Variability of the Iceland‐Scotland Overflow Water Transport Through the Charlie‐Gibbs Fracture Zone: Results From an Eddying Simulation and Observations
Variability of the Iceland‐Scotland Overflow Water Transport Through the Charlie‐Gibbs Fracture Zone: Results From an Eddying Simulation and Observations
复制标题
通过查理-吉布斯断裂带的冰岛-苏格兰溢流水输送的变化：涡流模拟和观测的结果
DOI：
10.1029/2018jc013895
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
E. Chassignet
中科院分区：
文献类型：
--
作者：
Xiaobiao Xu;A. Bower;H. Furey;E. Chassignet
观测结果表明，冰岛-苏格兰通过Charlie-Gibbs断裂带（CGFZ）向西的输送是高度可变的。本研究探讨（a）这种变异性来自哪里，以及（B）它是如何与冰岛盆地上游位置的ISOW输送和其他ISOW输送路径的变异性相关的。这些分析是基于一个35年1/12°涡旋大西洋模拟，它很好地代表了在感兴趣的地区观测到的ISAW的主要特征，特别是通过CGFZ的传输变率。结果表明：（1）在北大西洋流锋的纬向位移作用下，CGFZ内的正压输送与ISOW输送的变率密切相关，并可能由CGFZ以东西欧海盆大尺度纬向风应力的扰动引起;（B）从冰岛海盆北方到CGFZ地区，ISOW输运的变异性增加了3倍，这两个地点的输运时间序列不相关，进一步表明CGFZ的变异性不是来自上游源; CGFZ的ISOW输送的变率与沿中大西洋海岭东部斜坡沿着向南的ISOW输送的变率有很强的相关性，表明这两个ISOW途径之间存在异相共变转运。在这个关键位置的观测显示，东风波是高度可变的，有时甚至会逆转为东风波向东。本研究使用数值模型来调查变异性的来源以及在该位置发现的变异性与其他地方的关系。该模型再现了大部分观察到的ISOW变异。结果表明，深海ISOW的变化与上层海流的南北移动有关，并可能是由大尺度东西向风的扰动引起的。此外，在CGFZ的ISOW比其上游源在冰岛盆地北方和中部的变化更大，并通过CGFZ的向西向急流一起变化，在相反的阶段，与一个向南的分支沿着大西洋中脊的东部斜坡。
Observations show that the westward transport of the Iceland-Scotland over fl ow water (ISOW) through the Charlie-Gibbs Fracture Zone (CGFZ) is highly variable. This study examines (a) where this variability comes from and (b) how it is related to the variability of ISOW transport at upstream locations in the Iceland Basin and other ISOW fl ow pathways. The analyses are based on a 35-year 1/12° eddying Atlantic simulation that represents well the main features of the observed ISOW in the area of interest, in particular, the transport variability through the CGFZ. The results show that (a) the variability of the ISOW transport is closely correlated with that of the barotropic transports in the CGFZ associated with the meridional displacement of the North Atlantic Current front and is possibly induced by fl uctuations of large-scale zonal wind stress in the Western European Basin east of the CGFZ; (b) the variability of the ISOW transport is increased by a factor of 3 from the northern part of the Iceland Basin to the CGFZ region and transport time series at these two locations are not correlated, further suggesting that the variability at the CGFZ does not come from the upstream source; and (c) the variability of the ISOW transport at the CGFZ is strongly anticorrelated to that of the southward ISOW transport along the eastern fl ank of the Mid-Atlantic Ridge, suggesting an out-of-phase covarying transport between these two ISOW pathways. Observations at this critical location revealed that the fl ow is highly variable, sometimes even reversed to fl ow eastward. This study uses a numerical model to investigate the source of the variability and the relationship of the variability found at this location to other places. The model reproduces most of the observed ISOW variability. The results suggest that the ISOW variability in the deep ocean is linked to a north-south shift of the current in the upper ocean and is possibly induced by fl uctuations of large-scale wind in east-west direction. Furthermore, the ISOW at the CGFZ is much more variable than its upstream source in the northern and central Iceland Basin, and the westward fl ow through the CGFZ varies together, in an opposite phase, with a southward fl owing branch along the eastern fl ank of the Mid-Atlantic Ridge.
影响因子：
4.1
作者：
Sijia Zou;S. Lozier;W. Zenk;A. Bower;W. Johns
通讯作者：
Sijia Zou;S. Lozier;W. Zenk;A. Bower;W. Johns
DOI：
10.1016/j.dsr2.2010.10.061
发表时间：
2011-09-01
影响因子：
3
作者：
Rhein, Monika;Kieke, Dagmar;Yashayaev, Igor
通讯作者：
Yashayaev, Igor