On Geometrical Aspects of Interior Ocean Mixing
On Geometrical Aspects of Interior Ocean Mixing
复制标题
内部海洋混合的几何方面
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
S. Griffies
中科院分区：
文献类型：
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作者：
T. McDougall;S. Groeskamp;S. Griffies
摘要对中性扩散的全三维扩散张量的小斜率近似得到的示踪通量与层状海洋模型和理论研究中常用的投影非正交扩散通量完全相同。通过这种小斜率近似获得的中性扩散并不完全在正确的中性示踪剂梯度方向上。也就是说，使用小斜率近似导致示踪剂在没有示踪剂中性梯度的方向上的通量非常小。对于（示踪剂）温度或盐度，正确的外中性梯度与其小斜率近似值之间的差与中性螺旋度成正比。作者还指出，小规模湍流混合过程对示踪剂的扩散是各向同性的（即，在每个空间方向上都是相同的），因此称这种过程为“无中性扩散”或“垂直扩散”严格来说是一种误称。这种认识还隐含着……
AbstractThe small-slope approximation to the full three-dimensional diffusion tensor of epineutral diffusion gives exactly the same tracer flux as the commonly used projected nonorthogonal diffusive flux of layered ocean models and of theoretical studies. The epineutral diffusion achieved by this small-slope approximation is not exactly in the direction of the correct epineutral tracer gradient. That is, the use of the small-slope approximation leads to a very small flux of tracer in a direction in which there is no epineutral gradient of tracer. For (the tracer) temperature or salinity, the difference between the correct epineutral gradient and the small-slope approximation to it is proportional to neutral helicity. The authors also make the point that small-scale turbulent mixing processes act to diffuse tracers isotropically (i.e., the same in each spatial direction) and hence it is strictly a misnomer to call this process “dianeutral diffusion” or “vertical diffusion.” This realization also has implic...