warm temperatures

Alaskan Wildfires | Earth Wise

August 4, 2022 By EarthWise Leave a Comment

Alaska is on a pace for a record fire season this year. As of mid-July, more than 2.7 million acres had burned, which is more than 10 times the total area burned in all of 2021.

Alaskan fires have been spurred on by warm temperatures, a diminished snowpack, and an unusually large number of lightning strikes. May was one of the warmest and driest on record leading to lots of fires in June. More than 300 wildfires ignited during June. Many were sparked by nearly 5,000 lightning strikes early in the month.

There have already been some very large fires, including the East Fork Fire, near the Yukon Delta which had burned more than 250,000 acres by the beginning of July, and the Lime Complex Fire, in the southwest part of the state, which had burned more than 865,000 acres by mid-July.

The all-time record fire season in Alaska was 2004, when more than 6 million acres went up in flames. Wildfires are a natural part of the Boreal North ecosystem: the great northern forest region. But the fires occurring now are very different from those of a century ago and more. The combination of more fuel in the form of dry vegetation, more lightning strikes, higher temperatures, and lower humidity leads to fires that burn hotter and burn deeper into the ground. Such fires don’t just scorch trees and burn the undergrowth. They consume everything leaving a barren landscape of ash. Million-acre fires occur more than twice as often as they did before 1990.

The state may set a new record for wildfire acreage before the season is over. Nearly 6,000 firefighters and support personnel continue to battle blazes across the state.

**********

Web Links

Alaska Is on Track for a Record Fire Season

Photo, posted June 18, 2022, courtesy of Ryan McPherson/BLM Alaska Fire Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A New Low For Lake Powell | Earth Wise

November 2, 2021 By EarthWise Leave a Comment

Lake Powell is the second largest reservoir by capacity in the United States. It straddles the border of southeastern Utah and northeastern Arizona and was created by the Glen Canyon Dam, completed in 1963. The reservoir serves as a bank account of water that is drawn upon in times of drought and has made it possible to weather extended droughts by sustaining the needs of cities, industries, and agriculture in western states. Hydroelectric power by the dam’s eight generators provides electricity to seven states.

As a result of the protracted drought in the west, the water levels in Lake Powell have reached the lowest point since 1969. As of September 20, the lake held only 30% of its capacity and federal managers started releasing water from upstream reservoirs to help keep Lake Powell from dropping below the so-called minimum power threshold which is the water elevation that must be maintained to keep the dam’s hydropower turbines working properly.

With the entire Lower Colorado River water system below 40% of capacity, Bureau of Reclamation recently announced that water allocations in the U.S. Southwest would be cut over the next year. The Colorado River basin is managed to provide water to millions of people including those in San Diego, Las Vegas, Phoenix, and Los Angeles.

Successive dry winter seasons over the past two years along with a failed 2020 summer southwestern monsoon, have led to the lowest precipitation levels on record in the Southwest going at least as far back as 1895. With warm temperatures, reduced snowpack, and increased evaporation of soil moisture, most of the American West suffers from persistent and widespread drought.

**********

Web Links

Lake Powell Reaches New Low

Photo, posted June 28, 2021, courtesy of the USFWS – Mountain Prairie via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.