Noctilucent clouds

Discussion in 'Astronomy, Exobiology, & Cosmology' started by sculptor, Jun 6, 2021.

  1. sculptor Valued Senior Member

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    8,476
    Low solar activity = more Noctilucent clouds
    = interesting evening light show

    Are y'all seeing them where you live?
     
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  3. exchemist Valued Senior Member

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    Why are they more common at times of low solar activity?

    All I could find was that we can perhaps expect more of them with more methane emission, as the climate changes.
     
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  5. sideshowbob Sorry, wrong number. Valued Senior Member

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    I noticed them just recently. They looked like snow clouds to me. We're near the shortest nights of the year so there's only a few hours of darkness.
     
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  7. sculptor Valued Senior Member

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    8,476
    During a solar minimum, noctilucent clouds tend to become more prevalent as this period favors the frosting of meteor smoke high above the Earth. Water molecules stick to specks of meteor smoke, gathering into icy clouds that glow electric blue when they are hit by high altitude sunlight. Extreme ultraviolet radiation (EUV) radiation can destroy those water molecules before they freeze. As a result, less EUV during solar minimum can result in more noctilucent clouds.
    from
    https://peratonweather.com/blog/202...-have-been-unusually-prevalent-in-recent-days
     
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  8. exchemist Valued Senior Member

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    12,538
    That's very interesting about meteor dust. I subsequently found the same thing referred to on the NASA site: https://www.nasa.gov/mission_pages/aim/news/meteor-smoke.html

    What I didn't find was an explanation of why you get more at a solar minimum - unless I missed it somehow.
     
  9. sculptor Valued Senior Member

    Messages:
    8,476
    yep
    you missed it
    it was in the quoted
    "Extreme ultraviolet radiation (EUV) radiation can destroy those water molecules before they freeze. As a result, less EUV during solar minimum can result in more noctilucent clouds."

    from that, it seems that the dust is still there
    just no water
    thereby no ice
    thereby no ice clouds

    ..........................
    I recently saw a joke about Ikea water
    guy opens the package
    and finds
    2 canisters of H
    and
    1 canister of O
     
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