The Interaction of Internal Solitary Waves and Sea Ice in the laboratory

Abstract

<p>Internal Waves are commonly observed along density interfaces across the world’s oceans. In the Arctic Ocean, the internal wave field is much less energetic than at lower latitudes, but due to relative quiescence of the region, nonlinear internal waves are particularly important for mixing there. This mixing is responsible for bringing heat from warm Atlantic Water at intermediate depth towards the surface where it has ramifications for the formation and melt of sea ice, as well as the general circulation of the Arctic Ocean. In the rapidly changing Arctic Ocean, as sea ice extent declines, understanding how internal waves interact with sea ice, and how sea ice affects them is crucial, particularly in the marginal ice zone.</p><p>Using laboratory experiments of internal solitary waves (ISWs) propagating under model ice the interaction of ice and internal solitary waves is investigated. Specifically, (i) Particle Tracking Velocimetry is used to measure the motion of floating discs (with the same density as sea ice ρ = 910kg/m³), to determine how ice moves in response to the near-surface internal wave-induced flow using is quantified. Additionally, (ii) Particle Image Velocimetry is used to determine how the near-surface internal wave-induced flow dynamics are impacted by the presence and motion of the model sea-ice, which acts as a rough upper boundary condition and moves with the flow.</p>