Slashdot is powered by your submissions, so send in your scoop


Forgot your password?
Earth Space Science

Noctilucent Clouds Spread and Mystify 227

Wired has a feature on noctilucent clouds, once seen only at high latitudes but increasingly visible now lower down the globe. The clouds result from ice crystals at altitudes of 50 miles, higher than five 9s of the atmosphere. What water ice is doing up there, in a region 100 million times drier than the Sahara desert, is only one of the mysteries associated with the clouds. They are a recent phenomenon: the first scientific description of noctilucent clouds was penned in 1885. For a time it was believed that the clouds were an effect resulting from the eruption of the Krakatoa volcano two years before. Since 2002, the clouds have been sighted — and photographed — as far south as Oregon, Colorado, and Utah. Some scientists believe that human-caused climate change is playing a role, but others doubt this. Two satellites are in orbit to study the clouds; NASA's AIM generated this day-by-day movie of clouds in the vicinity of the North Pole during 2008.
This discussion has been archived. No new comments can be posted.

Noctilucent Clouds Spread and Mystify

Comments Filter:
  • by nacturation ( 646836 ) * <<moc.liamg> <ta> <noitarutcan>> on Sunday July 19, 2009 @06:00PM (#28750591) Journal

    Something else to handle the load of serving the movie: []

    • Why The Stripes (Score:5, Informative)

      by AtomicSnarl ( 549626 ) on Sunday July 19, 2009 @06:56PM (#28750963) Homepage
      The striped nature of the cloud features is probably because the data was gathered by the DMSP Weather Satellites [] using their low light detection sensors. These do not take a full-earth view of the world as the sun-synchronous GOES satellites [] do. DMSP vehicles operate in a lower orbit but a high angle and circular orbit. This brings them near the poles, and they cross the equator at roughly 9AM or 3PM locally to take advantage of the sun angle and shadows on clouds. They scan a wide path beneath them in visible and infrared channels, and have been used for years to do night light intensity mapping, such as for light pollution surveys. []

      The stripes are the paths from the several vehicles in orbit assembled over time when they passed near the poles.

      Your tax dollars at work!
  • Dry? (Score:2, Insightful)

    "What water ice is doing up there, in a region 100 million times drier than the Sahara desert"

    Bloody well isn't dryer than Mars and Mars has clouds and precipitation.

    • Re:Dry? (Score:4, Interesting)

      by dintech ( 998802 ) on Sunday July 19, 2009 @06:23PM (#28750735)

      This displeases me mightily:

      Some scientists believe that human-caused climate change is playing a role, but others doubt this.

      I've read lots of spiffy evidence to support climate change but it really itches my gizzard when 'scientists' attribute every tiny aberration in the weather to it.

      However, it might just turn out that these clouds are caused by cow farts and thrown away McDonalds wrappers so I should probably just wait for these opposing scientists to finish pansy-slapping each other before I start verbally abusing them from my arm-chair.

      • ...or we simply didnt notice them before.
        • by 4D6963 ( 933028 )

          Yeah, it's like all those hurricanes and droughts, there's always been as many as now, it's just that people back then just didn't notice or die from them.

          • It's only after the battle that you have time to notice the sting of a bee or the discomfort of a blister.
            --Deltora Shadowlands, Book 1 (great book series, btw)
            Mankind will always find something to complain about; all these technologies that are supposed to make life better (and usually do, I'll admit) just give us more time to look.
            • Re: (Score:3, Insightful)

              by pluther ( 647209 )

              Looking up at night and recording what you see isn't exactly a new phenomenon, or limited to our technology.

              People around the world have been doing both for a few millennia at least.

              And, while I lack any peer-reviewed data source here, I would posit that those in an agricultural environment will actually be paying *more* attention to what clouds are doing than those in an industrial area.

          • by radtea ( 464814 )

            there's always been as many as now,

            Hurricanes are not known to be affected in number or severity due to climate change, so it isn't clear why you bring them up, but with regard to droughts you are correct: there current frequency is quite different from the past. It's a lot lower.

            The Earth in the 19th - 20th century enjoyed an unusual period of climatic stability, and we are now reverting to more typical conditions. The probability of going 150 years without a major drought in central North America is p

            • by 4D6963 ( 933028 )

              Hurricanes are not known to be affected in number or severity due to climate change, so it isn't clear why you bring them up

              Because I know what I'm talking about. Well you could argue that you're right in that the number of hurricanes doesn't change, but the difference between a weak ass hurricane that dies on a beach and something like Katrina makes the whole difference between no one cares and the whole world cares.

              Here, have a clue [] : "All these hurricanes in such a short period of time begs the quest

          • Yeah, it's like all those hurricanes and droughts, there's always been as many as now, it's just that people back then just didn't notice or die from them.

            Or, they died and didn't leave sufficient records for the 3 lethal hurricanes after they died to be interpreted.

          • As far as hurricanes, its true, when you factor out observational bias.

            The number, or severity, of hurricanes which have made landfall in the united states absolutely has not been increasing over the past 150 years. On the other hand we now detect 100% of all hurricanes even when they do not make landfall, know at all times their severity, and so forth. The # of hurrican plots in the publicly available data sets has increased due to this observational bias.

            As far as clouds.. more eyes and better equipme
        • "or we simply didnt notice them before"

          Yeah, nobody bothered looking at the night sky before electric light was invented.
          • Nobody bothered writing much of anything about it down for a hundred thousand years, and it was another two thousand years after that before anyone was thorough and systematic about it (aside from navigation purposes).

        • I've watched these clouds last week on the island of Juist, Germany. It was quite amazing and mysterious, something like Aurora Borealis. You do not overlook a phenomen like this. If they had been around all through history, many cultures would have believed them to be spirits or gods and worshipped them.

      • by icebike ( 68054 )

        Right. We don't know where they come from, exactly how high they are, or exactly what they are made of, but we know god damed well they are caused by man made global warming.

        Never mind they may be the very thing cooling the earth by reflecting more sunlight/heat into space than their thinness could possibly trap below.

        If you ask me, since its seen so rarely, its probably the Big Splash. []

        • Now THAT is a theory I can get behind. I have been running scenarios through my mind to guess how and why the ice would get up that high and exclusively at the polar areas. It seems to me that the polar areas are the only places that are moving slowly enough to maintain the group of particles that had collected. As the particles approach the equator, the decision to escape of be captured by gravity become much more definite given the great slinging effect at those speeds. And if in fact the particles en

          • by Nikker ( 749551 )
            It's likely because of the.climate change in the region being at the right balance. In one hand the polar regions have a massive density of water. In the other hand we have a warming climate. What are the chances that the surface temp is high enough for vapour to rise in enough quantity to collect in a central area above the poles? Maybe as the air thins it pulls the water particles appart spreading them out? With all this ice melting as the surface warms gradually the vapour may remain fairly cold as
      • It pisses a lot of scientists off to be referred to as "scientists". The term reduces a huge range of work and an even larger range of opinions down to what sounds like a single collective body (which in fact does not exist). As a general rule, any article which does not name the scientists making a claim can be ignored.
      • "I've read lots of spiffy evidence to support climate change but it really itches my gizzard when 'scientists' attribute every tiny aberration in the weather to it."

        It's called "speculation" but journalists universally fail to use that word when it's performed by a scientist.

        Personally I don't think it's very good speculation in TFA. It's true that above 5km the temprature DROPS because of AGW. However that seems irrelevant since ignoring any AGW change it is still cold enough to freeze any water vapo
        • Remember also that as the temperature drops the solubility of water in air drops--this is why it is so dry up there normally. The air physically cannot hold much water at that temperature. So as the temperature up there decreases over time there should be LESS cloud formation, because there will be less moisture from which to form clouds.

      • Re:Dry? (Score:4, Funny)

        by corbettw ( 214229 ) on Monday July 20, 2009 @01:34AM (#28753179) Journal
        You just don't understand how dangerous anthropogenic global warming (AGW) or anthropogenic climate change (ACC) are, do you?

        AGW will re-write your hard drive. Not only that, it will scramble any disks that are even close to your computer. If you are at work, it will download porn to your hard drive and the hard drives of all your co-workers.

        It will recalibrate your refrigerator's coolness setting so all your ice cream goes melty. It will demagnetize the strips on all your credit cards, screw up the tracking on your television and use subspace field harmonics to scratch any CDs you try to play.

        It will give your ex-girlfriend your new phone number. It will mix Kool-aid into your fishtank. It will drink all your beer and leave dirty socks on the coffee table when company comes over. It will put a dead kitten in the back pocket of your good suit pants and hide your car keys when you are late for work.

        AGW will make you fall in love with a penguin. It will give you nightmares about circus midgets. It will pour sugar in your gas tank and shave off both your eyebrows while dating your girlfriend behind your back and billing the dinner and hotel room to your Discover card.

        It will seduce your grandmother. It does not matter if she is dead, such is the power of AGW, it reaches out beyond the grave to sully those things we hold most dear.

        It moves your car randomly around parking lots so you can't find it. It will kick your dog. It will leave libidinous messages on your boss's voice mail in your voice. It is insidious and subtle. It is dangerous and terrifying to behold. It is also a rather interesting shade of mauve.

        AGW will give you Dutch Elm disease. It will leave the toilet seat up. It will make a batch of Methamphetamines in your bathtub and then leave bacon cooking on the stove while it goes out to chase gradeschoolers with your new snowblower.
      • I've read lots of spiffy evidence to support climate change but it really itches my gizzard when 'scientists' attribute every tiny aberration in the weather to it.

        But it is logical to consider climate change as a possible contributor to weather change, and all that is being said it that this might be caused by a climate change.
        Personally, I think it would be very strange if a climate change didn't cause a weather change.

      • Re: (Score:3, Informative)

        I think your displeasure should be directed at the media source, not "scientists". The fact that it says "Some scientists", without any indication whatsoever of who these scientists are is a massive red flag about whether or not any scientists actually did claim this, and if they did, whether it was 2 scientists vs 1000 scientists.
    • That comparison doesn't quite make sense to me since Antarctica is considered a desert and the driest continent on Earth.
  • I'm in... (Score:4, Insightful)

    by fuzzyfuzzyfungus ( 1223518 ) on Sunday July 19, 2009 @06:08PM (#28750641) Journal
    Before the chemtrail conspiracists show up. Somebody break out the Orgone generators! []
    • I remember in some science-fiction I read many years ago, some clouds were camouflaged UFOs. Actually the clouds were living beings!


      Get out the tinfoil!

      Or maybe the umbrellas, I don't know...

    • Oh wow, man. That is hilarious.

      Best text from that website:

      If you think or know you are already implanted with a chip from a vaccination, flu shot, dentist, surgeon (knowingly or unknowingly through their pharmaceutical supplies) then you can cause them to malfunction within 2 days with a rare earth magnet you can buy that are cheap! I bought 10 of these magnets..the Lord showed me where to put them and I used a band aide to hold them in place. I put them as He led me to. I started on a Friday night, on Sunday I put the last 2 on because they didn't need as many hours to fry the chips as the other ones did, by Monday morning I was cleared and had neutralized all of the chips! New chips, several years old, only need about 12-24 hours to neutralize. The ones you probably got as a kid via vaccines can take 24-36 hours. So I started on a Friday night and took them off on Monday.

      I haven't laughed that hard all day.

      Thanks :)

    • by Maxmin ( 921568 )

      Dude, no no no! This is all due to the HAARP [] project, part of the conspiracy to control the weather so that the earth will heat up enough to provide a "factual" basis for all those "scientific" research projects about global "warming!"

      For those of you wealthy enough to ride Virgin Galactic, through the ice cloud vortex at 50 miles, I strongly suggest bringing snow gear, and tinfoil hats to ward off the Teslan radio waves!

      • Hey. You can get away with a lot on Slashdot, but don't you go dissing Tesla.

        • by Maxmin ( 921568 )
          Hah. I have wondered how his wireless electricity scheme would've turned out. Looks like latter-day wireless electricity variations [] are showing up in certain fields, using inductance.
          • Wireless electricity isn't complicated--you can make a hilariously inefficient system easily. A system worth using on the other hand....

            As a point of how easy it is, Domino's Pizza uses wireless chargers to charge the batteries in the electric heated pizza bags. It's seriously not complicated technology. It's just too inefficient to be useful outside a few isolated applications.

    • Cheers for that, fuzzy. I haven't laughed so hard, and felt so sorry for the human race, in a long time.
  • by OverlordQ ( 264228 ) on Sunday July 19, 2009 @06:19PM (#28750709) Journal

    Kinda disappointing that the first thing nowadays when people see something new it's that "Wow, humans really stuffed up the planet" instead of "Wow, that's an interesting natural phenomenon"

    • Re: (Score:3, Funny)

      by tsm_sf ( 545316 )
      I'd like to come to your hometown, find a nice used bookstore, buy a copy of Silent Spring, drive out to your place, and beat you around the head with it.
      • Re: (Score:2, Flamebait)

        by budgenator ( 254554 )

        I'm just glad you weren't among the 100,105,780 people who have died from Malaria since since Carson's book was published and DDT was virtually banned and declaired a âoepotential human carcinogenâ without evidence by William Ruckelshaus []

        • Re: (Score:3, Informative)

          by dryeo ( 100693 )

          Where the hell do you get this number? Time machine? DDT has not been banned for vector control. Thousands of tons a year is still used to kill mosquito's and the fact that that is all it is used for is much more effective. Mosquito's and other insects get resistant to DDT pretty quick when it is used every where and the death toll from malaria would be much higher if DDT was not an effective control.
          The plan is to ban it once something else that is as good is developed.

  • APOD link (Score:3, Interesting)

    by Windrip ( 303053 ) on Sunday July 19, 2009 @06:31PM (#28750779) Journal
    APOD story []
  • I blame gays.

  • Space Shuttle? (Score:4, Insightful)

    by Robert1 ( 513674 ) on Sunday July 19, 2009 @06:34PM (#28750805) Homepage

    Aren't they caused by the space shuttle? I could swear there was an article a couple weeks ago on slashdot about it. Basically they found that they tend to form hours after the shuttle launch, particularly around Antarctica. The shuttle's boosters release X tons of water into the high atmosphere, at altitudes water can't regularly attain, which gets caught by high moving winds that drive it south, where they crystallize.

    Interestingly enough we just had a shuttle launch just a couple days ago.

  • by SEWilco ( 27983 ) on Sunday July 19, 2009 @07:08PM (#28751031) Journal
    Try my journal entry [] which connects noctilucent clouds to Space Shuttle launches and the Tunguska explosion.
  • Oh clouds show up... Climate change is the answer... Do we know? NO! But since climate change is happening it must be the reason... YEAH WHATEVER!!! This is an example of fooled by randomness. Might it be climate change? Sure, and then again it might not be. How about we get more facts...
  • by TheSHAD0W ( 258774 ) on Sunday July 19, 2009 @08:01PM (#28751313) Homepage

    One of the theories behind the correlation between the sunspot cycle and climate change is that the solar wind tends to deflect cosmic rays from the inner system, and that when sunspots are rare, the solar wind isn't as strong, which allows more cosmic rays to strike the upper atmosphere, generating clouds which deflect sunlight from the Earth. Since up until very recently there's been a sunspot drought, this might indicate a cause.

    • by dbIII ( 701233 )
      Cool, however that theory is unfortunatly only pushed by people that are not experts in sunspots or climate and who will also tell you that smoking tobacco is good for you - the "heartland institute". It's quite depressing that a marketing organisation is trying to talk everyone out of what even the oil industry realised was happening in the 1990s.
    • Since up until very recently there's been a sunspot drought, this might indicate a cause.

      Uh, no, there hasn't. Unless, by recently, you mean the last 4-5 years or so, since the peak of the previous sunspot cycle. Heck, there've been numerous sunspot cycles over the past 100 or so years, while the frequency of noctilucent cloud formation has steadily increased. Furthermore, this particular minimum isn't that much longer than previous ones (longer than average, yes, but not excessively so when compared to

      • Sunspots themselves don't generate the solar wind, but a reduction in sunspot activity correlates with a decreased solar wind. And yes, the solar wind is at a record low [].

        • Sunspots themselves don't generate the solar wind, but a reduction in sunspot activity correlates with a decreased solar wind.

          So you understand this, yet you don't understand the concept of sunspot *cycles*? Odd...

          And yes, the solar wind is at a record low.

          No, it *was* at a record low. Last September, during the depths of the solar minimum. It was not at a record low 5 years ago, during the height of the sunspot cycle. And it's on it's way back up as the current sunspot cycle begins to ramp back up.


          • Do we have data on the solar wind for prior to 25 years ago, which is what the article cites as the beginning of the increased cloud cover?

      • by Troed ( 102527 )

        No, his facts are correct. It seems you're the one that needs to study before posting. We're in the deepest minimum for (at least) a century.

  • That's a nice story in Wired, but we here on Slashdot discussed this topic back in 2007. []
  • It might be coincidental, but the altitude of this phenomenon is the same altitude as the outer edge of the ozone layer. The northern latitudes are also the areas where the earth's magnetic field allows some solar wind particles to a interact with our atmosphere. []

    A portion of the charged particles in the solar winds are protons - aka hydrogen ions. I think it's possible, but maybe not all that likely, that the water present at the

MESSAGE ACKNOWLEDGED -- The Pershing II missiles have been launched.