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Polar
Vortex Ripped in Half by Anomalous Jet Stream, High Arctic
Experiencing 32 Degree F Above Average Temperatures Over Broad Region
A dangerous and weather-wrecking polar heat amplification in the Arctic set off by human-caused global warming keeps kicking into higher and higher gear…
27
January, 2014
What
models predicted earlier this week and
what we reported on Thursday has finally happened. A major influx of
record-breaking winter warmth has flooded into the high Arctic,
disrupting the polar vortex to the point that it is currently ripped
in twain.
Average
temperatures over a broad area of the north polar region are now in
excess of 20 degrees Celsius (32 degrees Fahrenheit) above daily
norms for this time of year. Areas from Alaska to Norway to Greenland
to the North Pole are experiencing record or near record highs.
Meanwhile, the circumpolar Jet Stream has been malformed into an
extraordinarily exaggerated north-south Rossby Wave pattern. An
extreme amplification of a blocking pattern that has been in place
for more than 10 months, pumping a continual flow of heat into the
Arctic, and which, this winter, has resulted in numerous North
American cold snaps comparable to those that used to happen in the
1980s and 1990s.
(Global
temperature anomaly vs the 1985 to 1996 mean. Note the large regions
of the High Arctic experiencing temperatures that are 20 degrees C
above average or higher. Image source: NOAA)
The
result is a kind of north-south flip-flop in temperatures following a
polar vortex that has been ripped in half by a surge of anomalous
warmth and a periodic pulsing of the Arctic’s remnant cold
southward over the continents.
Yesterday,
the high temperature in Svalbard, for example, less than 600 miles
from the North Pole peaked at 32 degrees Fahrenheit, near all-time
record warmth for this frigid region. In contrast, the high for
Bethesda Maryland, thousands of miles to the south, was nine degrees
lower at 23 Fahrenheit.
Hottest
or near hottest ever temperatures in the Arctic are, in this case,
comparable to moderately colder than average weather over Siberia and
the Eastern US (As seen in the NOAA temperature anomaly map above. It
is also worth noting that the 1985-1996 base-line temperature for the
above map is already about .5 C above the 1880 average. So this map
doesn’t take into account the full extent and impact of
human-caused warming.).
The
Jet Stream anomaly that linked a very large and powerful flood of
warm air from the Pacific with another less powerful warm air
invasion riding up over Western Europe setting off such major polar
temperature extremes is now plainly visible in the University of
Washington upper air flow graphic below:
On
the Pacific side, we see a powerful ridge in the Jet Stream invading
deep into the Chukchi and Beaufort Seas before again turning south.
Some of the warmer air carried up by this extreme northward thrust of
the Jet, however, bleeds further north, spilling up and over the
North Pole. There it links with the second warm air thrust coming up
from Europe. To the south, the polar vortex is now misaligned and
severed. The two resulting, lesser, cold vortexes are now centered
hundreds of miles to the south of their typical zones — with one
over Hudson Bay and the other over the Yedoma region of Siberia.
Over
the next week, model forecasts predict this severing of the polar
vortex to continue with the current, anomalous, pattern remaining in
play at least until February 2nd.
What
we are observing is the start of the tumultuous and stormy throws of
an imperiled winter in the Northern Hemisphere. A crisis that is
bound to continue and worsen for at least some time. One that, if we
don’t stop our greenhouse gas emissions soon, will certainly
progress to a period in our not too distant future when winter no
longer exists, perhaps a century or two from now. But make no
mistake, these episodes of extreme polar warmth during wintertime
that flush the cold air out and southward are no less than the
palpitating heart of winter thrumming with the terrible arrhythmia of
its eventual demise.
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