NCI Australia user Dr Jenny Fisher is continuing to learn about chemical transport in the atmosphere using advanced models running on NCI's supercomputer. Following on from her earlier investigations into carbon monoxide transport, she is now trying to understand the fundamentals of nitrogen sources and transport over the remote oceans of the world.

Dr Fisher says, "I feel very lucky to be able to use the NCI supercomputer to do my research. I'm always trying to get to the best possible understanding of atmospheric processes, and this facility makes that possible."

Nitrogen in the air can come from a variety of natural and human sources, through either urban processes on land or biological activity in the oceans. To learn about nitrogen compounds and their dispersion in the atmosphere, Dr Fisher customised the popular GEOS-Chem model with more accurate nitrogen chemistry. Then she compared her model output to 20 years' worth of aircraft measurements of nitrogen in the atmosphere.

Understanding how various nitrogen compounds form, disperse and break down will ultimately help us improve our air pollution and climate models. Looking more closely at how this works over land and over oceans helps add detail and accuracy to the models too. This way, they more accurately replicate real-world conditions. They also give us useful information for understanding global climate change and pollution transport.

Dr Fisher says, "Our new understanding of chemical processes that comes from this research will be incorporated into complex atmospheric models used all over the world. Getting atmospheric chemistry right in our computer modelling benefits the whole community. "

Dr Fisher's improvements to the GEOS-Chem model are shared with atmospheric researchers around the world. That way, the global researcher community benefits from the improved model code.

Researchers are starting to get a better sense for how nitrogen compounds behave in the atmosphere, especially the way they move around over the remote oceans of the world. NCI Australia's supercomputer helps our users to bring this internationally significant research to life.

Read the journal article in the Journal of Geophysical Research Atmospheres here: https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JD029046