This schematic shows how greenhouse gas measurements are made for the Total Carbon Column Observing Network at NIWA's Lauder Atmospheric Research Station in Central Otago, New Zealand.
At Lauder Atmospheric Research station, an in situ air gas analyser sits by a Fourier Transform spectrometer. Together, these two instruments give precise and accurate measurements of total column amounts and surface concentrations of important greenhouse gases.
The ground-based total column measurements are calibrated to the World Meteorological Organization reference scale for greenhouse gases using aircraft measurements. These calibrated ground-based measurements are then used to validate and calibrate space-based total column measurements made by GOSAT, the Greenhouse Gases Observing Satellite (Image: Erika Mackay, NIWA).