The AirCore instrument is an atmospheric sampler flying under a meteorological balloon, capable of measuring the evolution of greenhouse gas concentrations (CO2, CH4, CO, N2O) from the surface to an altitude of approximately 30 kilometers during the balloon’s descent. The regular deployment of the instrument at French network sites and during international campaigns, such as the MAGIC campaign, enables 1) a better understanding of the vertical distribution of greenhouse gases, 2) the organization of calibration/validation activities for space missions, and 3) the evaluation of atmospheric transport models. For more details about the instrument, program, and data access, visit the website: