distributed in the mountainous areas or the South with higher temperature. These distribution characteristics were consistent with the spatial distribution of the number of thunderstorm days.