CSIRO research vessel Investigator has embarked on its longest voyage ever: a 60-day trip to the Southern Ocean.

The ship departed from Hobart on 5 January, on a 9260 kilometre round trip to the edge of the Antarctic ice and back up to Fremantle in early March.

Science teams on board are led by the Australian Antarctic Program Partnership (AAPP) and national science agency CSIRO.

The goal of the voyage is to improve ability to anticipate the impacts of future climate change.

The voyage, known as MISO (Multidisciplinary Investigations of the Southern Ocean), will explore how links between physics, biogeochemistry, plankton, aerosols and clouds influence the Earth’s climate.

CSIRO and AAPP co-chief scientist Steve Rintoul said the Southern Ocean takes up vast amounts of heat and carbon dioxide and has a profound influence on climate patterns in Australia and the rest of the world.

“To anticipate how climate and sea level will change in the future, we need to understand how the Southern Ocean works and how sensitive it is to change,” Dr Rintoul said.

“What’s amazing about the Southern Ocean is that everything is interconnected – we can’t hope to understand how the region influences climate unless we measure each piece and how it fits with the other parts of the system.”

Co-chief Scientist Annie Foppert from the AAPP at the University of Tasmania said the meltwater from the Antarctic ice sheet is reducing the amount of dense water sinking to the deep ocean around Antarctica, slowing ocean currents that control climate.

“Data collected on the MISO voyage will be compared to earlier measurements to track how the Southern Ocean is changing and what it means for climate and sea level rise,” Dr Foppert said.

“To track these changes in the deep ocean, we will deploy a dozen deep-diving robots. 

“These new floats, able to collect measurements down to six kilometres below the sea surface, will allow us to track how the ocean is changing for the next five years by profiling the full depth of the ocean.

“Observing the deep ocean so regularly and over such large swaths was impossible before this new technology.”

Scientists onboard RV Investigator from the University of Tasmania and the Bureau of Meteorology will also study gases and particles released by tiny marine organisms called phytoplankton, grown in special aquariums mounted on the ship’s deck. 

Gases and particles (or aerosols) released by the phytoplankton will be analysed to see how effectively they act as “seeds” for new clouds.

Dr Marc Mallet from the University of Tasmania said understanding cloud formation in the southern hemisphere was a blind spot for climate science and model projections.

“This voyage will test the hypothesis that aerosols released by phytoplankton seed clouds and explain the unique properties of the Southern Ocean atmosphere,” Dr Mallet said.  

“Improved understanding of cloud formation in the region will provide the foundation for more skilful weather and climate projections for Australia and the rest of the globe.”

The AAPP is a 10-year partnership program established in 2019, led by the University of Tasmania with partners the Australian Antarctic Division, CSIRO and the Bureau of Meteorology.

The research is supported by a grant of sea time on RV Investigator from the CSIRO Marine National Facility.