Atmosphere Ocean Science Friday Seminar

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Next-order balanced model captures submesoscale physics and statistics

Speaker: Ryan Shìjié Dù, CAOS

Location: Warren Weaver Hall 512

Date: Friday, September 29, 2023, 4 p.m.

Synopsis:

Using nonlinear simulations in two settings, we demonstrate that QG+1, a potential-vorticity (PV) based next-order in Rossby balanced model, captures several aspects of ocean submesoscale physics. In forced-dissipative 3D simulations under baroclinically unstable (Eady instability) backgrounds, the statistical equilibrium turbulence has long cyclonic tails, non-zero divergence, and a plethora of rapidly-intensifying fronts. Simulations of QG+1 under the classic strain-induced frontogenesis set-up show realistic frontal asymmetry and a finite-time blow-up. This suggests QG+1 is a useful tool for studying the balanced flow in ocean submesoscale, which dominates transport. The numerics of QG+1 are simple, only requiring solving Poisson problems in the inversion. We use Dedalus for all our simulations.