Recent changes in the Greenland–Scotland overflow‐derived water transport inferred from hydrographic observations in the southern Irminger Sea

Abstract

Recent decadal changes (1955–2007) in the baroclinic transport (TBC) of the Deep Western Boundary Current (DWBC) carrying the Greenland–Scotland overflow‐derived waters along the East Greenland slope are quantified from a set of hydrographic sections in vicinity of Cape Farewell. The updated historical record of TBC shows clear decadal variability (±2–2.5 Sv) with the transport minima in the 1950s and mid‐1990s, maximum in the early 1980s and moderate‐to‐high transport in the 2000s. Since the mid‐1990s, the DWBC TBC has increased by ∼2 Sv (significant at the 99.9% level), which constitute ∼20% of the mean absolute transport (9.0 Sv) as obtained from three cruises in 2002–2006. The DWBC TBC anomalies negatively correlate (R = –0.80) with thickness anomalies of the Labrador Sea Water (LSW) at its origin implying a close association, albeit not necessarily causative, between the DWBC transport east of Greenland and the LSW production.