As a deadly blizzard grips the United States, leading to the death of more than 60 people as of Tuesday and complete disruption of normal life, scientists have once again started to discuss if the rising temperatures of the Arctic are responsible for extreme cold conditions in the country and other areas of the Northern Hemisphere. According to a report in The Washington Post, the discussion gained momentum after a recent study, published in Science.org, revealed how the rapid warming of the Arctic might be allowing frigid air in the region to move southward more frequently than ever before. However, scientists said they need more data to arrive at a consensus about the claim. What are the findings of the study? The study largely focused on something called the polar vortex, which is a mass of cold, low-pressure air that consistently hovers over the Arctic region. It is denoted by the word “vortex” because it spins counter-clockwise, just like a hurricane does. Usually, the polar vortex remains strong and compact, meaning the mass of frigid air stays at the North Pole. But sometimes it weakens, like a wobbling top, and expands to influence the jet stream — an area of fast-moving air high in the atmosphere that surrounds the polar vortex. Once the jet stream is impacted, the cold polar air finds its way towards the mid-latitude regions. In the study, researchers found that the expansion of the polar vortex has been occurring more than twice as often in recent years and the reason for it is the rapidly warming Arctic. With the help of observational analysis and numerical modelling, the study demonstrated that the melting sea ice in Barents and Kara seas north of Russia and Scandinavia and increasing Siberian snowfall create larger and more energetic atmospheric waves that ultimately stretch the polar vortex, causing extreme winter weather in the US and other places. Judah Cohen, one of the authors of the paper and a climate scientist at Atmospheric and Environmental Research (AER), said that a similar chain of events took place back in 2021 when Texas witnessed a deadly cold storm that killed 246 people, The Washington Post reported. What are some other studies? This isn’t the first time that the soaring temperatures of the Arctic region are being held responsible for bouts of deadly cold weather in the mid-latitude regions. The debate started in 2012 after research published by a senior scientist at the Woodwell Climate Research Center in Massachusetts showed that the warming of the Arctic was reducing the temperature difference between the polar and tropical regions, which is the weakening of the jet stream and, thus, allowing the southward movement of frigid air. Although it has been more than a decade since this seminal study was published, there are still “mixed feelings” in the scientific community regarding its claim, The Washington Post reported. Researchers said that more evidence is needed to know whether and where warming is making the jet stream weaker.
