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Noctilucent Clouds Spread and Mystify

Posted by kdawson on from the nature's-own-light-pollution dept.

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.

3 of 227 comments (clear)

  1. Re:Dry? by dintech · · Score: 3, Interesting

    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.

  2. climate change and solar wind by TheSHAD0W · · Score: 3, Interesting

    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.

  3. Re:Or maybe, since temps have flatlined since '99, by RedWizzard · · Score: 3, Interesting

    Or maybe, since temps have flatlined since '99

    Temperatures have not flatlined since '99. That's simply a selective interpretation of the trend. The average temperature anomaly for '95-'99 was 0.468 degrees. For '00-'04 it was 0.572 degrees. For '05-'08 it was 0.665 degrees. How is that flatlined?

    It's pretty clear on this graph.