Flexibility the key for physical geography student

Sian Grigg

For Physical Geography PhD student Sian Grigg, Macquarie University’s academic flexibility is not just a marketing slogan, it’s a daily reality – not only has she two young children to look after, she also lives in France.

Grigg commenced her PhD in 2000 after completing a Bachelor of Arts (Honours) with her current Macquarie supervisor, Dr Neil Holbrook. Her research involves developing a new low-resolution ocean-atmosphere-sea ice water mass model for paleoclimate and earth system modelling.

“Basically, oceanography modellers use computer systems to model the ocean as it is at the moment,” she explains, “so that we can then have an accurate idea of what the ocean might have been like in the past, as well as predict what it might do under global warming in the future when the atmosphere will have more carbon dioxide.”

General Circulation Models (GCMs) are highly complicated, high-resolution, three-dimensional systems, which give extraordinary detail and have a high number of parameters. However, because of their complexity, GCM climate models require enormous computing resources and take a very long time to run. A mid-range GCM takes about a day on a supercomputer to run just a year’s simulation – and their results are often very difficult to understand.

Because of these problems, in the 1990s oceanographers began using low resolution ‘box models’ which helped them to understand the mechanisms at work in the GCMs, and still allowed for accurate predictions. Grigg used one of these box models for her Honours work, but is now developing a more complex system which will help fill the gap between the big GCMs and the simpler box models.

“I felt there was nothing in the middle, the box models were too simple and the GCMs took too long to run,” she says. “I live in France and can run my climate model on my laptop without needing a supercomputer. I can also run a simulation of 3000 years which will be finished in minutes rather than years, which means that I can change parameters, do lots and lots of runs and test the sensitivity to different things.”

Grigg says that Macquarie’s flexible approach to study has suited her perfectly as both an undergraduate and postgraduate.

“As an undergraduate I found that people were willing to let you try different things and Neil was willing to let me have a go with my Honours even though I had studied geography and politics in my BA rather than maths or physics, which I probably should have done. He and the rest of the Department have been very supportive of my move to France, and it’s a fabulous thing to have had the flexibility to do that, because it lets you make a life choice without totally cutting yourself off from something else. I don’t know whether that holds in other Australian universities and I know it definitely doesn’t hold internationally.

For more information, contact Grigg’s supervisor, Dr Neil Holbrook, at neil.holbrook@mq.edu.au

December 2004

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