An asymptotically reduced model of turbulent Langmuir circulation

Abstract

An asymptotically exact reduced model describing Langmuir circulation (LC), an upper ocean convective flow, in the strong surface wave forcing limit is constructed. Linear and secondary stability analyses suggest that the model captures correctly the dominant instability modes arising in strongly anisotropic, turbulent LC. The model is conceptually simpler, and may be more amenable to numerical simulation, than the three-dimensional Craik–Leibovich equations from which the reduced equation set is derived.

Keywords:

• Convection
• Langmuir circulation
• Multiscale asymptotic analysis
• Reduced equations
• Ocean mixed layer
• Streamwise vortices

Acknowledgments

G. P. Chini gratefully acknowledges funding for this work from NSF CAREER Award 0348981 administered by the Physical Oceanography Program. K. Julien acknowledges support from a University of Colorado Innovative Seed Grant.