中国东南地区热带气旋大风及其伴随天气的统计特征

Statistical Characteristics of Tropical Cyclone Gale and Its Accompanying Weather in Southeast China

利用2010~2016年中国地面站重要天气报文、中国气象局(CMA)热带气旋最佳路径数据集以及地面站逐小时降水资料,对热带气旋(TC)影响下我国东南地区地面大风及其伴随天气特征进行统计分析,结果表明:(1)该区域TC大风主要沿海岸线分布,至内陆频次递减;TC大风多以东北风向为主,登陆前大风站点居多,12级以上的强风速基本分布在距TC中心300 km范围内。(2)强热带风暴(STS)和台风(TY)强度TC引起的站点大风最多,但16级以上大风主要出现在强台风(STY)和超强台风(Super TY)强度等级。慢速TC引起的站点大风主要出现其移向右前侧,快速主要出现在其右后侧。TC大风中向岸风均值略大于离岸风,其中12级以上风速向岸风站点多于离岸风,但16级以上大风则是离岸风站点明显多于向岸风。(3)约89.8%的TC大风伴随降水,分布于TC中心附近,东北风为主,峰值出现在8月。约10.2%的TC大风无降水,主要分布在TC外围,北风和东南风为主,风速较弱,多出现于5月和12月。12级以上TC大风几乎均伴随着降水,而无降水TC大风风速达12级以上样本很少。(4)约23.8%的TC大风伴随强对流天气,以东北风为主,平均风速大于非强对流TC大风。TC大风伴随的强对流天气包括短时强降水和雷暴,以短时强降水居多(约占该类TC大风的79.5%),主要分布在TC中心附近东北象限,而雷暴TC大风则主要出现在TC外围(约占该类TC大风的28.0%),东南象限相对较少。(5)同时出现短时强降水和雷暴的TC大风仅占强对流TC大风的7.5%,TC大风的1.8%,说明TC大风伴随的短时强降水中不常见雷暴现象。

The China Meteorological Administration(CMA)tropical cyclone best track data and hour-by-hour precipitation data from 2010 to 2016 were used in a statistical analysis of surface gales and their accompanying weather in southeastern China under the influence of tropical cyclones(TCs),and the results show that:(1)In this region,TC gale is primarily dispersed along the coastline,with decreasing frequency from coast to inland;TC gale is dominated by the northeast wind direction,and the gale occurs primarily before the typhoon landfall.Strong wind speeds of magnitude 12 and higher are scattered within 300 km of the TC center;(2)TCs of tropical storm(TS)and typhoon(TY)intensity caused the most gales,while strong wind speeds of magnitude 16 and above are mainly found in the severe typhoon(STY)and super typhoon(Super TY)intensity classes.Gale induced by slow TC appears primarily on the right front side,while gale caused by quick TC appears primarily on the right rear side.The mean onshore wind speed of TC gales is slightly greater than the offshore wind speed,despite the fact that the station frequency of onshore wind is greater than that of offshore wind when the wind speed is between level 12 and level 16,and when the wind speed is above level 16,offshore wind is much greater than that of onshore wind;(3)The percentage of TC gales that are precipitationaccompanied accounts for roughly 89.8%of the total number of TC gales;these gales are primarily caused by northeasterly winds,peaking in August.About 10.2%of the TC’s gales are dry,with the majority occurring at the TC’s periphery with weak northerly and southeasterly winds,primarily in May and December.TC gales with wind speeds above level 12 are almost always accompanied by precipitation,while there are few samples of TC gales with wind speeds above 12 without precipitation;(4)TC gales accompanied by strong convective weather account for approximately 23.8%of the total TC gale,with northeasterly winds dominating,the average wind speed is larger than the non-strong convective TC gale;strong convective weather with short-term heavy precipitation and thunderstorms,with the majority of which is short-term heavy precipitation(approximately 79.5%of this type of TC gale),mainly distributed in the northeast quadrant near the TC center,while thunderstorm TC gale mainly appears in the periphery of TC(approximately 28.0%of this type of TC gale),of which there are relatively few in the southeast quadrant.(5)TC gale with both short-term heavy precipitation and thunderstorms accounts for only 1.8%of the total TC gale and 7.5%of strong convective TC gale,indicating that thunderstorms are not common in TC gale with short-term heavy precipitation.