The Changing Behavior of the West Greenland Current System in a Very High‐Resolution Model

Abstract

AbstractAnalyzing a high‐resolution (1/60°) numerical model over 2008–2018, the inter‐annual variability of the West Greenland Coastal Current (WGCC) on the shelf and West Greenland Current (WGC) at the shelf break is presented. Both currents flow from Cape Farewell and extend to Davis Strait, with their speeds and transports corresponding well with observations. The trend over the study period of the WGCC and WGC strength near southwest Greenland are opposite, with the former declining while the latter strengthened, both by a speed change above 0.1 m/s. Both currents are predominantly buoyancy forced, but wind forcing becomes more dominant approaching Davis Strait. The main exchanges from the two currents with the interior of the Labrador Sea occur between Cape Desolation and Fylla Bank. The net volume, freshwater, heat transport decreases between these two sections are 1.4 Sv, 13 mSv, 36.7 TW, respectively. The freshwater transport of the WGC itself does not drop in between these sections, receiving freshwater from the WGCC to compensate for the losses to the basin interior. Thus, we see significant freshwater (83.1 mSv) and heat transports (70.7 TW) of the WGC remaining at Fylla Bank that reach the northern basin instead of being fluxed into the interior of the Labrador Sea. This suggests that the exchange between the boundary current system and the interior is more limited than previously thought, and most of the Greenland and Arctic melt reaches the northern Labrador Sea. Our results highlight the importance of resolving the WGCC and shelf processes.