Weather goes haywire over Europe: scientists baffled by erratic swings of jet stream
December 25, 2012 – CLIMATE – From
deadly cold in Russia, floods in Britain and balmy conditions that have
residents in southwest France rummaging for their bathing suits, the
weather has gone haywire across Europe in the days leading up to
Christmas. The mercury in Moscow has fallen to minus 25 degrees Celsius
(minus 13 degrees Fahrenheit) — unseasonably cold in a country where
such chills don’t normally arrive until January or February. The cold
has claimed 90 lives in Russia since mid-December and 83 in Ukraine,
with eastern Eurasia in the grips of an unusually icy month that has
seen temperatures drop to as low as minus 50 degrees C in eastern
Siberia. Another 57 people have died from the cold in Poland this month,
and officials say the icy front is probably “the most severe of the
last 70 years,” according to Regis Crepet, a forecaster with
Meteo-Consult. While the former Eastern bloc shivers and Britain fights
severe flooding after heavy rains, holiday-makers and residents in the
south of France and in Italy have dug out their shorts and swimwear to
welcome an unexpected blast of beach weather. Temperatures on Sunday
climbed to 24.3 degrees C in Biarritz on the Atlantic coast, nearly 12
degrees hotter than the seasonal average, and nudging the 1983 record of
24.4 degrees C. “These are remarkable temperatures that we do not see
every year,” French weather forecaster Patrick Galois said. In Catania
on Italy’s Sicily coast, beach temperatures on Christmas day are
forecast to climb as high as 22 degrees C in some places, while in
Austria, the small village of Brand at an altitude of more than 1,000
meters (3,200 feet), noted a December 24 record of 17.7 degrees C. Jim
Palmer, professor of climate physics at Oxford University, told AFP the
weather extremes are explained by the northern hemisphere “jet stream,” a
ribbon of air that speeds around the planet high up in the atmosphere.
The stream is akin to a length of rope “that you wiggle a bit,” said
Palmer — its undulations differing from year to year. This winter the
jet stream is particularly wavy, pulling cold air in over Russia from
the far north, and bringing hotter air up from the south over France and
its neighbors. “The question: Is the waviness and the unusual
configuration of the jet stream the result of climate change? We don’t
know. The models are probably not quite good enough to tell us,” said
Palmer, though there was “some evidence” this may be the case. -TD
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