Total column CO2 measurements at Darwin, Australia ndash; site description and calibration against in situ aircraft profiles

摘要

An automated Fourier Transform Spectroscopic (FTS) solar observatory wasestablished in Darwin, Australia in August 2005. The laboratory is part ofthe Total Carbon Column Observing Network, and measures atmospheric columnabundances of CO and O and other gases. Measured COcolumns were calibrated against integrated aircraft profiles obtained duringthe TWP-ICE campaign in January–February 2006, and show good agreement withcalibrations for a similar instrument in Park Falls, Wisconsin. A clear-skylow airmass relative precision of 0.1% is demonstrated in the COand O retrieved column-averaged volume mixing ratios. The 1%negative bias in the FTS relative to the World MeteorologicalOrganization (WMO) calibrated in situ scale is within the uncertainties ofthe NIR spectroscopy and analysis.