From Topographic Internal Gravity Waves to Turbulence

Internal gravity waves are a key process linking the large-scale mechanical forcing of the oceans to small-scale turbulence and mixing. In this review, we focus on internal waves generated by barotropic tidal flow over topography. We review progress made in the past decade toward understanding the different processes that can lead to turbulence during the generation, propagation, and reflection of internal waves and how these processes affect mixing. We consider different modeling strategies and new tools that have been developed. Simulation results, thewealth of observationalmaterial collected during large-scale experiments, and new laboratory data reveal how the cascade of energy from tidal flow to turbulence occurs through a host of nonlinear processes, including intensified boundary flows, wave breaking, wave-wave interactions, and the instability of high-mode internal wave beams. The roles of various nondimensional parameters involving the ocean state, roughness geometry, and tidal forcing are described. 195 Click here to view this article's online features: • Download figures as PPT slides • Navigate linked references • Download citations • Explore related articles • Search keywords ANNUAL REVIEWS Further A nn u. R ev . F lu id M ec h. 2 01 7. 49 :1 95 -2 20 . D ow nl oa de d fr om w w w .a nn ua lr ev ie w s. or g A cc es s pr ov id ed b y U ni ve rs ity o f C al if or ni a Sa n D ie go o n 01 /1 2/ 17 . F or p er so na l u se o nl y. FL49CH09-Sarkar ARI 16 November 2016 11:57 Barotropic tide: oscillatory motion that is in phase across the entire water column and driven by lunar and solar gravitation forces