SOLACE voyage

Voyage summary

Research voyage out of Hobart to the Southern Ocean to study and quantify carbon sequestration in subpolar and polar waters. This research is part of the SOLACE (Southern Ocean Large Area Carbon Export ) project and seeks to capture a detailed picture of how plant life in the Southern Ocean helps remove carbon dioxide from the Earth’s atmosphere.

The voyage will combine ship-board observations, deep-diving robotic profiling floats, automated ocean gliders and satellite measurements to improve understanding of the movement of carbon between the atmosphere and ocean via biological pathways. A program of trawling will also be used to survey marine life in the twilight zone (ocean between 200m to 1000m depths). The twilight zone contains the largest and least exploited fish stocks of the world’s oceans.

Ship-board measurements will be taken at two primary sites: 1) SOTS (Southern Ocean Time Series ) site, and 2) location of a polar bloom (high chlorophyll feature) at approximately 55˚S.

The voyage also includes the following research projects:

• Cosmic ray measurements from underway instrument (Dr Grahame Rosolen, CSIRO)
• Cloud Aerosol Precipitation Radiation Interactions eXperiment - CAPRIX (Dr Alain Protat, BOM)

The science team on this voyage includes 32 participants from four institutions: CSIRO, University of Tasmania, Australian National University (ANU) and Curtin University.

This will be the second time the vessel has been at sea over Christmas.

Voyage outcomes

The SOLACE voyage has provided the first accurate baseline for an important natural carbon sink in the subpolar and polar Southern Ocean. Shipboard estimates will be extrapolated over a larger region using an integrated suite of additional measurements – satellite remote sensing, ocean glider surveys and profiling robotic floats with multiple sensors – to provide a 4D view of this carbon sink.

The SOLACE voyage integrated detailed ecological measurements using sophisticated camera systems and midwater trawls to provide new insights into how water mass properties set the ecology of the Twilight Zone that underlies the sunlit part of the ocean. The SOLACE voyage will provide an inventory of the fauna of the Twilight Zone in different water masses, along with their biomass. These ecological measurements will be linked with biogeochemical observations to better understand the interplay of food webs and the elemental cycles of carbon, nitrogen and phosphorus.

The datasets collected on SOLACE will provide a Southern Hemisphere/Southern Ocean contribution to a new international program called JETZON - Joint Exploration of the Twilight Zone Ocean Network (jetzon.org ). This will link our regional findings with on Northern Hemisphere analogues, and using data synthesis and modelling we can jointly produce more accurate global maps of this natural carbon sink that will be taken up by the IPCC and other end users.