青海省雷暴日数分布及其气候变化趋势

Thunderstorm Days Distribution and Climate Change Trend in Qinghai Province

利用青海省50个地面观测站常规雷暴观测资料,分析了1981~2010年气候期的青海省年雷暴日数、雷暴初终日及夏季雷暴日数分布情况,结果显示:青海省年雷暴日数分布呈东南向西北阶梯式递减的分布,最大值在东南部的玉树、果洛南部,最小值在海西、格尔木西部;雷暴初日在3月下旬至6月上旬,由东南向西北推进,终日在8月下旬至10月上旬并由西北向东南推迟;主雷暴发生期的夏季雷暴日数分布和年雷暴日数分布基本一致。和1971~2000年气候期进行了对比分析,结果表明在这前后两个气候期中,青海省年雷暴日数均呈现减少的趋势,东南雷暴多发地区减少幅度大于西北雷暴少发地区;初、终日则表现为提前的变化趋势,且终日的提前幅度较大;夏季雷暴日数表现为也减少趋势,但和年雷暴日数减少分布略有不同。

Based on the conventional thunderstorm observation data of 50 surface observation stations in Qinghai province, the distribution of annual thunderstorm days, thunderstorm beginning and ending days and thunderstorm days in summer in 1981~2010 climate period in Qinghai province were analyzed. The results showed that the annual thunderstorm days distribution in Qinghai province showed a stepwise decreasing distribution from southeast to northwest, with the maximum value in the south of Yushu and Guoluo in the southeast, and the minimum value in Haixi and Guoluo Western Golmud;the thunderstorm starts from late March to early June and advances from southeast to northwest, and ends from late August to early October and delays from northwest to southeast;the distribution of thunderstorm days in summer is consistent with that in a year. Compared with the previous climate period from 1971 to 2000, the results show that the annual thunderstorm days in Qinghai province show a decreasing trend, and the decreasing range in the southeast thunderstorm prone area is greater than that in the northwest thunderstorm prone area;the first day and the last day are ahead of time, and the last day is ahead of time;the number of thunderstorm days in summer also shows a decreasing trend, but the distribution is slightly different from that of annual thunderstorm days.