Sea change can forecast South American wildfires

Nov 10, 2011
A NASA satellite captured this image of active fires along the Madeira River in Brazil in 2010, a year that had unusually high fire activity. Fires are shown in red and plumes of gray smoke are visible. Credit: Credit: NASA/Earth Observatory

Tiny temperature changes on the Atlantic and Pacific oceans provide an excellent way to forecast wildfires in South American rainforests, according to UC Irvine and other researchers funded by NASA.

"It enables us three to five months in advance to predict the severity of the fire season," said UCI assistant project scientist Yang Chen, lead author of a paper that will be published Friday, Nov. 11, in the journal Science.

Wildfires, once rare in tropical forests, have become a major threat to humans and biodiversity across an "arc of deforestation" in Brazil, Bolivia and Peru due to clear-cutting and agricultural burns. The study's authors said the new findings could aid fire and public health officials, planners issuing burn permits, and broader efforts to stem climate change. Rainforests are vital carbon dioxide storage basins, and woodlands consumed by fire across the southern continent are responsible for about a quarter of the released from forests globally.

"This work has very clear implications for conserving ," said co-author James Randerson, UCI professor. "During the 21st century, there are expectations that drought may intensify, and forests may become even more vulnerable. Understanding in advance whether you're going to have an exceptionally bad year will become critically important for managing them."

The prediction method is similar to that for storms. Just as can be harbingers of powerful Atlantic hurricanes or conditions that influence rainfall in California and elsewhere on the Pacific Rim, they can be used to model drought-inducing atmospheric changes. Utilizing archival satellite data from NASA, Chen and fellow scientists painstakingly plotted a decade of water and wildfire duration and intensity across central South America.

They found that temperature increases of as little as a quarter of a degree Celsius on the Atlantic and a single degree on the Pacific matched up with more deadly blazes across broad swaths of the Amazon over the next year.

"These changes are slight, but they trigger big effects in these tropical forest ecosystems," Chen said. Ocean temperatures affect atmospheric winds and clouds that can reduce or increase rainfall over the continent.

The scientists tested their theory by forecasting – based on water temperature readings – South America's 2010 fire season and then checking actual data afterward. Their accuracy was striking. Last year saw the biggest temperature increases on both oceans and, several months later, far drier conditions on land.

"We predicted a massive spike in fires in 2010, and it occurred," said Randerson, citing conflagrations across hundreds of miles. In one state, they had forecast worse fires than occurred, then learned later that officials there had sharply reduced clear-cutting the year before. Overall, while deforestation has declined in the past decade, wildfires have not because of prescribed farming burns that escape into nearby woods.

The scientists are compiling data for the 2012 fire season and plan to release their findings this winter for officials to use next year. The next step will be to see if the prediction method works for forests in Siberia, Indonesia and West Africa.

Explore further: Bridgmanite: World's most abundant mineral finally named

Provided by University of California - Irvine

5 /5 (1 vote)

Related Stories

Future fire -- still a wide open climate question

Jul 07, 2011

How the frequency and intensity of wildfires and intentional biomass burning will change in a future climate requires closer scientific attention, according to CSIRO's Dr Melita Keywood.

Deforestation reduces rainfall in Africa

Sep 19, 2011

Deforestation in the rainforests of West Africa reduces rainfall over the rest of the forest, according to new University of Leeds research published in Geophysical Research Letters.

Prescribed burns may help reduce US carbon footprint

Mar 17, 2010

The use of prescribed burns to manage Western forests may help the United States reduce its carbon footprint. A new study finds that such burns, often used by forest managers to reduce underbrush and protect bigger trees, ...

Study: Climate adds fuel to Asian wildfire emissions

Apr 30, 2009

In the last decade, Asian farmers have cleared tens of thousands of square miles of forests to accommodate the world's growing demand for palm oil, an increasingly popular food ingredient. Ancient peatlands ...

Recommended for you

Bridgmanite: World's most abundant mineral finally named

15 hours ago

A team of geologists in the U.S. has finally found an analyzable sample of the most abundant mineral in the world allowing them to give it a name: bridgmanite. In their paper published in the journal Science, the te ...

Volcano in south Japan erupts, disrupting flights

22 hours ago

A volcano in southern Japan is blasting out chunks of magma in the first such eruption in 22 years, causing flight cancellations and prompting warnings to stay away from its crater.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.