Detecting Southern Ocean change via repeat sampling

Voyage summary

Research voyage to Antarctica to study the deep ocean and atmosphere of the Southern Ocean to increase understanding of its role and impact on our climate.

The Southern Ocean plays a critical role in the Earth’s climate system. The region takes up more of the extra heat and carbon dioxide added by human activities than any other latitude band of the ocean. This voyage aims to collect data to increase understanding of how and why the Southern Ocean is changing and the implications for climate, sea level rise and biological productivity in the sea.

The voyage is an international collaboration with three main projects with the following objectives:

1. Quantify changes in water properties and circulation of the Southern Ocean between Australia and Antarctica
2. Determine the distributions of trace metals and isotopes, their change with time and the physical, chemical and biological processes controlling those evolving distributions
3. Quantify cloud-aerosol-precipitation-radiation processes and interactions over the Southern Ocean, and their variability as a function of latitude and large-scale context
   (CAPRICORN).

The CAPRICORN project will involve a combination of aircraft, ship-based and satellite observations will collect detailed data on clouds and the interaction between incoming radiation, aerosol production and rainfall.

Eleven deep water Argo floats will be deployed during the voyage which will allow scientists, for the first time, to continuously measure changes in the deep ocean to depths of 5000 m and greater.

Voyage outcomes

Data collected from this voyage will help address major gaps in our understanding of how the Southern Ocean influences our climate system. By collecting, analysing and understanding new deep ocean and atmospheric data, scientists will be able to produce a better global picture to improve future climate projections. This will improve our understanding of the role of the Southern Ocean in Earth's climate system, helping inform Australia's strategy for climate change mitigation and adaptation.

The measurements collected on this voyage will contribute to a number of larger international collaborations, with voyage partners including the Bureau of Meteorology (BOM) and the US National Centre for Atmospheric Research (NCAR).

Of note, researchers collected unprecedented cloud, precipitation and surface radiation data that will allow for better understanding of cloud-radiation interactions and have pinpointed the large-scale conditions that hinder climate models from accurately representing them.