Continuous atmospheric CO2, CH4 and CO measurements at the Observatoire Pérenne de l'Environnement (OPE) station in France from 2011 to 2018 - Conil, S.; Helle, J.; Langrene, L.; Laurent, O.; Delmotte, M.; Ramonet, M. (Atmos. Meas. Tech., 2019)