Structure and variability of the West Greenland Current in Summer derived from 6 repeat standard sections

Six historical sections across the West Greenland Current are examined. Three sections have been regularly occupied since the late 1950s, while the three southern ones have been taken since 1984. Significant variability is observed for the freshwater core of the coastal current on the shelf, with salinity varying by over 3 units between years. There is also significant variability in the shape and offshore position of the main shelf break front, leading to large variability in Eulerian velocities. Significant presence of Irminger Water is seen during the 1960s and the 2000s, being found right across the sections in recent years. Maximum mean transport relative to the 34.8 isohaline of 5.5±3.9Sv, relative to 700 db, for 1984–2005, is observed at the Cape Desolation section. Transports decrease to the north, with the majority of the exchange with the interior of the Labrador Sea occurring between Cape Desolation and Fylla Bank. Inter-decadal transport variability is observed at Fylla Bank while a decline in transports since peaks in the early 1990s is seen at Cape Farewell and Cape Desolation. Freshwater transport is largest at Cape Desolation, with a mean Summer transport of 60.2±20.5mSv. Freshwater transport increases slightly between Cape Farewell and Cape Desolation and we suggest it is related to local discharge by glaciers into Juliannehaab Bight, as well as the melting of sea-ice. We also find that years of high Greenland ice cap melt are consistently associated with years of high freshwater transport at Cape Desolation, suggesting a portion of the freshwater transport of the West Greenland Current may be associated with melt from the Greenland ice sheet. Finally, significantly enhanced freshwater transports (33 mSv at Cape Desolation compared to the long term mean) are seen in 2008, probably a signature of the record Arctic Ocean ice melt and export in 2007.