Wildfire smoke in the stratosphere

In the last ten years a great deal has been learned about the long-range dispersal of wildfire smoke. As Wildfire Today reported on August 9, 2010, smoke from fires in Russia last summer was tracked as it crossed the Pacific and entered the airspace above Canada.

A meteorologist told us at that time:

Based on the amount of smoke being produced by the Russian fires and at least this one occurrence [on August 3] of smoke being tracked across the eastern Pacific, I think it’s a reasonable assumption that some amount of smoke from Russia has made its way into North America.

An aerosol plume (center) generated by fires in central Russia in late July of 2010 (red denotes fire at ground level) traveled all the way to Alaska. NASA GSFC, MODIS Rapid Response

The photo above is astounding. Not only does it show the smoke plume rising many kilometers straight up into the atmosphere as if it were shot out of a cannon, but you can also see the result of moisture, a by-product of combustion, condensing and forming clouds downwind, far below the top of the tallest smoke plume.

The photo came from an excellent article by Sid Perkins which appeared on the Science News site, an excerpt of which is below. Oddly, the article is dated November 6, 2010, perhaps to match the date of a paper edition of their publication. (Remember when people used to read magazines printed on dead trees?)


Layers of the atmosphere…While it has been known for decades that large wildfires can create or enhance thunderstorm clouds, leading to what are called pyrocumulonimbus clouds, only recently have scientists discovered that the clouds can boost smoke into the stratosphere [20-50 kilometers above sea level]. Once in this layer of the atmosphere — immediately above the troposphere, where most of Earth’s weather happens — the smoke can be caught by jet stream winds and carried long distances, says Mike Fromm, a meteorologist at the Naval Research Laboratory in Washington, D.C.

Before the late 1990s, anomalous plumes of stratospheric aerosols were usually blamed on remote and therefore undetected volcanic eruptions, Fromm noted in August at the American Geophysical Union’s Meeting of the Americas in Iguaçú Falls, Brazil. But new analyses of satellite data, presented at the meeting and chronicled in the September Bulletin of the American Meteorological Society, reveal that pyrocumulonimbus clouds, or pyroCbs, regularly send smoke to the stratosphere. During the 2002 North American fire season alone, pyroCbs lofted aerosols to this layer more than a dozen times.

“In 2000, few scientists believed that these clouds could inject aerosols into the stratosphere,” says Pao Wang, an atmospheric scientist at the University of Wisconsin–Madison. “Now it’s almost taken for granted that they do.”

Along with aerosols, the high-flying plumes carry a heavy load of the chemically active gases that are produced in substantial quantities during a fire, especially in the smoldering phase. While their chemical and climatic effects aren’t fully known, the plumes’ dark particles tend to absorb sunlight, warming themselves and the atmosphere around them while cooling Earth’s surface slightly. A fuller understanding will help scientists fine-tune climate models, adjusting contributions of various aerosol sources.

In many ways, says Fromm, pyroCbs are just like other cumulonimbus clouds: They can provide prodigious amounts of precipitation and spawn a lot of lightning. Where pyroCbs differ from standard storm clouds, however, is in their source of convection. While it’s the heat produced by condensing water vapor that drives the updrafts in the towering thunderheads of cumulonimbus clouds, those in pyroCbs are largely driven by the intense heat of the wildfire at ground level.

That gives pyroCbs an extra push: The momentum from particularly strong updrafts enables the fire-fueled clouds to routinely make it to the lower reaches of the stratosphere. Even the tops of typical cumulonimbus clouds, in contrast, rarely rise out of the troposphere.

As a column of smoke rises from a wildfire, it pulls in surrounding humid air. The moisture in that air condenses to form the pyroCb cloud as the plume reaches high altitudes.

“Nobody really knows what happens inside these clouds,” Fromm says. But satellite images clearly show that smoke carried upward inside the clouds emerges from the top as if from a chimney, he notes.

(the rest of the article)

New smoke forecasting system unveiled for western Canada

smoke forecasting system western Canada
This is a screen grab from the Western Canada BlueSky Smoke Forecasting System

With all the problems caused by the extremely dense wildfire smoke in Russia, it is timely that the provinces of Alberta and British Columbia have unveiled a new system for predicting where and in what concentrations wildfire smoke will occur.

When you visit the BC Air Quality web site an animation will begin. If there are no major fires burning, it may be difficult to see anything happening, but if you increase the Play Speed, it will become more obvious. The software is called Western Canada BlueSky Smoke Forecasting System and cost $95,000 to develop.


Russian smoke invades North America

Wildfire Today contacted the National Weather Service and asked if the massive amount of smoke generated by the wildfires in Russia is drifting across North America. They pointed us toward this narrative of smoke observed in satellite imagery on August 3, 2010. Here is an excerpt:

…Some of this smoke [in Alaska and northwestern Canada] was likely due to fires scattered across central and east central Alaska as well as northwestern Canada. However, it is possible that smoke from the fires in Russia was also being transported across the Arctic into this region. Another band of smoke which is likely from the Russian fires was seen in visible satellite imagery this evening through breaks in the clouds moving to the northeast across the Pacific between 44N170W and 49N161W. The smoke may extend even farther to the northeast, but cloudiness prevented additional information from satellite imagery.

A meteorologist also told us:

Based on the amount of smoke being produced by the Russian fires and at least this one occurrence [on August 3] of smoke being tracked across the eastern Pacific, I think it’s a reasonable assumption that some amount of smoke from Russia has made its way into North America. Unfortunately, cloudiness frequently interferes with the tracking of smoke and low stratus clouds are common across the eastern Pacific. If smoke from Russia is being transported into Canada and is obscured by cloudiness, we cannot verify where the smoke came from once it has arrived there especially with so many fires in Canada also producing copious amounts of smoke.

smoke map
NOAA map of smoke detected through satellite imagery, Aug. 9, 2010

And, if you are hungry for even more details, check out this very technical PowerPoint presentation about the Russian smoke. Clicking that link will download a copy of the file, possibly in a new window, depending on your browser.

Smoke in Russia

smoke from fires Russia
A group of tourist wearing masks to protect themselves from the smog walk in Red square in Moscow, Russia, 09 August 2010. EPA/Yuri Kochetkov

The carbon monoxide (CO) levels in parts of Russia caused by the numerous wildfires have been described as being five to seven times the maximum safe level, but the articles don’t specify the actual CO readings in parts per million. The U.S. National Ambient Air Quality Standards for CO levels in outdoor air are 9 ppm (40,000 micrograms per meter cubed) for 8 hours, and 35 ppm for 1 hour. CO cannot be filtered out by using cheap dust masks, bandannas, or “Hot Shield” masks unfortunately marketed to wildland firefighters.

The effects of CO are listed below.

effects of carbon monoxide

The smoke and CO is so severe that some are evacuating, including employees of the Canadian embassy.

On Sunday authorities in Moscow opened 120 “anti-smog” centers, air-conditioned rooms where residents can take a break from the record-setting heat and the smoke.

In the United States we have done the same thing at fire camps that were socked in with smoke trapped by inversions. In 1988 (and also other years) when the Logistics sections on fires in northern California set up tents with air filtration that were supposed to provide off-duty firefighters some relief from the smoke. (Was oxygen provided too? Can anyone provide more details about this?)

National Weather Service meteorologists say smoke from Russia has drifted all the way into Canada.

Wildfires in Russia may disperse radioactive particles from Chernobyl nuclear disaster

smoke in Moscow
A woman wears a mask in central Moscow to protect herself from smog caused by fires outside the city. Photograph: Mikhail Voskresensky/Reuters

The Russian government has warned residents that the wildfires burning through their country may pose a nuclear threat by releasing radioactive particles contained in trees and plants following the 1986 Chernobyl nuclear disaster.

The government claims that 160,000 people are fighting the numerous fires, but they appear to be losing the battle as additional fires worsen the situation, leaving at least 52 people dead and more than 3,500 homeless as entire villages are consumed in fires.

About 140 flights were delayed on Friday at the Moscow airport when smoke from the fires reduced the visibility at times to as little as 1,100 feet.

The Guardian reports that the Russian government is employing questionable tactics to put the best light on the wildfire situation:

United Russia, the pro-Kremlin party which dominates parliament, has boasted of sending volunteers to help extinguish the fires. But that claim was thrown into doubt yesterday when the party was accused of doctoring a photograph placed on its website.

A sharp-eyed blogger noticed that the picture showing volunteers apparently wrestling with a piece of timber in a smoky wood had been created in 2008 and altered in Photoshop last Saturday. The smoke, he claimed, had been added for effect.

United Russia immediately removed the picture but did not respond to requests for comment.