ANCHORAGE, Alaska — Alaska is burning in ways rarely or never seen before this year, from the largest wildfire in a normally mostly fire-safe region in the Southwest to two blazes that tore through forests and produced smoke hundreds of miles into the Bering Sea community blew from Nome, where the normally crystal clear air was pushed into the extremely unhealthy category.
More than 530 wildfires have already burned an area the size of Connecticut, and the usual worst of the fire season is upon us. While little property was burned, some residents had to be evacuated and one person was killed – a helicopter pilot died last month when he crashed trying to carry a load of firefighters’ equipment.
Recent rains have helped, but longer-term forecasts show a pattern similar to 2004, when July’s rains gave way to high-pressure systems, hot days, low humidity and lightning strikes that sparked Alaska’s worst fire year.
In mid-July 2004, the area burned was about the same as it is today, but by the time the fire season ended, 10,156 square miles (26,304 square kilometers) had been charred.
“The frequency of these major seasons has doubled since the second half of the 20th century,” said Rick Thoman, climate specialist at the Alaska Center for Climate Assessment and Policy at the University of Alaska’s International Arctic Research Center. “And there’s no reason to think it won’t continue.”
Heat waves and droughts, exacerbated by a warming climate, are making wildfires more frequent, more destructive and more difficult to fight in many places. This month, wildfires have ravaged Portugal, Spain, France, England and Germany, which have seen record-breaking temperatures.
California has recorded its largest, most devastating and deadliest wildfires in the past five years, and with the state mired in drought, authorities are bracing for a late summer and fall filled with smoke and flames.
Alaska, the nation’s largest state, was also dry. Parts saw an early snowmelt and then a mostly rain-free June that dried out the duff layer – the ribbon of decaying moss and grasses that covers the floors of boreal forests and tundra. This organic matter can be up to 2 feet thick, but is in various stages of decay.
On May 31, a lightning strike began in the Duff Layer in the Yukon-Kuskokwim Delta East Fork Fire, an area of southwest Alaska that rarely burns. Two communities with a combined population of about 700 were threatened, but no mandatory evacuations were ordered, making 671 square kilometers the largest wildfire of all time in the delta. Firefighters were able to protect the communities.
Such a fire is directly attributable to climate change, Thoman said. More vegetation grows on the tundra, willows and alders are more dense in the transition area between the tundra and the forests, and the spruces along the river valleys become denser and move further uphill from these valleys.
“The amount of fuel available has increased significantly, and that’s due to decades of warmer springs and summers in the region, which are a direct result of a warming climate,” he said. “And of course, fires burn hotter with more fuel available. They burn longer. They are more resilient to weather changes.”
In Alaska, just over half of all wildfires are started by lightning and the remainder are caused by accidental, intentional, or negligent human activity. Of the 4,687 square miles (12,140 square kilometers) burned so far this year, only 2 square miles (5 square kilometers) are from man-made fires.
It is neither feasible nor necessary to attempt to fight all of Alaska’s wildfires. Fires play a key role in the state’s ecology, removing low-lying debris, thinning trees and renewing habitats for plants and animals. As such, Alaska usually lets most burn out or wait for rain and snow to do the job. Firefighting agents are used to fight fires in populated areas.
So far this year there have been about 145,000 lightning strikes in Alaska and adjacent areas of Canada, as counted by the Bureau of Land Management’s lightning detection network. A staggering 42% occurred between July 5 and July 11, when weather systems produced rain but also started about 50 fires.
“Concentrated flashes, where we get a significant portion of the entire season’s flashes back-to-back in a few days, is actually pretty typical of Alaskan flashes,” Thoman said. “Lots of lightning in this concentrated area that have ignited some fires in areas that had not previously had fires.”
While there was little property damage, smoke from the fires has caused dangerous breathing problems. In one instance, two fires burning near Lake Iliamna combined and burned about 75 square miles (194 square kilometers) of boreal forest in one day, creating smoke and ash that high winds carried hundreds of miles northwest to Nome and the air quality index pushed the extremely unhealthy category.
“I never thought you could get that bad air quality back 400 miles from the active fires, and it’s a testament to how hot those fires were,” Thoman said.
https://www.nbcnews.com/science/environment/alaska-experiencing-wildfires-s-never-seen-rcna39808 Alaska is experiencing unprecedented wildfires