• Western boundary measurements have been collected continuously since March 2009 with an array of pressure-equipped inverted echo sounders (USA-NOAA) along 34.5S that have been supported with ship time and hydrographic (CTD) observations from partners in Argentina (UBA/SHN) and Brazil (USP, Navy).
• In December 2012, this western array was augmented by three additional current-and-pressure-equipped inverted echo sounders (Brazil-USP).
• In December 2013, Brazil (USP) augmented the western array by adding a bottom pressure sensor and a moored ADCP on the western shelf and upper slope.
• France (LPO) deployed eight current-and-pressure-equipped inverted echo sounders and two bottom-moored ADCPs on the eastern boundary in September 2013.
• South Africa (UCT, DEA) deployed an array of short and tall moorings measuring temperature, salinity and velocity on the eastern boundary in September 2014.
• France (LPO)/South Africa (UCT, DEA) deployed seven pressure-equipped inverted echo sounders along oblique Goodhope line in December 2014.
• Trans-basin expendable bathythermograph sections are collected quarterly (USA-NOAA) along 34.5S, with trans-basin conductivity-temperature-depth sections collected less frequently in the region of 25S-34.5S as well (USA-NOAA/NSF, United Kingdom, Brazil).
• A group of North and South American countries operating through the Intra-Americas-Institute for Climate Change Research (IAI) have a large shelf-monitoring program planned for the western boundary that complement well the western end of the trans-basin array (USA-MIT, USA-OSU, Argentina-SHN).
• In 2013, Germany (GEOMAR) deployed a western boundary current array of tall moorings as part of TMA-RACE, and and an eastern boundary current array of CPIES as part of SACUS, along 11S. Trans-basin and boundary transects are conducted on a regular basis.

Other existing global in situ and satellite data sets will provide crucial information for analysis and attribution of the data from the recommended program:

• USA-NOAA/CIMAS has been funded to investigate the meridional variability of the SAMOC using altimetry observations; with a comparison/validation component using Argo, XBT, model-derived estimates.
• Several groups already collect additional hydrographic observations in the region that would be extremely valuable for analysis purposes (Argentina, Brazil, France, Germany, Spain, Russia, South Africa, the United Kingdom, the United States).
• The global observing system, particularly the ARGO float network, the global drifter array, and satellite observations of sea height, sea-surface temperature, sea-surface salinity (SMOS and Aquarius), and surface wind will also be crucial for analysis and attribution of signals observed by the moored system.