The Beaufort Gyre’s Diffusive Staircase: Finescale Signatures of Gyre‐Scale Transport

Abstract

AbstractArctic Ocean waters sourced from the Atlantic contain a vast amount of heat. In the Arctic’s Beaufort Gyre, diffusive convection is the primary mechanism by which this heat is transported vertically. This mixing process is characterized by a “staircase” where convective layers are separated by interfaces in temperature and salinity. It is not well‐understood what governs layer thickness, which is an important parameter in heat transport. Here we relate staircase properties to the background water‐mass structure of the Beaufort Gyre via analysis of Ice‐Tethered Profiler observations. We find that staircase layer thicknesses vary with intrusive features below the staircase and the stratification overlying the staircase. We relate these features to the pathway of anomalously warm Atlantic Water in the Beaufort Gyre. Results suggest that intrusive features in context with the Gyre’s large‐scale geostrophic flow may be key to understanding layer thicknesses and the propagation of warm waters into the Gyre.