Horizontal density structure and restratification of the Arctic Ocean surface layer

• Main Authors: Timmermans, Mary-Louise, Cole, Sylvia T, Toole, John M
• Format: Journal Article
• Language: English
• Published: American Meteorological Society 01.04.2012
• Subjects: Arctic; Ocean dynamics

Ice-tethered profiler (ITP) measurements from the Arctic Ocean’s Canada Basin indicate an ocean surface layer beneath sea ice with significant horizontal density structure on scales of hundreds of kilometers to the order 1 km submesoscale. The observed horizontal gradients in density are dynamically important in that they are associated with restratification of the surface ocean when dense water flows under light water. Such restratification is prevalent in wintertime and competes with convective mixing upon buoyancy forcing (e.g., ice growth and brine rejection) and shear-driven mixing when the ice moves relative to the ocean. Frontal structure and estimates of the balanced Richardson number point to the likelihood of dynamical restratification by isopycnal tilt and submesoscale baroclinic instability. Based on the evidence here, it is likely that submesoscale processes play an important role in setting surface-layer properties and lateral density variability in the Arctic Ocean. Funding was provided by the NationalScience Foundation Office of Polar ProgramsArctic Sciences Section under Awards ARC-0519899,ARC-0856479, and ARC-0806306. Support was alsoprovided by the Woods Hole Oceanographic InstitutionArctic Research Initiative. Author Posting. © American Meteorological Society, 2012. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 42 (2012): 659–668, doi:10.1175/JPO-D-11-0125.1.