Cape Grim Baseline Air Pollution Station - Atmospheric CO2 Measurements 1976- 2004

The CSIRO archive of observed atmospheric CO2 concentrations at the Cape Grim Baseline Air Pollution Station in North-West Tasmania for the period 1976 until 2004. Measurements of atmospheric CO2 levels began in 1976 and have continued until the present day, giving an unprecedented view of the overall change in CO2 composition over the 30+ year time-frame. These started with the URAS-2T instrument until Jun 1990, continuing with the Siemens Ultramat 5E system until July 2004, followed by the LOFLO Mk2 instrument until the present day. All use NDIR (non-dispersive infrared) analysis techniques with LOFLO being CSIRO developed to make measurements consuming smaller volumes of calibration gas, requiring less operator intervention and having less bias than traditional NDIR measurement techniques. Logged data is available in a single ascii text file in hourly averaged periods containing CO2 concentration, wind speed and direction, a baseline and quality flag. Conditions are considered baseline when wind directions are between 190 & 280° bringing air from the southern ocean. The file size for the given variables is approximately 400 KB for an hourly averaged year of data, with the period from 1976-2004 being approx 11.0 MB.