Atlantic water variability on the SE Greenland continental shelf and its relationship to SST and bathymetry

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Sutherland, David A., Straneo, Fiamma, Stenson, Garry B., Davidson, Fraser J. M., Hammill, Mike O., Rosing-Asvid, Aqqalu
• Format: Article in Journal/Newspaper
• Language: English
• Published: John Wiley & Sons 2013
• Subjects: East Greenland Current; Irminger Current; Bathymetry; SST; Ice-ocean interactions; Marine mammal tagging; Arctic; Canada; Greenland; East Greenland; east greenland current; Greenland Institute of Natural Resources
• Online Access: https://hdl.handle.net/1912/5926

Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 118 (2013): 847–855, doi:10.1029/2012JC008354. Interaction of warm, Atlantic-origin water (AW) and colder, polar origin water (PW) advecting southward in the East Greenland Current (EGC) influences the heat content of water entering Greenland's outlet glacial fjords. Here we use depth and temperature data derived from deep-diving seals to map out water mass variability across the continental shelf and to augment existing bathymetric products. We compare depths derived from the seal dives with the IBCAO Version 3 bathymetric database over the shelf and find differences up to 300 m near several large submarine canyons. In the vertical temperature structure, we find two dominant modes: a cold mode, with the typical AW/PW layering observed in the EGC, and a warm mode, where AW is present throughout the water column. The prevalence of these modes varies seasonally and spatially across the continental shelf, implying distinct AW pathways. In addition, we find that satellite sea surface temperatures (SST) correlate significantly with temperatures in the upper 50 m (R = 0.54), but this correlation decreases with depth (R = 0.22 at 200 m), and becomes insignificant below 250 m. Thus, care must be taken in using SST as a proxy for heat content, as AW mainly resides in these deeper layers. Funding for this work came from National Science Foundation OPP grant 0909373 and OCE grant 1130008, plus the WHOI Arctic Research Initiative. The Greenland Institute of Natural Resources and the Department of Fisheries and Oceans, Canada, supported the seal tagging logistics. 2013-08-20