Sensors to cut cost of checking carbon

Australian
Tuesday 28/6/2011 Page: 35

AUSTRALIAN scientists are spearheading the international development of technology to analyse greenhouse gases and climate change. The Greenhouse Gas Monitor joint research project was awarded $2.3 million last week by the Australian Space and Research Program. The project is designed to develop a mobile sensor unit to vastly boost the number of earthbound measurement stations globally that monitor CO₂. The project, which includes a team from the University of Wollongong's GeoQuest group, will use terrestrial and satellite technology to develop a data collection and feedback system.

By increasing the number of measuring sites, scientists could increase their data volume and the diversity of environmental source conditions, yielding more accurate information and improved weather and climate change forecasting. "So you would be able to prove your computer model and say more accurately where CO₂, is coming from or where it is going to, and that has big implications for things like emissions trading schemes", project researcher and Centre for Atmospheric Chemistry senior research fellow Nicholas Jones said.

The project will enhance international efforts by Japan and the US to launch satellites capable of precisely measuring atmospheric CO₂ and methane from space. To make the satellites useful, the data must be tied back to ground measurements. Current sensors capture CO₂ measurements from Total Column Carbon Observing Network stations, which cost about $1m each and weigh 600kg. The instrument follows the sun and allows scientists to measure CO₂, and methane between the ground and the top of the atmosphere.

Wollongong has one of three TCCON instruments in the southern hemisphere. The others are in Darwin and New Zealand. There are 15 worldwide. "The problem is that, to really make use of the satellite measurements, you want to calibrate them not just in 15 places, but several hundred, preferably 1000 or may be more", Dr Jones said. "What GGM is about is whether we can do the same kind of measurement from the ground but at a tenth of the cost".

He said the team had a candidate technology that could take measurements as accurately as the TCCON. The aim was to develop a mobile instrument for less than $100,000. "In the next 24 months, we are going to be looking at a couple of these technologies, developing them and comparing them with our TCCON data and if it works out we will then commercialise this instrument". The team's mobile prototype is a thumb sized crystal in a box inside a miniature heater.

Dr Jones said the mobile system would be autonomous and made up of a solar tracker to direct sunlight into the instrument, a spectrometer and computer control able to analyse data and send it back to a base station. "So there will be some kind of data archiving system, which then has to grab that data and send it off to the end user, such as the Bureau of Meteorology". The GGM partners also include University of Melbourne and Australian National University, the Bureau of Meteorology, Rosebank Engineering and Vipac Engineers and Scientists.

"We are probably one to two years ahead of the rest of the field, so we are hoping that we can get something to market before someone else does", Dr Jones said. He said the technology would also help in the scientific understanding of the carbon cycle and in climate modelling and the effects of El Nino and La Nina. "If we are able to predict those sorts of events more accurately, that has huge implications in terms of economic impact on the country", he said.