Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: (Fwd) The Most Anomalous Refraction Yet or What ?
    From: George Huxtable
    Date: 2009 Aug 4, 19:54 +0100

    I had written-
    
    > However, the picture does show a bit of interesting atmospheric 
    > disturbance,
    > in that there's an inversion occurs within the lowest few minutes near the
    > horizon, causing the main, highly overexposed, Sun disc to flare out at 
    > its
    > lower limb, just where it touches the horizon.
    
    and Marcel replied-
    
    The Omega-sun shows up with super-adiabatic lapse rates, i.e.
    temperature gradients much less than -10�C/km. Inversions are
    generally related to positive temperature gradients (where the sea is
    cold and the air warm), they produce a different picture of the sun,
    not an Omega-sun.
    
    Marcel is referring here to a temperature-inversion, when the air 
    temperature, instead of decreasing with increasing height, increases. I was 
    not, but didn't make my meaning clear, sorry to say. The inversion I was 
    referring to was not a temperature inversion, but an image inversion, in 
    which a mirage-effect can cause ships near the horizon to appear 
    upside-down, and that sliver of the Sun disc to be inverted in a similar 
    way.
    
    George.
    
    contact George Huxtable, at  george{at}hux.me.uk
    or at +44 1865 820222 (from UK, 01865 820222)
    or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. 
    
    
    --~--~---------~--~----~------------~-------~--~----~
    NavList message boards: www.fer3.com/arc
    Or post by email to: NavList@fer3.com
    To unsubscribe, email NavList-unsubscribe@fer3.com
    -~----------~----~----~----~------~----~------~--~---
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site