Posted on 12/26/2006 12:49:04 PM PST by NormsRevenge
GRANTS PASS, Ore. - Using fire scars on nearly 5,000 tree stumps dating back 450 years, scientists have found that extended periods of major wildfires in the West occurred when the North Atlantic Ocean was going through periodic warming.
With the North Atlantic at the start of a recurring warming period that typically lasts 20 to 60 years, the West could be in for an extended period of multiple fires on the scale of those seen in 2002 and 2006, said Thomas W. Swetnam. He's the director of the Laboratory of Tree Ring Research at the University of Arizona and a co-author of the study published in the Dec. 26 issue of the Proceedings of the National Academy of Sciences.
"This study and others have demonstrated that there is an underlying climatic influence on fuels and then on the weather conditions that promote fires," said Dan Cayan, climate researcher at the Scripps Institution of Oceanography, who did not take part in the study.
Ron Neilson, a U.S. Forest Service scientist who has developed models that predict wildfire danger based on climate models, agreed with the study's conclusions, and noted all the oceans are affected by global warming. And that in turn could exacerbate the wildfire cycle.
Scientists have long seen a relationship between weather in the United States and El Nino, a warming of water in the South Pacific.
When El Nino is strong, the Northwest typically has drought and severe fire seasons, and the Southwest has rain. When the cycle reverses, known as La Nina, the South Pacific cools, the Northwest has more rain, and the Southwest has drought and fires.
Less well understood are two other climate drivers, the Pacific Decadal Oscillation, known as the PDO, centered in the North Pacific, which typically changes every 10 to 20 years, and the Atlantic Multidecadal Oscillation, or AMO, which is marked by warming and cooling periods of 20 to 60 years in the North Atlantic.
El Nino-La Nina is thought to be the most influential cycle, but the Atlantic and Pacific oscillations can magnify or diminish those effects when strong phases of the three cycles come together, Swetnam said.
"Over the last 400-plus years in our fire history study, when the AMO was positive (producing warm temperatures in the North Atlantic), then you would get big fires breaking out synchronously across the West," Swetnam said. "That's what we saw in 2002 and 2006."
The year 2002 saw three huge fires that stretched firefighting resources to the breaking point: Biscuit burned 500,000 acres in southwestern Oregon, Rodeo-Chedeski burned 462,000 acres in Arizona, and the Hayman fire burned 136,000 acres in Colorado.
In 2006, 89,000 fires burned across 9.5 million acres. The U.S. Forest Service spent $1.5 billion fighting those fires — about $100 million over budget.
Another factor in the larger fires, said Swetnam, is that after a century of fighting wildfires, fuel is building up in the nation's forests.
The study gathered data from 241 logging sites around the West, compiling the dates of 33,795 fire scars on 4,700 stumps to develop a history of fires in the West dating to 1550.
The fire history was compared to a reconstruction of the Atlantic Decadal Oscillation, the Pacific Decadal Oscillation, and El Nino.
The most severe fire seasons fell between 1660 and 1710, when the Atlantic Multidecadal Oscillation was at its warmest, the study found. The least severe fire seasons happened from 1787 to 1849, when North Atlantic temperatures were at their coolest.
The study comes after another published this year in the journal Science found that a sudden and dramatic increase in western wildfires in the late 1980s was related to a pattern of earlier springs and warmer summers. Swetnam and Cayan both took part in that study.
Greg McCabe, a climatologist for the U.S. Geological Survey in Denver, said his research has been showing a connection between North Atlantic Ocean temperatures and the drought that is gripping much of the West, which creates conditions for major fires.
"I think what Tom has written is really good," McCabe said. "More and more people are starting to see there is something there. We do know the tropical Pacific (home to the ocean warming condition known as El Nino) is a key player in global climate. But on longer time scales it looks like the Atlantic also has some influence."
I would guess wildfire is related somehow to rainfall. When it is hot here that usually means it hasn't rained at all except some lightning storms.
Lovely timing, Mother Nature, right at the point where there are going to be fewer and fewer adminstrative managers to work fire season each year...and they will be open to greater and greater liability when things go wrong....
study links scientist to begging for grants
let them get real jobs
maybe in service or health sector like the rest of us
But if it gets dry enough, you get seasons with very little dry lightning, not that I'd wish that on the West, seeing how I live out here...
Well, they should saw Helen Thomas and Sen. Byrd, and study the rings.
Last year it was damp and cool enough to not have a full blown fire season. Not that it rained noticeably, but it was damp a lot after the end of June.
I wish there was a hint of a causal explanation here. How does a warmer Atlantic affect forests that are, practically speaking, upwind?
They are doing real jobs. You might not approve of the system, or how it's financed, but it is important info in the long run that helps people know how to deal with lands, their management, protecting watershed so people have enough water to drink, ranching use and, when you can keep the greens under control, lumber use.
The watershed use, weather forecasting and working with what's called urban-wildland interface' areas so they don't go up in smoke at great cost to the public sector are probably the most important areas that this research impacts.
you mean 2006? how about 9.8 million acres burned. The year before that it was a split between Alaska and the lower 48. But the year before that was one of those lovely years where only Alaska got heavy burning in any quantity.
It was also a bust for agriculture. Even the black spruce hardly grew an inch. Too cool, not enough rain.
If you look at fire season histories, not uncommon for years with incredibly bad fire years to be followed by a year that is too dry to burn much...
With no link to the so-called "greenhouse gases" evidently(?)
IMHO, they overplay man's impact, regularly...Study the longterm climatology of the world, and you will find the temps go up and down a lot as several oscillations do their thing...
In other news, Dr. Spock, a Vulcan scientist from a distant planet, has developed a model that predicts wildfire danger and global warming are due to "dark energy forces of dying stars" about 26 light years away from earth. Because all stars are related, our sun develops "sun spots" (a dark spot in remembrance of fallen stars) which directly cause these environmental problems. For more details, please go to "catchafallenstar.com".
Ya....because when I think "Trees", I think "Arizona".
Thanks!
It's all becoming much clearer now,, dark energy and all. lol
Some real links where you can learn more about this sort of stuff for real:
http://www.firelab.org/
http://www.nifc.gov/
http://www.fs.fed.us/rm/
http://www.fs.fed.us/rm/main/fire_res.html
http://www.treesearch.fs.fed.us/
Hey buddy, as an analytical chemist, I've spent 16 years "in the system" and have made many observations at many levels and I'd have to conclude that "analytical, objective science" doesn't exist anymore in the US and will probably not exist for some time to come. Now political science............that's a different story.
Having said that, I think it's only fair that I'll share a thread with you. "This thread is at an executive level", above the numbers and stuff.....
http://www.freerepublic.com/focus/f-news/1753276/posts
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