南极中山站附近地表大风的统计特征研究  

Statistical characteristics of surface gales near Zhongshan Station in Antarctica

作　　者：钟文亮 徐昕 息涛[3] ZHONG Wenliang;XU Xin;XI Tao(School of Atmospheric Sciences/Key Laboratory of Mesoscale Severe Weather,Nanjing University,Nanjing 210023,China;Key Laboratory of Radar Meteorology,China Meteorological Administration,Nanjing 210000,China;Meteorological Service Center of Liaoning Province,Shenyang 110166,China)

机构地区：[1]南京大学大气科学学院/中尺度灾害性天气教育部重点实验室,南京210023 [2]中国气象局雷达气象重点开放实验室,南京210000 [3]辽宁省气象服务中心,沈阳110166

出　　处：《气象科学》2023年第6期711-722,共12页Journal of the Meteorological Sciences

基　　金：第二次青藏高原综合科学考察研究资助项目(2019QZKK0105);国家自然科学基金资助项目(42122036)。

摘　　要：利用近20 a的ERA5再分析资料研究了南极中山站附近的大风和极端大风事件的统计与环流特征。结果表明,春季大风事件的发生频次最高,夏季最少;冬季大风事件的平均持续时间最长,夏季最短;但大风事件的平均强度无明显季节变化。极端大风事件的发生频次具有显著的季节差异,冬季发生频次约为夏季的6倍、春秋的2倍,但平均持续时间和强度无明显季节变化。大风发生期间,南极对流层上层为单一极涡控制。在对流层中层,中低纬暖湿气流的向极入侵使得极涡破碎分裂,在中山站东侧产生高压脊,脊前冷空气下沉在地表堆积形成冷高压反气旋,其偏东气流在地形下坡风的作用下产生大风事件。上述环流特征在冬季最强、夏季最弱,从而导致大风事件的季节变化。By using the ERA5 reanalysis data in recent 20 years,the statistical and circulation characteristics of gale and extreme gale events near the Zhongshan station in Antarctica were analyzed.Results show that the occurrence frequency of gale events is the highest in spring and the least in summer.The mean duration time of gale events is the longest in winter and the shortest in summer.However,there is no seasonal variation of the mean intensity of gale events.For extreme gale events,seasonal variations are found in their occurrence frequency.In winter,the occurrence frequency is about 6 times of that in summer,and twice of that in spring and autumn.There is little difference in the mean duration time and intensity in each season.During gale events,the upper troposphere of Antarctica is dominated by a unique polar vortex.In the middle troposphere,the polar vortex breaks up owing to the intrusion of warm moist air from the mid-lower latitudes,forming a ridge to the east of Zhongshan Station.The sinking air ahead of the ridge creates of anticyclonic cold high at the surface.Gales occur near Zhongshan Station as the easterly flow of the anticyclone goes downslope the plateau.The aforementioned circulation features are the strongest(weakest)in winter(spring),which thus gives rise to the seasonal variation of gale events.

关 键 词：南极 大风 极涡 地形 

分 类 号：P425[天文地球—大气科学及气象学]