Please explain 22 degree halo

Please explain 22 degree halo

Forums Cloud Identification Help Please explain 22 degree halo

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    • #591057
      Gail Holt avatarGail Holt
      Participant

      Good Morning,

      Thursday’s cloud-a-day was a beautiful and spectacular 22 degree halo, and the explanation is that it is so named because the angle between the direction of the Sun and that of any point on the halo is always 22 degrees. I simply can’t visualise where this angle lies… can someone do a geometric diagram showing me just where this angle is? Or maybe my confusion is to do with the line of the direction of the sun? A diagram would help.

      Many thanks.

      Gail

    • #591179
      Michael Lerch avatarMichael Lerch
      Participant

      ..Its not an angle..its a distance..Degrees in this case refers to astronomic or celestial degrees..the sky is measured in degrees of a celestial dome..360 degrees in a circle..Hope this helps..Hold your hand out..Fully extend your arm. Spread your fingers apart. The distance between your tip of the thumb and the tip of your pinky finger is 20-22 degrees. So if you put your thumb on the sun the 22degree halo is out there where your pinky finger tip is..Have Fun!

    • #591185
      Gail Holt avatarGail Holt
      Participant

      Ahhhh… thank you so much.  I was thinking of geometric angle degrees not celestial astronomic degrees. It now all makes sense… I should have twigged being a (very) amateur astronomer.

    • #591278
      Hans Stocker avatarHans Stocker
      Participant

      Gail, here you can find a nice diagram that shows why it is called a 22 degrees halo: diagram

    • #591298
      Ruth Quist avatarRuth Quist
      Participant

      Hans and Michael, thanks to both of you in explaining the interesting 22 degrees.  Like Gail, it is a hard concept to understand.

    • #591306
      Gail Holt avatarGail Holt
      Participant

      Thanks all, especially Hans for the diagram.

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