Alaska is burning this year in ways rarely if ever seen, from the largest wildfire in the usually largely fireproof Southwest region to a pair of wildfires that tore through forests. It produces smoke that travels hundreds of miles to the Bering Sea community of Nome. The normally crystal clear air was relegated to the extremely unhealthy category.
An area the size of Connecticut has already burned and the worst of the usual fire season is ahead. While little property has burned, some residents have been forced to evacuate and one person has died — a helicopter pilot died last month while trying to carry a load of supplies to firefighters. Crashed during
Recent rains have helped, but long-term forecasts show a pattern similar to 2004, when July rains gave way to a high-pressure system, hot days, low humidity and lightning strikes that marked Alaska’s worst fire year. gave air to
In 2004, the area burned by mid-July was about the same as now, but by the end of the fire season, 10,156 square miles (26,304 square kilometers) had burned.
“The frequency of these major climates has doubled since the second half of the 20th century,” said Rick Thomann, a climatologist at the Alaska Center for Climate Assessment and Policy at the International Arctic Research Center in Alaska. “And there’s no reason to think that won’t continue.” .
Heat waves and droughts, exacerbated by a warming climate, are making wildfires more frequent, destructive, and in many places harder to fight. Wildfires have raged in Portugal, Spain, France, England and Germany this month, which has seen record high temperatures.
California has recorded its largest, most destructive and deadliest wildfires in the past five years, and with the state’s deep drought, officials are bracing for a late summer and season full of smoke and flames. are
The nation’s largest state, Alaska, has also been dry. Parts saw early snowmelt and then a largely rain-free June that dried out the duff layer — the band of decaying mosses and grasses that blankets the floor of boreal forests and tundra. This organic matter can be up to 2 feet (0.61 m) thick but in various stages of decay.
On May 31, a lightning strike over a duff layer in the Yukon-Koskom Delta The East Fork Fire, an area of southwestern Alaska that rarely burns. Two communities with a combined population of about 700 were threatened, but no mandatory evacuations were ordered after the 259-square-mile (671 square km) delta became the largest wildfire ever. Firefighters were able to protect communities.
Such fires were directly attributable to climate change, Thoman said. More vegetation is growing on the tundra, willow and alder trees are denser in the transition zone between tundra and forest, and spruce is becoming denser along river valleys and upstream from these valleys.
“The amount of available fuel has increased significantly, and that’s from decades of warm springs and summers in the region, which is a direct result of the warming climate,” he said. “And, of course, fires are hotter with more fuel available. They burn longer. They’re more resistant to changes in weather.”
In Alaska, more than half of all wildfires are caused by lightning, and the rest are caused by humans, either accidentally, intentionally, or negligently. Of the 4,687 square miles (12,140 sq km) burned so far this year, only 2 square miles (5 sq km) have been caused by human-caused fires.
Trying to fight Alaskan wildfires is not possible or necessary. Fires play a key role in the state’s ecology by clearing debris, thinning trees, and renewing habitat for plants and animals, so Alaska usually lets itself burn or rain. And lets wait for the ice to work. Firefighting resources are used to fight fires in populated areas.
So far this year, about 145,000 lightning strikes have occurred in Alaska and contiguous areas of Canada, as counted by the Bureau of Land Management’s lightning detection network. Between July 5 and 11, a surprising 42 percent of the incidents occurred when weather systems produced rain, but also about 50 fires.
“Concentrated lightning, where we get a significant portion of the entire season’s lightning over a few days in a row, is actually quite common for Alaskan lightning,” Thoman said. “There was a lot of lightning in that concentrated area that started a lot of fires in areas that weren’t on fire at that point.”
Although there was little damage to property, smoke from the fire created hazardous breathing conditions. In one case, two fires burning near Lake Iliamna merged and burned about 75 square miles (194 square kilometers) of boreal forest in one day, producing smoke and ash that was blown hundreds of miles north by strong winds. reached Nome in the west, pushing up the air quality index. Very unhealthy category.
“I never would have thought you could get that poor air quality back 400 miles from an active fire, and that’s a testament to how hot that fire was,” Thoman said.
Mark Thiessen, Associated Press
Alaska Climate Change Environment Wildfires