TCCON is a network of ground-based Fourier Transform Spectrometers recording direct solar spectra in the near infrared spectral region. From these spectra, accurate and precise column-averaged abundances of CO2, CH4, N2O, HF, CO, H2O, and HDO are retrieved and reported here. A technical report describing the GGG2020 version of the retrievals and their comparison to the previous version is found here; solar, Voigt telluric, and non-Voigt telluric spectral linelists used in the retrievals are publically available. A technical report describing the previous (GGG2014) version of the retrievals is found here.

Data in netCDF format are publicly available no later than one year after the spectra are recorded; many sites release their data earlier. Citation and data use requirements are included in the license associated with each record. Column averaging kernels and a priori profiles are included in the files. Information on how to use these can be found here. To produce TCCON a priori profiles for locations and times where there are no TCCON measurements, a stand-alone program can be downloaded. A JSON file describing the correspondence between GGG2014 and GGG2020 public file variable names can be downloaded.

A JSON file containing the current list of TCCON site locations can be downloaded here . Documentation for this file is available on the TCCON wiki .
Please review the TCCON data use guidelines before downloading TCCON data. A tool is available to generate citations for TCCON data and sites in Bibtex format.

Sign up to the TCCON Users email list by sending an email to tccon-users-join@caltech.edu with the subject ‘subscribe’.