ZONATION OF NEAR-SURFACE DRAKE PASSAGE WATERS BASED ON DISCRIMINANT ANALYSIS OF ENVIRONMENTAL DATA

PAPARAZZO, F.E.; SCHLOSS, I.R.; ALDER, V.A.; ESTEVES, J.L.

Buenos Aires, Argentina.

Conferencia; SCAR XXXI & Open Science Conference; 2010

SCAR-DNA-IAA

The objective of the present work was to study the near-surface expression of the different limits and zones previously defined for the Drake Passage. A pool of 382 near-surface samples obtained during four summer-fall cruises (2001-2004) of the joint Argentinean-French “Argau” project on board the “Almirante Irizar” in the Drake Passage was analyzed. Nitrate, phosphate, silicate, temperature, salinity and chlorophyll-a data were considered in a Multivariate Discriminant Function Analysis (MDFA) to construct the discriminant matrix, and a random sample of 25% of these data was used to verify the model. The main near-surface detectable limits were the slope of the South American continental shelf (3,000 m isobath), the Polar Front and the Southern Antarctic Circumpolar Current Front. Variability was further interpreted upon dividing data into summer and fall. In summer, the MDFA showed a 90.6% of concordance between expected/observed zones (Wilks' Lambda: 0.08; p