SOMAR-LES for multiscale modeling of internal tide generation

ORAL

Abstract

A novel modeling technique is developed to study baroclinic energy conversion when the barotropic tide oscillates over underwater topography. In SOMAR-LES, a Large Eddy Simulation (LES) model that resolves turbulence scales is coupled with a large-scale model, Stratified Ocean Model with Adaptive Refinement (SOMAR). Thus, we overcome the constraints posed by the wide range of temporal and spatial scales during tide and topographic interaction. Two-way coupling is developed: LES is driven with large scale forcing, and SOMAR receives feedback in the form of eddy viscosity and diffusivity. Numerical simulations are performed with SOMAR-LES for supercritical and subcritical ridges with ridge length scales of $ \mathcal{O}$(10 km) and barotropic forcing that corresponds to the regime of low outer excursion number, $Ex = U_0/\omega l \simeq 0.1$. Results from the coupled model are compared against ongoing high-resolution LES to ascertain the accuracy of this technique. The simulation data is analyzed to quantify baroclinic energy conversion and the change in modal composition from near to far field.

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Authors

  • Vamsi Krishna Chalamalla

    • UC San Diego
    • University of California San Diego

  • Edward Santilli

    • Philadelphia University

  • Masoud Jalali

    • University of California San Diego

  • Alberto Scotti

    • Dept. of Marine Sciences, UNC-CH
    • University of North Carolina, Chapel Hill
    • Department of Marine Sciences, University of North Carolina, Chapel Hill, NC 27599, USA

  • Sutanu Sarkar

    • University of California at San Diego
    • UC San Diego
    • University of California, San Diego
    • University of California San Diego