On eddy diffusion profiles in oceanic bottom boundary layers associated with cold eddies and filaments
✍ Scribed by Tal Ezer; Georges L. Weatherly
- Publisher
- Springer
- Year
- 1989
- Tongue
- English
- Weight
- 824 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0006-8314
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✦ Synopsis
The oceanic bottom boundary-layer model of Weatherly and Martin (1978) is used to study the vertical structure of the eddy diffusivity in a region with initially imposed bottom mixed-layer thickness. Because of near-bottom oceanic features, such as the Cold Filament (Weatherly and Kelley, 1982) and cold eddies (Ebbesmeyer et al., 1988), the bottom mixed-layer thickness is not the sole result of boundary-layer mixing; this is the incentive for this study. For a given geostrophic forcing and imposed mixed-layer depth, a formula for the eddy diffusion coefficient is found. This parameterization of the eddy diffusivity improves previous formulas used in oceanic and atmospheric boundary layers in the upper portion of the boundary layer. A simple model of a Cold Filament-like feature demonstrates the structure of the bottom boundary layer, the bottom mixed layer, and the relation between the two. A lens-like cross section of cold blobs, often used in analytical models, may be inappropriate if bottom friction is important.
Preface
Since this is a study of the oceanic bottom boundary layer, some explanation is in order as to why it was submitted to this journal. Many oceanographers interested in boundary-layer processes read Boundary-Layer Meteorology. However, we think that this study may also be of interest to some atmospheric boundary-layer researchers. For example, it may be of direct relevance to meteorologists interested in parameterizing vertical diffusivity profiles in nocturnal atmospheric boundary layers or in atmospheric boundary layers in polar regions. In any event, we are grateful to the editor and the reviewer for allowing us to publish a paper on the other boundary layer of this planet in Boundary-Layer Meteorology.