EarthCARE spots birth of rare fire cloud over Europe

Leipzig, 30.10.2026 – Nicole Docter, Anja Hühnerbein, Sebastian Bley

first pyrocumulunimbus (pyroCb) cloud ever observed over France

Climate change means wildfires are becoming a more common threat in Europe. Thanks to EarthCARE’s multispectral imager, we can track their widespread atmospheric effects, including wildfire-induced thunderstorms.

June and July of 2026 have been exceptionally hot and dry - western Europe’s hottest on record - favouring extreme wildfires. This year has been one of the worst on record for wildfires, following a record-breaking 2025 that saw over 1 million hectares burnt. The area burnt is expected to increase by at least 39% per year by the end of the century, even in a low emissions scenario.

On 24 July 2026, a wildfire near Bordeaux, France generated the first pyrocumulunimbus (pyroCb) cloud ever observed over France.

Intense fire releases smoke, water vapour and ash high into the atmosphere, even reaching the stratosphere due to intense heating. A wildfire can therefore create its own thunderstorm with strong winds and potentially lightning.

The European Space Agency’s Earth Cloud, Aerosol and Radiation Explorer (EarthCARE) satellite captured the early stages of this pyroCb thanks to its multispectral imager (MSI). The MSI is one of EarthCARE’s four instruments, which work in synergy to reveal the mysteries of clouds and aerosols and their role in regulating Earth’s energy balance.

The first image shows a complete natural-colour Red Green Blue image (RGB) from MSI. A zoomed-in section highlights parts of the smoke plume, which are visible in in light bluish tones, as it spread over the Gulf of Biscay.

The second image shows the corresponding cloud and aerosol optical thickness from MSI. The operational cloud and aerosol processors, M-CLD and M-AOT, were forced to retrieve aerosol and cloud optical thickness simultaneously regardless of the underlying cloud masking.

In the bi-variate display of optical thickness from aerosol and cloud, light yellow shows high aerosol and cloud optical thickness directly in the smoke plume. Orange-red indicates high aerosol loading at the edges, whereas light cyan-blue indicates thick clouds and no aerosol. The wildfire smoke plume therefore consists of aerosols that are already acting as cloud condensation nuclei.

As the day went on, the initial smoke plume further developed into a pyroCb, as seen in the third figure, which shows a true colour RGB composite film observed by the flexible combined imager (FCI) on the Meteosat Third Generation Imager 1 (MTG-I1). 

The MSI images add another dimension to EarthCARE’s monitoring of wildfires, with the satellite already monitoring of the entire life cycle of a wildfire plume as it traversed the stratosphere all the way from Canada to the Mediterranean before finally reentering the troposphere over North Africa and the Middle East.

With the satellite planned to fly well into the mid-2030s, we expect to see a range of insights into the effects of wildfires in Europe and beyond, helping us understand our rapidly changing climate.

Nicole Docter, Anja Hühnerbein, Sebastian Bley / EarthCARE data, science and innovation cluster (DISC) MSI team