Atmospheric abundances of Nitrogen dioxide (NO2), Nitrogen oxide (NOx), Nitric oxide (NO) and Ozone (O3) have been measured at Antarctic station Dome C (-75.10 lat., 123.33 long., 3233 m a.s.l). They have been retrieved from direct and in-situ atmospheric measurements using newly developed optical instruments based on absorption spectroscopy (incoherent broadband cavity enhanced absorption spectroscopy or IBBCEAS). These instruments directly measure NO2 with a detection limit of 30 pptv (parts per trillion by volume or 1E-12 mol/mol) (3σ). We performed two sets of measurements in December 2019 (4th to 9th) and January 2020 (16th to 25th) to capture the early and late photolytic season, respectively. The dataset also contains photolysis rate coefficients of Nitrogen dioxide and Ozone, and the Ozone production rate.

Calculation of the O3 production rate P_{O3}:P_{O3} = (k_{RO2+NO}[RO2] + k_{HO2+NO}[HO2]) * [NO] * Vwith k_{RO2+NO} and k_{HO2+NO} the kinetic rate coefficients of the reactions RO2 + NO → NO2 + RO and HO2 + NO → NO2 + OH, respectively, expressed in cm3/molecules/s; [RO2] and [HO2], the species concentrations expressed in molecule/cm3 and derived from the correlation between J(NO2) and [RO2] and the [RO2]/[HO2] ratio (Kukui et al., 2014); [NO] the concentration of NO expressed in molecule/cm**3; and V the arbitrary volume expressed as 1 cm * 1cm * H_PBL cm with polar boundary layer height H_PBL, given by the MAR regional model.