Wildfires are increasingly gaining steam overnight in North America, taxing firefighting resources. New research says drought conditions may be the main driver.
“Active day, quiet night” has long been the common understanding of how fires burn. Frontline responders would use the cooler nights to recoup – until recently.
“They don't have the time to drink water or to fall asleep,” said Kaiwei Luo, a researcher at the University of Alberta and an author of the study published in the journal Nature.
After studying satellite data for thousands of fires over several years, Luo said flames now often stay strong after dark.
His research shows that about 20% of large wildfires in recent years burned overnight. That number went up to 35% in mountainous areas.
The region is in a record-breaking megadrought, and Luo said dry conditions are overpowering the effects of nighttime cooling and leading to more extreme fires.
Drought can also come after heat waves, Luo said, like has been seen with the Shelly Fire in Northern California, which is currently burning more than 15,000 acres.
“The warmed-up temperature can suck the moisture or water from vegetation,” Luo said, meaning there’s a lot of dry fuel to burn.
Luo added that with more fires burning 24/7, fire responders will need more resources, people and equipment.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNR in Nevada, KUNC in Colorado and KANW in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.
