This collection contains hourly averaged greenhouse gas observations of CH₄ and CO₂ at five stations in the Barcelona metropolitan area, starting in May 2021. In addition, one of the stations also provides CO observations. These measurements are performed by ICTA-UAB in the framework of the ERC URBAG project (https://urbag.eu/) and contribute to the ICOS Cities (also known as PAUL) project (GA 101037319).

Measurements are carried out using Picarro CRDS instruments. Instrument drift is monitored using a daily target tank, and a four-point working standard calibration is performed every 2–3 weeks. The working standards are calibrated against six NOAA secondary standards.