University Of Wyoming Researchers Are Changing Climate Models From The Air

Jan 15, 2021

Wildfire research has become increasingly important in recent years as climate change has caused fires to become more common and more intense. But wildfire smoke could be having a bigger effect on the climate than previously thought. Wyoming Public Radio's Ivy Engel spoke to Shane Murphy, a University of Wyoming researcher who studied the smoke from inside the plumes.

Shane Murphy: So basically, we operated off of the C-130 aircraft, which N-CAR runs. So I don't know if you're familiar with the C-130, it's giant cargo aircraft, and so we fill the C-130 with instrumentation. Every university brings their own suite of instrumentation on and so when we wrote the grants, we figured out which teams we would need, what instrumentation we need to accomplish the goals of analyzing the gases in the smoke and the particles in the smoke, and how the smoke impacts clouds. And so all the teams work together to try to answer these big scientific questions. So the project actually had this big field deployment in Boise in Summer 2018, and the science is just getting out now because it takes a long time to analyze all this data and stuff.

Ivy Engel: Could you describe what it looks like inside of the plane? Because it seems pretty cramped.

SM: Imagine a large house. And you have to fill that up with instrumentation. And then once all that instrumentation is on there, you're right, there's just an aisle left in the middle for you to walk up and down. And then pretty much the whole rest of the plane is crammed with instrumentation with a little room left for the scientist to sit and turn and operate it. And then up in the front of the plane, one research scientist, so that would vary from flight to flight, will direct the flight. So we'll have a plan which fire we're going after, and then during the flight, we'll look at real time images from satellites. And so people on the ground are analyzing that data as it's coming in and telling us where to go and how to adjust, and then the flight scientist that's up in front will communicate with the pilots and say, 'this looks good or turn here, or we want to measure this part of the plume.' And the pilots are really knowledgeable.

IE: That's got to be nuts.

SM: You'd think it'd be scary. But it's actually not very scary because the pilots are just so competent from N-CAR, they're really highly trained, and so they're always on top of it. And usually, the way we would operate is the flight controllers would give us a chunk of airspace where just we could operate that was away from any firefighting operations or air traffic. Because when you're in the smoke, you often can't see, so we are often operating under what you call instrument flight control rules instead of visual flight control rules, because the smoke is so thick, it's like you're flying in a cloud.

IE: That's so cool. So how far could you go to get to a fire to test it?

The C-130 is one of three planes run by NSF. It's also one of the biggest.
Credit Ivy Engel

SM: Long ways. So we were based out of Boise because that kind of tends to be central to the region that might be burning. And if you remember 2018, almost the entire western US was on fire. So we measured fires in California, Oregon, Washington, Utah, Montana, Wyoming, we might have snuck in. The plane can stay airborne for about eight, eight to nine hours. So yeah, it's a little tiring to sit on the plane for eight hours. What people often don't realize is when you take a commercial plane, they fly very high, one, and they also report to each other where the turbulence is. And in these projects, we're often flying low because we want to be in the smoke and there's no reports of where the turbulence is so that it tends to be quite turbulent compared to what you think of a commercial flight.

IE: My goodness, I can imagine. And, I mean, fires create their own weather anyway.

SM: Absolutely. And that's one thing we had to be really careful about. So right where the fire is active, we weren't actually able to measure right above the fire, because the plume coming off of the fire can be really intense with really huge updrafts, as bad or worse than a thunderstorm. And so that can actually damage the plane. So we stayed away from right where the fire was burning, and we'd start measuring just a couple miles downwind.

IE: Brown carbon, how's that related to the different reflectivity of smoke particles? Is that just a part of the spectrum of color?

SM: Yeah, no, that's a great question. So imagine you're at your campfire. And sometimes your campfire will give us this really black smoke when maybe it's gotten a log quite burnt and so it's burning really hot, you'll just see this black soot coming off. And other times, maybe you have some wet wood or stuff, you'll put off this really white billowy smoke. And everything in between. So you can imagine a forest fire, you have all those particles being emitted. And so for a long time, people thought the only thing that absorbed sunlight was the black carbon and everything else kind of reflected light. But now we've learned that there's this kind of in between stuff that we call brown carbon. And it's not a very scientific name, it's just that you know, the soot is black, the other stuff is white, and this is somewhere in between, so it's kind of brownish in color. And so, people just actually recently kind of figured out this was a fairly big deal over the last maybe 10 years. And then they realized that it doesn't last forever. And it's all mixed together, it's all in the same particles, and that stuff tends to absorb some wavelengths of light and not absorb other wavelengths of light. And so it's complicated in that sense, and then also, as it gets reacted in the atmosphere, it disappears. And so really refining that is important, because if it lasts a long time, then wildfire smoke will have a more warming effect. If it lasts a shorter time wildfire smoke will have a more cooling effect. So you have to understand what wavelength of light it absorbs, and how long it lasts in the atmosphere, and it depends on all kinds of things. But it lasts a day or two in the atmosphere and we have a lot of good measurements of how much it absorbs the blue light versus red light. And so yeah, we added quite a bit of information on both those topics.

IE: Okay. And so what can we do with this information? Is this knowledge for knowledge's sake, or is this something we can do something about?

SM: In short, what you do with this stuff is you compare it to models. And what we found is most of the climate models were assuming that the smoke emitted by the fires was much more absorbing than what the measurements showed. So then you improve the models, and then the models do a better job of predicting future climate. And so I think that's the net payoff is we get a better estimate of what the climate is going to be like in 10, 20, 30 years, so we can plan better. We understand if it's going to be more warming or cooling, and can react accordingly.