东南印度洋海洋锋面处低空大气的垂向分布结构

VERTICAL STRUCTURE OF THE LOW LEVEL ATMOSPHERE AROUND THE SOUTHEAST INDIAN OCEAN FRONTS

本文利用中国第25次南极科学考察期间获取的现场观测数据研究了东南印度洋(弗里曼特尔至中山站间)海洋锋面附近的低空大气风场以及温度场垂向分布特征。结果表明:弗里曼特尔港至中山站之间的亚南极锋锋面暖水侧与冷水侧风速垂向分布结构不同,锋面暖水侧风速垂向梯度小,风速梯度最大值出现在500 m高度附近,而锋面冷水侧低空风速梯度最大值出现在150 m高度附近,揭示了中纬度海气相互作用机制在东南印度洋海洋锋面附近起重要作用。同时,本文还发现了亚南极锋锋面上空存在一支强的低空纬向急流,急流中心位于300 m高度处;极锋上空低空风速强而高空风速弱。

During the 25th Chinese Antarctic expedition, a new GPS radiosonde system was launched to detect the verti- cal structure of the atmosphere around the southeast Indian Ocean fronts region. Detailed information on the vertical profiles of wind speed and air temperature above the fronts between the Chinese Antarctic station, Zhongshan and the port of Fremantle, Australia, was obtained. The research showed that a distinct vertical structure appeared at the warm/cold side of the sub-Antarctic front between Zhongshan Station and Fremantle. The low level wind speed at the warm side was stronger than at the cold side, a finding that confirmed the special atmosphere-ocean interac- tion at the front area in the southeast Indian Ocean region. A low-level jet was observed above the sub-Antarctic front between Zhongshan Station and Fremantle. The vertical structure of the atmosphere around the Antarctic front was quite different compared with the sub-Antarctic front.