Long Term Observation of Upper Ocean Fluxes and Pycnocline Diffusivity the Canada Basin
Abstract
Last century, the ice pack of the Canada Basin had a large component of multi-year ice, and the areal extent of summer melting was relatively limited. Consequences of the limited open water were a weak internal wave field and correspondingly weak interior turbulence levels conditions well observed by the 1997-1998 Surface Heat Budget of the Arctic (SHEBA) field program. During the last 15 years, summer melt-back in the Beaufort Sea has freshened the ocean surface layer, strengthening the seasonal pycnocline, which, in turn, tends to inhibit vertical turbulent transport between the surface layer and underlying layers. However large areas of open water allow energetic, near-inertial waves to develop enhancing energy input to the ocean, increasing turbulent diffusivity of the pycnocline, and promoting vertical turbulent transport. It remains an open question as to how these two competing effects affect vertical transport and exchange in the Arctic ocean. The primary goal of this research is to make longterm (spanning multiple seasons and geographic areas) and concurrent measurements of near surface heat, salt and momentum fluxes, and pycnocline fluxes and internal wave and turbulence fields in the pycnocline of the Chukchi and Beaufort Seas to map out the spatial/temporal variability of these fields in relation to the ice cover conditions and proximity to bathymetric features. To meet these goals Autonomous Ocean Flux Buoys are being modified to extend their measurements of heat, salt and momentum turbulent fluxes just below the ocean/ice interface to include observations of pycnocline diffusivity over a 6m layer well within the seasonal pycnocline, 50m below the ice floe supporting the buoy. These buoy systems will be deployed in the fall of 2020 and 2021 on ice floes in the Beaufort Sea next to WHOI Ice Tethered Profilers to identify and model processes controlling the widespread ice melt in the Canada Basin.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 20, 2020
- Source ID
- N000142012633
Entities
People
- Timothy Stanton
Organizations
- Office of Naval Research
- San José State University
- United States Navy