Key points
- The Kennaook/Cape Grim Baseline Air Pollution Station in Tasmania monitors some of the cleanest air in the world.
- The remote location makes it ideal for studying aerosol and cloud interactions in the Southern Hemisphere to understand how the atmosphere is warming.
- Australian and international students visited the station to meet with leading scientists to better understand Earth system and climate modelling.
For almost 50 years, the Kennaook/Cape Grim Baseline Air Pollution Station in northwest Tasmania has been collecting data on aerosols and clouds. This data tracks changes in our atmosphere.
The remote location has some of the cleanest air in the world. It’s here that the next generation of atmospheric scientists from Australia and overseas breathed in our science to inform future research – and how best to monitor changes in our atmosphere.
Collecting the cleanest air in the world
So how do we collect and measure air at Kennaook/Cape Grim?
Australian and international students got to see our 80-metre-tall telecommunications tower at the station up close. This tower houses some of our air intakes. The air intakes channel air from the outside environment into the lab. We also measure the wind direction and determine if the air is ‘pristine’ or not.
In the lab, we use this air to assess the composition and chemistry of our atmosphere so we can monitor if it is changing. This is particularly important given the impact of long-lived greenhouse gases and their effect on the climate.
We also measure aerosols and reactive gases. Aerosols can cool or warm the atmosphere by directly scattering or absorbing light, or by changing the way clouds form and behave.
Reactive gases can also warm the atmosphere. They promote important chemical reactions in the atmosphere that form aerosols and clean up the atmosphere by breaking down pollutants.
Other instrumentation gathers information on the weather and additional climate indicators like wind speed and direction, rainfall, temperature, humidity and solar radiation. We are also collaborating with the United States Department of Energy’s Atmospheric Radiation Measurement (ARM) User Facility. They have provided technology to measure clouds and the physical characteristics of rain.
The station is a scientific haven for monitoring the incremental changes occurring around us.
The importance of monitoring the Southern Ocean
The Southern Ocean is a vast area of water which has a strong influence on our Earth's climate. The exchange of heat and gas between the air and the sea takes heat from near the surface and transfers it into the deep ocean.
Understanding the Southern Ocean is important as cloud properties in the Southern Hemisphere are different to those in the Northern Hemisphere.
Over the Southern Ocean the air is cleaner, so water droplets stay in a liquid state. The main aerosols that form 'super-cooled' clouds here are derived from biological sources (like phytoplankton). However, in the Northern Hemisphere particles such as dust blown from deserts and pollution, can trigger 'ice clouds'.
This is an important distinction, as some climate models can be biased to Northern Hemisphere conditions.
CAPE-k crusaders
Our CAPE-k (Cloud and Precipitation Experiment at Kennaook) project, which complements our decades-long air monitoring, is generating more accurate projections on the Earth’s climate – and how it is changing in the south.
Together with the Bureau of Meteorology and the United States Department of Energy’s ARM User Facility, we’re filling a gap to better understand cloud properties in the Southern Hemisphere, and how this informs climate modelling. For example, knowing approximately how much sunlight is reflected back to space over the Southern Ocean will help better understand how much heat is trapped in Earth’s atmosphere.
This work was showcased to students studying atmospheric science during a week-long visit to facilitate learning and foster the next generation of climate scientists. They got to see how our research is helping to monitor the Earth’s changing climate, now and into the future.