Scientists Look For Climate Change Clues in Wildfire Soot

Aug 15, 2013

You may know that on a hot, sunny day, it’s better to be sitting in a white car than a black one. White reflects sunlight, while black absorbs more of it.

The same concept applies to researchers trying to figure out what effect wildfires have on climate change. And part of the answer is whether the smoke particles are dark or reflective.

Outside of a white, paint-peeling hanger in Pasco sits a glossy small science plane that looks like some kind of fancy jet airliner for executives. It’s those ones that you see when you’re on the Boeing 747, and you look out and then you see the really fancy plane guiding by you toward the runway.

On board, there are no fancy champagne chillers, or plush seating. Instead, it looks like a server farm. Stacks of equipment are anchored down in chest high cages with very little room to walk around. 

Art Sedlacek is a physical chemist from Brookhaven National Lab. Most people would run away from wildfires, but Sedlacek leads a team of researchers who fly directly into smoke plumes. 

“Here you’re going through basically blue sky and then you hit this wall of white haze. And when you’re in the column itself it goes from a white to an orange haze color. The absorptive properties of these biomass burns just change the character of what it is. It’s somewhat surreal almost for all of us,” Sedlacek said.  

Sedlacek says the data his team is gathering will help determine what happens when a fire moves from an active burning stage with flames to a smoldering stage. If you imagine a tiny smoke particle, it’s black when it first leaves the flames and as it travels farther away it gathers reflective material. 

So black smoke equals warming, white smoke equals cooling? 

“That’s exactly right,” said Sedlacek.

Now the task is to see if a particular wildfire puts off more of those dark soot particles or the reflective ones, and for how long. As to how the wildfires are affecting climate change, that will take years of more study to answer.