Lee side slope fire behavior. A wind eddy on the lee slope can push the fire up the slope opposite the prevailing wind direction. At the ridge top, the fire can also move horizontally, 90 degrees off the main wind direction. Screen grab from the video.
In November, 2012 we wrote about some of the research that was conducted to study and document what can only be described as a fire tornado in Australia, a tornado-like event that can be generated by a wildfire. In recent years a new term has been coined — firenado — which seems appropriate.
It occurred near Chapman in the Australian Capitol Territories during the McIntyres Hut Fire January 18, 2003. After studying the event, Rick McRae of the ACT and others discovered that it traveled across 25 kilometers at 30 kph (19 mph), had horizontal winds of 250 kph (149 mph), and vertical winds of 150 kph (93 mph). Damage that occurred to trees and structures is much like what you would see after a tornado in Oklahoma.
Australia’s ABC TV produced an excellent video that goes surprisingly deeply into some of the scientific principles of this phenomenon, including fire behavior when a strong wind pushes a fire up a slope. This can result in spot fires at the bottom of the slope on the other side, the lee slope, which can be pushed rapidly up the lee slope by a wind eddy in the opposite direction of the prevailing wind (see the screen grab above from the video). They also documented how a fire at the top of the ridge can travel across the ridge at 90 degrees to the direction of the prevailing wind.
Knowledge about this kind of fire behavior is something that wildland firefighters should retain in their “slide file”, in the unfortunate event that they find themselves in danger of being entrapped and are considering using the lee side of a ridge as an escape route or a sheltering location.
Check out our November, 2012 article for more information about this 2003 event. The video below illustrates some of the findings developed by the fire researchers.
The information in the video can be even more interesting when considered along with the winds at the site of the Yarnell Hill Fire entrapment, as modeled by WindWizard. The image below is from page 79 of the Yarnell Hill Fire SAIT report. Click the image to see a slightly larger version.
Tractor plow at the 2002 Blackjack Bay Fire, Okeefenokee NWR, Florida and Georgia. Photo by Bill Gabbert
We did some research on the history of line of duty deaths involving the operators of tractor plows while working on fires.
Most, but not all, of the incidents are listed in the NWCG publication “Historical Wildland Firefighter Fatalities 1910 – 1996”.
The site of the 1998 tractor plow fatality in Arkansas. NIOSH photo.The underside of a tractor plow at the 2002 Blackjack Bay Fire, Okeefenokee NWR, Florida and Georgia. Photo by Bill Gabbert
Federal employees working for the United States Forest Service and the citizens of the United States have published the results of research done on behalf of the taxpayers, titled Climate Change and Wildfire. If you want to read it you will have to pay $35.95 to the for-profit Elsevier corporation headquartered in the Netherlands that published the paper. It was written by research meteorologists Yongqiang Liu and Scott Goodrick from the Forest Service’s Southern Research Station (SRS) and Warren Heilman from the Northern Research Station. The concept of Open Access to taxpayer-funded research still has a long way to go in the U.S. Forest Service.
Below are some highlights of the research, according to the USDA Forest Service’s Southern Research Station. We will have to take their word for it. The agency suggests that “for the full text of the article” go to the Elsevier web site, where you have to pay $35.95.
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(UPDATE at 11:44 a.m. MST, February 24, 2014)
After we reached out to her and left a message, we received a phone call today from Zoë Hoyle, the author of the press release about the research that was issued May 20, 2013. She said the link to the full text of the article which directed web site visitors to the pay wall was an error. She said the usual practice of USFS researchers is to place their results on http://www.treesearch.fs.fed.us/ where they can be read at no charge, but that still has not taken place. Ms. Hoyle said, however, that the paper should be on treesearch by the end of this week.
In the meantime, one of our readers, Liz H., used Google Scholar to find a copy of it at firescience.gov. Thanks Liz.
And thanks go out also to Ms. Hoyle for correcting the oversight. We are pleased to hear that the usual practice of the USFS is to publish their research on treesearch, an open access format on the internet.
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(UPDATE at 1:54 p.m. MST, February 24, 2014)
Ms. Hoyle contacted us again to let us know that the USFS was able to expedite the placement of the research paper on treesearch, where it can now be viewed without having to pay the company from the Netherlands $35.95.
Here is one of the illustrations from the paper, about the interactions between the climate and fire.
Below is an excerpt from the May 20, 2013 USFS news release about the research.
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“While research has historically focused on fire-weather interactions, there is increasing attention paid to fire-climate interactions,” says Liu, lead author and team leader with the SRS Center for Forest Disturbance Science. “Weather, the day-to-day state of the atmosphere in a region, influences individual fires within a fire season. In contrast, when we talk about fire climate, we’re looking at the statistics of weather over a certain period. Fire climate sets atmospheric conditions for fire activity in longer time frames and larger geographic scales.”
Wildfires impact atmospheric conditions through emissions of gases, particles, water, and heat. Some of the article focuses on radiative forcing from fire emissions. Radiative forcing refers to the change in net (down minus up) irradiance (solar plus longwave) at the tropopause, the top of the troposphere where most weather takes place.
Smoke particles can generate radiative forcing mainly through scattering and absorbing solar radiation (direct radiative forcing), and modifying the cloud droplet concentrations and lifetime, and hence the cloud radiative properties (indirect radiative forcing). The change in radiation can cause further changes in global temperatures and precipitation.
“Wildfire emissions can have remarkable impacts on radiative forcing,” says Liu.
“During fire events or burning seasons, smoke particles reduce overall solar radiation absorbed by the atmosphere at local and regional levels. At the global scale, fire emissions of carbon dioxide contribute substantially to the global greenhouse effect.”
Other major findings covered in the synthesis include:
The radiative forcing of smoke particles can generate significant regional climate effects, leading to lower temperatures at the ground surface.
Smoke particles mostly suppress cloud formation and precipitation. Fire events could lead to more droughts.
Black carbon, essentially the fine particles of carbon that color smoke, plays different roles in affecting climate. In the middle and lower atmosphere, its presence could lead to a more stable atmosphere. Black carbon plays a special role in the snow-climate feedback loop, accelerating snow melting.
Land surface changes may be triggered that also play into future effects. “Wildfire is a disturbance of ecosystems,” says Liu. “Besides the atmospheric impacts, wildfires also modify terrestrial ecosystem services such as carbon sequestration, soil fertility, grazing value, biodiversity, and tourism. The effects can in turn trigger land use changes that in turn affect the atmosphere.”
The article concludes by outlining issues that lead to uncertainties in understanding fire-climate interactions and the future research needed to address them.
Full text of the article: [note from Bill. We deleted the link to the for-profit web site with the pay wall]
President Obama to meet with western governors about wildfire funding
On Monday President Obama will meet with the governors of some western states to discuss a change he is proposing in next year’s budget about how wildfires are funded. A busy and expensive wildfire season means the federal land management agencies have to rob dollars from routine ongoing non-fire activities to pay unusually high fire suppression expenses. And these busy and expensive fire seasons seem to be occurring with more regularity in recent years. The budget proposal for fiscal year 2015 would be similar to a bill introduced in the House, the Wildfire Disaster Funding Act of 2014 (H.R. 3992), which would create an emergency funding process for fire response. The funding mechanism would be structured along the same lines as procedures for paying for other natural disasters like floods and hurricanes.
Wildfires challenged early pioneers
The Santa Fe New Mexican has an interesting article by Marc Simmons about how early settlers had to occasionally deal with prairie fires as they traveled by horseback and wagon train across New Mexico and west Texas. Below is an excerpt:
…On another trip [in the 1830s, Josiah] Gregg’s caravan was chased by an approaching prairie fire, and it escaped just in time by reaching a bare stretch of country, devoid of grass. “These conflagrations,” he wrote, “are enough to inspire terror and daunt the stoutest heart.”
Capt. Randolph B. Marcy, leading a military expedition across the Southwest in the 1850s, had an experience similar to Gregg’s. One of his soldiers carelessly caught the grass on fire, threatening the supply wagons. He declared that only the most strenuous efforts by his 200 men in setting counter fires around the train saved the expedition from disaster.
Great danger, he said, came from troops throwing a lighted match or ashes from a pipe into the grass while marching. Matches were just then coming into general use, so that was a new problem.
When a prairie fire struck, various steps could be taken in the emergency. Marcy mentioned one, setting a counter or back fire. The hope was when the two fires met, the progress of both would be checked and they would die out.
However, we question something the author identified as one of the causes of fires that threatened travelers:
…But the sun could be blamed on occasion, when its refracted light on a piece of broken glass or bit of metal cast off by a wagon train set the grass ablaze.
It is very unusual for glass, broken or otherwise, to start a fire. But if a bottle contains water, in very rare circumstances it can act like a lens and concentrate sunlight, similar to a magnifying glass. We have never heard of an ordinary piece of metal causing a fire.
Utah’s “firefighting cows”
In recent years ranchers and state lawmakers in Utah have argued with the federal government over water rights on federal land that is used by cattle ranchers. In order to bolster their case, some of the ranchers point out that the animals reduce vegetation — and the threat from fires.
Utah is a “livestock state” that recognizes the benefits that cattle confer on pubic lands, including keeping vegetative overgrowth at bay and thus reducing wildfire threats, said Sterling Brown of the Utah Farm Bureau.
“Cattle are one way to properly manage public lands,” he said. “We have deemed much of our livestock as firefighting cows because they have helped reduce fires out there.”
An article by J. P. Plutt on the University of Montana Extension site describes how to quickly construct a helicopter dip tank or water reservoir with hay bales and a tarp. Add a pump and some fire hose and it can be used to protect a structure…
An article in the Washington Post claims the Administration intends to reinstate the competitive sourcing program within the U.S. Forest Service in 2009. The author, Stephen Barr, raises some interesting issues about how this could affect responses to fires and other emergencies…
The Sonoma County widow of one of two air tanker pilots killed while fighting a fire in Mendocino County in 2001 has lost her bid to seek federal death benefits.
The U.S. Supreme Court on Tuesday denied an appeal filed by Christine Wells-Groff of Windsor to seek federal death benefits for her and other widows of firefighting pilots, including the widow of a Redding man, killed in the line of duty…
Jeanne Pincha-Tulley, Incident Commander of one of the Type 1 Incident Management Teams in California, was featured earlier in a story in The Union in Grass Valley, California. Here is an excerpt…
Yesterday the latest version of the drought monitor for the United States was released, current as of February 18. Below is the description:
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“During the past week, a persistent pattern of ridging (high pressure) over the Southwest and troughing (low pressure) over the East prevailed. Unfortunately, the ample moisture that finally visited drought-ravaged California (especially north-central sections) last week was shunted northward by the southwestern ridge into the Pacific Northwest this period, dumping widespread precipitation totals of 4-8 inches, locally 12-18 inches, from extreme northwestern California into western Washington. Additionally, the precipitation was accompanied by mild air, producing mainly rain instead of snow in southern sections of the Cascades in Oregon and limiting any snow pack increase for those mountains.
Farther north, however, the precipitation fell as snow in the northern Cascades (Washington) and northern Rockies, increasing the average basin SNOTEL snow water content by 10-20 percentage points in six days (from Feb. 12 to 18). Farther east, a series of winter storms brought wintry precipitation to the Midwest (light to moderate snow), Southeast (severe icing in Georgia and South Carolina), and the Northeast (heavy snow) as cold air remained entrenched in those regions. In contrast, dry and mild weather continued in the southwestern quarter of the Nation, further degrading conditions there. In Hawaii, scattered showers continued, with Kauai and Oahu receiving the greatest totals, while Puerto Rico and most of Alaska saw light precipitation, except for moderate amounts (more than 2 inches) in the southeastern Alaskan Panhandle.”
