Ocean temperatures can predict Amazon fire season severity

From the  NASA/Goddard Space Flight Center

GREENBELT, Md. — By analyzing nearly a decade of satellite data, a team of scientists led by researchers from the University of California, Irvine and funded by NASA has created a model that can successfully predict the severity and geographic distribution of fires in the Amazon rain forest and the rest of South America months in advance.

Though previous research has shown that human settlement patterns are the primary factor that drives the distribution of fires in the Amazon, the new research demonstrates that environmental factors – specifically small variations in ocean temperatures – amplify human impacts and underpin much of the variability in the number of fires the region experiences from one year to the next.

“Higher than normal sea surface temperatures in the Atlantic and the Pacific proved to be red flags that a severe fire season was on its way in four to six months,” said Yang Chen, the University of California, Irvine, scientist who led the research. Chen and his colleagues found temperature changes of as little as .25°C (.45°F) in the North Atlantic and 1°C (1.8 °F) in the Central Pacific can be used to forecast the severity of the fire season across much of the Amazon.

The researchers believe that unusually warm sea surface temperatures cause regional precipitation patterns to shift north in the southern Amazon during the wet season. “The result is that soils don’t get fully saturated. Months later, humidity and rainfall levels decline, and the vegetation becomes drier and more flammable,” said James Randerson, a scientist at University of California, Irvine who co-authored the study.

To establish the connection between fire activity and sea surface temperatures the researchers analyzed nine years of fire activity data collected by Moderate Resolution Imaging Spectroradiometer instruments (MODIS) on NASA’s Terra and Aqua satellites and compared the number of fires to records of sea surface temperatures maintained by the National Oceanic and Atmospheric Administration. Years with anomalously cool ocean temperatures had fewer fires, while years that experienced unusually warm ocean temperatures experienced more fires. The team also looked for and found changes in precipitations patterns as measured by the Tropical Rainfall Measuring Mission (TRMM), a satellite managed jointly by NASA and the Japan Aerospace Exploration Agency (JAXA).

While a Columbia University-led study published in July of this year showed that sea surface temperatures in the Northern Atlantic could be used to forecast fire severity across the a small section of the western Amazon in Peru and Brazil, the new study considers a much broader swath of South America and takes into account how ocean temperatures in both the Pacific and Atlantic Oceans affect the continent’s fires.

The University of California, Irvine team also developed and validated an innovative computer model that they used to predict 2010 fire activity and could be used to forecast fire season severity in the future. The team’s model successfully predicted that prolonged drought and severe fires would occur during the 2010 fire season, which is exactly what happened.

“Fire activity can vary dramatically. Satellites detected about twice as many fires during 2010 as they did in 2009,” said Doug Morton, a scientist based at NASA’s Goddard Space Flight Center in Greenbelt, Md. who coauthored the new study. The researchers have to wait a few more months before they can determine whether the model’s predictions for the 2011 fire season were also accurate.

“For the 2010 season, the model successfully captured not only the severity of wildfire activity, but it also got much of the east-west spatial distribution right,” said Randerson. By looking back at a full decade of data, the scientists noticed a distinctive pattern: fires in the southern and southwestern part of the Amazon were most strongly influenced by sea surface temperatures in the North Atlantic, but fires in the eastern part of the Amazon were strongly affected by sea surface temperatures in the central Pacific.

A number of different types of fires occur in the region, including fires for deforestation, agricultural management, and wildfires in savannas and tropical forests. In addition to successfully predicting the overall fire severity, the model also captured the variability in forest and savanna fires from one year to the next when considered separately.

The researchers are optimistic that the findings may help serve as the foundation of an early warning system for fires that would help South American authorities prepare for severe fire seasons. Morton noted an early warning system could play a critical role in helping authorities blunt the negative impacts of heavy fires years such as those the region has experienced in 2005, 2007, and 2010.

Fire activity is a growing concern in the Amazon, a humid region that would experience very few fires in the absence of human activity. “Deforestation rates in the Amazon have declined significantly in recent years due to government regulations, but fire activity has been holding steady and even going up in some areas due to increases in escaped agricultural fires,” said Ruth DeFries, a scientist at Columbia University, New York, and a co-author on the paper.

South American fires have a particularly important impact on climate. Fires from deforestation contribute about half of the carbon emissions from deforestation in South America and a recent analysis showed that for the continent creates about 15 percent of the worldwide carbon emissions from fires. Climate models predict that the region will receive less rainfall as climate change progresses, which would increase the risk of forest fires and lead to greater carbon emissions.

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The study was published in the Nov. 11th edition of Science. Researchers from Duke University, Columbia University, and the University of Maryland are also coauthors on the study.

For more information and related images, please visit:

http://www.nasa.gov/mission_pages/fires/main/amazon-fire-season.html

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24 thoughts on “Ocean temperatures can predict Amazon fire season severity

  1. “South American fires have a particularly important impact on climate. Fires from deforestation contribute about half of the carbon emissions from deforestation in South America and a recent analysis showed that for the continent creates about 15 percent of the worldwide carbon emissions from fires. Climate models predict that the region will receive less rainfall as climate change progresses, which would increase the risk of forest fires and lead to greater carbon emissions.”

    ####

    Suprising result for an area that constitutes 12% of the worlds land, including antartica.

  2. a recent analysis showed that the continent creates about 15 percent of the worldwide carbon emissions from fires
    ===============================
    yea, we’re down to only a 85% unaccounted for…………/snark

  3. And the oceans temps in the NH don’t effect the frequency of forest fires – seems like a worthwhile follow-up study. That darn ocean, which we thought was only a home for fishes, is more important than we thought.

  4. The conditions in the years/months preceding the fires which determine the eventual fuel loads may also need to be incorporated into the modeling.
    Interestingly, it has been observed in some blue gum plantations in Australia that dense growth actually reduces, even stops the spread of fires through some such plantations, it is thought due to restrictions of the oxygen supply by the dense foliage.

  5. People might be interested in the current slashdot ( http://slashdot.org/ ) which has a ‘vote now’ on whether climate change is real or not. The ‘Yes it is!’ crowd are winning by about 5:1….

  6. “The researchers believe that unusually warm sea surface temperatures cause regional precipitation patterns to shift north in the southern Amazon during the wet season.”

    Are there no records of precipitation for these regions that might – or might not – confirm such a shift ? Speculation is such a poor substitute for physical evidence.

    Was no research undertaken in the regions concerned to measure the moisture content of soil and vegatation ? Well, no actually; but then sitting in a comfortable lab on a well-funded campus is so much more agreeable than wandering around, ever so slightly moist, in wild places.

  7. I thought most fires in Amazonia were deliberately set to clear forest for agribusiness. So, with La Niña conditions in the Pacific, do we expect fewer fires next year or will there continue to be many fires due to “human settlement patterns”?

  8. The fire season still seems to be concentrated around the parts of the amazon where clearing is or has taken place.
    And…
    “Climate models predict that the region will receive less rainfall as climate change progresses, which would increase the risk of forest fires and lead to greater carbon emissions.”.
    Of course as there are more forest fires the models are proved correct, so it’s impossible for the the fires to have been caused by people lighting fires deliberately, or that clearing the trees will change the hydrology including the ability of the land to hold water. I mean, why would removing trees mean that rain water would run off the land quicker, instead of being held back by all those trees where it can hang about and get evaporated and turned into rain. No, that’s not what happens.

  9. “Fire activity is a growing concern in the Amazon, a humid region that would experience very few fires in the absence of human activity.”
    I have another reason for the increased fire activity during the dry years. Have you ever tried to start a fire in the rain and everything is wet? Obviously the slash and burn subsistence agriculturalists have figured it out.

  10. Since carbon (CO2) emissions are good, it’s kind of moot, but the burned-over areas start regrowing immediately, which is a carbon(-dioxide) sink. The issue is irrelevant, except for funding grabs.

  11. Dodgy Geezer says: November 11, 2011 at 1:30 pm
    [... slahdot .. vote now’ on whether climate change is real or not]

    Oh, well I guess the children took a break from their constant Windows vs. Linux ‘debate’ , and the Apple is better than Zune ‘debate, and the Google is/is not evil ‘debate’ , and the other self-informed diatribes they persist with. Let them have their fun, they don’t get out much and sice it is dark in the basement many do not understand what the Sun actually is, let alone what it could do.

    Leave them be, it is just another computer game for them to play, don’t spoil their fun.
    We were all young and knew everyting once. It is their time now.

  12. What does “red” mean, what does “blue”? Why is all the color in the dry grass areas of SA and not the Amazon, but a lot of the text seams to focus on jungle. Its like saying that the US is Earthquake prone because of California.

  13. This was fully known before, at least by those that had examined the rainfall patterns produced by the ENSO.

    Every additional study showing this (and there have been many others), makes it more difficult for the pro-AGW exaggerators to get away with predicting that the Amazon will dry up due to climate change (and there have lots of those produced as well, many by the WWF which are cited by the IPCC for example).

  14. “Higher than normal sea surface temperatures…”
    Half the time we expect something to be higher than normal.

  15. These researchers didn’t already know that during an El Nino year, the Walker circulation drops down on Brazil?

  16. Well, my BS meter jumped when I read the title, then it pegged after trying to figure out that graphic. I couldn’t read more after the first sentence. Almost a decade? Out of how many millions of decades of climate? I decided to force myself to keep reading. Predict successfully? How many decades have they tracked these predictions? They admit humans are the main factor, then pretend their model still shows the catastrophic affects of AGW. Hmm… I couldn’t take it. I had to skip through. I notice they think there is some way it will help plan for fighting forest fires. I doubt anyone will notice. They will do what they can every year. A bad year will still be a bad year.
    I also appreciate the comments regarding doing all this research in an air conditioned lab with satellite data and virtual reality models. I don’t see much science, just confirmation bias.

  17. “…a model that can successfully predict the severity and geographic distribution of fires in the Amazon rain forest and the rest of South America months in advance.”

    This claim is BS. They made no predictions. The paper describes after-the-fact fitting of a model to the observations.
    The authors need to make a prediction for a future season, then wait to see if it is correct. Then repeat 10 or 20 times, and keep track of how accurate the predictions are. Only then can they start to lay claim to being able to successfully predict anything.

  18. Eventually, those fire-dry, barren South American and African soils are picked up by the wind and carried over the oceans where they fall as fertilizer. The natural cycles of Earth and all life in it are rich in energy, complicated, robust, and VERY resistent to political say-so.

    These cycles are made up of both large and small drivers, but clearly the trades and oceans are the major equatorial players. A little more or less CO2, regardless of the source, can barely change the direction of wind-blown gnat’s ass hair.

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