A discussion of flow pathways in the central and eastern equatorial Pacific
A discussion of flow pathways in the central and eastern equatorial Pacific
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DOI：
10.1175/jpo3042.1
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发表时间：
2007-05-01
影响因子：
3.5
通讯作者：
Schiller, Andreas
中科院分区：
文献类型：
--
作者：
Brown, Jaclyn N.;Godfrey, J. Stuart;Schiller, Andreas
一个允许涡流的全球海洋模式被用来解释运动学在赤道太平洋中部和东部，从160度E到美国海岸。由于该区域的高度变异性，对纬向流的观测研究是相互矛盾的，特别是关于净流量是向北还是向南。与大多数海洋学数据集不同，模型输出可以在高时间和空间分辨率下进行分析，为真实的海洋行为提供线索。在该模型中，一个净向南流动发生在赤道以东的160度W，在最密度层全年。在中太平洋，从160 ° E到160 ° W，净流量是向北的，但随季节变化，主要发生在混合层。这是赤道潜流水流入北方半球的关键区域。三维流动是非常复杂的，并具有季节性.重要的是，这些流动是在一个等密度的框架进行分析，否则的途径是非常误导。在今年上半年，在赤道两侧发现了赤道热带细胞的证据，达到+/- 5度。这些细胞的存在似乎不需要任何细胞膜下涌。在下半年，当热带不稳定波活跃时，这些单元被一股强大的表面向南流动所覆盖，这似乎是一种团状输送。除非以上述方式计算流量，否则这种输运是不明显的。
An eddy-permitting global ocean model is used to interpret kinematics within the central and eastern equatorial Pacific Ocean, from 160 degrees E to the coast of America. Because of high levels of variability in this region, observational studies of meridional flow are contradictory, in particular as to whether the net flow is northward or southward. Unlike most oceanographic datasets, model output can be analyzed at high temporal and spatial resolution, providing clues as to real ocean behavior. In the model, a net southward flow occurs across the equator east of 160 degrees W, at most density layers throughout the year. In the central Pacific, from 160 degrees E to 160 degrees W, the net flow is northward but varies with season and occurs primarily in the mixed layer. This is a key region for the flow of Equatorial Undercurrent water into the Northern Hemisphere. The three- dimensional flow is very complex and seasonally dependent. It is vital that these flows are analyzed in an isopycnal framework, or else the pathways are very misleading. In the first half of the year, evidence is found of meridional tropical cells on either side of the equator out to +/- 5 degrees. These cells appear to exist without any need for diapycnal downwelling. In the second half of the year, when tropical instability waves are active, the cells are overlaid by a strong surface southward flow that appears to be a bolus- type transport. This transport is not apparent unless the flow is calculated in the aforementioned manner.