By Mark Kaufman
Some fires won't die.
They survive underground during the winter and then reemerge the following spring, as documented in places like Alaska. They're called "overwintering," "holdover," or "zombie" fires, and they may have now awoken in the Arctic Circle — a fast-warming region that experienced unprecedented fires in 2019. The European Union's Copernicus Atmosphere Monitoring Service is now watching these fires, via satellite.