Freshwater export from the Labrador Current to the North Atlantic Current at the Tail of the Grand Banks of Newfoundland
MetadataShow full item record
KeywordLabrador Current; Subpolar gyre; Freshwater; North Atlantic Current; Boundary current retroflection
Historical hydrographic data, spanning the period 1896-2006, are used to examine the annual mean and seasonal variations in the distribution of freshwater along and across the shelf/slope boundary along the Labrador and Newfoundland Shelves and the Grand Banks of Newfoundland. Particular attention is paid to the export of freshwater along the eastern Grand Banks, between Flemish Cap and the Tail of the Grand Banks, as this has long been identified as a preferential region for the loss of mass and freshwater from the boundary. The data are combined into isopycnally averaged long-term annual and monthly mean gridded property fields and the evolving distribution of fresh arctic-origin water is analyzed in fields of salinity anomaly, expressed as departures from the “central water” temperature-salinity relation of the Gulf Stream. The climatology confirms that cold/fresh northern-source waters are advected offshore within the retroflecting Labrador Current along the full length of the boundary between Flemish Cap and the Tail of the Grand Banks. In fact, it is estimated that most of the equatorward baroclinic transport at the boundary must retroflect back toward the north in order to explain the annual mean distribution of salinity in the climatology. While the retroflection of the Labrador Current appears seasonally robust, the freshwater distribution within the retroflection region varies in response to (1) the freshness of the water available for export which is set by the arrival and rapid flushing of the seasonal freshwater pulse at the boundary, (2) seasonal buoyancy forcing at the surface which alters the vertical stratification across the retroflection region, restricting certain isopycnal export pathways, and (3) the density structure along the eastern Grand Banks, which defines the progressive retroflection of the Labrador Current.
Author Posting. © The Author(s), 2009. 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 Deep Sea Research Part I: Oceanographic Research Papers 57 (2010): 258-283, doi:10.1016/j.dsr.2009.11.006.
Suggested CitationPreprint: Fratantoni, Paula S., McCartney, Michael S., "Freshwater export from the Labrador Current to the North Atlantic Current at the Tail of the Grand Banks of Newfoundland", 2009-11, https://doi.org/10.1016/j.dsr.2009.11.006, https://hdl.handle.net/1912/3222
Showing items related by title, author, creator and subject.
Time series measurements of transient tracers and tracer-derived transport in the Deep Western Boundary Current between the Labrador Sea and the subtropical Atlantic Ocean at Line W Smith, John N.; Smethie, William M.; Yashayaev, Igor; Curry, Ruth G.; Azetsu-Scott, Kumiko (John Wiley & Sons, 2016-11-10)Time series measurements of the nuclear fuel reprocessing tracer 129I and the gas ventilation tracer CFC-11 were undertaken on the AR7W section in the Labrador Sea (1997–2014) and on Line W (2004–2014), located over the ...
Pickart, Robert S.; Spall, Michael A. (American Meteorological Society, 2007-09)The overturning and horizontal circulations of the Labrador Sea are deduced from a composite vertical section across the basin. The data come from the late-spring/early-summer occupations of the World Ocean Circulation ...
Lead isotope data collected from the R/V Pourquoi pas (GEOVIDE) in the North Atlantic, Labrador Sea (section GA01) during 2014 Boyle, Edward A.; Zurbrick, Cheryl (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: email@example.com, 2019-06-06)Lead isotope data collected from the R/V Pourquoi pas (GEOVIDE) in the North Atlantic, Labrador Sea (section GA01) during 2014 For a complete list of measurements, refer to the full dataset description in the supplemental ...