Key points
- Scientists have embarked on a three-week research voyage to measure some of the cleanest air in the world off the coast of Tasmania.
- The research is tracking changes in the atmosphere across the Southern Ocean – including climate indicators, such as clouds, trace gases and aerosols.
- It’s the first time scientists will directly compare data from Kennaook/Cape Grim Baseline Air Pollution Station with measurements at sea, offering new insights for climate modelling.
In a remote part of the Southern Ocean off the coast of northwest Tasmania, a team of scientists aboard CSIRO research vessel (RV) Investigator have been hard at work.
They’ve braved eight-metre swells to gather critical data that will help improve climate modelling and deepen our understanding of how human activity is influencing the global atmosphere.
What’s brought them to this part of the world is air – clean air.
They’re spending three weeks at sea for our COAST-K voyage (Clean Ocean Air Sampling upwind of Tasmania – Kennaook).
A breath of fresh air
Clean air is something Kennaook/Cape Grim is known for. The air arriving at this site from the Southern Ocean is exceptionally clean as it hasn’t made recent contact with land.
This makes it ideal for measuring the chemical composition of the atmosphere with minimal influence from human activity, such as road traffic and agriculture. It allows us to establish a natural baseline so we can then quantify the impact of human activity on the atmosphere.
The Kennaook/Cape Grim Baseline Air Pollution Station first began measuring the composition of the atmosphere in April 1976 and has been in continuous operation ever since.
For the first time, our scientists are comparing air quality taken at sea close to the station, and over 1000 km off the coast over the Southern Ocean from our mobile station – RV Investigator.
This important calibration will ensure our data is robust to accurately measure the atmosphere, from land and at sea. This information will feed into our climate modelling research so we can better estimate what changes are happening, why and what it might mean for the future.
The right climate: measurements on land and at sea
Both the Kennaook/Cape Grim Baseline Air Pollution Station and RV Investigator are monitoring stations for the World Meteorological Organization’s Global Atmosphere Watch. They form part of an observational network charged with understanding the increasing influence of human activity on the atmosphere.
The technology and systems onboard RV Investigator are internationally unique and were specifically designed to enable highly accurate monitoring of the atmosphere wherever the vessel travels. This includes the massive expanses of the Southern Ocean.
The vessel bristles with scientific systems that turn it into the technological equivalent of a bloodhound’s nose. This includes instruments to measure the tiniest traces of atmospheric gases – such as carbon dioxide, ozone and methane – and to count individual aerosol particles.
The information we are gathering will be used to improve models by providing important ground-truthing for regional and global climate modelling, air quality modelling, smoke forecasting and Earth System models.
Change in the air: atmosphere and climate modelling
Since the Kennaook/Cape Grim Baseline Air Pollution Station began taking measurements nearly 50 years ago, carbon dioxide levels have increased by nearly 30 per cent. This has adverse implications for future climate change.
Our COAST-K voyage will help improve climate monitoring for Australia. It will also reduce gaps in climate science for the Southern Hemisphere, as many climate models are biased to Northern Hemisphere conditions.
One such gap is our understanding of the Southern Ocean, which is critical because it plays a major role in absorbing heat and carbon dioxide from the atmosphere and has a strong influence on the earth’s climate.
We’re unpacking how clouds form and behave in the Southern Hemisphere, and the role of aerosols. This will tell us how much heat is reaching the Earth's surface, and how much heat is being trapped in the climate system.
Using state-of-the-art technology, including a full suite of atmospheric measurements and sampling systems, is enabling us to build a comprehensive understanding of the relationship between ocean productivity, aerosol formation, cloud microphysics, cloud dynamics, rainfall properties and surface radiation.
The science team undertaking the voyage is an international team, comprised of researchers from CSIRO, the Australian Bureau of Meteorology, Queensland University of Technology, the University of Melbourne, the University of Wollongong, Monash University, Colorado State University in the USA and Karlsruhe Institute of Technology, Germany.
RV Investigator is part of our Marine National Facility, which receives funding from the Australian Government’s National Collaborative Research Infrastructure Strategy and is operated by CSIRO on behalf of the nation.
The Kennaook/Cape Grim Baseline Air Pollution Station is a joint responsibility of CSIRO and the Australian Bureau of Meteorology.