SOTS: automated moorings for climate and carbon cycle studies in the Southern Ocean

Maintenance of Southern Ocean Time Series (SOTS) automated moorings for long-term monitoring of the Southern Ocean.
Voyage No

IN2016_V02

11 Mar, 2016

to

17 Apr, 2016

Hobart

to

Hobart

Chief Scientist

Prof Tom Trull

Institution

Antarctic Climate and Ecosystems CRC

Voyage summary

Research voyage to the Southern Ocean to maintain the Southern Ocean Time Series (SOTS) automated moorings that collect long-term ocean monitoring data. Of note, this voyage combined three primary projects into a single voyage of RV Investigator.

The main objective of the voyage will be the deployment (SAZ and FluxPulse) and recovery (SOFS, Pulse and SAZ) of SOTS moorings. SOTS uses a set of three automated deep-ocean moorings to measure exchanges of heat, water, carbon dioxide, and oxygen between the ocean and atmosphere at a point where they are most intense and have been least studied. The data collected contributes to forward projections of anthropogenic climate warming, inform the setting of emissions targets, illuminate controls on climate variability, and provide a baseline for impacts on ocean pelagic ecology.

The voyage combined two additional primary projects:

  • CAPRICORN: clouds, aerosols, precipitation, radiation and atmospheric composition over the Southern Ocean (Dr Alain Protat, BOM): This project will collect cloud, aerosol, precipitation, radiation and atmospheric composition measurements over the Southern Ocean over 30 days. Intensive in situ data will also be collected to support satellite and climate model (ACCESS) validation.
  • EDDY: linking eddy physics and biogeochemistry in the Antarctic Circumpolar Current south of Tasmania (A/Prof Peter Strutton, UTAS): This project seeks to understand how eddy circulation impacts elemental cycling in the Southern Ocean.

Voyage impact

As a result of the primary project on this voyage, researchers assembled an integrated view of the seasonality of the processes that control the productivity of the sub-Antarctic food web. This analysis extends from the physics of ocean mixing and insulation, to the chemistry of ocean nutrients and the biological responses of phytoplankton and zooplankton.

Data collected from the CAPRICORN project will be used in improving skill of weather forecast models to simulate frontal cloud systems and research on eddy physics and biogeochemistry will advance our understanding and modelling of Southern Ocean eddies.

Researchers observed the significant impact that eddies have on the atmosphere, achieving the first detailed inter-comparison between the two most common eddy types in the sub-Antarctic.

Of note, bringing together three teams on one voyage was a success, with the vessel capacity and capability allowing significant efficiencies to be created. As a result, with many ideas were exchanged by those on board and opportunities for multi-disciplinary research explored. Many instruments were deployed for the first time on RV Investigator, and the operation of equipment and collection of data performed successfully.