Deep Western Boundary Current measurements at 34.5°S in the South Atlantic: Observed variability and structure during 2009-2014

MEINEN, C. S.; CAMPOS, E. J. D.; GARZOLI, S. L.; PIOLA, A. R.; CHIDICHIMO, M. P.; PEREZ, R. C.; DONG, S.

Praga

Simposio; 26th International Union of Geodesy and Geophysics (IUGG) General Assembly; 2015

International Union of Geodesy and Geophysics (IUGG)

The Deep Western Boundary Current (DWBC) at 34.5°S in the South Atlantic has been observed continuously for just over five years from 2009 to 2014 using a line of four pressure-equipped inverted echo sounders (PIES). The array was further augmented in late 2012 with an additional two current-and-pressure-equipped inverted echo sounders (CPIES). The data from these PIES and CPIES instruments can, when combined with hydrographic information from the region, provide daily estimates of the full-water-column profiles of temperature, salinity, density and the meridional component of the absolute geostrophic velocity. Variations in the DWBC, which carries a significant fraction of the cold deep limb of the Meridional Overturning Circulation, have previously been shown (using data from 2009-2010) to equal or exceed those found in a longer-term observing array at 26.5°N in the North Atlantic. This presentation will include an additional three years of data at 34.5°S to evaluate the magnitude and time scales of the observed DWBC variations to do a more complete comparison with other latitudes. The CPIES instruments deployed in 2012 also greatly improved the horizontal resolution of the overall array, and as such new insights on the horizontal structure of the DWBC will also be presented.