A simple model of the Arctic Ocean response to annular atmospheric modes
A simple model of the Arctic Ocean response to annular atmospheric modes
复制标题
北冰洋对环形大气模式响应的简单模型
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
P. Schlosser
中科院分区：
文献类型：
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作者：
B. Newton;L. Tremblay;M. Cane;P. Schlosser
[1]一个动力机制，调制的倾斜的海面高度和密度跃层深度之间的北极中部和大陆架。一个简单的分析模型，被迫与理想化的纬向风超过一个理想化的，2层，圆柱代表北冰洋。Ekman输送与海面和密度跃层倾斜异常和盆地尺度环流有关，以响应环形风异常。我们将结果与验潮数据以及更现实的数值模拟结果进行比较，发现该模型解释了北极沿海验潮站年际至十年尺度海面高度异常的主要部分。例如，分析模型表明，在1985年至1993年期间观测到的北极沿海海面高度上升约18厘米，其中约10厘米的上升可能是对西风增加的反应，西风增加与大气变率的北方环形模态的强正相位有关。从模式的密度跃层深度异常时间序列被用来计算相对新鲜的极地水流出到北大西洋的隐含变化。比较表明，Ekman传输机制是重要的变化，在出口的浮力从北冰洋的季节，年际和十年的时间尺度。
[1] A dynamical mechanism is described that modulates the tilt of the sea-surface height and pycnocline depth between the central Arctic and the continental shelves. A simple analytical model is presented, forced with idealized zonal winds over an idealized, 2-layer, cylinder representing the Arctic Ocean. Ekman transports are linked to sea-surface and pycnocline tilt anomalies and basin-scale circulation in response to an annular wind anomaly. We compare the results to tide gauge data, as well as results from a more realistic numerical simulation and find that the model explains a major fraction of the interannual-to-decade scale sea-surface height anomalies at Arctic coastal tide gauges. The analytical model indicates, for example, that on the order of 10 cm of the observed rise of about 18 cm in coastal Arctic sea-surface height between about 1985 and 1993 was probably a response to increased Westerly winds associated with a strong positive phase of the Northern Annular Mode of atmospheric variability. The pycnocline depth anomaly time series from the model is used to calculate implied changes in the outflow of relatively fresh Polar Water to the North Atlantic. The comparisons indicate that the Ekman transport mechanism is important to changes in the export of buoyancy from the Arctic Ocean on seasonal, interannual, and decadal timescales.