This data set contains in-situ trace gas mesurements of CO, CO2, H2O and O3 measured onboard of the research aircraft Polar 6 during HALO-(AC)³ in March/April 2022. Measurements of CO where performed using an Aerolaser ultra fast CO monitor model AL5002 (Aerolaser), for CO2 and H2O the LI-7200 closed CO2/H2O Analyzer (LI-COR Biosciences GmbH) was used and O3 was measured with the Dual Beam Ozone Monitor (2B-Tech). The data provides time, location and trace gas mixing ratios (if available). Measurements were performed out of Longyearbyen (Spitzbergen).