Periodic Reporting for period 2 - FireIce (Fire in the land of ice: Climatic drivers and feedbacks)
Berichtszeitraum: 2023-04-01 bis 2024-09-30
Boreal forest and Arctic tundra fires are becoming more frequent and extreme with climate change. Recent notable Arctic-boreal fire extremes include 2019, 2020 and 2021 in Eastern Siberia and 2023 in Canada. Arctic-boreal ecoystems store large amounts of carbon in permafrost soils. Fires have the potential to release part of this carbon as greenhouse gases and as such invigorate a positive feedback loop between climate change and Arctic-boreal fires.
FireIce’s overarching objective is to investigate climatic drivers and feedbacks from Arctic-boreal fires. FireIce therefore uses a combination of field, remote sensing and modeling techniques. FireIce aims at quantifying the greenhouse gas emissions, both the direct emissions during fires and longer-term emissions after fire-induced permafrost thaw. In addition, FireIce investigates the drivers of and controls on fire ignition, size and severity, thereby enabling better predictions of future Arctic-boreal fires.
FireIce’s overarching objective is to investigate climatic drivers and feedbacks from Arctic-boreal fires. FireIce therefore uses a combination of field, remote sensing and modeling techniques. FireIce aims at quantifying the greenhouse gas emissions, both the direct emissions during fires and longer-term emissions after fire-induced permafrost thaw. In addition, FireIce investigates the drivers of and controls on fire ignition, size and severity, thereby enabling better predictions of future Arctic-boreal fires.
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.
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.
The FireIce has progressed beyond the state of the art in several parts of the project. We mapped all Arctic-boreal fires since 2012 from satellite imagery with the highest temporal resolution, i.e. sub-daily, so far. We also attributed fire ignitions and burned area to anthopogenic and lightning causes, and found that 77 % of the burned area in intact extratropical forests stems from lightning. In addition, our holistic framework that integrates climate feedbacks from greenhouse gas emissions (during and after the fire), aerosols emissions, surface albedo changes and post-fire carbon sequestration of vegetation is the first of its kind at continental scale. The inclusion of fire-induced permafrost degratation is a new and important contribution to this framework.
By the end of project a PhD dissertation will fill critical knowledge gaps of fire effects on carbon combustion and permafrost thaw from field studies in Siberia (Russia), Alaska (USA) and Quebec (Canada). Another PhD dissertation will complete the fire-climate feedbacks framework, and will further zoom in on the relationships between fire and permafrost thaw. We will further investigate the climatic drivers of recent extreme Arctic-boreal fire activity, including Canada in 2023, with an emphasis on large lightning fires.
By the end of project a PhD dissertation will fill critical knowledge gaps of fire effects on carbon combustion and permafrost thaw from field studies in Siberia (Russia), Alaska (USA) and Quebec (Canada). Another PhD dissertation will complete the fire-climate feedbacks framework, and will further zoom in on the relationships between fire and permafrost thaw. We will further investigate the climatic drivers of recent extreme Arctic-boreal fire activity, including Canada in 2023, with an emphasis on large lightning fires.