Sea surface temperature variability of the Labrador Current over the last 2000 years
Résumé
This study presents the first sub-decadal scale sea-surface temperature (SSTs) time-series derived from alkenone paleothermometry, covering the last 2000-year ocean temperature history of the the Labrador Sea region. The records obtained from two sites off Newfoundland document SST variations in a climatically crucial component of the Western North Atlantic circulation system, the southernmost Labrador Current (LC). This boundary current is a major conduit of cold and ice loaded fresh waters originating from the Arctic, which has a major impact on climate in the entire North Atlantic region. Our results demonstrate a clear link between the LC strength and the Northern Annular Mode (NAM), supporting the idea of a more persistent +NAM system and stronger LC during the Medieval Climate Anomaly (MCA). They also suggest enhanced LC activity under future warming with major implications for global thermohaline circulation.