Tundra Fires in Alaska: A Weather Perspective

Over the past 20 years, wildfires have burned more than 1.5 million acres of tundra landscape in Alaska. Tundra fire has been shown to deeply influence local ecology and global carbon cycling while posing a serious threat to rural Alaskan communities. Moreover, tundra fire regimes are likely changing rapidly alongside global climate change. Despite its growing importance, the meteorological conditions behind tundra fire spread have not been studied in detail. This analysis takes advantage of newly available daily fire spread perimeters for Alaska alongside high resolution weather reanalysis data and ground observing station records to identify active fire spread days and the specific weather conditions that help drive them. This analysis has revealed clear synoptic weather patterns associated with fire growth such as weak near-surface pressure fields in conjunction with weak upper atmospheric flow. Furthermore, this analysis suggests that the primary driver behind tundra fire is most often the existence of strong surface solar heating associated with sunny weather. Notably, synoptic wind fields have shown to be an overall poor predictor of tundra fire spread. These findings challenge current tundra fire models which are based on grass fire fuels and heavily weight wind as a driver of fire spread. This research will greatly help meteorologists at the National Weather Service and Alaska Fire Service predict active tundra fire days to protect life and property. Moving forward, this study can be leveraged to help improve specialized tundra fire spread models and inform further meteorological analysis of tundra fires.