Arctic warming could affect the Northwest in unexpected ways
SPOKANE, Wash.– The National Oceanic and Atmospheric Administration’s Arctic Report Card for 2021 shows the continuing changes caused by extremely warm weather at the top of the world.
October 2020 to September 2021 was the seventh warmest on record in the polar north. It’s the eighth above-average year in a row there. Arctic sea ice is also setting a new normal. The ice pack at the end of the summer, the month of September, is younger, thinner, and less extensive in the last 15 years than ever recorded before.
The warmth and the lack of ice cover also causes a feedback loop, where the darker surface of the Arctic Ocean absorbs more energy from the sun and warms the air above it as a result. This adds to the warming already taking place because of human-caused greenhouse gasses. The warming leads to a host of other impacts that you can see in this graphic from NOAA or by reading the summary of the report.
Are there consequences for the Inland Northwest?
For decades, scientists have hypothesized that melting arctic ice could impact the atmosphere in the fall and early winter because of the lower ice cover during those times.
Many studies have tried to prove that this melting alters the path of the jet stream, the belts of high winds that separate warmer, more tropical air from colder, more polar air. As the jet stream moves, so does the weather. A popular theory is that this warming helps weaken the infamous polar vortex, which can lead to a “wavier” jet stream and more outbreaks of frigid weather.
However, an experiment using more accurate computer simulations of ice melt in 2021 showed that while melting arctic ice may play a role in cooling Asia and Europe in the fall and winter, it did the opposite in North America. So far, there are lots of pieces of evidence, but not a crystal clear picture of if polar warming could lead to more brief outbreaks of frigid weather.
Another study published in October 2021 shows another potential impact of ice melt. These scientists were able to make a connection between melting arctic ice and fire season in the western U.S.
Here’s how it works:
Warmer Arctic temperatures between July and October help move the jet stream further north over the Pacific. This helps enhance our normal summer and fall weather patterns in the West that lead to the dry, hot weather that’s behind our fire seasons. However, this study showed that this pattern could stay more common through fall and even into early winter, September to December.
In other words, there’s evidence to support that the lower arctic ice coverage in summer and fall will help modify the path of the jet stream and extend fire season in the West as the earth continues to warm.
COPYRIGHT 2022 BY KXLY. ALL RIGHTS RESERVED. THIS MATERIAL MAY NOT BE PUBLISHED, BROADCAST, REWRITTEN OR REDISTRIBUTED.