TRANSPORT, POTENTIAL VORTICITY, AND CURRENT TEMPERATURE STRUCTURE ACROSS NORTHWEST PROVIDENCE AND SANTAREN CHANNELS AND THE FLORIDA CURRENTOFF CAY-SAL BANK

Currents and temperatures were measured using Pegasus current profiler s across Northwest Providence and Santaren Channels and across the Flo rida Current off Cay Sal Bank during four cruises from November 1990 t o September 1991. On average, Northwest Providence (1.2 Sv) and Santar en (1.8 Sv) contribute about 3 Sv to the total Florida Current transpo rt farther north (e.g., 27 degrees N). Partitioning of transport into temperature layers shows that about one-half of this transport is of ' '18 degrees C'' water (17 degrees C-19.5 degrees C); this can account for all of the ''excess'' 18 degrees C water observed in previous expe riments. This excess is thought to be injected into the 18 degrees C l ayer in its region of formation in the northwestern North Atlantic Oce an. Due to its large thickness, potential vorticities in this layer in its area of formation are very low. In our data, lowest potential vor ticities in this layer are found on the northern end of Northwest Prov idence Channel and are comparable to those observed on the eastern sid e of the Florida Current at 27 degrees N. On average a low-potential-v orticity 18 degrees C layer was not found in the Florida Current off C ay Sal Bank.