A few weeks ago, on a Sunday morning, I woke up to the smell of smoke and the sound of helicopters overhead. There was a wildfire up sunshine canyon, very close to our town of Boulder.
My initial thoughts were of course to check all my friends and neighbors were ok, and if there was any volunteer help needed. Everything was fine on those counts, with firefighters battling the blaze and evacuations and shelters set up for those affected. I then realized, if I could detect the presence of the fire with my nose, I could detect it even better with my scientific instruments that were sitting in my lab a few miles away.
Wildfires affect both air quality and climate, and have recently been getting more frequent and more intense in North America, in part due to hotter, drier summers. We need to better understand the emissions from wildfires in order to predict how they will affect health and climate.
While colleagues of mine from NOAA and CIRES are studying wildfires intensively in lab studies airborne missions (see the video at the end of this post), it is always useful to get more data, especially when it’s literally drifting past your lab window, and it’s interesting to know how our local community is being affected. I called round some colleagues, and many were interested to join me in scrambling some instruments together to see if we could characterize emissions from this fire.
The wind had now changed directing, blowing the smoke away from our side of town. This was very good news in terms of air quality for the residents and also because the risk of the fire coming closer to town was much lower. It also meant that any signal from the fire in the air passing over NOAA was now extremely low. At night we often get an inversion layer over the town, which essentially traps air below it, allowing whatever is being emitted to build up to higher concentrations in that trapped air. Therefore we figured our best shot of measuring the sunshine fire emissions was to measure over night.
We assembled in the lab around 8pm and quickly set to work bringing instruments into a lab with a sampling port through the roof. There was a sense of camaraderie and excitement that is one of the things I love about doing atmospheric science. We helped each other set up instruments and sampling lines, and opened the port up on the roof. By 11pm everything was running. Despite it being a weekend, and many people being out of town, we managed to set up a suite of instruments measuring aerosol size distributions, composition and extinction, along with black carbon. These are some of the emissions from fires that directly affect both health and climate.
We left the instruments running overnight. When I woke up and came back to the lab early the next morning I still couldn’t smell smoke, and data showed that we hadn’t seen signal from the fire all night. This was of course good news for the city, and we were all pleased and impressed at how quickly the fire had been contained.
While that night of measurements didn’t tell us anything scientifically about fires, it did prompt us to get planning for the wildfire season that hits later in the year. I set up some meetings to discuss scientific objectives and logistics of doing rapid response measurement like this again in the future. We’re now developing a plan for measurements that can be set up at very short notice in Boulder when smoke from wildfires affects the city again.
Video about the more intensive fire studies being carried out by CIRES and NOAA scientists: