The TRR 181 seminar is held by Dr. Han Wang (Universität Hamburg) on November 28, 11 am in Bundesstr. 53, Hamburg, room 22/23.

Scattering of surface waves by ocean currents

Abstract

Ocean turbulence at meso- and submesocales affects the propagation of surface waves through refraction and scattering, inducing spatial modulations in significant wave height (SWH). We develop a theoretical framework that relates these modulations to the current that induces them. We exploit theasymptotic smallness of the ratio of typical current speed to wave group speed to derive a linear map -- the "U2H map" -- between surface current velocity and SWH anomaly. Analytic expressions of the U2H map show how the SWH responds differently to the vortical and divergent parts of the current, and how theanisotropy of the wave spectrum is key to large current-induced SWH anomalies. In this talk, I will describe the method, its benchmarking against WAVEWATCH III outputs, and its implications for oceanic flows.