Southern Ocean atmospheric research

Why we research the Southern Ocean atmosphere

The Southern Ocean region is very important to Australian and global climate and weather. Yet there's a lot we don't understand about how clouds and precipitation form over the Southern Ocean.

Part of the problem is that there aren't as many observations available for that part of the world.

Cloud droplets need small particles in the atmosphere, called aerosols, to be able to form. The main sources of aerosols over the Southern Ocean are:

• sea salt
• emissions from upper ocean biological activity.

This compares to, for example, smoke and pollution over land. It means that how clouds and precipitation form over the Southern Ocean is different.

This research project aims to gather and analyse state-of-the-art observations in the Southern Ocean region to understand how:

• the interactions between aerosols, clouds and precipitation work
• these interactions impact the Earth's surface radiation budget. That is, how much shortwave and longwave radiation from the Sun reaches Earth's surface.

It will help us use the lessons learned from observations to improve our global models. We use these models to forecast weather and future climate.

Analysing Southern Ocean atmospheric observations

Working with Australian and international collaborators, we collected cutting-edge aerosol, cloud, precipitation and surface radiation observations. This data was collected as part of 6 field experiments between 2015 and 2024.

Five of these experiments were conducted using the research vessel (RV) Investigator and the Aurora Australis icebreaker ship. (You can take a virtual tour of RV Investigator on the Marine National Facility website.) The other experiment was a 2-year deployment of instruments at Macquarie Island (latitude 54° South). Read details of the first 4 experiments in the Bulletin of the American Meteorological Society (30 November 2020). 

Analysis of these unprecedented observations is in progress. This work has already provided unique insights into aerosol-cloud formation processes. For example, there are fascinating differences in dominant aerosol sources and resulting cloud properties between the middle of the Southern Ocean and closer to the coast of Antarctica. This might explain why these 2 regions have very different errors in the surface radiation budget in global models.

We're working with the United Kingdom Meteorological Office to conduct sensitivity tests that aim to improve the representation of aerosol-cloud interactions in the Australian global climate model – the Australian Community Climate and Earth-System Simulator (ACCESS).

Research partners

This research is supported by the Australian Antarctic Program Partnership.

Our national research partners include:

• CSIRO
• Australian Antarctic Division
• University of Tasmania
• Monash University
• University of Melbourne
• Queensland University of Technology.