It is estimated that 1.15 million tonnes of CO were emitted by fires in 2022.

For this molecule, underground compartments are becoming the dominant source!

Our model estimates that 6.15 million tonnes of CO2 were emitted by the fires.
In terms of this molecule, soil and aerial parts account for an equal share.
The Landes region dominates this assessment (large surface area burned, high concentration of C in the soil).

In total, it is estimated that 4.5 million tonnes (dry mass) will be combusted in 2022, all compartments combined.

Subterranean compartments, in particular soil and lignite, play an important role in this balance.

We have thus built a new fire emission model, with aerial compartments (trees, shrubs, herbaceous plants, litter) and underground compartments (soil, peat bogs, lignite).
This 10m-resolution model is calibrated with data from the Atmospheric towers.

We have observed that this type of combustion can be favored by various factors: a high carbon density in the soil, the presence of peat bogs or lignite, low fire propagation speed, high fire intensity, etc.

Smoldering combustion can occur in various ecosystem compartments (e.g. wood), but such high values are generally associated with combustion in the subterranean soil layers. This corroborates evidence of fumaroles and deep combustion (Landes).

The quantities of CO and CO2 vary from site to site:
In the Mediterranean (OHP), the signal corresponds to normal surface combustion (low CO).
In the Landes (BIS) and Brittany (ROC), very high CO values are obtained at times

*MCE=CO2/(CO2+CO)

We had to retrace the path of the molecules from the fire, in the atmosphere and thus obtain the points of intersection with the atmospheric towers (including @icos-ri.eu towers)

This work was carried out by colleagues from @universitereims.bsky.social (C.Abdallah, T. Lauvaux & L.Joly)🙏

In 🔵⚪🔴, we have a nationwide network of atmospheric towers, which measure molecule quantities in real time.
We have taken advantage of the proximity of certain towers (OHP, ROC, BIS) to wildfires to analyze changes in CO2 and CO

While fires affect ecosystems with low biomass in the Mediterranean (garrigue, low forest), this redistribution of occurrence to temperate forests increases the amount of biomass affected 🌳

Total: 2.55 million tonnes of vegetation affected in 2022

In 2022, the area burnt in France amounts to 42,500 hectares 🔥
Very large fires in the Landes (26,800 ha vs. 494 ha/year over 2006-2021)
Numerous fires in temperate forests (7,800 ha vs. 216 ha/year)
Surface burned within norms in the Mediterranean (7,900 ha)

The scars of the fires encircling Los Angeles as seen by Sentinel-2 (SWIR) on January 12 🛰🔥