The East Greenland Coastal Current : structure, variability, and forcing

This work was funded by the National Science Foundation grant OCE-0450658. DS was also partially supported by the Woods Hole Oceanographic Institution Academic Programs Office.

The subtidal circulation of the southeast Greenland shelf is described using a setof high-resolution hydrographic and velocity transects occupied in summer 2004. Themain feature is the East Greenland Coastal Current (EGCC), a low-salinity, high-velocityjet with a wedge-shaped hydrographic structure characteristic of other surface buoyancydrivencurrents. The EGCC was observed along the entire Greenland shelf south ofDenmark Strait, while the transect north of the strait showed only a weak shelf flow. Thisobservation, in conjunction with water mass considerations and other supportingevidence, suggests that the EGCC is an inner branch of the East Greenland Current(EGC) that forms south of Denmark Strait. It is argued that bathymetric steering is themost likely reason why the EGC apparently bifurcates at this location. Repeat sectionsoccupied at Cape Farewell between 1997 and 2004 show that the alongshelf wind stresscan have a strong influence on the structure and strength of the EGCC and EGC ontimescales of 2-3 days. Accounting for the wind-induced effects, the volume transport ofthe combined EGCC/EGC system is roughly constant (~2 Sv) over the study domain,from 68°N to Cape Farewell near 60°N. The corresponding freshwater transport increasesby roughly 60% over this distance (59 to 96 mSv, referenced to a salinity of 34.8). Thistrend is consistent with a simple freshwater budget of the EGCC/EGC system thataccounts for meltwater runoff, melting sea-ice and icebergs, and net precipitation minusevaporation.

Author Posting. © Elsevier B.V. , 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Progress In Oceanography 78 (2008): 58-77, doi:10.1016/j.pocean.2007.09.006.