Formaldehyde over Africa measured by Sentinel-5A

Launched a little over three months ago, Copernicus Sentinel-5A has returned its first images – including a global map of ozone, maps of nitrogen dioxide over the Middle East and South Africa, formaldehyde over parts of Africa, and emissions of sulphur dioxide from an active volcano in Russia – showcasing the mission’s powerful capability to monitor atmospheric gases worldwide.

This image presents a vertical column density of formaldehyde on 13 October 2025. Elevated concentrations along the northwestern coast of Angola are linked to emissions from wildfires, while enhanced levels over the Central African Republic stem from a combination of fire activity and biogenic emissions. Formaldehyde is a carcinogenic air pollutant.

Because formaldehyde is typically concentrated near the surface, clouds can obscure the satellite’s view, reducing data coverage. The current data are preliminary, so biases in partially cloudy regions will be corrected as data processing improves.

Read full story: Sentinel-5 debuts images of atmospheric gases