Open AccessComposition and fluxes of freshwater through Davis Strait using multiple chemical tracers
Author(s) -
AzetsuScott Kumiko,
Petrie Brian,
Yeats Philip,
Lee Craig
Publication year - 2012
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2012jc008172
Subject(s) - meltwater , oceanography , geology , sea ice , arctic ice pack , arctic , hydrography , meteoric water , outflow , melt pond , water mass , glacier , antarctic sea ice , geomorphology , groundwater , geotechnical engineering
Freshwater transport through Davis Strait can supply additional buoyancy to the deep convection region of the Labrador Sea which influences the strength of the meridional overturning circulation and consequently the global climate. The freshwater contribution from local sea ice meltwater, meteoric water (fluvial, glaciofluvial and precipitation) and the Arctic outflow were quantified using oxygen isotope composition ( δ 18 O), salinity and nutrient relationships in September–October, 2004. Freshwater transported by the Arctic outflow was isolated using a modified nutrient relationship method and further deconvoluted into sea ice meltwater, meteoric water and Pacific water. For the first time, fluxes of individual freshwater components were estimated using observations of the velocity field derived from mooring arrays and geostrophic currents from hydrography. The Arctic outflow dominated in western Davis Strait (>60%) and its influence extended eastward close to the Greenland Slope. The sea ice meltwater fraction was small (<2%) and limited to the surface layer of the central and western Strait. The meteoric water fraction was highest on the Greenland Shelf (>6%) and attributed to glacial meltwater. The freshwater inventory of the 0–100 m layer was equivalent to 7.4 m in western Davis Strait: 8 m from the Arctic outflow and −0.6 m from brine rejection. In eastern Davis Strait, the freshwater inventory was 4 m: 3 m from meteoric water and 1 m from sea ice meltwater. The Arctic outflow contributed 82–99 mSv to the southward freshwater transport about 67–81% of the total; glacial meltwater contributed the largest northward transport of 10–30 mSv.