Monday 8 July 2013

The Canadian wildfires


Wildfires in Canada affect the Arctic



6 July, 2013



created by Sam Carana with screenshot from wunderground.com


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.


created by Sam Carana with screenshot from wunderground.com


created by Sam Carana with screenshot from wunderground.com

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.

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 NSIDC

Below, a similar image showing methane on the afternoon of July 6, 2013.
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 NSIDC

In conclusion, while carbon pollutions gets a lot of attention, the Arctic is also strongly affected by other emissions that can result from wildfires.

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