摘要
采用1948—2010年NCEP/NCAR逐日再分析资料,计算大西洋风暴轴特征指数和西伯利亚高压特征指数,研究了冬季北大西洋风暴轴的变化及其对西伯利亚高压的影响。结果表明:风暴轴经度指数与西伯利亚高压纬度、强度、面积指数显著相关。风暴轴经度指数正异常月,大西洋天气尺度瞬变波活动向东扩展到欧洲乃至乌拉尔山以东,西伯利亚及东亚地区反气旋式波破碎加强,瞬变波对月平均气流的反馈作用使得欧亚大陆上空50°N以北西风加速、50°N以南西风减速;中纬度经向环流加强,气候态的西欧沿岸脊、欧洲东部槽、青藏高原北部脊均加强,东亚大槽减弱东移;在西伯利亚地区,暖空气向北输送加强,来自极区的冷空气南下减弱,致使西伯利亚及东亚地区温度偏高,西伯利亚高压面积减少、纬度偏南、强度减弱。风暴轴经度指数负异常月的情况则反之。
Based on the NCEP/NCAR daily reanalysis data during 1948-2010,this paper calculates the Atlantic storm track（AST） and the Siberian High（SH） indexes,and studies the variability of AST and its influence on SH.Results show that there are significant relationships between the longitude index （STIX） of AST and those indices describing the latitude,intensity and area of SH.When the STIX is in the positive months,the synoptic transient waves extend from Atlantic to Europe and even to the east of Mount Ural,thus intensify the anticyclone wave breaking （AWB） in Siberian and East Asian.Through the feedback of the transient waves on the monthly mean flow,the westerly is strengthened to the north of 50°N and weakened to the south of 50°N over Eurasia.The meridinal circulation in midlatitudes is strengthened,thus the ridges over the coastal West Europe and the northern Tibetan Plateau and the trough over East Europe are intensified,while the deep trough of East Asia is weakened and moves eastward.More warm air is transported to the north while the cold air from Arctic is inhibited over Siberian area,so it becomes warmer in Siberian and East Asia regions,the area of SH becomes smaller,and the SH moves southward and becomes weaker.When the STIX is in the negative months,the situation is reverse.
出处
《大气科学学报》
CSCD
北大核心
2015年第2期232-240,共9页
Transactions of Atmospheric Sciences
基金
公益性行业(气象)科研专项(GYHY201306028)
国家自然科学基金资助项目(41075070)
江苏高校优势学科建设工程资助项目(PAPD)
关键词
大西洋风暴轴
西伯利亚高压
波破碎
温度平流
Atlatic storm track
Siberian High
wave breaking
temperature advection
