A new analysis of sediment cores from the burned area revealed that this was the most destructive tundra fire at that site for at least 5,000 years. Models built on 60 years of climate and fire data found that even moderate increases in warm-season temperatures in the region dramatically increase the likelihood of such fires.
The study was published this October in the Journal of Geophysical Research.
After the Anaktuvuk fire, University of Illinois plant biology professor Feng Sheng Hu sought to answer a simple question: Was this seemingly historic fire an anomaly, or were large fires a regular occurrence in the region?
“If such fires occur every 200 years or every 500 years, it’s a natural event,” Hu said. “But another possibility is that these are truly unprecedented events caused by, say, greenhouse warming.”
On a trip to Alaska in 2008, Hu chartered a helicopter to the region of the Anaktuvuk fire and collected sediment cores from two affected lakes. He and his colleagues analyzed the distribution of charcoal particles in these cores and used established techniques to determine the approximate ages of different sediment layers.
The team found no evidence of a fire of similar scale and intensity in sediments representing roughly 5,000 years at that locale.
The researchers then analyzed 60 years of fire, temperature and precipitation records from the Alaskan tundra to determine whether specific climate conditions prevailed in years with significant tundra fires. They developed a model relating the tundra area burned in Alaska each year to the mean temperature and precipitation in the warmest period of the year: June through September.This analysis uncovered a striking pattern, Hu said.
For the past 60 years, annual mean temperatures during this warm season have fluctuated between about 6 and 9 degrees Celsius (42.8 to 48.2 degrees Fahrenheit), with temperatures trending upward since 1995. In 2007, the year of the historic fire, the mean temperature was a record 11.1 degrees Celsius, while precipitation and soil moisture dipped to an all-time low.
Higher precipitation, if it occurs, could dampen the effects of higher temperatures, but only to a limited extent, said Philip Higuera, a professor of forest ecology and biogeosciences at the University of Idaho and a co-author on the study.
“As temperature rises, so too does evaporation,” he said. “So even if future precipitation increases, it’s likely that increased evaporation will result in overall lower moisture availability. This affects plants, but it also makes dead vegetation more flammable and fire prone.”
The study team also included researchers from the University of Alaska Fairbanks, Neptune and Company, and the University of Washington.
The National Science Foundation and the Joint Fire Science Program supported this study.
Diana Yates | University of Illinois
Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter
17.08.2017 | Swansea University
Climate change: In their old age, trees still accumulate large quantities of carbon
17.08.2017 | Universität Hamburg
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences