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    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 
    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
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