Data from observations made at the Cape Verde Atmospheric Observatory (CVAO) which exists to advance understanding of climatically significant interactions between the atmosphere and ocean and to provide a regional focal point and long-term data.

The observatory is based on Calhau Island of São Vicente, Cape Verde at 16.848N, 24.871W, in the tropical Eastern North Atlantic Ocean, a region which is data poor but plays a key role in atmosphere-ocean interactions of climate-related and biogeochemical parameters including greenhouse gases. It is an open-ocean site that is representative of a region likely to be sensitive to future climate change, and is minimally influenced by local effects and intermittent continental pollution.

Since November 2011, real-time N2O (Nitrous Oxide) and CO (Carbon Monoxide) concentrations have been simultaneously and continuously measured using an Off-Axis Integrated-Cavity Output Spectroscopy (OA-ICOS) analyser (Los Gatos Inc). In November 2012, 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).

The dataset contains hourly measurements of CO, CO2, N2O and CH4. Data were collected by collaboration between the University of Exeter and the Max Planck Institute for Biogeochemistry.