华北地区雷暴大风的时空分布及物理量统计特征分析  

Temporal and Spatial Distribution of North China Thunder-gust Winds and the Statistical Analysis of Physical Characteristics

作　　者：方翀 王西贵[2] 盛杰 曹艳察 FANG Chong WANG Xigui SHENG Jie CAO Yancha(National Meteorological Centre, Beijing 100081, China Huainan Meteorological Observatory, Huainan 232007, China)

机构地区：[1]国家气象中心,北京100081 [2]淮南市气象局,淮南232007

出　　处：《高原气象》2017年第5期1368-1385,共18页Plateau Meteorology

基　　金：中国气象局2014年预报员专项(CMAYBY2014-084);国家重点基础研究发展计划项目(2013CB430106);国家自然科学基金项目(41375051)

摘　　要：利用2011—2015年4—9月华北地区主要区域(北京、天津、河北、山西)的重要天气报和雷暴观测资料,统计分析了该地区雷暴大风的时空分布等特征。结果表明,华北地区雷暴大风出现最多的月份为6—7月,最多的时次为下午到前半夜,大范围雷暴大风天气过程起始时间多为13:00(北京时,下同)-15:00,持续时间为4~8 h,高海拔地区出现雷暴大风的频次大于低海拔地区。在将华北地区站点分为高海拔站点和低海拔站点的基础上,使用2011—2013年4—9月的NCEP物理量分析场对雷暴大风过程的指示性进行统计分析,结果表明:多数常用的热力指标需考虑季节因素;下沉对流有效位能阈值基本不随季节变化,并对高海拔和低海拔区域的雷暴大风的出现及其范围均有一定的指示性;对流抑制能量、0~3 km垂直风切变、低层散度、500 hPa风场、整层可降水量、500 hPa相对湿度08:00—14:00变化等物理量在一些具体方面对于雷暴大风的出现及范围有一定的指示性。主要发生在高海拔地区的雷暴大风天气过程,850 hPa的相对湿度均在50%以下;主要发生在低海拔地区的雷暴大风天气过程,850 hPa的相对湿度基本在50%以上;850 hPa相对湿度较大的大范围雷暴大风天气过程,850 hPa和500 hPa的温差在24~28℃,850 hPa相对湿度较小的大范围雷暴大风天气过程,850 hPa和500 hPa的温差则常常达到30℃或以上。This study analysed the temporal and spatial distributions of thunder-gust winds in North China（ Beijing,Tianjin,Hebei,Shanxi） based on the observed thunder data and significant weather reports from April to September during 2011—2015. The results showed that the thunder-gust winds occur mostly in June and July and from afternoon to early night; The start times of the large-scale thunder-gust winds are mainly from 13： 00（ Beijing time,the same as after） to 15： 00 and the durations are 4 to 8 hours; The frequency of gust on the plateau is greater than that on the flatland. This study divides the stations in North China into plateau stations and flatland stations based the altitudes of the stations,and analyzed the physical indicative characteristics of the thunder-gust wind processes by using the NCEP physical analysis field from April to September during 2011—2013. The results showed that most of the commonly used thermodynamic indexes need to take into account the seasonal factors; The threshold of DCAPE does not change with the seasons and has some indication of the occurrence and range of thunder-gust winds on the plateau and the flatland. In addition,CIN,vertical wind shear between 0 and3 km,low-level divergence,the 500 hPa wind field,PWAT and the changes of the relative humidity of 500 hPa from 08： 00 to 14： 00 have some indication of the occurrence and range of thunder-gust winds in some specific aspects. The relative humidity of 850 hPa is below50% when the thunder-gust wind process happened on the plateau,and the relative humidity of 850 hPa is larger than 50% when the thunder-gust wind process happened on the flatland. For the large-scale thunder-gust wind process occurring with large relative humidity of 850 hPa,the temperature difference between 850 hPa and 500 hPa is around 24 ~ 28 ℃,and for the large-scale thunder-gust wind process occurring with small relative humidity of 850 hPa,the temperature difference between 850 hPa and 500 hPa must be over 30 ℃.

关 键 词：雷暴大风 重要天气报 时空分布 物理量 温湿垂直配置 

分 类 号：P446[天文地球—大气科学及气象学]