Spotlight on a Student: PhD Candidate Rob Ryan
Measuring Australia's air quality using atmospheric spectroscopy
What is your research about?
My research aims to understand the different factors, natural and anthropogenic, influencing air quality around Australia. We typically think of Australia as having good air quality by global standards, however the reality is far more complicated. In fact, Australia’s our per capita emissions of toxic pollutants, such as nitrogen oxides (NOx), are among the highest in the world. This is largely due to our reliance both commercially and personally on road transport, and on coal-fired power generation. In densely populated and industrialised urban areas, the public’s personal pollution exposure still contributes a significant health burden to our economy, a factor which requires far greater attention when considering Australia’s energy future.
We owe our good air quality more to low population density than good management. It is generally accepted that wind from Australia’s rural areas can rapidly transport clean air through our polluted cities, restoring good air quality. But how ‘clean’ really is that rural air? It contains numerous gases and particles of natural origin, from sources including plants, animals, soil, dust and fires. The impact of these natural atmospheric constituents with pollutants in urban regions is largely unknown. Do the natural components help to ‘clean up’ urban air, or do they mix to form a volatile atmospheric cocktail?
I’m seeking to understand these processes using atmospheric spectroscopy. This relies on measuring gases that absorb sunlight as it traverses the atmosphere, and allows us to determine how gases of different origins are distributed throughout the atmosphere.
On their own, these measurements are useful for understanding local scale atmospheric chemistry. For example, in a recent paper I showed that part of the NOx cycle in northern Melbourne is likely driven by soil-based processes, not just vehicle pollution. As a result, the chemical oxidising power of the atmosphere is potentially higher than previously thought. In a broader context, these measurements will help inform regional and global scale models of the atmosphere, as its chemistry and dynamics responds to ongoing climate change.
Who are your supervisors?
I am supervised by Dr Robyn Schofield and Prof. Peter Rayner in the School of Earth Sciences at the University of Melbourne. I am lucky to have great support from them and the other members of their research groups, as well as external support from a wide network of collaborators at CSIRO, Bureau of Meteorology, University of Wollongong and Heidelberg University in Germany.
What do you want to do next?
Being an analytical chemist at heart, I love measuring things, and I plan to keep doing so! I hope to complete my PhD in the coming year, after which I will take some time to consider all available options, academic or institutional, around the world in atmospheric chemistry.
Funding and awards
I am grateful for ongoing support through the ARC Centre of Excellence for Climate System Science for my PhD studies. I am also extremely fortunate to have travelled widely throughout my PhD so far for conferences and field work. This has been made possible by generous funding from the International DOAS Workshop to attend their conference in Yokohama, Japan in 2017, and Rotary’s Global Environmental Sustainability Award to attend the 2018 European Geophysical Union Conference in Vienna.
Rob will be presenting his research at the upcoming MEI Symposium on Wednesday 12 December 2018. To find out more about Rob's work you can email him at r.ryan7@student.unimelb.edu.au, or his supervisors Dr Robyn Schofield at robyn.schofield@unimelb.edu.au, and Prof. Peter Rayner at prayner@unimelb.edu.au.