Seasonal Cycle of the Coastal West Greenland Current System Between Cape Farewell and Cape Desolation From a Very High‐Resolution Numerical Model

Abstract

AbstractThe shelf based West Greenland Current System carries both Arctic Water and Greenland meltwater around Cape Farewell, the southern tip of Greenland, where it may impact the deep water formation in the Labrador Sea. Nevertheless, this current system remains largely unknown due to limited observations. Using a very high‐resolution (1°/60°) numerical simulation integrated from 2005 to 2014, the annual cycle of the current structure in the vicinity of southern Greenland is analyzed to present the seasonal variability of the West Greenland Current System. A distinct shelf break West Greenland Coastal Current (WGCC) exists for about half the year between Cape Farewell and Cape Desolation, although it merges with the main jet of the West Greenland Current (WGC) in winter and separates in summer. The WGC has three components at Juliannehaab Bight: A shelf component, a shelf‐break component and a main slope jet. The shelf system is most energetic in fall, when the freshwater transport is also the greatest in a range of 25–40 mSv, with a broad transport minimum in spring in a range of 15–25 mSv. The seasonal cycle is strongest near Cape Farewell and weakest at Cape Desolation. The strength of the shelf system decreases as one moves north as water is lost offshore, with strongest transports of 0.61 Sv to the east of Cape Farewell and weakest of 0.41 Sv at Cape Desolation. This decrease in transport between Cape Farewell and Cape Desolation suggests substantial exchange between WGCC and WGC in this region.