Accession Number:

ADA289104

Title:

Tomographic Observations of Deep Convection and the Thermal Evolution of the Greenland Sea Gyre 1988-1989.

Descriptive Note:

Doctoral thesis,

Corporate Author:

WOODS HOLE OCEANOGRAPHIC INSTITUTION MA

Personal Author(s):

Report Date:

1994-02-01

Pagination or Media Count:

175.0

Abstract:

The Greenland Sea Gyre is studied using results from the 1988-89 Greenland Sea Tomography Experiment. Thermal evolution of the gyre center divides into three periods a preconditioning phase, a deep mixing phase, and a restratification phase. During preconditioning, ice forms and rejects brine into the surface waters, enabling destabilization of the water column. The onset of the deep mixing phase occurs after ice formation in the gyre center stops, resulting in an area of open water where large heat fluxes can occur. In surrounding regions, including the odden region to the south, ice is still being formed, and the mixed layer does not deepen significantly. The effects of advection are deduced from heat and salt budgets, and appear to be important only during the restratification phase for intermediate depths, and only during the summer for the surface waters. Dynamical processes for bringing the Arctic Intermediate Water AIW to the surface in order to form deep water are not needed in this scenario, rather the surface waters are modified until they match the density of the AIW after which surface cooling drives convection.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Snow, Ice and Permafrost
  • Meteorology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE