Tuesday 14 July 2015

Wildfire Smoke over North Pole

Wildfire Smoke over North Pole — Web Cam Shows Melt Ponds Beneath Brown Carbon Haze



14 July, 2015
For Alaska and Canada, as of today, an unprecedented 12,000,000 acres of forest and tundra overlying the rapidly thawing and human greenhouse gas emissions warmed permafrost has burned — going up in vast, billowing clouds of smoke. This smoke has spread out, caught up in the meandering Jet Stream, and is now visible in far-flung locations by both ground and satellite observation.
In addition to painting skies across Canada, Alaska and the Western and Central US milky white, upper level smoke from the fires has crossed Greenland and the North Atlantic, entered the Central Arctic Ocean and is now visible as a hazy pall over web cameras observing North Pole melt.
North Pole Web Cam Smoke Haze Melt Ponds
(Melt ponds and teetering markers near North Pole web cam beneath skies painted gray-brown by wildfire smoke. Image source: North Pole Environmental Observatory.)

In the above image we can see this smoke haze painting the sky a brown-gray pallor in the NEOPAWS North Pole web cam image. Beneath these skies, the sea ice surface has melted to the point that the marker strakes are wobbling off kilter and that substantial melt ponds are cutting deep furrows into the polar ice. The hazy hew of skies in this image together with an overhead cirrus cloud cover tinted brown indicates that smoke particles have been lofted into the Jet Stream level.
Wildfire Smoke over Sea Ice

Satellite tracking of the smoke also confirms ground-based observations. For as of July 6 a large bellow of smoke had wafted up from the unprecedented wildfires burning in Alaska (now at 4.44 million acres and climbing). Drawn up in a high amplitude Jet Stream wave this smoke could clearly be seen traversing the Beaufort and Chukchi Seas in the MODIS satellite shot:
Wildfire smoke over sea ice


Upper level smoke plume in herring bone pattern at center frame
(Top and bottom frame images tracking a plume of wildfire smoke emitting from Alaska, crossing the Beaufort and Chukchi seas on July 7 and entering the Central Arctic on July 12. Image source: LANCE MODIS.)

By Sunday, this smoke had become entrained in the draw between a cyclonic circulation over the Laptev Sea and an anticyclone formation on the Greenland side of the Arctic. It’s a dipole pattern that has now lasted for more than a week. One that is regarded as rather unhealthy for late season sea ice totals. Note the herring-bone formation of darkened upper level clouds drawn through the dipole and running diagonally from upper left frame to lower right of the second image. The pole in image 2 is also in the lower right frame.
Conditions in Context — Brown Carbon at Jet Stream Level is an Amplifying Feedback
Lofting large amounts of brown carbon into the Jet Stream level of the atmosphere is an amplifying feedback to human-caused warming. One occurring in addition to the added rate of carbon release generated by these wildfires as well as to a transient negative feedback coming from generating thick, low level clouds, that block out sunlight.
High level clouds alone aid in the heating of the Earth — allowing visible sunlight to penetrate while trapping long rave radiation rebounding from the Earth’s surface. Painting these clouds dark through brown carbon smoke particulate emission into the upper atmosphere provides an added heat kick by further lowering cloud albedo and by re-radiating an overall greater portion of the transient heat. As a final insult, the brown carbon aloft eventually precipitates down to the surface. When such precipitation lands on ice sheets and northern hemisphere snow cover, it darkens the snow and enhances melt. A kind of ominous global warming fallout.
Smokey haze over North Pole melt ponds — one albedo reducing process being reinforced by the other.
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Hat Tip to Colorado Bob
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