Figure: TCCON Stations (2025)
The Total Carbon Column Observing Network (TCCON) is a network of ground-based Fourier Transform Spectrometers recording direct solar spectra in the near-infrared spectral region. The project was initiated in 2004 with support from NIWA (New Zealand) and NASA (US). It has expanded to international co-investigators across the world. The primary data products are high precision total column-averaged dry-air mole fractions of CO2 and CH4. Other gases including H2O, HDO, CO and N2O are also retrieved and archived.
Sites for the network span the globe to provide diverse and targeted data for use as validation sites for the GOSAT series, OCO-series, TROPOMI, and other satellites, as well as monitoring the seasonal cycle and long-term evolution of CO2 and CH4 and CO.
The Network shares common methodologies, technical issues, and membership with the NDACC FTIR Working Group. The Network aims to provide a temporally dense, globally consistent data coverage network-wide by using a common retrieval technique. The retrieved columns are tied to the ground-based in situ networks by scaling to (in situ) balloon and aircraft profiles.
Details and data can be found at the TCCON website. TCCON data are also available from CaltechData at: https://tccondata.org/. The latest TCCON information, including site details, can be found at the TCCON Wiki https://tccon-wiki.caltech.edu/. The chair of TCCON is Debra Wunch (Americas); co-chairs are Thorsten Warneke (Europe / Africa) and Nicholas Deutscher (Asia, Oceania).
The primary reference for TCCON is: D. Wunch, G.C. Toon, J.-F.L. Blavier, R.A. Washenfelder, J. Notholt, B.J. Connor, D.W.T. Griffith, V. Sherlock, P.O. Wennberg. The Total Carbon Column Observing Network. Phil. Trans. R. Soc. A (2011) 369, doi:10.1098/rsta.2010.0240
A running tabulation of papers that use TCCON data is also available.
Updated September 2025