‘Polar vortex’ is the new buzzword of 2014 for the millions of Americans learning about its role in producing record cold temperatures across the country. Meteorologists have known for years that the pattern of the polar vortex determines how much cold air escapes from the Arctic and makes its way to the U.S. during the winter. Now climate scientists want to know if a warmer Arctic is influencing its behavior.
The polar vortex is a high altitude low-pressure system that hovers over the Arctic in winter. When the polar vortex is strong, it acts like a spinning bowl balanced on the top of the North Pole. The image (below) shows a strong phase of the polar vortex in mid-November 2013. Dark purple depicts the most frigid air tightly contained in an oval-shaped formation inside the invisible bowl. The light purple line forming the outermost boundary of the cold Arctic air is the jet stream in its normal west-to-east pattern.
In early January, a sudden stratospheric warming event weakened and broke down the polar vortex, allowing fragments of cold air to slosh out of the bowl into mid-latitudes. The image (at the top of this post) shows the weakened vortex formation on January 5, 2014. The high pressure building up in the Arctic slowed down the jet stream, which caused it to buckle into deep folds and flow farther south than usual, introducing cold Arctic air into the central and eastern U.S.
In recent years, climate scientists have noticed that the jet stream has taken on a more wavy shape instead of the more typical oval around the North Pole, leading to outbreaks of colder weather down in the mid-latitudes and milder temperatures in the Arctic, a so-called “warm Arctic-cold continents” pattern. Whether this is normal randomness or related to the significant climate changes occurring in the Arctic is not entirely clear, especially when considering individual events. But less sea ice and snow cover in the Arctic and relatively warmer Arctic air temperatures at the end of autumn suggest a more wavy jet stream pattern and more variability between the straight and wavy pattern.
Understanding the connections between the Arctic warming trend and more severe weather in the mid-latitudes remains an active area of research. But even as Earth’s average temperature rises, natural patterns of climate variability are expected to still operate in a warmer world. There have been many other cases of natural climate oscillations influencing our winter weather in recent years. The unusually cold winter of 2009-2010 proved that record-breaking snowstorms can still coexist with global warming, as did the frigid start to 2011, which resulted in another wintry winter for the eastern United States.
So it is official than a SSW.
SSW have been around since it was first observed in in 1951. Interesting thing this happened last year as well the sudden stratospheric warming event. Interesting though I have not seen any peer review articles that tieback SSW events to AGW or Arctic sea ice loss at least any current research. The only research’s tends to point to south-central Asia as the origin of these events.
Anyway if you know anybody in the polar group, it would be nice for them to post something about these particular events and any tiebacks to either Arctic sea ice loss or AGW in general.
I would like to see more review articles on this subject too, especially on historical patterns and phenomena, I find Jennifer Francis’s lectures very interesting and thought provoking. I notice that the southern stream can get quite lively to, but does not seem to affect weather so much as it does in the North, I have been watching the streams of late via the following link, which the Earth can be manoeuvred as in “google earth”
http://earth.nullschool.net/#current/wind/isobaric/500hPa/orthographic=-49.83,49.33,768
Is worthwhile recalling:
I. “Solar activity is declining very fast at the moment,” Mike Lockwood, professor of space environmental physics at Reading University, UK, told New Scientist. “We estimate faster than at any time in the last 9300 years.”
“And less solar activity can slow the jet stream , triggering a suite of interlinked extreme weather events …” (http://www.newscientist.com/article/dn24512-solar-activity-heads-for-lowest-low-in-four-centuries.html)
II. “When we have had periods where the sun has been quieter than usual we tend to get these much harsher winters,” Sunderland University climate scientist Dennis Wheeler told …”
“After the maximum of solar cycle 24, from approximately 2014 we can expect the start of deep cooling with a Little Ice Age in 2055,” wrote Habibullo Abdussamatov of the Russian Academy of Science” (http://www.trunews.com/multiple-lines-evidence-suggest-global-cooling/)
Considering were currently at a high for this solar maximum and for the last week we’ve had solar flux of 260-210 DRAO. And 10.7 cm (upper atmosphere) flux NASA/MSFC along with a January 6 sunspot count of 225. It would seem unlikely that this would be considered a minimum.
Also to the sudden stratospheric warming event that occurred in 2002 for Antarctica was on the upward side of the last solar cycle.
So SSW doesn’t seem to occur during solar minimum only.
“Mike is probably right that there is a chance of the sun returning to a level of activity similar to the Maunder Minimum,” says atmospheric physicist Joanna Haigh of Imperial College. But she adds: “Even under the most optimistic scenario [of minimal global warming and a deep solar minimum] the solar cooling would only just offset greenhouse gas warming. So no ice age.”
It is more likely that it will simply reduce the warming a little, and set us up for greater warming if it receded.
From the source cured.
Thought we all knew that. Good that you out that out for those who didn’t.
first out = put
And I can’t blame my spell checker. My excuse is that P and O are next to each other on the keyboard and they switched places on me when I wasn’t looking.
I hate this spell checker. Cited just got changed to cured.