Deep western boundary current and southern frontal systems of the Antarctic Circumpolar Current southeast of the Kerguelen Plateau
Deep western boundary current and southern frontal systems of the Antarctic Circumpolar Current southeast of the Kerguelen Plateau
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DOI：
10.1029/2007jc004627
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发表时间：
2008-08
影响因子：
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通讯作者：
S. Aoki;N. Fujii;S. Ushio;Y. Yoshikawa;S. Watanabe;G. Mizuta;Y. Fukamachi;M. Wakatsuchi
中科院分区：
文献类型：
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作者：
S. Aoki;N. Fujii;S. Ushio;Y. Yoshikawa;S. Watanabe;G. Mizuta;Y. Fukamachi;M. Wakatsuchi
[1]对克尔盖伦高原东南部的南极绕极流（ACC）的西深边界流和南锋面系统的结构进行了研究。在南纬58°附近进行了自上而下的水文测量，在南纬56°和61°附近进行了两次航行观测。中深浮子也被用来描述地下流场和温度场。在58°S剖面上，高原外围有一个冷丘，其东西两侧有西北和东南气流。观测到的气流结构为高度正压性。底水向赤道方向的最大输送量为22 Sv，包括可能的10 Sv气旋再环流。深环流的输送可以用高原底坡和上覆的ACC经小鹿槽向东南流动形成的封闭等流中的位涡均匀化来解释。冷穹的空间尺度在58°S处约为100 km，在56°S和61°S附近也发现了类似的冷穹，并在61°S附近发现了ACC南边界的特征。中深度浮子轨迹和最高温度分布也证实了ACC南部锋面的急剧偏移。这表明赤道偏移高达54°S，温暖的ACC水就在南锋面系统的东边。
[1] The structures of the deep western boundary current and southern frontal systems of the Antarctic Circumpolar Current (ACC) southeast of the Kerguelen Plateau were investigated. Top-to-bottom hydrography was conducted around 58°S, and two underway observations were made around 56°S and 61°S. Middepth floats were also used to describe the subsurface flow and temperature fields. Along the 58°S section, a cold dome was located just off the plateau, and northwestward and southeastward flows were found in its western and eastern sides. The observed flow structure was highly barotropic. The maximum volume transport of the bottom water was 22 Sv equatorward, including a possible cyclonic recirculation of 10 Sv. The transport of the deep recirculation can be explained by the potential vorticity homogenization in the closed isopachs formed by the bottom slope off the plateau and the overlying ACC flowing southeastward through the Fawn Trough. The spatial scale of the cold dome, which showed a signature of the southern ACC front, was around 100 km at 58°S, and the similar cold domes were also found around 56°S and 61°S, along with a signature of the southern boundary of ACC around 61°S. The sharp excursion of the southern ACC front was also confirmed by the middepth float trajectories and the distribution of temperature maximum. This indicates the equatorward excursion up to 54°S, with the warmer ACC water just east of the southern frontal systems.