Eddy advective and diffusive transports of heat and salt in the Southern Ocean
Eddy advective and diffusive transports of heat and salt in the Southern Ocean
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DOI：
10.1175/jpo3057.1
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发表时间：
2007-05-01
影响因子：
3.5
通讯作者：
de Cuevas, B. A.
中科院分区：
文献类型：
--
作者：
Lee, Mei-Man;Nurser, A. J. George;de Cuevas, B. A.
有两种不同的机制，通过这种机制，涡旋提供了等密度线上示踪剂的系统输送：平流输送，与等密度线的滑塌有关，以及扩散输送，与向下梯度扩散有关。根据大尺度示踪剂的分布，涡动平流输送与涡动扩散输送方向相同或相反。因此，涡动平流和涡动扩散对某些示踪剂可以相互加强，但对其他示踪剂则相反。利用标度分析，认为涡动平流输送和扩散输送的相对方向可以简单地由示踪剂和等密度线的相对斜率确定。本文用一个涡旋分辨（1/12度）的全球海洋模式来说明南大洋温度和盐度的两种涡旋输送机制。其他示踪剂，如氧，的应用进行了讨论。诊断涡扩散温度（和盐度）被发现是相当不同的涡扩散涡平流输送速度。
There are two distinct mechanisms by which eddies provide systematic transport of tracer on isopycnals: the advective transport, associated with the slumping of isopycnals, and the diffusive transport, associated with down- gradient diffusion. Depending on the large-scale tracer distribution, eddy advective transport has either the same direction as or opposite direction to eddy diffusive transport. As a consequence, eddy advection and eddy diffusion can reinforce each other for some tracers but oppose each other for other tracers. Using scaling analysis, it is argued that the relative directions of eddy advective and diffusive transports can be determined simply from the relative slopes of tracers and isopycnals. An eddy- resolving (1/12 degrees) global ocean model is used to illustrate the two eddy transport mechanisms for temperature and salinity in the Southern Ocean. Applications to other tracers, such as oxygen, are discussed. The diagnosed eddy diffusivity for temperature (and salinity) is found to be considerably different from the eddy diffusivity for eddy advective transport velocity.