BRISTOL, United Kingdom – Much of the world can expect a particularly intense winter in the coming weeks, according to a study released recently by a team from the United Kingdom. The researchers report that a major meteorological event is taking place high in the sky, above the North Pole.
This sudden stratospheric warming (SSW) is estimated to occur in early January 2021. What exactly does this mean? The Earth’s stratosphere is a layer of the atmosphere located about six to 30 miles above the ground. Scientists consider an SSW event to be one of the most extreme atmospheric phenomena. It usually leads to an increase in atmospheric temperature of about 122 degrees Fahrenheit in just a few days!
(Credit: University of Bristol)
SSW events are known to subsequently produce periods of extreme cold and intense snowstorms. More recently, an SSW in 2018 called the “East Beast” brought heavy snow to the UK, Ireland and much of Europe.
Why does warming in the atmosphere lead to winter?
If the hot stratosphere air shoots down and reaches the planet’s surface, a change in the jet stream occurs, generating extremely cold temperatures in Europe and North Asia. As for when this happens, the schedule can vary significantly. Sometimes, hot air takes weeks to reach the surface, but in other cases it arrives within a few days.
The researchers analyzed 40 previous SSW events that occurred in the last 60 years. The team also developed a way to track an SSW signal down from the sky to the surface.
Where is the ‘beast’ going to?
The study authors say regions such as Siberia and northwestern Europe are at high risk for extreme winter and snowstorms in the coming weeks.
“Although an extreme cold event is not a certainty, about two-thirds of SSWs have a significant impact on the surface climate. What’s more, today’s SSW is potentially the most dangerous type, where the polar vortex splits into two smaller ‘childish’ vortexes, ”said the study’s author, Dr. Richard Hall of the University of Bristol, in a statement.
“The extreme cold that these polar vortex ruptures bring is a stark reminder of how the weather can change suddenly. Even with climate change warming our planet, these events will still occur, which means that we must be adaptable to an increasingly extreme variation in temperatures, ”adds Dann Mitchell, associate professor of atmospheric sciences in Bristol.
“Our study quantifies for the first time the probabilities of when we can expect extreme surface weather after a sudden stratospheric warming event (SSW). These vary widely, but it is important that impacts appear faster and stronger after the events in which the stratospheric polar vortex splits in two, as predicted in the event that is currently taking place. Despite this advance, many questions remain as to the mechanisms that cause these dramatic events and how they can influence the surface, so this is an important and exciting area for future research, ”concludes study co-author, Dr. William Seviour, from the University of Exeter.
The study was published in Journal of Geophysical Research.