Real-time N2O (Nitrous Oxide) and CO (Carbon Monoxide) concentrations are simultaneously and continuously measured using an Off-Axis Integrated-Cavity Output Spectroscopy (OA-ICOS) analyser (Los Gatos Inc). A Greenhouse Gas Analyser (GGA) using the same fundamental measuring technique was added and placed in series to measure CO2 (Carbon Dioxide) and CH4 (Methane) concentrations. Both devices are configured to sample at a frequency of 1Hz and both have the precision and accuracy to conform to measurement recommendations as defined by Global Atmosphere Watch (GAW). It is operated by the University of Exeter and the Max Planck Institute for Biogeochemistry at Cape Verde Atmospheric Observatory.