LANL studies wildfire smoke’s climate impact

New tool will improve analysis of humidity

Researchers at Los Alamos National Laboratory have developed a first-ofits-kind tool to learn if smoke from wildfires is warming the climate.

The humidified single-scattering albedometer will analyze moisture levels in wildfire smoke plumes and study how water binds with soot particles.

While the science behind the device is complex, its purpose is simple — to see if wildfire smoke is heating the atmosphere.

Manvendra Dubey, a researcher at the laboratory for more than 20 years, said the impacts of carbon emissions and greenhouse gases are “without a doubt” affecting our climate.

“Given the drought and the La Niña conditions, the forecast indicates this will be an active year [for fires] that we need to prepare for,” he said. “Climate change can intensify this and the record-breaking Western and Australian fires the last few years are kind of common indicators that we need to adapt.”

Dubey said he believes this new tool will allow wildfire emissions to be analyzed like never before. In the past, humidity in smoke could never be tested due to tools evaporating the water before a reading could be determined.

Smoke from fires is composed of a number of chemicals and toxic gases, plus particles like black and brown carbon. When combined with water in the air, these particles can grow, lofting smoke plumes higher into the air and absorbing light, Dubey said.

Previous research showed smoke from wildfires, or even volcano eruptions, reflect sunlight, causing a net cooling effect on the atmosphere, the researcher said. But LANL experiments with the device found for the first time that water coating the black, soot-like material enhanced light absorption by up to 20 percent — thus creating a heating effect.

Experts said models and research into this topic need to be continued.

Christian Carrico, an associate

professor at the New Mexico Institute of Mining and Technology and a partner in the research, has explored the effects of aerosols — fine particles in the air — on climate change. He said wildfire smoke and other emissions that contain soot have a different effect than greenhouse gases.

“It will affect as well atmospheric stability and cloud formations, because all of a sudden you have this aerosol layer that’s absorbing and heating the surrounding atmosphere aloft, and that can affect the the atmospheric stability,” Carrico said.

He said the next step for the research is field testing.

“We have an interest not only in wildfires, but in measuring emissions from prescribed burning, as well as going to some of the more polluted urban areas,” Carrico said.

This research will provide new, supportive modeling for the state — particularly with Gov. Michelle Lujan Grisham’s push to reduce greenhouse gas emissions, an official with the state Forestry Division said.

“We now are starting to have a set of studies that take the long view and compare the carbon emissions from an unplanned catastrophic wildfire versus prescribed burning, which does have emissions and does create smoke, but it’s in a planned environment and it’s done with the intention of avoiding the catastrophic release,” said Laura McCarthy of the Forestry Division.

McCarthy has been Lujan Grisham’s intermittent representative on the Wildland Fire Leadership Council. This year, the council has been focusing on wildfire smoke. McCarthy said she believes LANL’s new tool and subsequent research will be extremely valuable in learning more about the effects of smoke on the state’s climate.

“We have models that try to answer the question of whether increased catastrophic release of carbon in wildfire is going to lead to some kind of cooling effect,” she said. “But I don’t think those models are considered to be very reliable. This research is gonna help us refine those models and come to better and better understanding.”

The findings and emerging data developed from this new tool will help New Mexico “move toward better answers” to big-picture questions and have policy implications, she added.

The research, funded in part by the Department of Energy, was completed with help from scientists around the country, including researchers from New Mexico Tech.

We have an interest not only in wildfires, but in measuring emissions from prescribed burning.” Christian Carrico, associate professor at the New Mexico Institute of Mining and Technology