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. The HF and HDO retrievals are uncalibrated and hence preliminary. Data are updated monthly on the first of the month. The data become publicly available no later than one year after the measurements are recorded, and many sites choose to release their data much sooner.
For the latest TCCON information, please visit the TCCON Wiki. For citation information and our data policy, please see our Data Use Policy. For site-specific information and data analysis descriptions, please read the Data Description. Auxiliary data (column averaging kernels, a priori profiles) are included in the netCDF files provided below. Information on how to use our column averaging kernels and a priori profiles can be found on our Auxiliary Data page.
A technical report describing the GGG2014 TCCON data version can be found on the documentation page. Our telluric linelist can be downloaded from the atm page. Our solar line list can be downloaded from the solar page. A program to generate our a priori profiles can be downloaded from the a priori page. Please note that the a priori profiles used in the TCCON retrievals are included in the data files below. If you need to produce TCCON a priori profiles for locations and times where there are no TCCON measurements, please use the program linked above.
The TCCON is closely affiliated with the Network for the Detection of Atmospheric Composition Change Infrared Working Group (NDACC-IRWG). In contrast with TCCON, which produces column-averaged dry-air mole fractions, the NDACC produces vertical profiles of the concentrations of many of the same gases and several others. The NDACC website and links to their database can be found at www.acd.ucar.edu/irwg.