The chilling weather phenomenon that hit much of the U.S. in January is explained by scientist Eric Fetzer using data from NASA’s AIRS instrument. To see a data only version, watch at:

This movie of temperature observations from NASA’s Atmospheric Infrared Sounder (AIRS) instrument on NASA’s Aqua spacecraft depicts the first major North American weather event of 2014: cold air moving out of the Arctic and south to cover much of the continent. The temperatures shown are at a pressure of 850 hectopascals (hPa, formerly knows as millibars; sea level pressure is normally around 1000 hPa). Pressures of 850 hPa correspond to an altitude of about 3,000 feet (1 kilometer) above sea level. The temperatures in the movie range from about minus 18 degrees Fahrenheit (245 Kelvin or minus 28 degrees Celsius) to warmer than 66 degrees Fahrenheit (290 Kelvin or about 17 degrees Celsius). The very coldest temperatures in purples and blues are minus 18 to 17 degrees Fahrenheit (minus 28 to about minus 8 degrees Celsius).

The most obvious feature of the movie is the tongue of cold air moving out of Canada and southward to cover much of the eastern United States during early January 2014. This event was covered extensively in the media, and introduced the term ‘polar vortex’ to a broader audience.

This global perspective illustrates some features not noted in all the recent media attention. Perhaps most obvious: this is not a global phenomenon. The eastern half of the United States includes only about one percent of the total surface area of the planet (about two million of 197 million square miles). One advantage of satellite observations, as from AIRS, is coverage of the entire planet. A truly global perspective is required when studying variations in climate, and this event must be compared against a number of other phenomena occurring around the planet. Note that Alaska and northern Eurasia were warm during this period of unusual cold over the eastern United States.

About AIRS

The Atmospheric Infrared Sounder, AIRS, in conjunction with the Advanced Microwave Sounding Unit, AMSU, sense emitted infrared and microwave radiation from the Earth to provide a three-dimensional look at Earth’s weather and climate. Working in tandem, the two instruments make simultaneous observations all the way down to the Earth’s surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, three-dimensional map of atmospheric temperature and humidity, cloud amounts and heights, greenhouse gas concentrations, and many other atmospheric phenomena. The AIRS and AMSU fly onboard NASA’s Aqua spacecraft and are managed by the Jet Propulsion Laboratory, Pasadena, California, under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

More information about AIRS can be found at

Image Credit: NASA/JPL

Category: Science, UnScience, Weekend

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12 Responses to “Polar Vortex Behind U.S. Big Chill Explained”

  1. rd says:

    I think he missed two major technical points in this presentation:

    1. Very cold air swept south over a high percentage of American voters who are not used to such cold temperatures, thereby conclusively proving that global warming has ended as temperatures in other parts of the world are unimportant.

    2. Polar vortex sounds like a really cool, esoteric technical term so every media outlet weatherperson (an non-weatherpeople) will be giving this new, previously unknown phenomenom as the reason why temeprature drop below average. We are seeing this weather effect occuring already this week as another bout of cold air is due to arrive and I am hearing about the polar vortex again.

  2. GoBigRed says:

    I believe Donald Trump already outed the Polar Vortex as a hoax, what more is there to know?

  3. Iamthe50percent says:

    I appreciated the video which describes the polar vortex, but it really didn’t explain it, i.e. why it happened this year but not in others. Maybe I missed something.

  4. CD4P says:

    Continental cooling is so passe.

  5. Willy2 says:

    Interesting video.

    An additional reason for all the cold weather is (increased) volcanic activity in the Far East of Asia. There’s a string of volcanoes on the russian Kuril Islands, the russian peninsula Kamchatka, the Aleutians & in Alaska.
    When one of these volcanoes erupt then they blow volcanic dust into the air. And that makes it more difficult for sunlight/-warmth to reach the earth. Hence the lower temperatures of the artic airmasses.

    • Iamthe50percent says:

      Bingo! Finally a reason for “Why now?” And it makes a lot of sense.

      • Willy2 says:

        - Kamchatka is a very active seismic region with e.g. active volcanoes !!!! GOOGLE it !!!)
        - I don’t know how many of those asian volcanoes have erupted in the last month(s). But it seems the combination of the eratic Polar Vortex and volcanic eruptions have conspired this and last month to make the live of US citizens in (especially) the north eastern US pretty miserable.

    • Greg0658 says:

      were you in search of my biPolarVortex dark matter .. I was wondering back in this time period:
      if Haarp & SpaceStation are working in cahoots to setup stocks in Fracking, OilSands and Keystone for Texas & oilmen income streams … glad thats tinfoil hat and nothing more

  6. dsawy says:

    Listening to all the whinging by the eastern press about the recent cold was highly amusing.

    Having gone to college in upstate NY about 30 miles from the Canadian border, I can remember entire months in the early 80′s where the high temperature for the day would be -10F. The night time temps would get down to -30F to -45F.

    -20F was where we reckoned “real cold” began. That’s when you’d pull the battery out of your car at night and bring it into the house. If you didn’t, you had basically no chance of getting your car started in the morning. Diesel locomotives and trucks never shut down – for about six weeks (mid-January to the end of February), you could step outside at night in the small town where we were and hear diesel engines idling for miles in all directions.

    Come March, when the temperatures would start getting above zero F during the day, we became so hardened by the ultra-cold temps we’d play touch football in t-shirts and jeans and think it was pretty warm.

  7. curmudgeon2000 says:

    Missing from most of the East Coast media blather about the cold condtions there is that
    the West coast, and specifically California, is experiencing record high temperatures and drought.
    This is the result of a large, stationary high pressure ridge that has been sitting over the Western
    U.S. and is displacing the jet stream. That high pressure area is being fueled by warmer water
    in the Pacific Ocean, where surface temperatures are above average. So in a sense, yes, the
    movement of “polar vortex” soutward into the Eastern U.S. is a global phenomena, and is in
    large part the result of warmer condtions elsewhere on the planet.