The Harwell TCCON observatory

Abstract. The Harwell observatory, located in Oxfordshire, UK (51.571° N, 1.315° W), now part of the Total Carbon Column Observing Network (TCCON), has been performing ground-based remote sensing of averaged dry columns of atmospheric greenhouse gases since September 2020. Measurements are performed through near-infrared and shortwave infrared high-resolution spectroscopy of the atmosphere's transmission in direct sun viewing geometry, following the TCCON methodology. We report on the development, the measurements, and the performance of the observing system installed at Harwell. The hardware and software are described and characterized, as well as the outputted data quality, based on the 4-year data record collected so far. The Harwell site is demonstrated to produce data of high quality, well in line with the requirements for the TCCON infrastructure. The dataset is available at https://doi.org/10.14291/tccon.ggg2020.harwell01.R0 (Weidmann et al., 2023).