2013年夏季南极南设得兰群岛周边海域透光层水团结构

南设得兰群岛位于德雷克海峡南侧, 南经布兰斯菲尔德海峡与南极半岛相望。该区域一直是南大洋海洋学研究的热点区域, 近些年已成为南极磷虾渔业的重要作业区。透光层作为海洋生物活动最为集中的区域, 也是海洋中生产力最为丰富的区域。了解透光层水团的特性及变化, 一方面可为南极半岛海洋学研究提供基础信息, 同时也可为南极磷虾等中上层海洋生物的分布及其致因提供科学支撑。通过分析2013年1月至3月南设得兰群岛周边海域5个断面的透光层温、盐数据, 本研究梳理了该区域的水团属性和分布。结果显示, 南设得兰群岛北侧较深水区水团垂向结构明显, 由上至下依次为南极夏季表层水、冬季水和绕极深层水。位于南设得兰群岛南侧的布兰斯菲尔德海峡内, 威德尔海过渡水特征几乎占据了整个布兰斯菲尔德海峡。但布兰斯菲尔德海峡西南侧水团结构较为复杂, 包括了威德尔海过渡水、别林斯高晋海过渡水和德雷克海峡水等。阐明南设得兰群岛周边复杂的水团结构对于进一步开展南大洋生物-物理相互作用研究具有重要的科学意义。

Water mass structure in the euphotic zone around South Shetland Islands,Antarctic during summer 2013

The South Shetland Islands are located in the south side of the Scotia Sea and separated from the Antarctic Peninsula by Bransfield Strait. The region has been a focus of oceanographic research and has become an important fishing ground for Antarctic krill (Euphausia superba) recently. The euphotic zone is the most productive zone in the ocean and occurs the highest concentration of marine biota. Understanding of the characteristics and dynamics of water masses in the euphotic zone can provide basic information for oceanographic research, and also provide scientific support for the distribution and habitat of pelagic organisms, such as the Antarctic krill. In this study, we analyzed temperature and salinity profile data collected from the euphotic zone along five transects around the South Shetland Islands between January and March 2013. Results indicate a clear vertical water mass structure in the deeper areas in the north part of the South Shetland Islands. Antarctic Summer Surface Water, Winter Water and Circumpolar Deep Water occur from surface down, respectively. The Bransfield Strait, which locates in the south of the South Shetland Islands, is almost entirely dominated by the Transitional Zonal Water with Weddell Sea influence (TWW). The water mass structure is complex in its southwestern basin of the Bransfield Strait; the TWW, the Transitional Zonal Water with Bellingshausen Sea influence, and water from the Drake Passage occur in this region. Elucidating the complicated water mass structure around the South Shetland Islands is scientifically important for further study on biophysical interactions in the Southern Ocean.