Wednesday, October 10, 2012

Arctic summer wind shift

Arctic summer wind shift could affect sea ice loss and U.S./European weather

Changes in summer Arctic wind patterns contribute not only to an unprecedented loss of Arctic sea ice, but could also bring about shifts in North American and European weather, concludes the NOAA-led study The recent shift in early summer Arctic atmospheric circulation.

Image from the North Pole webcam shows (July 27, 2010) ponds created by the summer sea ice melt.  (Credit: NOAA)
A research team led by James Overland, Ph.D., of NOAA’s Pacific Marine Environmental Laboratory in Seattle, Washington, examined the wind patterns in the subarctic in the early summer between 2007 and 2012 as compared to the average for 1981 to 2010. They discovered that the previously normal west-to-east flowing upper-level winds have been replaced by a more north-south undulating, or wave-like pattern. This new wind pattern transports warmer air into the Arctic and pushes Arctic air farther south, and may influence the likelihood of persistent weather conditions in the mid-latitudes.

“Our research reveals a change in the summer Arctic wind pattern over the past six years. This shift demonstrates a physical connection between reduced Arctic sea ice in the summer, loss of Greenland ice, and potentially, weather in North American and Europe,” said Overland, an oceanographer who leads the laboratory’s Coastal and Arctic Research Division.

The shift provides additional evidence that changes in the Arctic are not only directly because of global warming, as shown by warmer air and sea temperatures, but are also part of an “Arctic amplification” through which multiple Arctic-specific physical processes interact to accelerate temperature change, ice variability, and ecological impacts.

The study was co-authored by scientists from Rutgers University in New Jersey, the University of Sheffield in the United Kingdom, and the Joint Institute for the Study of the Atmosphere and Ocean, a partnership of NOAA and the University of Washington.

Before 2007, typical summer winds at the Arctic surface were more variable but tended to flow from the west. Since then, the summer winds were found to blow more consistently from the south, through the Bering Strait, across the North Pole, and out toward the Atlantic Ocean relative to the mean pattern in previous decades. These winds transfer additional heat from the south toward the North Pole and push sea ice across the Arctic and out into the Atlantic Ocean, contributing to record losses of summer sea ice. The 2012 Arctic summer sea ice minimum far surpassed 2007 as the lowest on record.

“Higher pressure over the North American continent and Greenland is driving these changes in the early summer wind patterns,” said Edward Hanna, Ph.D, of the University of Sheffield.

These shifts in winds not only affect weather patterns throughout the Arctic but are also thought to influence weather in Greenland, the United States, and western Europe. Understanding such links is an ongoing area of research, the scientists said. The effects of Arctic amplification will increase as more summer ice retreats over coming decades. Enhanced warming of the Arctic affects the jet stream by slowing its west-to-east winds and by promoting larger north-south meanders in the flow. Predicting those meanders and where the weather associated with them will be located in any given year, however, remains a challenge.

The researchers say that with more solar energy going into the Arctic Ocean because of lost ice, there is reason to expect more extreme weather events, such as heavy snowfall, heat waves, and flooding in North America and Europe but these will vary in location, intensity, and timescales.

“What we're seeing is stark evidence that the gradual temperature increase is not the important story related to climate change; it's the rapid regional changes and increased frequency of extreme weather that global warming is causing. As the Arctic warms at twice the global rate, we expect an increased probability of extreme weather events across the temperate latitudes of the northern hemisphere, where billions of people live,” said Jennifer Francis, Ph.D, of Rutgers.

Screenshot from above video

View related video, links to further videos and references below.




Does Arctic Amplification Fuel Extreme Weather in Mid-Latitudes?
Jennifer Francis, Rutgers University, 25 January 2012, in collaboration with Steve Vavros, University of Wisconsin


Sources

- Arctic summer wind shift could affect sea ice loss and U.S./European weather, says NOAA-led study
http://www.noaanews.noaa.gov/stories2012/20121010_arcticwinds.html

- The recent shift in early summer Arctic atmospheric circulation
http://www.agu.org/pubs/crossref/2012/2012GL053268.shtml


Videos


- Does Arctic Amplification Fuel Extreme Weather in Mid-Latitudes?
Featuring Jennifer Francis, Rutgers University, January 25, 2012
Published on Mar 29, 2012 by noiv
http://www.youtube.com/watch?v=4spEuh8vswE



- Weather and Climate Summit, Day 5, Session 9
Presentation by Dr. Jennifer Francis, Rutgers University. Topic: The Arctic Paradox
Uploaded by StormCenterInc on Jan 23, 2012
https://www.youtube.com/watch?v=RtRvcXUIyZg
http://marine.rutgers.edu/~francis/pres/Francis_Vavrus_2012GL051000_pub.pdf


- Jennifer Francis: What the Ice is Telling Us
Published on Sep 26, 2012 by greenmanbucket
http://www.youtube.com/watch?v=rZflv8GpgUA


- Jennifer Francis: An Interesting Fall and Winter
Brief clip from a longer conversation with Arctic Specialist Jennifer Francis of Rutgers University.
Published on Sep 25, 2012 by greenmanbucket
http://www.youtube.com/watch?v=D58xDmzMnpk


- Weird Winter - Mad March - Part 1
Published on Apr 16, 2012 by greenman3610
http://www.youtube.com/watch?v=_-1iBHAivmw



- Weird Winter - Mad March - Part 2
Published on Apr 16, 2012 by yaleclimateforum
http://www.youtube.com/watch?v=HTAZue6ylZ8



- BBC on Sea Ice - featuring Professor Peter Wadhams
Published on Sep 6, 2012 by greenmanbucket
http://www.youtube.com/watch?v=_6umZfpv6eM


Related

- Accelerated Warming in the Arctic
http://arctic-news.blogspot.com/2012/09/accelerated-warming-in-the-arctic.html

- Changes to Polar Vortex affect mile-deep ocean circulation patterns
http://arctic-news.blogspot.com/2012/09/changes-to-polar-vortex-affect-mile-deep-ocean-circulation-patterns.html

- Diagram of Doom
http://arctic-news.blogspot.com/2012/08/diagram-of-doom.html

- Opening the Doorways to Doom
http://arctic-news.blogspot.com/2012/08/opening-the-doorways-to-doom.html

- How extreme will it get?
http://arctic-news.blogspot.com/2012/07/how-extreme-will-it-get.html

1 comment:

  1. The Arctic Dipole set up since 2007 is consistent with when CH4 levels diverged upward on a trajectory indicating methane release from melt of methane ice and permafrost. It's consistent with what's happening with more clear sky over Greenland and melt there and the winds that are pushing the Arctic sea ice out. East Siberian Arctic Shelf is where the hugest concentration of methane hydrate on shallow sea floor is and the side of Arctic away from where most Summer sea ice is.
    The pattern looks to hold maybe till Greenland is clear of ice and Russian Siberia is free of carbon on land and shallow sea if that's the driver.. Short term - likely intensification of desertification pressure on N America in crop belt going quickly to radically extreme..
    Where is everybody on this because discussion by Biden and Ryan along with moderator of debate didn't touch it and neither is it on TV world screen.. What's happening to group think?
    Are we so enamored by TV and world play to think
    -Think for a moment what it means to be too late.
    What will it take to get people's interest focused on trying to alter the course of Earth fate.. Yikes because if it's doable to take on the task to undo past harm of greenhouse gas from our use of fossil fuels that time is fast disappearing. Game is on 2C if temp can be led to return to safe levels and CH4 kept from precipitous release to the sky. Dipole needs correction and weather needs to return to norm.

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