When the Fourmile Canyon fire was burning west of Boulder, Colorado in September, 2010, Jim Roberts, a chemist with NOAA’s Earth System Research Laboratory, was surrounded by something he had previously studied at the U.S. Forest Service’s Missoula Fire Science Laboratory in Montana — smoke, and lots of it. In Missoula he used a new instrument they had built, a custom mass spectrometer, to examine the levels of isocyanic acid in the atmosphere and in smoke. Isocyanic acid has been difficult to detect with conventional measurement techniques. At Missoula, he measured the levels of the chemical in smoke generated when the researchers burned vegetation in the lab and in cigarette smoke.
When the Fourmile Canyon fire started, Roberts had the mass spectrometer at the University of Colorado at Boulder’s Cooperative Institute for Research in Environmental Sciences.
Here is an excerpt from the Daily Camera:
Isocyanic acid easily dissolves in water, which makes it possible for the acid to also dissolve into moist tissues in the body, including the lungs. The full health effects of exposure to isocyanic acid in the air aren’t fully understood, but the chemical has been linked to cataracts, cardiovascular disease and rheumatoid arthritis.
Last September, the researchers had the opportunity to measure the presence of the acid in a real wildfire. On Labor Day, the Fourmile Fire began burning in the foothills west of Boulder, just a few miles upwind of the state-of-the-art atmospheric instruments housed at NOAA’s campus on Broadway.
“Boulder has a world-class atmospheric chemistry building and only once in its lifetime is it going to have a full-on hit from a wildfire,” said Joost de Gouw, a co-author of the study and a researcher at the Cooperative Institute for Research in the Environmental Science. “So just everyone in that building turned on their instruments.”
CIRES is a joint institute of the University of Colorado and NOAA.
The sensitive new spectrometer used in Missoula also picked up the isocyanic acid in the plume of smoke from the Fourmile Fire.
Smoke from a prescribed fire in southern Mississippi caused a chain-reaction crash that involved a school bus on Friday. The U. S. Forest Service conducted a prescribed fire near Bethel Road in Harrison County which produced smoke that mixed with fog, reducing the visibility to near zero. As the school bus entered the smoke on Highway 15, the driver quickly slowed down and was hit from behind, followed by a six-vehicle chain-reaction crash. Thankfully there were no serious injuries.
Mississippi Highway Patrol spokesman Master Sergeant Johnny Poulos said:
The conditions today were not favorable for safe driving. We have the fog that came in that actually kept the smoke down to the roadway. Just a really bad situation when you’re trying to drive and navigate, especially with a school bus.
The Forest Service had signs posted on the highway that warned drivers about the smoke. Spokesman Mario Rossilli released a statement for the agency:
Safety is a top priority for the National Forests in Mississippi. Fortunately, according to reports, there were no serious injuries sustained in the accident today. The National Forests in Mississippi has already begun what will be a comprehensive review of this incident. We are always looking for ways to further enhance safety. Prescribed burning is actually one method of creating a safer forest environment for visitors, including those in vehicles, by reducing the threat of catastrophic wildfire. Stakeholders, including local, county and state law enforcement are notified before burns are initiated. Our Forest Service Law Enforcement Officers are active participants in our prescribed burns.
Here is a video about the accident from WLOX in Biloxi, MS:
Much of the emphasis appears to be directed at how to deal with the public’s perception and tolerance of smoke. Smoke is becoming an increasingly sensitive subject to the population due to larger wildfires burning for longer periods of time, concern about the effects of wildfire smoke on global warming, and prescribed fires continuing to be an important tool for land managers.
One aspect of wildfire smoke that Wildfire Today has written about frequently is the short and long term effects of smoke on the health of firefighters. On April 23, 2010 we covered the study that NIOSH and the U.S. Fire Administration are conducting about cancer among structural firefighters. We called out the land management agencies and the firefighting associations:
There needs to be a concerted effort to conduct a similar study on wildland firefighters. It should be led by a physician/epidemiologist and should evaluate the long term health and occurrence of cancer and other diseases among wildland firefighters. There is a lot of grant money out there and it should be possible to get some of it pointed towards this overlooked niche of firefighting.
The JFSP five-year plan does mention research on the effects of smoke on wildland firefighters, but at times it seems like an afterthought. For example, the objective for one of four research themes, “Smoke and Populations”, sometimes includes the “impact of smoke on populations” (page 26), and in other places it is described as “impact of smoke on populations and fire fighters” (page 21).
However, the plan does list some specific “Smoke Science Foci” that may benefit firefighters:
- 2011: (SSP T3 -2): Epidemiological research/literature review to determine human health risk from high PM loadings.
- 2011 (SSP T3-4): Fire fighter smoke health hazards: trends in health and exposure.
- 2012 (SSP T3-5): Review of epidemiological research to determine human health risk from high PM, high ozone and high aromatic hydrocarbon loadings with a focus on synergisms between pollutants.
We hope that the “foci” turns into actual research.
After burning for 10 days, the Arabia Bay fire in south Georgia continues to put up a great deal of smoke as it slowly eats its way through a swamp northwest of Homerville. Smoke from the fire has required some highways to be closed temporarily, as well as the Clinch County school system which had to close yesterday. The Clinch Memorial Hospital had to transfer several patients with respiratory issues to South Georgia Regional Medical Center in Valdosta.
On Thursday firefighters conducted a 300-acre burnout to secure the area around the Arabia Bay Church on the southeast corner of the fire. On Friday, weather permitting, they expect to continue the burnout on the east side to secure that flank. So far, 1,170 acres have burned and the fire is being managed by Steve Abbot’s Type 3 Incident Management Team along with a total of 38 personnel. They are calling it 50% contained.
Firefighters have constructed a tractor plow line around the entire 5,000-acre swamp but are unable to fight the fire directly out in the wetlands. Their strategy is to wait for the fire to burn up to their prepared lines, and conduct burnouts when they can. It is likely that the entire swamp will burn eventually.
The Georgia Forestry Commission is posting occasional updates on Facebook.
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.
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?)
…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.