MULTIPLE COLD BRANCHES AND THERMAL FRONTS IN THE PATAGONIAN SHELF BREAK DERIVED FROM SATELLITE DATA

BÁRBARA CRISTIE FRANCO; ALBERTO RICARDO PIOLA; ANDRÉS LUJÁN RIVAS; ANA BALDONI; JUAN PABLO PISONI

Orlando, Florida, USA

Congreso; 2008 Ocean Sciences Meeting; 2008

American Society of Limnology and Oceanography. American Geophysical Union. Oceanography Society and Estuarine Research Federation.

The Patagonian shelf break region presents high primary production and biologicaldiversity associated with sharp sea surface temperature (SST) gradients. Frontal displacementspresumably impact on the distribution of benthic and pelagic species. Eighteen year(1985-2002) SST data are used to study the intraseasonal variability of the shelf break front(SBF) between 39°-44°S. The cross-shelf break SST gradients reveal distinct, previouslyundocumented thermal fronts located both, offshore and inshore of the SBF. Throughoutthe year the SBF forms a persistent feature located closed to the 200 m isobath, while twodistinct negative gradient maxima are located inshore and offshore of this location. DailySST images reveal the presence of three branches of cold waters whose edges delineatethe above mentioned fronts. The two offshore branches appear to be associated with theMalvinas Current, while a third branch is located ~40 km onshore from the SBF. Ourresults suggest that these distinct flow branches and fronts may play a significant role inthe ecology of a variety of commercial species, further suggesting the use of SST as a toolfor fisheries management.