The new polar vortex blog hosted by NOAA says ‘some winters come and go without a single interesting thing happening in the stratosphere’, but this one wasn’t one of those. The blog also notes: ‘Odds of polar vortex collapse boosted during El Niño…But not all the El Niños’. The article below says ‘Changes to the polar vortex influence the jet stream, which can in turn impact weather across the Northern Hemisphere’ (caption to NOAA graphic).
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The polar vortex circling the Arctic is swirling in the wrong direction after surprise warming in the upper atmosphere triggered a major reversal event earlier this month, says Live Science.
It is one of the most extreme atmospheric U-turns seen in recent memory.
In the past, disruptions to the polar vortex — a rotating mass of cold air that circles the Arctic — have triggered extremely cold weather and storms across large parts of the U.S.
The current change in the vortex’s direction probably won’t lead to a similar “big freeze.” But the sudden switch-up has caused a record-breaking “ozone spike” above the North Pole.
The polar vortex is most prominent during winter months and extends into the stratosphere — the second layer of the atmosphere up to around 30 miles (50 kilometers) above the surface. The vortex spins counterclockwise with wind speeds of around 155 mph (250 km/h), which is around the same speed as a Category 5 hurricane, according to the U.K. Met Office. A similar vortex also encircles Antarctica during the southern winter.
Polar vortices occasionally reverse temporarily. These events can last for days, weeks or months and are caused by sudden stratospheric warming (SSW), when the temperatures in the stratosphere climb by as much as 90 degrees Fahrenheit (50 degrees Celsius) in the space of a couple of days, according to the Met Office.
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The current reversal event in the Arctic began on March 4. However, the winds are starting to slow down, hinting that the vortex will return to its normal trajectory soon, Spaceweather.com reported.
“It was a substantial reversal,” Amy Butler, a climate scientist at the National Oceanic and Atmospheric Administration (NOAA) and author of NOAA’s new polar vortex blog, told Spaceweather.com. The speed of the reversed winds puts the event in the top six on record, she added.
Full article here.
Tallbloke's Talkshop 
This recent article (extract) brings auroras into the discussion.
Northern Lights slash a surprising amount of winter energy bills. Here’s why.
The precipitating particles that cause auroras, he said, leave their energy high in the atmosphere and lead to the creation of molecules like nitric oxides. These molecules last a very long time in the dark polar atmosphere during winter and can move very slowly — over a span of weeks to a month — to our stratosphere where the ozone layer is. Here, the molecules can destroy ozone, which helps regulate our planet’s temperature.
Ozone absorbs ultraviolet radiation from the sun and infrared radiation coming up from lower in the atmosphere. Changes in ozone, Asikainen said, influence the temperature of the polar stratosphere. In the polar stratosphere, ozone loss is associated with cooling of the stratosphere — strengthening swirling cold winds known as the polar vortex.
Residents in northern Europe and the United States know the polar vortex all too well, and there is another in the southern hemisphere. The stratosphere’s polar vortex is a whirlpool of cold air blowing around the polar region during winter. A weaker polar vortex undulates and can unleash Arctic blasts to lower latitudes. A strong, tightly wound polar vortex keeps the Arctic air at the pole. [bold added]
https://www.msn.com/en-us/weather/topstories/northern-lights-slash-a-surprising-amount-of-winter-energy-bills-here-s-why/ar-BB1kpniR
noted in UK weather, . So I rather wish it would spin backwards until it disappears up its own axial orfice so we could discuss stuff we can do something to change for the better.
Like how to build stronger bridges (I recall that Baltimore one was scary to drive over when I did it). No way multiple spans should have so progressively and quickly collapsed so easily, like some kids first Meccano bridge. The damage should have been confined to spans directly affected.. The spans should never had been so obviously hard wired together, much more interpendent, surely? It looks like a bailey bridge, not a highway. I’m not a mechanical engineer but…… That bridge was under engineered and then some. And there are plenty more like that in the USA. Try the MIssissippi for a start. Perehap they should have bought this one……. https://www.facebook.com/watch/?v=708444640415306
Anyway, as for this vortex, how many people know which way it was spinning in the first place…. or care much. I suppose there must be retired academics who have spent an untroubled lifetime being “specialised” in such pointless things at public expense, so will find them of interest from their Iberian peninsula winter retirement homes. And It was good Kylie song… I’m, spinning around, etc. I am just proving i have got too much time, or am bored of real and serious stuff. Best…..
As I commented in January, there are more known unknowns of climate science here experts pretend.
“Welcome to the Polar Vortex Blog! NOAA Climate.gov
https://www.climate.gov/news-features/blogs/polar-vortex/welcome-polar-vortex-blog
Weather models are however stuffed full of Navier-Stokes equations even though the theory of turbulence $1m prize is still on offer from Clay Mathematics Institute.
Order from chaos: Vortex studies are first proof of decades-old theory ScienceDaily
https://www.sciencedaily.com/releases/2019/06/190627143950.htm
And they say climate science is settled!”
“after surprise warming in the upper atmosphere”
gee, I didn’t realize my truck exhaust and back porch grill CO2 emissions had enough velocity to go that high up! [/snark]