By Yereth Rosen
ANCHORAGE, Alaska, May 19 (Reuters) - In the boreal forests of the planet s far north, where the climate is warming faster than almost anywhere else in the world, some wildfires are surviving winter snows and sparking back up again in spring.
Now scientists from the Netherlands and Alaska have figured out how to calculate the scope of those zombie fires that smolder year-round in the peaty soil.
From 2002 to 2018, an average of about 1% of the burning in Alaska and in Canada s Northwest Territories was caused by overwintering fires that survived from one summer to the next, according to a study, published Wednesday in Nature. But in one year, zombie fires accounted for 38% of the region s burning.
A new report finds that while so-called "zombie fires" are currently responsible for a small portion of the land scarred by wildfires today in the world's boreal forests, they could become more prevalent as the climate warms.
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Each winter, as snow blankets Alaska and northern Canada, the wildfires of the summer extinguish, and calm prevails at least on the surface. Beneath all that white serenity, some of those fires actually continue smoldering underground, chewing through carbon-rich peat, biding their time. When spring arrives and the chilly landscape defrosts, these “overwintering” fires pop up from below that’s why scientists call them zombie fires.
Now, a new analysis in the journal
Nature quantifies their extent for the first time, and shows what conditions are most likely to make the fires reanimate. Using satellite data and reports from the ground, researchers developed an algorithm that could detect where over a decade s worth of fires dozens in total burned in Alaska and Canada’s Northwest Territories, snowed over, and ignited again in the spring. Basically, they correlated burn scars with nearby areas where a new fi
Study finds burn area from fires that survive winter varies depending on warmth of summers
Smoke rises from a wildfire south of Talkeetna, Alaska, in 2019. Photograph: Lance King/Getty Images
Smoke rises from a wildfire south of Talkeetna, Alaska, in 2019. Photograph: Lance King/Getty Images
Staffandagencies
Wed 19 May 2021 13.01 EDT
First published on Wed 19 May 2021 12.15 EDT
In the boreal forests of the far northern hemisphere, where the climate is warming faster than almost anywhere else, some wildfires are surviving winter snows and picking up again in spring.
Now scientists from the Netherlands and Alaska have figured out how to calculate the scope of those âzombie firesâ that smoulder year-round in the peaty soil.
Nature, an international research team reveals how it used a complex computer algorithm to spot the zombie fires that have risen from their peat-filled grave, so to speak, in satellite imagery.
What Are Zombie Fires?
Zombie fires, also known as overwintering or holdover fires, are different than the flaming fires that have devastated California and Australia in recent years.
Packed deep within carbon-rich soils and insulated by feet of snow, zombie fires can smolder for months, long after firefighters have extinguished the surface flames. As the snow melts and the soil begins to dry out, flames can reignite on the surface and spark larger blazes. This poses a problem not only for people and property, but for the climate, too.