Adventures in an Airborne Lab

In research, “you have to be ready for things to break,” says Anne Perring, an assistant chemistry professor. That’s especially true when your scientific equipment is hurtling through the sky at hundreds of miles per hour. It was summer 2019, and Perring’s student Brady Mediavilla ’20 was aboard an old Alitalia jetliner turned airborne laboratory, chasing wildfires for science. As the aircraft flew straight into a plume of smoke, other researchers aboard were chattering to each other through headsets, excited about the measurements they were taking. But Mediavilla wasn’t seeing many data points at all. That seemed odd. He used his laptop to chat with Perring, who was in an Idaho airplane hangar, poring over data. After consulting with her and other colleagues, including several who were on the plane, Mediavilla figured out the problem and fixed it by the end of that day’s outing. Talk about troubleshooting on the fly.

Perring and Mediavilla are a small part of a big government project seeking to understand how smoke from fires affects climate change and human health. The project, called FIREX-AQ, is a joint effort between NASA, the National Oceanic and Atmospheric Administration, and more than 40 partner institutions. The work took on new meaning as the 2020 wildfire season ravaged more than 8.2 million acres and brought eerie orange haze to the western United States. As climate change takes hold, extreme wildfire seasons are happening more frequently. For Perring, it’s personal. “I grew up in the Bay Area,” she says. “My mom is in California and has been housebound,” with poor air quality taking away the outdoor freedoms she could enjoy during the COVID-19 pandemic.

Perring’s particular focus is black carbon, a microscopic solid particle in smoke that is so charred it can no longer burn. Black carbon is a hazard to human lungs. It is also a driver of climate change, because it can absorb light from the sun and warm the Earth. 

Scientists know that fires produce black carbon. But predicting how much will be made from a given fire based on weather conditions and the types of vegetation burning is a challenge. They also can’t anticipate how thickly other chemicals from the fire might coat the black carbon, which increases black carbon’s global warming potential and affects how long it will linger in the atmosphere and how far it can travel. 

Perring’s instrument on the aircraft counted and sized the particles of black carbon present in each sample of smoke the jet encountered. The equipment measured to what extent other chemicals coated the particles. It’s hard-won data. On one of Mediavilla’s flights, the research craft encountered a fire so intense that its upward air currents generated a thunderstorm. Those weather systems are “crazy,” Perring says. “He has a strong stomach.” 

Mediavilla has written computer programs to analyze data from tens of millions of particles, an effort that Perring plans to submit for publication in a scientific journal soon. As for what they’ve learned about black carbon, Perring says that’s still a work in progress. “We’re seeing that there’s more variability in black carbon’s microphysical properties than we appreciated before,” she says. But that’s not enough information to plug into a computer model that predicts whether a fire in California’s wine country should prompt Perring’s mom to stay indoors. Perring is still plugging away at her data, though, because as she watches the West burn on television, she knows her work matters. “We all share the same air,” she says. “Trying to understand how something happening in one place affects people in that place and also people far down wind feels useful.” 

— Carmen Drahl 


Remote Sensing in Siberia

With the increased number of large forest fires occurring, how has vegetation growth — and, therefore, climate change — been affected? Three Colgate researchers have been using uncrewed aerial vehicles (UAV) to survey wildfire recovery rates in Russia’s Siberian forests. 

The groundbreaking work of geography major Elena Forbath ’21; Anna Talucci, a geography postdoctoral fellow; and Associate Professor of Geography Michael Loranty was featured in the journal Remote Sensing.

The team of researchers went to Siberia last year to study how forest recovery after a wildfire can impact climate change — specifically, how vegetation growth, or lack thereof, decreases the availability of plant-based carbon sequestration. 

“The bottom line is there won’t be enough vegetation to sequester carbon as more carbon enters the atmosphere,” Forbath explains. “With the increased number of fires, we won’t have enough plants to sequester massive amounts of carbon, so it’s another issue related to climate change.”

When looking at how vegetation has been growing after these fires, the team asked: If it is growing, how long has it taken? “It requires quite a bit of time for those forests to recover from these fires, given the analyses we’ve used,” Forbath says.

The work had two major components: to analyze the impact on carbon sequestration for these forests recovering from fires and to examine the effectiveness of UAV use for this research. In the past, researchers relied on satellite imagery to study the effects of large wildfires in major forested areas.

Talucci says the difference between satellites and UAV image resolution is notable, as satellite imagery offers a resolution of about 30 meters per pixel on the screen. With the drone data, scientists can see 1–2 centimeters per pixel. There’s also an improvement on temporal data, because field-based measurements and UAV-based measurements can be acquired at the same time. “This can help us better understand the linkages between field measures and UAV measures,” she explains.“Field data taken by humans can be time intensive,” Talucci adds. “You still need humans to collect UAV data, but in this case, they can study an entire 250- meter transect instead of eight plots. This provides a landscape perspective, which for large-scale ecological disturbances, is ideal.”

— Dan DeVries