Halfway the project, we have made significant progress in estimating fire emissions, characterzing fire-induced permafrost thaw and mapping Arctic-boreal ignitions and fires.
In 2023, we conducted a field expedition in the Alaskan tundra to measure the effects of fire on soil carbon and permafrost. We are currently preparing a field expedition in burned forests in Quebec, Canada. In addition, the FireIce team has contributed to work integrating field and geospatial measurements over Arctic-boreal North America and globally.
We have set up a holistic framework to investigate different climate feedbacks after boreal fires, including direct emissions of greenhouse gases and aerosols, longer-term emissions of greenhouse gases after fire-induced permafrost degradation, surface albedo changes and post-fire vegetation recovery. In addition, to better understand fire-induced permafrost thaw processes, we investigated environmental drivers and remote sensing proxies of fire-induced permafrost thaw We also derived and analyzed post-fire ground subsidence from satellite images over several tundra fire scars.
We mapped all Arctic-boreal ignitions and fires between 2012 and 2023 from satellite imagery and used this fire atlas to define an Arcic-boreal pyrogeography. We further optimized remote sensing algorithms to estimate fuel loads, burned area and fire severity. Furthermore, we investigated the trends and drivers of Arctic-boreal fire intensity in the 2000s based on satellite image time series.
We investigated how snowmelt timing influences the timing and quantity of Arctic-boreal fire ignitions in North America. We contributed to a study that improved fire risk assessments in boreal peatlands by assimilating satellite data in a peatland-specific land surface model. We also contributed to a study that evaluated how fire weather and fuel characteristics co-influence wildfire occurrence. We derived the first global map of anthropogenic vs. lightning fires. Finally, we contributed an important analysis on lightning fires to a global review and re-analysis of relationships between climate change and fires.