Variability in circulation and exchange in a sub-Atlantic island fjord

亚南极岛屿南乔治亚岛位于斯科舍海的北部边界，在南极绕极洋流的路径上。周围的大陆架被深峡谷横穿，这些峡谷连接着南乔治亚州的峡湾和大陆架边缘。岛上发现的许多冰川都终止于这些峡湾的顶部。卫星图像显示，富含铁的冰川面粉羽状物从峡湾延伸到大陆架[1]，促成了该岛北部广泛的浮游植物水华和相关的大气碳强烈下降区域。岛屿峡湾也是许多鱼类物种的重要产卵区，包括商业捕捞的鳕鱼。然而，南乔治亚湾水域的循环，以及影响它们与大陆架和更广阔的海洋交换的过程，人们知之甚少。此外，南乔治亚地区正在经历快速的环境变化。1925至2006年间，南乔治亚州附近的近地表水域的冬季温度上升了约2.3摄氏度[2]，岛上的大部分冰川正在消退[3]。该项目旨在提高我们目前对南乔治亚湾环流和陆架交换的了解，并考虑正在进行的环境变化的潜在影响。

The sub-Antarctic island of South Georgia lies at the northern boundary of the Scotia Sea in the path of the Antarctic Circumpolar Current. The surrounding shelf is traversed by deep canyons that connect the fjords of South Georgia with the shelf edge. Many of the glaciers found on the island terminate at the head of these fjords. Satellite images show iron-rich glacial flour plumes extending onto the shelf from the fjords [1], contributing to the extensive phytoplankton blooms and associated region of strong atmospheric carbon drawdown to the north of the island. The island fjords are also important spawning areas for many fish species, including the commercially-fished Mackerel icefish.However, the circulation of South Georgia's fjord waters, and processes impacting their exchange with the shelf and wider ocean, are poorly understood. In addition, the South Georgia region is undergoing rapid environmental change. Near-surface waters near South Georgia have seen a rise in wintertime temperatures of ~2.3degree C between 1925 and 2006 [2], and the majority of glaciers on the island are in retreat [3]. This project aims to improve our current understanding of fjord circulation and shelf-exchange at South Georgia, and consider the potential impacts of ongoing environmental change.