青海强对流天气时空特征及其对气候变暖的响应

Characteristics of Temporal and Spatial Distribution of Severe Convective Weather and Its Response to Climate Warming in Qinghai Province

利用青海省38个测站1960～2006年4～10月冰雹、雷暴日数资料,其中24站有连续的温度资料,采用线性回归分析、经验正交函数(EOF)等方法,分析了青海冰雹、雷暴的时空特征及对气候变暖的响应。结果发现:47 a来38站平均雷暴、冰雹日数的年内分布都为单峰型分布,雷暴和冰雹日数都在7月达到峰值;年平均冰雹、雷暴日数均具有明显的线性下降趋势,平均冰雹、雷暴日数空间分布特征呈南多北少的纬向分布;年冰雹日数在海南地区、玉树西北部和海西西部地区(负变化)与其它地区呈反位相变化关系;年雷暴日数在海西北部大柴旦地区、海北祁连和海东西宁地区(正变化)与其它地区呈反位相变化关系,变化敏感区位于年平均冰雹、雷暴日数大值区。7月份海东、海西及果洛地区冰雹、雷暴日数与其温度无显著的相关性,海南、海北地区冰雹、雷暴日数与温度呈显著负相关,黄南和玉树地区冰雹日数与温度呈显著负相关。

By using the hail and thunderstorm days data at 38 weather stations from April to October in the period of 1960-2006 in Qinghai Province,including 24 stations＇ temperature data,the characteristics of temporal and spatial distribution of severe convective weather and its response to the climate warming were analyzed through the linear regression analysis and EOF method.The results show that the annual distribution of the average hail and thunderstorm days at 38 weather stations in recent 47 years was the single-peak type and reached their peak in July.The annual average days of hail and thunderstorms presented obvious linear downward trend and zonal distribution with more in the south and less in the north regions of Qinghai Province.In Hainan,northwestern Yushu and western Haixi,the change of annual hail days was different from the other regions.The change of annual thunderstorm days in Dachaidan,Qilian and Xi＇ning was different from the other regions.The annual hail and thunderstorm days at the most of stations may tend to decrease with annual average temperature increase.In July,the hail and thunderstorm days in Haidong,Haixi and Guoluo had no significant correlation with temperature,but obvious negative correlation in Hainan and Haibei,and only hail days had negative correlation with temperature in Huangnan and Yushu.