Scientists have uncovered key attributes of so-called “brown carbon” from wildfires.
Scientists have uncovered key attributes of so-called “brown carbon” from wildfires, airborne atmospheric particles that may have influenced current climate models that failed to take the material’s warming effects into account. The work was described by a collaborative team of researchers from Los Alamos National Laboratory, Carnegie Mellon University and the University of Montana in the journal Nature Geosciences this week.
Wildfire fuel being burned in the fire laboratory as the aerosols from the top are being sucked into inlets and sampled at the Missoula Fire Sciences Laboratory in Missoula, Montana by Los Alamos and Carnegie Mellon University scientists. Photo courtesy of the University of Montana and U.S. Forest Service.
“Biomass burning and wildfires emit fine particulates that are toxic to humans and can warm or cool climate. While their toxicity is certain, their specific climatic effects remain unclear and are a hot research topic,” said Manvendra Dubey, a senior Los Alamos climate scientist. “Smoke from wildfires accounts for one-third of the Earth’s ‘black’ carbon — the familiar charred particles that are associated with fires with large flames. While black carbon is relatively simple — solely consisting of carbon — brown carbon contains a complex soup of organic material, making it difficult to identify, characterize and model.”
Black carbon or soot that absorbs sunlight at all wavelengths is a well-known, potent warmer. Its twin, organic carbon co-emitted by fires, reflects sunlight and so can cool the climate. These two opposing effects cancel each other out, causing current climate models to predict that wildfires have a small net effect on climate. However, there is a third form of emission, called brown carbon, that absorbs sunlight at short blue wavelengths that is also in the soup of fire emissions.
The study discovered that brown carbon shares a common production mechanism with black carbon. Brown carbon’s optical properties and volatility are highly variable and complex and no systematic treatment has been feasible in current models. In fact “what makes matters worse is many models treat brown carbon as organic carbon, a double whammy since they are computing a cooling effect for what is actually a warming particle,” said Dubey. Clearly, he said, models could be significantly under-estimating warming effect of fires both now and in the future.
“You might call brown carbon frustrated black carbon that is made when the wood isn’t fully cooked all the way,” said Dubey. Brown carbon warms the atmosphere similarly to black carbon, but the actual prevalence of brown carbon in wildfire smoke has been a large question mark. This study should answer this by providing a simple treatment of all absorbing fire particles in models and improve climate predictions.
The Los Alamos team of Dubey, Allison Aiken and Shang Liu performed controlled laboratory experiments of the optical properties of particles emitted by globally important fuels. They carefully manipulated the particles by heating to remove the volatile components and then monitored changes in optical properties. Analysis revealed that the least volatile fraction, that is most likely to be transported globally similar to refractory black carbon, is much more light absorbing than the volatile fraction.
This finding clearly establishes the “global significance of brown carbon aerosol, a research area prioritized by DOE’s Atmospheric System Research (ASR) program, and our discovery shows how this missing warming agent can be effectively treated in DOE’s climate models” said Dubey.
The three-institution research team included both experimentalists and modelers who understand each other’s languages and the experimentalists, know what the modelers need, and had this in mind for the experimental design, noted Rawad Saleh, a postdoctoral researcher at Carnegie Mellon and one of the leads on the study.
The U.S. Department of Energy’s Atmospheric System Research Program funded the Los Alamos research.
Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by Los Alamos National Security, LLC, a team composed of Bechtel National, the University of California, The Babcock & Wilcox Company, and URS for the Department of Energy's National Nuclear Security Administration.
Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.
Nancy Ambrosiano | Eurek Alert!
Researchers find higher than expected carbon emissions from inland waterways
25.05.2016 | Washington State University
Rutgers scientists help create world's largest coral gene database
24.05.2016 | Rutgers University
Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.
The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...
In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.
In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...
Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices
Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.
When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene
In 2010 the Nobel Prize in physics was awarded for the discovery of the exceptional material graphene, which consists of a single layer of carbon atoms...
The trend-forward world of display technology relies on innovative materials and novel approaches to steadily advance the visual experience, for example through higher pixel densities, better contrast, larger formats or user-friendler design. Fraunhofer ISC’s newly developed materials for optics and electronics now broaden the application potential of next generation displays. Learn about lower cost-effective wet-chemical printing procedures and the new materials at the Fraunhofer ISC booth # 1021 in North Hall D during the SID International Symposium on Information Display held from 22 to 27 May 2016 at San Francisco’s Moscone Center.
24.05.2016 | Event News
20.05.2016 | Event News
19.05.2016 | Event News
25.05.2016 | Trade Fair News
25.05.2016 | Life Sciences
25.05.2016 | Power and Electrical Engineering