BRANCHING OF ATLANTIC WATER WITHIN THE GREENLAND-SPITSBERGEN PASSAGE - AN ESTIMATE OF RECIRCULATION

Atlantic Water (AW) supplies the largest source of hear, mass, and salt to the Arctic Ocean via Fram Strait (Greenland-Spitsbergen Passage), yet it represents only a fraction of the Atlantic Water that resides in the Greenland, Iceland, Norwegian, and Parents Seas. This is a result of both the branching of the central core of AW along its northward flow and the modification of its TS signature through air-sea-ice interactions and internal mixing. This paper addresses the quantitative analysis of the three dominant Atlantic Water cores within Fram Strait and north of 76 degrees N using an ll-year(1977 to 1987) hydrographic database. Spatial variations of heat, volume, and salt along its how path of some 600 ion showed mat the major core of Atlantic Water that directly enters the Arctic Ocean (Svalbard branch) did not extend past 20 degrees E. Of the 9719 km(3) of Atlantic Water existing within the region, one third resided within the Svalbard branch; the remainder, 22% and 45%, were held within the Return Atlantic Current and the Yermak branches, respectively Restricting the analysis to a southern limit of 79 degrees N effectively removed the Return Atlantic Current and showed a nearly equal split between the two remaining branches. Work completed by Bourke et al. (1988) indicated that the Yermak branch is largely recirculated to the south; if true, this analysis supports Rudels' (1987) model estimate of a 50% recirculation of AW within this region.