Centre for Atmospheric Chemistry

Welcome to the Centre for Atmospheric Chemistry

Research at the Centre for Atmospheric Chemistry advances understanding of atmospheric trace gas and aerosol chemistry, atmosphere/biosphere exchange of trace gases, and long-term changes in atmospheric composition and chemistry - from local to global scales.

Over more than 25 years, we have established the most intensive atmospheric composition and chemistry research and training program in Australian universities. We collaborate widely in Australian and international atmospheric science communities including other universities, CSIRO, ANSTO, BOM, federal and state government departments and international networks.

To get an idea of the centre's research activities, check out the "What's Cool" page.



We operate two sites in the TCCON and NDACC networks at the university campus in Wollongong and at Darwin Airport. Each consists of a high resolution Fourier Transform Spectrometer for mid- and/or near-IR spectra (Bruker IFS125), including solar tracker coupled to FTS.

We also operate two portable low resolution solar spectrometers, with trackers, for mobile measurements of total column amounts of trace gases.

Contact: Prof David Griffith

We make spectrally resolved measurements of both global and direct beam irradiance in the visible and UV, as well as MAX-DOAS scattered light measurements.

Contact: A/Prof Stephen Wilson

Global UV measurements based on a scanning monochromator system located at Cape Grim have been operating since 2000. This system is being replaced by systems based on a small diode array spectrometer and filters developed primarily by the Bureau of Meteorology.

Direct beam measurements include fixed wavelength sunphotometers for measuring Aerosol Optical Depth (in conjunction with the network operated by the Bureau of Meteorology). We also have spectrally resolved measurements which are used for atmospheric trace gas measurements.
MAX-DOAS measurements, which measure scattered sun light to determine the vertical distribution of trace gases are currently operating in both Cape Grim, Tasmania and at the University of Wollongong. One system will also be available for campaign work when needed.

Over the past 10 years we have developed an FTIR-based trace gas analyser for high precision, high accuracy analysis of CO2, CH4, CO, N2O and d13C in CO2 in air. We operate several such instruments for clean and urban air monitoring and combined with auxiliary equipment for flux and exchange measurements:

  • soil chambers
  • micrometeorological equipment
  • water equilibrator for flux measurements from water surfaces
  • ozone, NOx analysers

The FTIR analyser has been commercialised and is available from Ecotech Pty Ltd.

CAC has developed an open path FTIR (OP-FTIR) spectrometer to measure gas emission rates from nearby sources. The OP-FTIR spectrometer measures the gas concentration in the atmosphere over an extended path, typically up to 130 m. While the instrument has been developed by CAC to measure agricultural emissions and fire emissions, the system can be used to measure the concentration of multiple infra-red active gases in the atmosphere including for example boundary emissions from industries and fugitive emissions from pipelines or gas and coal fields.

The heart of the OP-FTIR design is a Bruker infra-red spectrometer and a modified Schmidt-Cassegrain telescope which expands and projects the infra-red beam to a distant retro-reflector. The reflector returns the beam to a mechanically cooled MCT detector at the spectrometer. The instrument is mounted onto a heavy duty tripod via an Automated Instrument Mount (AIM) that allows the instrument’s orientation to be alternated between up to 6 reflectors. The system operates continuously under the control of software written by CAC. The concentration of the target gas is analysed in real-time using the MALT analysis program.

In typical operation of the OP-FTIR system, the measurement path is located downwind from the gas source, for example a fire or livestock, and perpendicular to the predominant wind direction, with the gas carried from the source into the measurement path by the wind.

ContactsDr Frances Phillips, Prof David Griffith

We use the GEOS-Chem global three-dimensional chemical transport model and the STILT particle dispersion model to interpret observations from a variety of platforms and better understand the chemical composition of the atmosphere, with particular focus on Australia and the Southern Hemisphere. For more information, see our Modelling and Analysis Research.

ContactDr Jenny Fisher


The FTIR trace gas analyser is manufactured, supplied and supported as the Spectronus trace gas and isotope analyser by Australian company Ecotech Pty Ltd under license to UOW. The analyser has been sold internationally in Europe, USA, China, Korea and other countries as well as Australia. More information is available from Ecotech.

AIM has been designed and built by the CAC in collaboration with Illawarra Automation and Control (IAAC Pty. Ltd., Unanderra, NSW). AIM has been developed to mount our Open Path FTIR onto a heavy duty tripod to allow alignment of the instrument to multiple distant mirrors. Software allows for continuous measurements of the multiple measurement paths allowing a higher level of information capture. Although AIM has been designed for our Open Path Instruments, it would be suitable for any application requiring computer control of the orientation of an instrument to multiple targets with a high degree of repeatability.

The AIM is capable of holding instrumentation up to 45 kg in weight. Movement is 350 degrees in the horizontal and +/-15 degrees in the azimuth. Movement resolution is 1mm @ 100m using the pre-set step interval. The AIM unit is controlled through an interface box using in house written software on a PC, either as standalone software or integrated to the software controlling our open path FTIR. The software provides the ability to align the instrument to up to 6 measurement positions plus home position. The AIM unit weighs~15 kg, operates on 240 V and a power consumption of ~500W.

Extensive testing and field deployment have proven the systems pointing accuracy and repeatability. A unit has been sold to Alberta University in Canada and has received very positive feedback about its performance.

AIM is a commercial enterprise between CAC and IAAC. For further information about AIM please contact Travis NaylorGraham KettlewellDr Frances Phillips, or Prof David Griffith.

The Greenhouse Gas Measurement (GGM) instrument was developed under the Australian Space Research Programme. This project consisted of a consortium of University, Government, and a private company to develop a novel, terrestrial instrument to autonomously measure carbon dioxide and other greenhouse gases in the atmosphere. Work continues at Wollongong to characterise low-resolution FTIR spectrometers, the Bruker Cube and Bruker EM27/Sun. For more information, contact Nicholas Jones.

CAC has supplied the open path analyser to several research groups in Australia and Canada. A commercial instrument based on the CAC design is offered by Bruker Optics, Germany.

Contact The Centre for Atmospheric Chemistry