The start of spring is expected to be disrupted by a sudden stratospheric warming (SSW) event that will occur in the upcoming weeks. SSWs, which can cause the stratosphere to suddenly heat up by up to 122 ℉ in a week, happens once every two years.
Stratospheric Polar Vortex
The stratospheric polar vortex, which is a flow of winds from the Arctic that move from west to east, also rapidly slows down or even changes course.
And even if this phenomenon occurs miles above ground, it can produce a significant change in temperatures as well as weather patterns when the vortex is disrupted.
These events are brought on by very large atmospheric waves, according to Amy H. Butler, a National Oceanic and Atmospheric Administration (NOAA) Chemical Sciences Laboratory atmospheric scientist in Colorado.
These waves appear as high and low-pressure systems on most weather maps.
But in the winter, these waves can occasionally become more powerful and travel up into the stratosphere, where the weather happens.
Butler continued to say that these atmospheric waves then occasionally break, depositing enormous amounts of momentum and heat, just the same as ocean waves on a beach.
This is what slows down the polar vortex winds and warms the stratosphere.
Sudden Stratospheric Warming Event
The jet stream is most likely to move south due to the impending abrupt warming event.
As a result, cold weather would spread to the eastern United States, parts of Asia, and northern Europe.
Except for a few fleeting Arctic blasts, the latter region has experienced milder temperatures for the majority of this winter.
Zachary Lawrence, an NOAA research scientist, said that current predictions show some areas of the stratosphere will experience a four-day temperature change from about -40 to 32 degrees Fahrenheit.
Due to the timing of this, it is likely to have an impact on the start of spring.
Lawrence added that due to the typical latency of a few weeks for the troposphere to truly feel an SSW, this SSW, which occurred in mid-February, may have an impact on the start of spring in the eastern US.
To the dismay of many, the winter in the eastern US was relatively warm; therefore, a cooler spring start may be on the horizon.
This could imply conditions that are toasty for winter but cool for spring or something along those lines.
Even though these events happen every two years, the predictability of their effects is still poorly understood, according to Nicholas Davis and several of his colleagues in their study published in Nature Communications in March 2022.
Past SSWs and Climate Change
By looking at previous SSWs that have occurred, scientists can discover more information about these weather occurrences.
The eastern US warmed at the start of January 2021 due to an SSW.
Then, after 20 days, the region experienced a sharp drop in temperature and the arrival of cold weather.
The weather pattern persisted for approximately a month, according to a study by Simon Lee published in April 2021 in the journal Weather by RMetS.
Many of the unusual weather occurrences across the United States and other regions of the globe can be attributed to the polar vortex.
Some scientists think that the vortex has been more disrupted than usual because of climate change.
This may move in various ways as a result of the rising temperatures.
Without being disturbed, the polar vortex moves air from west to east, dividing the cold air in the north from the milder air in the south.
Warming temperatures, on the other hand, might obstruct this flow, making the polar vortex less stable.
Uncertainty surrounds this theory, but over the past few decades, vortex disruptions have been linked to rising temperatures.
Lawrence explained further that waves generated by weather patterns and movements of the jet stream in the troposphere travel vertically into the stratosphere, where they collide with the stratospheric polar vortex, Newsweek reported.
Related Article: Isolated Tornadoes, Damaging Winds To Unload in Southern Southern US; Dallas, Memphis to Expect Flooding Rainfall