Coherence of Antarctic sea levels, Southern Hemisphere Annular Mode, and flow through Drake Passage
Coherence of Antarctic sea levels, Southern Hemisphere Annular Mode, and flow through Drake Passage
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南极海平面、南半球环形模态和德雷克海峡流量的相干性
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发表时间：
2003
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影响因子：
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通讯作者：
A. Pyne
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作者：
C. Hughes;P. Woodworth;M. Meredith;V. Stepanov;T. Whitworth;A. Pyne
从少量的验潮仪可知，南极洲周围的次表层压力（经反气压计效应校正的海平面）在大约半个大陆周围呈现连贯变化，并且这种连贯信号与南极涛动或南半球环状模形式的大气强迫有关。在此，我们证实这种连贯性延伸到更广泛的验潮仪网络，以及延伸到远离海岸的大陆架部分（通过海底压力计测量）。我们利用一个具有实际强迫的允许涡旋的海洋模型的时间序列，将连贯模式与通过德雷克海峡的输送波动联系起来，并利用一个1°分辨率的正压模型证实，这些波动主要是由于正压动力学，尽管在年际时间尺度上斜压动力学预计将发挥越来越大的作用。
It is known from small sets of tide gauges that sub‐surface pressure (sea level corrected for the inverse barometer effect) around Antarctica varies coherently around about half of the continent, and that this coherent signal is related to atmospheric forcing in the form of the Antarctic Oscillation, or Southern Hemisphere Annular Mode. We here confirm that this coherence extends to a more extensive network of tide gauges, and to parts of the continental shelf far from the shore, as measured by bottom pressure gauges. We use time series from an eddy‐permitting ocean model with realistic forcing to relate the coherent mode to fluctuations in transport through Drake Passage, and confirm, using a 1° resolution barotropic model, that the fluctuations are predominantly due to barotropic dynamics, although baroclinic dynamics are expected to play an increasing role at interannual timescales.