Another Study Cites Arctic Ice Loss in Extreme Events

September 1, 2015

nsidc_0901It’s countdown time, as we watch the arctic sea ice drift toward the September minimum.
In March, traditionally the winter high mark, the ice set a record for lowest Maximum extent.
A new record low would be a stretch this year, but it may well be second or third lowest.

A comparison, as of August 17, of the last few years, speaks volumes.


The predictable climate denial crock around sea ice is,  whenever we have a year that is not a new record low, (which obviously does not happen every year) we hear that sea ice is “recovering”.  Might not work so much this year.

sea_ice3_recoverThe new research described below.

The new study, published Monday in the journal Nature Geoscience, advances a growing body of science demonstrating that these record-breaking extremes have not been a pause in the advance of human-driven climate change but a result of it.

The newly published study, led by Jong-Seong Kug of South Korea’s Pohang University of Science and Technology, used climate and weather observations as well as climate change modeling to investigate potential connections between these and other extreme cold winter weather systems over North America and South Asia last winter and historically low levels of summer sea ice in areas of the Arctic Ocean.

Kug and his colleagues determined that the reduced extent of summer sea ice in the Beaufort and Chukchi seas during the summer of 2014 led to a bulge of warmer temperatures in the lower atmosphere.

Those warm-temperature areas are “an indication that the jet stream is taking a big northward swing, creating what we call a very strong ridge,” said Jennifer Francis, an atmospheric scientist at Rutgers University who studies Arctic ice and its effects on weather patterns in lower latitudes of the northern hemisphere.

“Downstream of that ridge, the effect is like taking a jump rope and giving it a big whip: It creates a big wave further downstream, a southward dip in the jet stream,” Francis said. “That means that cold air is able to plunge down into that area from the Arctic, and that’s been contributing to these very cold winters in eastern North America.”

Carbon Brief:

Analysing air temperature records from 1979 to 2014, the researchers found that when conditions over the Barents-Kara Sea region were warmer than usual, East Asia tended to experience a cold winter. This link has also been identified by other scientists.

The new study also finds that higher-than-average temperatures over the East Siberian-Chukchi Sea region were often followed by severe winters in North America.

This has been the situation over eastern parts of the US and Canada for the past two winters, says Prof Jennifer Francis from Rutgers University. Francis wasn’t involved in this study, but has been actively involved in research into whether Arctic warming is affecting weather elsewhere.

I waded into this during the depths of 2013-14’s “Polar Vortex” winter, in a video the National Journal called “..the one video to shut down climate deniers.”

Big step forward

So how do warm conditions in these particular areas of the Arctic cast a chill all the way over in Asia and America? Similarly to other studies, the researchers point the finger at the jet stream – a river of high-speed winds flowing west to east high up in the atmosphere.

The jet stream is driven by the temperature difference between the Arctic and the mid-latitudes. As the Arctic warms, the temperature difference decreases, weakening the jet stream, Francis explains to Carbon Brief:

“[The researchers] find that bulges in the upper atmosphere – indicative of large northward swings in the jet stream – occur in tandem with the regional Arctic warming.”

These wavy patterns of the jet stream draw cold air from the Arctic over North America and East Asia. This also leads to a greater number of high pressure “blocking” weather systems, so the cold conditions can stay put for much of the winter.

The new paper will help settle the debate over whether Arctic warming is affecting mid-latitude weather, Francis says:

“The new study takes a big step toward clarifying a controversial and important issue: whether and how rapid Arctic warming and the disappearance of sea ice are contributing to increased weather extremes in lower latitudes.”

Nature Geoscience – Two distinct influences of Arctic warming on cold winters over North America and East Asia:

Here we identify two distinct influences of Arctic warming which may lead to cold winters over East Asia or North America, based on observational analyses and extensive climate model results. We find that severe winters across East Asia are associated with anomalous warmth in the Barents–Kara Sea region, whereas severe winters over North America are related to anomalous warmth in the East Siberian–Chukchi Sea region. Each regional warming over the Arctic Ocean is accompanied by the local development of an anomalous anticyclone and the downstream development of a mid-latitude trough. The resulting northerly flow of cold air provides favourable conditions for severe winters in East Asia or North America. These links between Arctic and mid-latitude weather are also robustly found in idealized climate model experiments and CMIP5 multi-model simulations. We suggest that our results may help improve seasonal prediction of winter weather and extreme events in these regions.

The wild card this year will be the huge El Nino event devloping in the Pacific, which usually means mild winters in North America. Weather Channel discussion here.


5 Responses to “Another Study Cites Arctic Ice Loss in Extreme Events”

  1. […] Meanwhile, another study cites arctic ice loss as a factor in extreme events. […]

  2. MorinMoss Says:

    Peter, if I may offer a suggestion, 2007 should be included in one of those comparisons as it’s currently the 2nd lowest extent, is well ahead of any year except 2012 and was a sharp drop from the previous record.

    You can pick and choose any year going back to 1979 if you use the ChArctic Interactive page to create your own graph.

  3. uknowispeaksense Says:

    and it looks this year we won’t be hearing that the Antarctic is growing……

  4. indy222 Says:

    It’s “El Nino” vs “The Blob” – where’s schlock horror movie icon Roger Corman when we need him? Who’ll win the battle for the heart and mind of the polar Jet Stream? We shall see, but I’m rooting for El Nino for California’s sake.

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