NASA Earth Observatory: Intense fires burning in the boreal forests of Russia, Alaska and Canada darkened Northern skies with smoke in July 2009. Large fires were burning in both Russia and Alaska in late July, and this image tracks the smoke from those fires by illustrating the concentration of carbon monoxide in the atmosphere.

Smoke from Fires in Russia and Alaska

Smoke from Fires in Russia and Alaska

CO Concentrations

CO Concentrations

Tundra fires are important for several reasons:

  • About a third of the world’s soil-based carbon is locked-up in high-latitude tundra and boreal forest ecosystems.
  • Burning tundra releases CO2 and destroys stored carbon (in organic matter) – one study estimates that 50 years of accumulated plant matter was lost after one severe fire.
  • Severely burned tundra emits twice as much carbon as undamaged tundra normally stores away, for up to a year after burning.
  • It also absorbs around 70 per cent more solar radiation, warming faster (due to blackening and loss of vegetative cover) – this causes thawing of the underlying permafrost (up to 10 centimetres deep).
  • Thawing permafrost undergoes anaerobic decomposition and releases methane (a greenhouse gas 25 times more potent than CO2).
  • This creates a positive feedback loop – burning and its later effects release carbon and melt permafrost. This causes more warming and makes further fires more likely.
  • Tundra fires will become more frequent in future because higher temperatures and increasing dryness increase the amount of vegetation available to burn (by prompting a shift from tundra comprised mainly of small herbs and grasses to one dominated by larger shrubs).

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The image above was made with data collected by the Measurements of Pollution in the Troposphere (MOPITT) sensor on NASA’s Terra satellite between July 20 and July 26, 2009. Spots of red show where carbon monoxide concentrations were high, while orange areas point to moderate concentrations. Gray regions indicate places where no measurements were made, probably because of persistent clouds. The highest concentrations of carbon monoxide are centered over large fire complexes in Russia. Fires in Alaska were also pumping carbon monoxide into the atmosphere.

Carbon monoxide is a component of smoke that can be tracked long after the smoke has dispersed enough to no longer be visible. Carbon monoxide helps reveal where smoke’s other invisible fine particles and polluting gases end up. These invisible particles and gases, including carbon monoxide, are ingredients in the production of ground-level ozone, a harmful pollutant.

This article based on these two New Scientist articles:

Alaskas biggest tundra fire sparks climate warning.

Global warming may raise tundra wildfire risk.