Wildfires can cause a lot of emissions. Obviously, when wood burns, carbon dioxide is emitted into the atmosphere. Wildfires also cause further emissions, such as methane, soot and carbon monoxide. A large part of such emissions can be broken relatively quickly down by hydroxyl, but when large emissions take place, this can take a while. In other words, the lifetime of gases such as methane is extended, particularly in the Arctic where hydroxyl levels are already very low to start with.
Furthermore, the soot that is emitted by such wildfires can settle down on snow and ice, changing its albedo and thus contributing to the demise of the snow and ice cover. As the image shows, soot can be blown high up into the Arctic, depending on the direction of the wind.
Wildfires in Canada and Alaska have now been raging for quite some time. The above image dates back to late last month. Today’s images can be quite similar, as illustrated by the two images below.
Smoke from wildfires can travel over quite long distances, as also evidenced by
these NASA satellite images showing wildfire smoke crossing the Atlantic Ocean. The relation between wildfire smoke and methane concentrations is further illustrated by the image below.
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methane levels July 5, 2013, over 1950 ppb in yellow in 6 layers from 718-840 mb
created by Sam Carana with methanetracker.org - sea ice data by SSMIS |
Below, a similar image showing methane on the afternoon of July 6, 2013.
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methane levels July 6, 2013, over 1950 ppb in yellow, 7 layers from 469-586 mb
created by Sam Carana with methanetracker.org - sea ice data by SSMIS |
Below, a screenshot created with methanetracker, showing some methane still persisting on July 8, 2013. On the right, the methane originating from the Quebec wildfires appears to have moved farther over the Atlantic Ocean, due to the
Coriolis effect. The image also shows some worryingly high methane concentrations in spots above the Arctic sea ice. The spots north of Alaska were also examined in the video at
Cruising for methane.
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methane levels on the morning of July 8, 2013, over 1950 ppb in yellow, 10 layers from 545 to 742 mb
created by Sam Carana with methanetracker.org |
Below, a
NASA satellite picture showing wildfires in Manitoba, Canada, captured by Terra satellite on June 29, 2013.
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| NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team |
In conclusion, while carbon pollution gets a lot of attention, the Arctic is also strongly affected by other emissions that can result from wildfires.
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