摘要
采用欧洲中期天气预报中心（ＥＣＭＷＦ）１９８０～１９８６年每日客观分析风场资料，对南海季风的爆发及其环流特征进行了研究。结果表明：低层南海季风明显存在４个阶段的季节循环，即冬季东北风盛行阶段、１月底至４月中旬的东南风过渡阶段、夏季强盛的西南风阶段、１０月初至１１月初的另一东南风过渡阶段，其中，１月底、２月初南海东南风的建立及其向东北、西北方向的传播是整个亚洲夏季西南风爆发的触发源。并且在对流层中从高到低，南海夏季风的垂直结构具有强热力性质的东北风－东南风－西南风的分布特征。此外，低层季风流场特征清楚表明，南海夏季风主要由西太平洋副热带高压西侧的西南气流、１０５～１２０°Ｅ处南半球越赤道转向气流以及起源于印度洋的西南气流３支构成，显示了南海季风在联结南亚季风和东亚副热带大陆季风中所起的独特重要作用。
Based on ECMWF daily objective wind analysis study is conducted of the onset and structure of summer monsoon in the SouthChina Sea. Results show that the monsoon at low levels passes through a seasonal cycle of four phases: 1) the northeasterly prevailing in winter; 2) the southeasterly blowing as the transition from late January to mid April; 3) the vigorous SW wind in summer; and 4) again, the transitional southeasterly spanning early October to early November. In particular, the southeasterly establishment over the sea in late Januaryearly February and spreading northeast and northwestward serve as a triggering factor of summer SW monsoon dominating all over Asia. The monsoon has structure of thermally strong NESESW winds in order from top to bottom in the troposphere. In addition, the lowlevel monsoon flowfield clearly shows that the study monsoon consists largely of SW flow on the west side of Western Pacific subtropical high, 105～120 °E crossequatorial veering flow from the Southern Hemisphere and SW flow of Indian Ocean origin, indicating the unique role of the research monsoon in bridging the counterparts in South Asia and subtropical East Asia.
出处
《南京气象学院学报》
CSCD
1997年第4期440-446,共7页
Journal of Nanjing Institute of Meteorology
基金
国家自然科学基金
关键词
南海
季风
季节循环
季风爆发
环流特征
SouthChina Sea monsoon, seasonal cycle, monsoon onset, circulation features
