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Original Research Papers

A condition on the average Richardson number for weak non-linearity of internal gravity waves

Authors:

Erik Lindborg ,

Linné Flow Centre, Department of Mechanics, KTH, S-100 44 Stockholm, SE
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James J. Riley

University of Washington, Seattle, Washington, US
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Abstract

A condition on the average Richardson number, Ri, for weak non-linearity of an internal gravity wavefield is derived using a quasi-normal assumption. For weak non-linearity to be satisfied it is required that Ri−1 « 0.5. This condition is very rarely satisfied in the ocean at vertical scales up to the order of 100 m, for which it is often found that Ri−1 ∼ 1. The analysis suggests that non-linear effects are of no less importance than linear effects in the dynamics of the interior of the ocean at these scales.

How to Cite: Lindborg, E. and Riley, J.J., 2007. A condition on the average Richardson number for weak non-linearity of internal gravity waves. Tellus A: Dynamic Meteorology and Oceanography, 59(5), pp.781–784. DOI: http://doi.org/10.1111/j.1600-0870.2007.00266.x
  Published on 01 Jan 2007
 Accepted on 7 Jun 2007            Submitted on 27 Apr 2006

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