【摘要】 使用旋转经验正交函数分析方法对山西省69个测站1971-2004年夏季雷暴日数资料进行了研究,结果表明,夏季雷暴日数可划分为4个区域,分别是北部区、南部盆地区、南部山地区和中部区,其时间系数曲线显示:北部区雷暴呈少—多—少的变化趋势,南部盆地区呈显著的减少趋势,而南部山地区和中部区有增多趋势。进一步使用NCEP/NCAR资料,分别对北部区和南部盆地区雷暴异常时的同期500hPa环流场、水汽通量矢量场进行了合成分析,结果表明,北部区雷暴的异常,与中高纬度地区(乌拉尔山、贝加尔湖)环流异常和西北路水汽通量矢量异常有关;而南部盆地区的雷暴异常,与副热带地区环流异常和西南水汽通量矢量异常有关,说明了两地区雷暴影响因子的差异。更多还原

【Abstract】 REOF analysis was used for summer thunderstorm day field of 69 observatories over Shanxi Province from 1971-2004.The results indicates that the thunderstorm day fields spatially are divided into 4 subregions: north region,south basin region,south mountain region and middle region.Inter-annual and inter decadal variability under the different geographical regions are different from each other.500hPa height fields and water vapor flux fields were also analyzed by using composition analysis.There are marked correlations between thunderstorm anomaly in north and anomaly of circulation in middle and high latitude(Ural and Baikal),and between thunderstorm anomaly in south basin and the circumfluence anomaly(subtropical high,Bengal gulf trough).Thunderstorm day anomaly of the north region is associated directly with the northwest vapor inflow flux vector,and the basin of south is associated directly with the southwest vapor inflow flux vector.The great differences suggest the different impact factors for north region and the south basin region in Shanxi.更多还原