Catch up on stories from the past week (and beyond) at the Slashdot story archive


Forgot your password?
NASA Space Science

Giant Atmospheric Waves Filmed Over Iowa 107

NJChopperMan writes "For all those of you that thought waves only existed in the ocean, Photos and video of undular bore waves were caught in Iowa last week." The story also touches on the role of undular bores in severe weather, but it's definitely second fiddle to the video of the waves.
This discussion has been archived. No new comments can be posted.

Giant Atmospheric Waves Filmed Over Iowa

Comments Filter:
  • by timmarhy ( 659436 ) on Friday October 19, 2007 @03:30AM (#21037889)
    i don't know how, but somehow, this is global warmings fault.
  • Bore waves? (Score:5, Funny)

    by mstahl ( 701501 ) <marrrrrk AT gmail DOT com> on Friday October 19, 2007 @03:37AM (#21037921) Homepage Journal
    Bore waves . . . in Iowa? *yawn* That sounds about right.
    • Yeah...hard to believe some people go there on ride bikes [], no less.
      • by ashitaka ( 27544 )
        Nice easy flat roads. Buncha good people to eat, drink and be merry with.

        Sounds fun to me.

        As you can see by the gallery, the cycling is secondary to the partying.
      • by mstahl ( 701501 )

        Lol are you from Iowa? Far be it from me to disparage our neighbours, the Tall Corn State (bearing in mind that Chicago alone is all that saves us here in Illinois from basically being lumped in with Iowa as a flyover state).

        Cheers! — max

  • by bombastinator ( 812664 ) on Friday October 19, 2007 @03:37AM (#21037929)
    I thought undular bores are those guys at parties who tell loud political jokes then try to sell you insurance or something.
    • No, they're the people who hear a word like 'bore' and have a knee jerk reaction to make a really lame joke that's a poor variation of a joke you've heard a thousand times before and is normally just the sort of thing someone would say when they have absolutely definitely run out of things to say at a party and they're trying really desperately hard to say something, anything, so as not to look completely and utterly lame.
  • on a map (Score:5, Informative)

    by Paktu ( 1103861 ) on Friday October 19, 2007 @03:37AM (#21037931)
    Here's [] a pretty good example of what this looks like on a weather map
    • by TapeCutter ( 624760 ) on Friday October 19, 2007 @06:04AM (#21038631) Journal
      I've been a casual cloud/storm nerd for decades and if you watch the sky long enough you can't help but notice "waves" and "drainpipes" at a more localized scale (particularly when a strong cold front is approaching).

      I currently live a 100M or so from the beach in Melbourne Australia. Small intense storms come in over the bay heading directly toward the beach so you get the front "ledge" of the storm cloud coming over while behind you is clear and the drama is still out in the bay. If you stay still and face toward one of these storms roughly when the cloud/sky boundry is directly over the beach you will feel the wind do a 180deg flip as if the storm is enhaling warm air and exhaling cold with a slight pause in between. It is more pronounced with slow moving storms and can last for 15 minutes or so with a regular inhale/exhale cycle of about a minute. The first exhale of an intense summer storm can feel like someone opened a fridge door if you have been sitting with your back turned and not seen it approaching.

      If rain/hail is heavy enough in the center of the storm you might also see prominent ridges running up the underside of the ledge similar to those in TFA but curved to fit the squashed drainpipe shape of the storm. When the rain/hail gets closer the wind will turn steady and cold (time to go inside).

      Disclaimer: Don't try observing it standing on the beach, and escpecially not with an umbrella!
      • by Cragen ( 697038 )
        When flying above the clouds on commercial flights, looking down on the clouds 10K+ feet below, it all certainly looks like the clouds have a "terrain" (cloud-ain?) with streams, rivers, hills, etc. Probably just seems that way, but it has always seemed like a "land of clouds" to me. (Maybe I am reading too much fantasy stuff...)
      • by mikael ( 484 ) on Friday October 19, 2007 @09:15AM (#21040153)
        If you stay still and face toward one of these storms roughly when the cloud/sky boundry is directly over the beach you will feel the wind do a 180deg flip as if the storm is enhaling warm air and exhaling cold with a slight pause in between.

        From some of the research on such phenomena (cloud dynamics), a small thunderstorm consists of a number of cells in which air is either moving upwards or downwards. This explains this visually []
        • Exactly how I see it.
          The center of a storm is a big blob of cold air getting dragged behind falling ice, similar to blob hitting the bottom of a lava lamp.

          The "breathing" is the bow wave it creates as it moves forward across the surface, that's why you have to be in front.
          Also explains why it is hard to detect in a fast moving storm - cold air is flooding the area and you are under the waves before you know it.
      • One time I drove my through a cold front from the cool dry side to the humid side it felt like someone just took a steaming hot washcloth and smothered me with it.
      • Re: (Score:2, Interesting)

        by ackthpt ( 218170 ) *

        Nice post, what's it doing here? ;-)

        When I was about 13 a friend and I rode our bicycles (the big old heavy steel ones of yor) about a mile away from home to purchase some candy and likely the latest issue of MAD. It was a typical hot and humid Summer day. On the way home we felt the wind pick up, kicking up dust and leaves and looked northward. Like a great steam locomotive out of the north a massive grey bank of thunderheads (large nimbus clouds with flared and flattened tops) was sweeping down. As i

        • "the big old heavy steel ones"

          I grew up in the 60's - is there another kind? :)

          Nice post, what's it doing here? ;-)

          Thanks - science is driven by our feelings of awe at the power and complexity of nature, as is religion.
          • by mikael ( 484 )
            I don't know if you saw my other link on the website, but the Cloud Appreciation Society [] has some amazing pictures.
            • Thanks for the link. :)

              I notice they have a picture of the "morning glory", I haven't seen it myself but my younger brother runs a safari style camping/touring bussiness around where it occurs so I am hoping to see it on one of my visits.
    • by fatphil ( 181876 )
      That's not pretty good - that's fantastic, compared to the one in TFI.
      I was going to just say "pffft! that's nothing, look at these instead" and point people to

      instead, but actually it appears bores (why's it called that? It's not contrained, not self-supporting.) can be quite impressive too.
      • by mikael ( 484 )
        The Cloud Appreciation Society [] have an interesting gallery on unusual cloud formations.
        • by fatphil ( 181876 )

          Wow. A huge thank you for that. My g/f's mother is a meteorologist, I've already passed that URL on to her, I'm sure she'll love the site too.
  • by 6Yankee ( 597075 ) on Friday October 19, 2007 @03:43AM (#21037961)
    TFA was pretty light on detail, but these look like a completely different animal from the (warning: gratuitous Wikipedia link) mountain waves [] so beloved of glider pilots. Wonder if they're soarable?
  • Everything we call real is made of things that cannot be regarded as real. There are some things so serious you have to laugh at them.
  • Sky == CRT? (Score:3, Funny)

    by jfim ( 1167051 ) on Friday October 19, 2007 @03:45AM (#21037983)
    Wow, now I know that the sky refreshes like a CRT now! :)
  • Really nice images! (Score:5, Interesting)

    by muecksteiner ( 102093 ) on Friday October 19, 2007 @03:50AM (#21038009)
    Atmosperic wave phenomena have been known for ages, and are hardly inconspicious in those places where they regularly form.

    The main "customers" for them are probably glider pilots; as far as I remember, all recent altitude records for soaring have been made using waves formed in mountain regions (14+km), and the current distance record by Klaus Ohlmann (insane 3000+km in one day) was also flown in the waves over the Andes. Thermal updrafts are toys by comparison.

    The one thing that you have to hand to the NASA guys is that they indeed caught some very fine specimens there, and in an unusual place, too. Normally, waves are induced by the flow of wind over a given, usually hilly, terrain. Gravity waves from thunderstorm activity are certainly a lot more esoteric, and what they are saying about them being catalysts for storms sounds really intriguing.

  • I wonder if aeroplanes could surf these waves and thereby save fuel?
    • Re:Surf's up (Score:4, Informative)

      by Tastecicles ( 1153671 ) on Friday October 19, 2007 @04:16AM (#21038131)
      They already ride the jetstream and save fuel/time on Transatlantic crossings. I forget which direction, but it's around half an hour saving on flight time. That's a /lot/ of fuel.
      • Re:Surf's up (Score:4, Informative)

        by Silver Sloth ( 770927 ) on Friday October 19, 2007 @05:03AM (#21038355)
        London -> New York 7.5 hrs
        New York -> London 6.5 hrs

        Given how much I hate long flights I love coming home.
        • Re: (Score:1, Funny)

          by Anonymous Coward
          London -> New York 7.5 hrs
          New York -> London 6.5 hrs

          That's due to all that red tape.
        • by g1zmo ( 315166 )
          This is what I've always heard, but some years ago I experienced just the opposite. I was on a flight from Philly to Barcelona which took about 11 hours, but the return flight from Paris to Dallas was closer to 9 hours. I never did find an explanation.
          • I was on a flight from Philly to Barcelona which took about 11 hours,

            It probably wasn't because of the jetstream - more likely they didn't have a gate at Barcelona until 11 hours in the future. That's a really long time for that flight.
    • I wonder if I could surf these waves and thereby generate adrenaline.
    • No. The waves move far too slowly to be useful in this regard, and given that they're immense gravity-waves some 5 miles apart, the plane would probably feel like a paper-boat caught in the wake of a super-tanker.
    • Catch a wave and you're sitting on top of Des Moines
  • by Zymergy ( 803632 ) * on Friday October 19, 2007 @03:58AM (#21038043)
    ...and thus they will both have fluid dynamic behaviors when vibrating (waves) at the interface of another fluid.
    Wave action happens at the disturbance interface (involving the propagation of and/or transfer of energy) between fluids of different densities.
    The Air/Water fluid interface where one observes common "waves" are observed as water waves because the air is transparent (but it too has waves).
    The difference here, is that we have two air masses of different temperatures and humidities (thus having differing densities) interfacing as fluids AND one of them happens to be an air mass that contains visible moisture in the form of clouds.
    It is likely that this type of air/air fluid "wave action" happens frequently at the interface between differing atmospheric air masses (AKA fronts), but in this example the clouds made it easily visible.
    Nice Image too: [] []
  • For all those of you that thought waves only existed in the ocean

    FYI, atmospheric waves are very common and have very similar structure. In fact, the study of both atmospheric and ocean waves is called Geophysical Fluid Dynamics. It is a fascinating field - my favorites are atmospheric waves in which the wavelength is such that two or three waves encircle the entire Earth.
    • Re: (Score:2, Interesting)

      More interesting are the waves set up by the harmonics of the Atlantic Ocean. There's a particular length (I forget exactly, but it's something close to 100 metres) that nautical engineers will never, ever build their ships to be, because they would get torn apart in the middle of the Atlantic by the simple harmonic motion of these waves.
      • Re: (Score:2, Informative)

        by Anonymous Coward
        Some told you that in a bar, and you should not have believed them. Spectral fatigue analysis is a bit more complex than that. Just trying to simulate the random seaway is difficult, search "pierson and moskowitz" for a good start. People get there PhDs just trying to develop ways to get design loads from wave spectrum. Generally these spectrum focus on the North Atlantic wave climate as it is the worst case environment that most boats would ever operate in.
    • These waves are called Rossby or planetary waves, in case anybody here wants to look into it further.
  • by scorpio_boy ( 694099 ) <`rolf' `at' `'> on Friday October 19, 2007 @04:18AM (#21038151) Homepage
    Seriously, go see the photos and video on my blog if you don't believe me at [] We call the resulting visual cloud a morning glory in Australia....
  • I saw the term "bore waves", and suddenly I had a vision of a story about a George Bush press conference...
  • Cute (Score:4, Funny)

    by tygerstripes ( 832644 ) on Friday October 19, 2007 @05:19AM (#21038415)
    The little yacht dithering about in the water under the impact of these waves is, somehow, very endearing. I keep wanting to give it a saucer of milk.
  • Nice to see this presented as a Quicktime movie. What other format could this be in where I can grab the play marker and drag it back-n-forth to scrub through the movie?
  • That film was obviously photoshopped! I mean, come ON! [/today's xkcd]
  • All of the presidential candidates who have been frequenting the area. I hear everything undulates after having that much asshole that close all at once!!!!
  • by Anonymous Coward
    Since the NASA site download seems slow right now: []
  • You can see these waves clearly in deserts and then a few minutes later you wish you hadn't.
  • (Think 1980s Flash Gordon)
  • by DrBuzzo ( 913503 ) on Friday October 19, 2007 @10:50AM (#21041677) Homepage
    This is just more evidence of the need for aluminum foil hats. That damn government with their satellites and chemtrails with the roswell, ufo, grassy knoll, glomar explorer, watergate it's all run by the damn illuminati who are with the freemasons in the center of the hallow, convex flat geocentric earth.
  • Things like undular bore waves are part of the reason why severe weather on a small scale will continue to be difficult (if not impossible) to predict for the foreseeable future. We have a better than ever handle on what's happening at the time, which is enough to give people 15-20 minutes warning ahead of time for severe weather and tornadoes (and has undoubtedly saved thousands of lives since the mid 1940s, when tornado warnings started to be issued).

    But it is still well beyond any computer model in exist
  • Great article. I saw one earlier this summer and it was the coolest thing I think I've seen in the sky. It's akin to something from ID4 (that crappy movie back in '96 with will Smith and aliens) and it's really imposing. Very cool stuff.
  • When I was a kid, one of these passed over our neighborhood. I remember how fast it was moving and how its shape was just to "uniform" to look like it belonged in nature. It was both fascinating and frightning at the same time. I recall it was darker than the one in the video shown in the parent article and had lightning coming out of it as well.

    Real freaky looking, and it unnerved the grown-ups as well as the kids.
  • [] I thought they were pretty cool when I saw this as well. Had to race like hell to get my camera and get out in front of the storm far enough to get some shots.
  • I saw something that looks similar (but I suspect is a different, though equally cool phenomenon) last December in Cupertino, CA driving west on I-280 (facing the Santa Cruz mountains).

    It looked like the clouds were emerging from the mountains as fine jets that got wider as they got further into Silicon Valley. Anyone know what this is?

    (At the time I thought perhaps they were clouds of flying monkeys from Microsoft's Mac Business Unit -- which is in those mountain

    • It's clear from the photos, especially the first one, what is going on here. "We don't know who struck first - us or them - but it was us who scorched the sky."
  • There is a much better video of atmospheric waves here [].
  • I accidentally read that headline as "Giant Atmospheric Whales Filmed Over Iowa." I immediately panicked and ran off and grabbed a towel and a copy of "The Hitchhiker's Guide to the Galaxy"...
  • There was this other undulating cloud video from Iowa from a few months ago... It's at 60x normal speed or thereabouts, so I'm not sure the people standing there would notice. Nevermind that the video is titled like a tabloid... It's still impressive. []

Forty two.