Meridional Overturning Circulation

South Atlantic Meridional Overturning Circulation

Assessment of the Meridional Overturning Circulation and Meridional Heat Transport and their Meridional Variability in the South Atlantic Ocean

PIs: Gustavo Goni and Shenfu Dong

This is a new project that proposes to make use of the 20-year of continuous altimetry measurements combined with sea surface temperature (SST) satellite-derived and in situ data to estimate the MOC and MHT in the South Atlantic and to investigate their latitudinal and temporal changes in the South Atlantic. To accomplish these proposed goals, this work will include several well-defined components

  • Estimation of the temporal evolution of the MOC/MHT at every 5o of latitude from 20oS to 40oS since 1993;
  • Assessment of the error of the above estimates through comparisons with XBT-derived estimates at 35oS and with CLIVAR A10 section estimates at 30oS;
  • Assessment of the individual contributions of the geostrophic and Ekman components to the MOC/MHT at different latitudes;
  • Investigation of year-to-year and inter-annual variability of the MOC/MHT and of their components (e.g., Ekman/geostrophic, gyre/overturning, boundary currents/interior, eddies/large-scale flow) and investigate potential links with wind forcing;
  • Development of South Atlantic 20-year proxies against which the performance of ocean general circulation models (e.g. HYCOM) and coupled climate models (e.g. CCSM4 and GFDL CM 2.1 and 2.4) can be evaluated;

Figure - Preliminary altimetry estimates of Meridional Heat Transport in the South Atlantic Ocean at 35oS.