Malvinas-slope water intrusions on the northern Patagonia continental shelf

[摘要] The Patagonia continental shelf located off southeastern South America isbounded offshore by the Malvinas Current, which extends northward fromnorthern Drake Passage (~55° S) to nearly 38° S. Thetransition between relatively warm-fresh shelf waters and SubantarcticWaters from the western boundary current is characterized by a thermohalinefront extending nearly 2500 km. We use satellite derived sea surfacetemperature, and chlorophyll-a data combined with hydrographic and surfacedrifter data to document the intrusions of slope waters onto the continentalshelf near 41° S. These intrusions create vertically coherent localizednegative temperature and positive salinity anomalies extending onshore about150 km from the shelf break. The region is associated with a center ofaction of the first mode of non-seasonal sea surface temperature variabilityand also relatively high chlorophyll-a variability, suggesting that theintrusions are important in promoting the local development ofphytoplankton. The generation of slope water penetrations at this locationmay be triggered by the inshore excursion of the 100 m isobath, whichappears to steer the Malvinas Current waters over the outer shelf.

[学科分类] 海洋学与技术