Signatures of the Mediterranean outflow from a North Atlantic climatology: 2. Diagnostic velocity fields
Signatures of the Mediterranean outflow from a North Atlantic climatology: 2. Diagnostic velocity fields
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北大西洋气候学的地中海流出特征：2. 诊断速度场
DOI：
10.1029/1999jc900204
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发表时间：
1999
影响因子：
--
通讯作者：
M. Iorga
中科院分区：
文献类型：
--
作者：
M. Iorga
这项研究的第一部分是基于东部盆地高分辨率盐度和密度图对地中海水扩散的描述性分析。在我们研究的第二部分中，地中海流出的两个具有代表性的等轴面的速度场(o-0。S=29.7，0-0。S=29.90)是根据一个诊断模型估算的，该模型将国家海洋数据中心的气候水文数据与直布罗陀海峡水交换的长期直接测量相结合。该模型受地转动力学、质量守恒、大陆架无通量条件和通过直布罗陀海峡的特定气流的约束。我们的主要数据来源是最近汇编的北大西洋数据库，其中包括等径面上平均的气候平均属性场。这些平均场是基于80多年(1909-1990)的资料，名义水平分辨率为0.5o。为了提供直布罗陀海峡的边界条件，我们使用了从1985年直布罗陀实验期间收集的数据开发的一个模型的结果。估计的速度场显示，地中海水从直布罗陀海峡流出，沿着伊比利亚南部海岸，然后进入塔古斯盆地，在那里它以反气旋的方式转向，形成了这个水团的水库。水流沿着东部边界继续向北，渗透到罗卡尔海峡。最后，模式流场没有显示地中海水域向西进入副热带气旋的显著平流。
Part 1 of this study is a descriptive analysis of the spreading of Mediterranean Water based on high-resolution maps of salinity and density in the eastern basin. In this second part of our study, velocity fields for two representative isopycnal surfaces of the Mediterranean outflow (o-0. s = 29.70 and o-0. s = 29.90) are estimated from a diagnostic model that combines climatological hydrographic data from the National Oceanic Data Center with long-term direct measurements of water exchange through the Strait of Gibraltar. The model is constrained by geostrophic dynamics, conservation of mass, no- flux conditions at the continental shelf, and specified flow through the Strait of Gibraltar. Our principal data source is a recently assembled database of the North Atlantic that consists of climatological mean property fields averaged on isopycnal surfaces. The mean fields are based on more than 80 years (1909-1990) of data and have a nominal horizontal resolution of 0.5 o . To provide boundary conditions at the Strait of Gibraltar, we use the results of a model developed from data collected during the Gibraltar Experiment in 1985. The estimated velocity fields show Mediterranean Water exiting the Strait of Gibraltar, following the southern Iberian coast, and then entering the Tagus Basin, where it turns anticyclonically to create a reservoir of this water mass. The flow continues northward along the eastern boundary, penetrating into the Rockall Channel. Finally, the model flow fields do not show a significant westward advection of Mediterranean waters into the subtropical gyre.