First validation results of S-5P methane and carbon monoxide using ground-based FTIR data from all stations of the TCCON and NDACC-IRWG networks

The Sentinel-5 Precursor (S5P) satellite was successfully launched on 13 October 2017 with the TROPOspheric Monitoring Instrument (TROPOMI) as the single payload onboard. It measures the Earth's reflected radiances from the ultraviolet to the shortwave infrared spectral range with a daily global coverage at a spatial resolution down to 7x7 km². The ongoing TCCON4S5P project led by the Royal Belgian Institute for Space Aeronomy (BIRA-IASB) and supported by the Total Carbon Column Observing Network (TCCON) and Network for the Detection of Atmospheric Composition Change-Infrared Working Group (NDACC-IRWG) communities was submitted as an answer to the ESA-AO (Announcement of Opportunity) for the calibration and validation of the S5P mission. This project focuses on the geophysical validation of S5P methane (CH₄) and carbon monoxide (CO) total column products using coinciding TCCON and public NDACC-IRWG data from both networks, which include currently about 25 and 13 globally distributed stations, respectively. The proposed validation will be carried out using rapid delivery data during the first twelve months of the validation period followed by a second phase where the focus will be on the continuous long-term validation during the operational lifetime of the satellite.

In this presentation we show the first validation results of S5P CH₄ and CO products using ground-based Fourier Transform InfraRed data from all stations of the TCCON and NDACC-IRWG networks. The site-dependent biases and correlations will be discussed in detail with focus on different geophysical and meteorological conditions.