Seasonal to interannual variability in density around the Canary Islands and their influence on the Atlantic meridional overturning circulation at 26°N
Seasonal to interannual variability in density around the Canary Islands and their influence on the Atlantic meridional overturning circulation at 26°N
复制标题
加那利群岛周围密度的季节到年际变化及其对北纬 26° 大西洋经向翻转环流的影响
DOI：
10.1002/2013jc009416
复制
发表时间：
2014
影响因子：
--
通讯作者：
A. Coward
中科院分区：
文献类型：
--
作者：
A. Duchez;E. Frajka‐Williams;Natalia Castro;J. Hirschi;A. Coward
从RAPID阵列获得的经向内部流由北纬26°东西边界的水平密度波动决定。这些密度变化的物理成因是大西洋经向翻转环流（AMOC）波动的原因，并通过它影响大西洋的经向热量输送。在这项模拟研究中，一个高分辨率海洋模型被用于研究与东部边界密度波动相关的AMOC变化的源头和起源。模型中的AMOC与RAPID的观测结果非常吻合，并且似乎能充分体现加那利群岛周围变化的小尺度特征。在本文中，我们通过经验正交函数分析、小波变换和小波相干性，确定了加那利群岛南部的密度结构、这些岛屿周围的局地风应力旋度（WSC）和AMOC之间的一种稳健关系。我们发现北纬26°东部边界的深层密度波动源于岛屿南部WSC空间模式的抽吸效应。这些深层密度波动通过它们对温跃层全盆地倾斜的影响，在季节和年际时间尺度上驱动AMOC。在季节时间尺度上，岛屿南部的密度波动由WSC驱动，并直接影响AMOC。在年际时间尺度上，尽管这些密度波动的起源不能用WSC引起的直接抽吸来解释，但在密度波动和向南的UMO输送之间发现了显著的相干性。
The meridional interior flow obtained from the RAPID array is determined by horizontal density fluctuations at the eastern and western boundary of 26°N. The physical causes of these density variations are responsible for fluctuations in the Atlantic Meridional Overturning Circulation (AMOC) and through it, the meridional heat transport of the Atlantic. In this modelling study, a high resolution ocean model is used to investigate the source and origin of the AMOC variability associated with the density fluctuations at the eastern boundary. The AMOC in the model is in good agreement with the RAPID observations and appears to adequately represent the smaller scale features of variability around the Canary Islands. In this paper, we identify a robust relationship between the density structure south of the Canary Islands, the local wind stress curl (WSC) around these islands and the AMOC using an empirical orthogonal functions analysis, wavelet transform and wavelet coherence. We find that the deep density fluctuations at the eastern boundary of 26°N arise from the pumping effect of the spatial pattern of WSC south of the islands. These deep density fluctuations drive the AMOC both on seasonal and interannual timescales, through their influence on the basinwide tilt of the thermocline. At seasonal timescales, the density fluctuations south of the islands are driven by the WSC and directly influence the AMOC. At interannual timescales, a significant coherence is found between the density fluctuation and the southward UMO transport although the origin of these density fluctuations is not explained by the the direct pumping caused by the WSC.
经向翻转环流在年际到年际时间尺度上的混沌变化
影响因子：
3.2
作者：
Hirschi J
通讯作者：
Hirschi J
影响因子：
3.2
作者：
Blaker, Adam T.;Hirschi, Joel J-M.;Madec, Gurvan
通讯作者：
Madec, Gurvan