The Cape Grim Baseline Atmospheric Pollution Station (CGBAPS) commenced operation in early 1976, fulfilling an Australian government commitment to participate in the WMO (World Meteorological Organization) recommended network of global background atmospheric stations, focussed on observing the long-term drivers of climate change and ozone depletion, in particular carbon dioxide (CO₂), chlorofluorocarbons (CFCs), surface ozone (O₃) and aerosols. Cape Grim was chosen as a site representative of the mid-latitudes of the Southern Hemisphere and complimented NOAA’s Southern Hemisphere sites at Cape Matatula, American Samoa (tropical Pacific) and at the South Pole. A brief history of the Cape Grim Station is given in Fraser (2007).

At Cape Grim, the ALE/GAGE/AGAGE programs started measuring atmospheric CFC-11, CFC-12, CH₃CCl₃, CCl₄, N₂O in 1978; CFC-113 in 1982; CH₄ in 1986; and CHCl₃, CO and H₂ all in 1993 by using a high-precision GC-multidetector (GC-MD) system. The first gas chromatograph-mass spectrometer with adsorption-desorption system (ADS GC-MS), was installed at Cape Grim in November 1997. This ADS GC-MS instrument was later retired in December 2004 and replaced by a new state of art Medusa GC-MS system that was installed and started operation in January 2004.

Air masses arriving at Cape Grim typically have long trajectories over the Southern Ocean (~40%) or have passed over southern continental Australia or Tasmania (60%). Cape Grim has proved invaluable in assessing the role of the Southern Ocean as a significant sink for atmospheric CO₂ and southern continental Australia as a source of methane (CH₄), nitrous oxide (N₂O) and synthetic greenhouse gases (SGGs) – in particular hydrofluorocarbons (HFCs) and CFCs. Cape Grim data have been used extensively in all international assessments of climate change and ozone depletion and in many inverse studies deriving global and regional emissions of CO₂, CH₄, N₂O and SGGs. 

Cape Grim is operated by the Australian government Bureau of Meteorology (BoM) and the extensive atmospheric science research program is overseen by CSIRO and BoM, involving other Australian government agencies (e.g. ANSTO – Australian Nuclear Science Technology Organisation) and universities (e.g. U. Wollongong) and international collaborations with AGAGE, USA laboratories (GIT, MIT, NOAA, SIO, UC Berkeley), European laboratories (Empa, LSCE, NILU, MPI, U. Bristol, U. East Anglia, U. Heidelberg) and Asian laboratories (CMA, NIES, SNU, MMS).   

Fraser, P., A brief history of the Cape Grim Baseline Air Pollution Station, in: Baseline Atmospheric Program Australia 2005-2006, J. Cainey, N. Derek & P. Krummel (eds.), Australian Bureau of Meteorology and CSIRO Marine and Atmospheric Research, Melbourne, Australia, 1-6, 2007. [PDF]

Cape Grim Baseline Air Pollution Station