Slope-Enhanced Fission of Salty Hetons under Sea Ice

Abstract

Abstract Ocean responses to a single brine source under ice and over a sloping bottom are investigated in numerical experiments. Brine sources considered herein are often much stronger than that anticipated from a single seawater freezing event in a time span of about 10 days. The authors have no evidence that such strong sources exist in the ocean, but the consequent heton-like eddies manifest interesting features over a bottom slope. The numerical model contains a stratified ocean capped by an ice layer. The convection initially generates a top cyclone and a submerged anticyclone vertically stacked together. Under sea ice, the top cyclone dissipates in time and often breaks up into several distinct cyclonic vortices. Through heton-type couplings, the breakaway shallow cyclones are often able to tear the underlying anticyclone apart to form distinct anticyclones. Top cyclones are eventually annihilated by ice-exerted friction, leaving submerged anticyclones in stable existence. Fission from a pair of ver...