Surface circulation at the tip of the Antarctic Peninsula from drifters
Surface circulation at the tip of the Antarctic Peninsula from drifters
复制标题
DOI：
10.1175/2008jpo3995.1
复制
发表时间：
2009
影响因子：
3.5
通讯作者：
A. Thompson;K. Heywood;S. Thorpe;A. Renner;A. Trasviña
中科院分区：
文献类型：
--
作者：
A. Thompson;K. Heywood;S. Thorpe;A. Renner;A. Trasviña
2007年2月，作为南极漂流实验：与等温泉和生态系统的联系(阿德利)项目的一部分，在南极半岛尖端以东部署了一个由40个浮游者组成的阵列，这些漂流者在15米深的地方漂流。从这些漂流者和一些当地历史漂流者那里获得的数据提供了迄今为止关于威德尔海西北部表层环流的最详细的观测结果。南极坡锋是南极半岛以东的主要特征，其特征是沿1000m等深线有一条约20 cm的S流(−1)。当遇到南斯科舍山脊时，斜坡前沿分叉，漂流者沿着三条路径中的一条。漂流者(I)向西进入布兰斯菲尔德海峡；(Ii)沿着南斯科舍海脊南缘向东的1000米等深线向东移动；或(Iii)被困在南斯科舍海脊上方的大漩涡中。漂移物强烈地受f/h(科里奥利频率/深度)等高线的控制，在地理坐标和局部与f/h等高线对齐的坐标中的前两个移位矩的计算表明，漂移物速度的涡平均分解表明，平均气流中的切变对沿f/h方向的弥散起主要作用，但涡旋过程在沿f/h等高线分散颗粒方面更重要。阿德利研究的结果表明，南极半岛顶端附近的环流可能通过南极磷虾输送和营养物质的输出影响南大洋生态系统的动态。
An array of 40 surface drifters, drogued at 15-m depth, was deployed in February 2007 to the east of the tip of the Antarctic Peninsula as part of the Antarctic Drifter Experiment: Links to Isobaths and Ecosystems (ADELIE) project. Data obtained from these drifters and from a select number of local historical drifters provide the most detailed observations to date of the surface circulation in the northwestern Weddell Sea. The Antarctic Slope Front (ASF), characterized by a ~20 cm s^(−1) current following the 1000-m isobath, is the dominant feature east of the peninsula. The slope front bifurcates when it encounters the South Scotia Ridge with the drifters following one of three paths. Drifters (i) are carried westward into Bransfield Strait; (ii) follow the 1000-m isobath to the east along the southern edge of the South Scotia Ridge; or (iii) become entrained in a large-standing eddy over the South Scotia Ridge. Drifters are strongly steered by contours of f /h (Coriolis frequency/depth) as shown by calculations of the first two moments of displacement in both geographic coordinates and coordinates locally aligned with contours of f /h. An eddy-mean decomposition of the drifter velocities indicates that shear in the mean flow makes the dominant contribution to dispersion in the along-f /h direction, but eddy processes are more important in dispersing particles across contours of f /h. The results of the ADELIE study suggest that the circulation near the tip of the Antarctic Peninsula may influence ecosystem dynamics in the Southern Ocean through Antarctic krill transport and the export of nutrients.