Title: Alaska’s Changing Environment | IARC
Headings: Alaska's Changing Environment 2019
Alaska's Changing Environment 2019
Documenting Alaska's physical and biological changes through observations
Seasons
Big fire seasons more frequent
Dramatically more smoky days
Storminess not increasing
River break-up happening earlier

Content: Big fire seasons more frequent
Warmer springs and earlier snow melt had lengthened the wildfire season to the point in 2006 when Alaska’s interagency fire management organization changed the “start date” for wildfire response from May 1 to April 1. While the year-to-year variability of acreage burned has changed little, the frequency of large wildfire seasons has increased dramatically. Wildfire seasons with more than one million acres (red bars in graph) burned have increased by 50% since 1990, compared to the 1950–1989 period. Dramatically more smoky days
As the frequency of big (1+ million acres) wildfire seasons has increased, so has the frequency of smoky days, posing a significant health hazard. Prior to 2004, Fairbanks had only one summer (1957) in the previous half century when there were more than three weeks of significant smoke. Since 2004, it has occurred five times, including twice since 2014. Storminess not increasing
Storminess, related to the frequency, duration, and intensity of wind, is one of the most important aspects of day-to-day weather for Alaskans. In and around Alaska there has been a slight overall decline in autumn (September–November) storminess over the past 40 years. Winter (December–February) storminess has shown no clear trend since 1990. There has also been no detectable trend in the number of moderate and strong storms during the past 70 years over the Bering and Chukchi Seas, where sea ice has retreated.