Where there's smoke, there's fire, and especially in the western United States, that smoke is usually from wildfires. From 1980 to 2015, Washington, Oregon, Idaho, Montana, Wyoming, and Colorado accounted for approximately 40 percent of the burned area in the lower 48 states. Though local impacts of smoke can be extreme, the smoke produced from these fires impacts air quality in every region in the U.S.
For how common wildfires are in our region, we do not know nearly enough about the composition of the smoke, how much it matters for our air quality, what happens when smoke and clouds interact, and whether that's important for understanding weather. With a $3.8 million grant from the National Science Foundation (NSF) Atmospheric Chemistry program, Colorado State University is one of five universities working to gather a more comprehensive data set aimed at understanding how wildfire smoke changes chemically with time. The other universities involved are University of Wyoming, University of Montana, University of Washington, and University of Colorado Boulder.
The frequency and intensity of western wildfires is increasing, and is expected to increase more with climate change. And as other anthropogenic sources of air pollutants, like emissions from cars, decrease, understanding how wildfires interact with environmental elements becomes more important.
Assistant Professor Emily Fischer in the Department of Atmospheric Science is lead investigator for the CSU team. She is joined by five other co-investigators on the project: Jeffrey Collett, Sonia Kreidenweis, Delphine Farmer, Paul DeMott and Amy Sullivan. The areas of knowledge represented by these faculty include trace gas chemistry, cloud and precipitation chemistry, aerosol-cloud interactions, and instrument development.
The data collection portion of the study will take place in summer 2018, when the NSF National Center for Atmospheric Research's C-130 aircraft will be used to collect data within smoke plumes.
"We'll fly as close to active fires as can be safely done and follow the plumes downwind," Fischer said.
Part of the challenge will be to identify the right conditions to fly. They will need to know when the smoke will be high enough in the atmosphere to safely fly through it, and when smoke and clouds might be interacting. Associate Professor Russ Schumacher will be assisting with the project by forecasting for the group so they can accurately assess when flight conditions are ripe. Firefighting efforts and airspace regulations will also be taken into consideration.
Very few samples of western U.S. wildfire smoke exist - at least not with the level of chemical specificity this study will capture. The payload on the C-130 will be maxed out with the instrumentation it's set to carry. Once the data is collected, it will be distributed to the researchers involved in the study, who will then look at a number of factors, like nitrogen composition, optical properties of smoke particles, and the changes smoke and clouds cause in each other.
"There have been many field campaigns that have opportunistically measured wildfire smoke, but none completely devoted to it at this scale for western wildfires," said Fischer.
While Fischer's scientific contribution will be to understand how secondary products in smoke are formed, other researchers and universities will rely on their own areas of expertise to analyze the data accordingly. The Environmental Protection Agency may utilize the measurements to develop and test their air quality models. The research expertise being leveraged from organizations outside of CSU is testament to the breadth of the campaign.
"I really enjoy team building, and pulling together various areas of expertise ... to do something really special, "Fischer said. "Pulling together a team like this is so much bigger than what I could do alone."