Changes of Florida Current Temperature and Salinity Transport and Impact on North Atlantic Circulation

Hydrographic and velocity measurements in the Straits of Florida since the 1980s show long-period shifts and variability of water masses and of temperature and salt transport. From the mid 1980s to 2000-2014, temperature and salinity show warming and salinification on all density surfaces below the surface layer, with the most distinct changes in mid-depth water on the eastern side of the strait that originates in the subtropical North Atlantic. These property changes translate into increased temperature and salt transports over this period, with larger but more variable changes in the center of the Florida Current. Although all regions across the strait have large variability in 5-year averages, the variability is lowest for water originating in the subtropical North Atlantic. Waters with a fresh South Atlantic signature have also become saltier, opposite from their observed freshening at their source. These patterns suggest that temperature and salt transport by the Florida Current are dominated by atmospheric forcing in the subtropical North Atlantic over this period.