Turbulent flux measurements of carbon dioxide, methane, ozone and dimethylsulfide from the RV Polarstern bow tower during the 2019-2020 MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition

These are the turbulent flux results for selected climate-active trace gas species measured from the bow tower on the icebreaker RV Polarstern during the MOSAiC expedition, from October 2019 to October 2020. Instrumentation on the bow tower included: a heated 3-D ultrasonic anemometer (Metek model USA-1) at a height of either 20m (Legs 1-3) or 18m (Legs 4-5); a Licor 7500DS open path water vapor sensor positioned 1.5 m below the transducer array of the Metek sonic; and an RM Young 2- D heated sonic anemometer positioned 0.5 m below the Licor. The 2-D sonic provided wind speed and wind direction for the gas sampling inlet control system, which limits air sampling to periods of favorable relative wind direction (typically ± 120° from the bow). Results are hourly means, filtered for optimal conditions. A full description of the flux calculations, filtering and averaging procedures, and variable definitions is provided in an associated readme document.