Wave-activity conservation laws and stability theorems for semi-geostrophic dynamics. Part 2. Pseudoenergy-based theory

Journal Article · Mon May 01 04:00:00 EDT 1995 · Journal of Fluid Mechanics

DOI:https://doi.org/10.1017/S0022112095002436· OSTI ID:117656

Kushner, P J; Shepherd, T G ^[1]

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1. Univ. of Toronto, Toronto (Canada)

A study of the semi-geostrophic (SG) geophysical fluid dynamics is presented. SG dynamics shares certain attractive properties with the better known and more widely used quasi-geostrophic (QG) model, but is also a good prototype for balanced models that are more accurate than QG dynamics. An invariant for the semi-geostrophic equations is derived and use it to obtain: (1) a linear stability theorem analogous to Arnold`s first theorem; and (2) a small-amplitude local conservation law for invariant, obeying the group-velocity in the WKB limit. The results are analogous to their quasi-geostrophic forms, and reduce to those forms in the limit of small Rossby number. 23 refs.

• Sponsoring Organization: USDOE
• OSTI ID: 117656
• Journal Information: Journal of Fluid Mechanics, Journal Name: Journal of Fluid Mechanics Vol. 290; ISSN JFLSA7; ISSN 0022-1120
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
99 GENERAL AND MISCELLANEOUS
BOUNDARY CONDITIONS
COMPRESSIBLE FLOW
COMPUTERIZED SIMULATION
MATHEMATICAL MODELS