中国雷暴气候分布特征及变化趋势

利用1951-2005年雷暴和冰雹观测资料,统计出中国743个站点的雷暴以及冰雹发生日数.统计结果表明,中国雷暴和冰雹等强对流天气发生的概率分布具有明显的地理和日变化差异,日间与夜间强对流天气分布变化很大.中国雷暴发生频繁的区域共有5个,分别是青藏高原东部、云南中南部、四川境内、华南两广地区及新疆西部,各区域雷暴日数存在不同的年际变化特征.全国雷暴日数除青藏高原地区略有上升外,总体呈下降趋势.冰雹发生频繁的区域主要在青藏高原祁连山地区,天山地区和华北北部为冰雹活动的次频繁中心.冰雹日的年际变化也因区域不同而有所区别.由中国雷暴日数的REOF分析可以看出,华南、长江流域等地区都存在独立的异常时空分布,与特定的大尺度环流密切相关.

Climate Characteristic and Variation Tendency of Thunderstorm in China

Based on the observations from 1951 to 2005,the occurring days of thunderstorm and hail at 743 stations in China are examined. Results show that the occurring probability distributions of thunder-storm and hail in China have obvious differences of geographic location and daily variation. Distribution of severe convection weather changes obviously during the day and night. The thunderstorm occurrs frequently in five regions of China, namely eastern Qinghai-Xizang Plateau, middle and south of Yunnan, Sichuan, South China and west of Xinjiang, where there exists different interannual variations for the thunderstorm days of different regions. Except slight increasing in Qinghai-Tibet Plateau,the thunder-storm days present decreasing tendency in the other areas of China.The hail ocCULTS frequently in the Qinghai-Xizang Plateau and Qilian Mountains, secondly in Tianshan Mountains and northern part of North China. The interannual variation of hail days iS also different in different regions.REOF analysis results show that the thunderstorm days anomalies exist independent temporal and spatial distributions in South China,the Yangtze River Basin and so on,which are closely related to the specific large-scale circulation.