In
wildfires
A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a ...
, a holdover fire, or overwintering fire is a
peat fire which persists from year to year. It is also sometimes called a "zombie fire".
Fires
Such fires typically occur in
Arctic tundra,
smouldering
Smouldering (British English) or smoldering (American English; see spelling differences) is the slow, flameless form of combustion, sustained by the heat evolved when oxygen directly attacks the surface of a condensed-phase fuel. Many solid ma ...
during the winter under the snow and then becoming more intense during the summer.
A study conducted from 2002–2018 in Alaska and the Northwest Territories found that this type of fire burned only 0.8% of the total area burned by all types of fires and that this type of fire caused only 0.5% of the total carbon emissions released by all types of fires.
During the summer of 2019, such fires were estimated to have generated 173 million
tonne
The tonne ( or ; symbol: t) is a unit of mass equal to 1,000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton in the United States to distinguish it from the non-metric units of the s ...
s of
carbon dioxide
Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...
(), with an estimate of 244 million tonnes from January to August 2019. The
smoke
Smoke is an aerosol (a suspension of airborne particulates and gases) emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwante ...
and
soot
Soot ( ) is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons. Soot is considered a hazardous substance with carcinogenic properties. Most broadly, the term includes all the particulate matter produced b ...
from such fires darken the region, so contributing to further warming and further fires. The loss of peat is also a loss of a store for . Images from
satellites
A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scientif ...
such as
Sentinel-2
Sentinel-2 is an Earth observation mission from the Copernicus Programme that acquires optical imagery at high spatial resolution (10 m to 60 m) over land and coastal waters. The mission's Sentinel-2A and Sentinel-2B satellites were joined in or ...
have been used to identify such hot spots.
See also
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Arctic methane emissions
Arctic methane emissions contribute to a rise in Atmospheric methane, methane concentrations in the atmosphere. Whilst the Arctic region is one of Methane emissions, many natural sources of the greenhouse gas methane, there is nowadays also a human ...
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Climate change
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...
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Polar amplification
Polar amplification is the phenomenon that any change in the net radiation balance (for example greenhouse intensification) tends to produce a larger change in temperature near the poles than in the planetary average. This is commonly referred to ...
References
Further reading
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External links
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{{Forestry
Types of fire
Fire prevention
Wildfire prevention