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

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

IN2020_V09

27 Aug, 2020

to

12 Sep, 2020

Hobart

to

Hobart

Chief Scientist

Dr Elizabeth Shadwick

Institution

CSIRO

Voyage summary

Research voyage to maintain long-term deep-water automated moorings for monitoring of the Southern Ocean. This is the first research voyage since the MNF research schedule was suspended in March 2020 due to the COVID-19 pandemic.

This voyage will contribute to global data sets and increase understanding of Southern Ocean characteristics, variability and processes. The Southern Ocean Time Series (SOTS) moorings provide year-long observations in a critical part of the Southern Ocean, where ocean interactions are most intense and least studied. This is information vital for informing ocean and climate monitoring.

As a result of impacts on the research schedule from the COVID-19 pandemic, this voyage will combine into a single voyage two research projects originally scheduled for separate voyages:

  • Southern Ocean Time Series (SOTS) maintenance (Dr Elizabeth Shadwick, CSIRO): Deploy two new SOTS moorings (SOFS-9 and SAZ-22) and recover two existing ones (SOFS-8 and SAZ-21). These automated deep-water moorings measure the exchanges of heat, water, carbon dioxide and oxygen between the ocean and atmosphere, and the physical and biological processes that control them.
  • Oceanographic mooring recovery (Dr Steve Rintoul, CSIRO): Recover an oceanographic mooring deployed during voyage IN2018_V05 to investigate Antarctic Circumpolar Current. This mooring has collected data to improve understanding of how Southern Ocean currents respond to changes in wind speed.

SOTS is part of the Integrated Marine Observing System (IMOS) , a global monitoring program to collect long time-series ocean data to better understand ocean and climate change and variability.

Three EM-APEX floats will be deployed during the voyage. EM-APEX floats measure the temperature, salinity and horizontal current velocity in the upper 500 metres of the ocean. Three Argo floats will also be deployed during the voyage, contributing to the global Argo network.

The science team on this voyage will have 13 participants (and 20 crew). This is the minimum science team required to achieve voyage research objectives. Participants are from CSIRO only and all are Tasmanian-based (due to current travel restrictions from COVID-19).

COVID-19 Protocols

This voyage is proceeding following a successful 8-day sea trials voyage on RV Investigator in early August where a range of COVID-19 protocols were implemented and assessed. To safeguard the health and well-being of participants, ten COVID-19 protocols will apply to all activities on this voyage, including testing of all participants for COVID-19 prior to departure.

For further information about the MNF COVID-19 Protocols, visit Restart of at-sea operations following COVID-19 shutdown

Voyage outcomes

The SOTS research improves understanding of the global climate system by focussing on a key region – the Southern Ocean. Careful sustained observations over the last decade and into the next increases our knowledge of how the ocean interacts with the atmosphere. Improved understanding is essential to enhance advice to the nation on climate variability affecting us now, develop future scenarios and impact assessments, and to make optimal decisions that will affect the nation’s future.

The work also directly addresses the issue of how ocean biogeochemistry and productivity respond to ocean dynamics, which is an important input to projecting future biogeochemical and ecosystem states. In addition, enhanced understanding of process occurring in the region related to clouds, ocean mixing, waves and rain will also lead to improved forecasts and warnings issued to the public.

As a result of this voyage, we have re-deployed the Southern Ocean Time Series moored platforms to provide an integrated and ongoing assessment of the seasonality of the processes that control air-sea exchanges important to climate, and upper ocean processes important to sub-antarctic productivity. This analysis extends from the physics of ocean mixing and insolation, to the chemistry of ocean nutrients and the biological responses of phytoplankton, zooplankton and fish. Many of the observations are available in real-time via the internet (www.imos.org.au ).

This work is part of the OceanSITES global array of time series observations (www.OceanSITES.org ) which is a network within the United Nations mandated Global Ocean Observing System (www.goosocean.org ).