Daily MOC measurements at 34.5°S in the South Atlantic: Results during 2009-2010 and 2013-2015 using near-boundary moorings and satellite winds

MEINEN, C. S.; SPEICH, S.; PEREZ, R. C.; KERSALE, M.; CHIDICHIMO, M. P.; VALLA, D. ; LE HENAFF, M. ; SATO, O.; THIERRY TERRE; PIOLA, A. R.; CAMPOS, E. J. D.; ANSORGE, I.; GARZOLI, S. L.

Portland

Congreso; Ocean Sciences Meeting 2018; 2018

AGU/ASLO

Daily estimates of the warm upper limb of the Meridional Overturning Circulation (MOC) at 34.5°S in the South Atlantic Ocean will be presented spanning two periods: 2009-2010 and 2013-2015. The MOC estimates are made using geostrophic estimates from moored pressure-equipped inverted echo sounders deployed on the western and eastern continental slopes coupled with satellite-based (CCMP) wind estimates. The peak-to-peak range of MOC values observed is roughly similar to that found in the longer record available at 26.5°N, and both time series exhibit strong sub-seasonal variability. Comparison of the records at the two latitudes finds no direct correlation, which is not perhaps surprising given the limited record lengths. Both time series do show significant interannual variations, however, which must be related via some complex mechanism(s) given the lack of major volume and/or heat storage changes between the two latitudes. Variations in the MOC will be decomposed to illustrate the relative contributions of the Ekman and geostrophic components to MOC variability on different time scales (e.g. sub-seasonal, seasonal, etc.). The MOC results will also be compared to available upper and lower limb MOC estimates from other observing systems.