Freshening of the Labrador Sea surface waters in the 1990s: Another great salinity anomaly?

Abstract

The observed Labrador Sea surface salinities for 1951–2001 in region [55W–40W, 45N–55N] show freshening in the 1990s which may rival the Great Salinity Anomaly (GSA) of the 1970s [Dickson et al., 1988]. The 1990s freshening is distinct in the lowest range of salinity values associated with the coastal waters. The variability of the highest salinity values, provided by the North Atlantic Current entering the Labrador Sea, shows that the high salinity Atlantic waters were not widely present in the 1970's and 1990s. This can be interpreted as weakened transport of saline waters to the area. This explanation is consistent with an Arctic‐North Atlantic model results forced by NCEP/NCAR Reanalysis data (for 1958–2001) which suggest that these periods are associated with a reduced meridional overturning. The model also associates the coastal freshening with southward current anomalies which are well correlated with the number of icebergs crossing 48N.