IMOS - ABOS Southern Ocean Time Series (SOTS) Sub-Facility

The Southern Ocean Time Series (SOTS) sub-facility provides high temporal resolution observations in sub-Antarctic waters. Observations are broad and include measurements of physical, chemical and biogeochemical parameters from multiple deep-water moorings. The emphasis is on inter-annual variations of upper ocean properties and their influence on exchange with the deep ocean. The time-series provided permit investigation into issues of ocean physics and chemistry, climate change, carbon cycling and biogeochemical controls on marine productivity. These moorings provide cost-effective observations and overcome the infrequent availability of ships in the region.

The SOTS site is located in the sub-Antarctic Zone (SAZ), southwest of Tasmania, near 47S, 142E. SOTS observations are made from 1) a deep ocean sediment trap mooring, used to collect sinking particles to quantify carbon transports. This mooring also provides current meter measurements and a deep ocean CTD to measure heat contents below the depth of ARGO profiling float measurements. 2) the Pulse biogeochemistry mooring, used to measure upper ocean carbon cycle and phytoplankton productivity processes included sensor measurements of dissolved gases (O2, N2) and bio-optical properties. This mooring also collects water samples for measures of dissolved carbon and nutrients, and phytoplankton microscopic identification. 3) additional biogeochemical sensors (CO2, O2, bio-optical, and bio-acoustic devices) mounted on the nearby Southern Ocean Flux Station air-sea flux mooring (and managed by the Air-Sea Flux Stations sub-facility).