锦州市雷暴时空分布及环流特征

Temporal and Spatial Distribution and Circulation Characteristics of Thunderstorms in Jinzhou

利用micaps常规天气资料对2006-2013年锦州地区雷暴天气过程从时空分布和环流分型两方面进行详细分析。结果表明,锦州雷暴日数的年际变化无明显增多或减少趋势,月分布呈单峰型,6月为峰值,平均每月出现10.9个雷暴日;雷暴日变化十分明显,多出现在11:00(中午)至23:00(夜间);受冷涡系统影响,连续2 d以上出现雷暴占总雷暴日的63.7%;区域性雷暴过程占总雷暴日的55.0%,略多于局地性雷暴过程;雷暴最早出现在2月下旬,最晚出现在11月中旬;雷暴地域差异不明显。锦州市雷暴的大尺度环流背景场主要分为冷涡型和西风槽型。二者的主要区别在于前者以经向型环流为主,受河套低涡或东北冷涡影响,后者则以纬向型环流为主;冷涡型又分为冷(低)涡直接影响型、底部短波槽型和后部横槽型。其主要区别在于冷(低)涡直接影响型,其涡位置偏南,雷暴出现在涡后偏北气流内;而后两种类型其低涡位置偏北,涡底短波槽或涡后横槽下摆触发雷暴天气,槽前西南气流和槽后西北气流内均可出现雷暴天气。

Based on the conventional meteorological data,the thunderstorm weather process in Jinzhou during the 2006-2013 years was analyzed in detail from two aspects of the temporal and spatial distribution and the circulation pattern. The results showed that the annual variation of thunderstorm days in Jinzhou had no obvious increasing or decreasing trend; The monthly distribution was unimodal,with the peak value in June,and there were 10.9 thunderstorm days on average per month; The diurnal variation of thunderstorm was very obvious,mostly from 11：00（noon） to 23：00（eve）; Affected by the cold vortex system,more than 2 consecutive days of thunderstorm accounted for 63.7% of the total; Area thunderstorm accounted for 55.0%,slightly more than the local thunderstorm; Thunderstorm first appeared in late February,the latest in mid November; Thunderstorms regional difference was not obvious. Large scale circulation background of thunderstorm in Jinzhou city was divided into cold vortex type and westerly trough type. The main difference between the two lies in the former was dominated by meridional circulation,affected by the northeast cold vortex or Hetao vortex,but the latter was dominated by zonal circulation. Cold vortex type was divided into cold（low） vortex directly influence type,bottom trough type and rear cross trough type. The direct influence type of the cold（low） vortex was characterized by the south of the vortex position and the thunderstorm occurring in the west airflow behind the vortex; But in the latter two types,the vortex position was northerly,and the short wave trough at the bottom or the cross trough back of the vortex swinging downward trigger thunderstorm weather,thunderstorm weather could occur in the southwest airflow in front of the trough or the northwest airflow behind the trough.