Volume and freshwater transports through the Canadian Arctic Archipelago–Baffin Bay system

Abstract

[1] Baffin Bay connects the Arctic Ocean and the Labrador Sea. It receives Polar water through the Canadian Arctic Archipelago and by the West Greenland Current. The Polar water is, after transformation, exported through Davis Strait. With control sections both upstream and downstream Baffin Bay invites the use of an idealized geostrophic approach to estimate transports. The baroclinic transports, driven by the density differences between the Arctic Ocean and Baffin Bay, are first determined. The density and upper layer depth are assumed the same in Lancaster Sound, Nares Strait and the West Greenland Current. Once the baroclinic transports are estimated the sea level difference between the Arctic Ocean and Baffin Bay is computed. Next the upper layer depth in Nares Strait and the West Greenland Current is reduced, while the sea level difference is kept constant. This allows for deep inflows through Nares Strait and the West Greenland Current. To establish a deep outflow through Davis Strait a "barotropic" sea level slope between the Arctic Ocean and the Labrador Sea is estimated from two "ideal" water columns. The transports are computed for different salinities in the Polar water and the salinity giving mass balance in the deeper layers is determined. The effects of possible increased melting of the Greenland icecap are examined. If the meltwater is added directly to Baffin Bay the effects are small, but if it is incorporated in the East and West Greenland Current a significant reduction of the outflow through the Archipelago might occur.

Volume and temperature transports through the main Arctic Gateways: A comparative study between an ocean reanalysis and mooring-derived data

“…Bay (area = 689 000 km²). This estimate is in good agreement with the 28 -38 W/m² (depending on salinity) presented by Rudels (2011), although it is discussed there that this heat loss appears rather small for such high latitudes. We check the influence of the spatial coverage of C-GLORSv7 data on the transport estimates by choosing only one reanalysis transport point for each observational point (i.e.…”

Arctic Ocean circulation and variability – advection and external forcing encounter constraints and local processes

“…The situation in the Baffin Bay and Canadian Arctic Archipelago is more complicated since there are two, actually three, control sections, two in the Archipelago and one in Davis Strait. This fact can be used to better determine the transports of volume and freshwater west of Greenland (Rudels, 1986a(Rudels, , 2011.…”

“…The freshwater transport due to a low salinity outflow forced by an imposed sea level difference between the Arctic Ocean and the North Atlantic is not taken into account. An attempt to introduce an additional "barotropic" sea level correction for the Canadian Arctic Archipelago -Baffin Bay system was made by Rudels (2011), who arrived at an additional freshwater export of 0.042 Sv and an increase of the volume transport by 0.8 Sv in the upper layer.…”

Warming of the Polar Water Layer in Disko Bay and Potential Impact on Jakobshavn Isbrae

“…This Arctic-origin polar water has a low temperature (;21.68C; Rudels 2011), extends to depths of 200-300 m, and is overlaid by a thin (25-50 m deep) warmer and fresher summer layer (Fissel et al 1982;Rudels 1986). The Baffin Island Current flows south along the east coast of Baffin Island, with the core of the current steadily following the continental slope, although some meanders occur offshore near the base of the slope (Fissel et al 1982).…”

“…Cold polar water is carried south in the Baffin Island Current, formed by mixing and sinking in the North Water polynya region of northern Baffin Bay, and mixed with Arctic water flowing out of Lancaster Sound (Lobb et al 2003;Rudels 2011). This Arctic-origin polar water has a low temperature (;21.68C; Rudels 2011), extends to depths of 200-300 m, and is overlaid by a thin (25-50 m deep) warmer and fresher summer layer (Fissel et al 1982;Rudels 1986).…”