Double-diffusive layering in the Eurasian Basin of the Arctic Ocean

The central basins of the Arctic Ocean, below the surface mixed layer and remote from peripheral boundary currents, comprise an extremely low energy oceanic environment. Water masses having distinctly different Θ–S characteristics are organised throughout the central basins in extensive layers, consistent with occurrence of double-diffusive convection. In the Eurasian Basin, these structures can be explained by invoking formation along the narrow frontal region associated with the confluence of Fram Strait and Barents Sea waters north of the Kara Sea, and subsequent advection by the main circulation field. The presence of features in the interior of the basins requires a combination of processes that could include self-induced migration, through double-diffusive convection, as well as advection, across the central regions having weak horizontal gradients in temperature and salinity.