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Re: Extremely poor conditions??
From: Gary LaPook
Date: 2012 Mar 20, 07:34 -0700

But abnormal refraction also raises the horizon. Fata morganas and other mirages are caused by the refraction raising objects at ground level, observed at essentially zero altitudes and the horizon is also raised. Your observations of the sun may also have been raised but not as much as the horizon since they were higher to begin with.

gl

--- On Tue, 3/20/12, Alexandre E Eremenko <eremenko@math.purdue.edu> wrote:

From: Alexandre E Eremenko <eremenko@math.purdue.edu>
Subject: [NavList] Re: Extremely poor conditions??
To: NavList@fer3.com
Date: Tuesday, March 20, 2012, 6:53 AM

John,

> I've heard of a report of some very impressive looming over Lake Michigan
> in the spring. I recall that people in a town in Michigan could see the
> lights of Milwaukee one night - 80 miles away and well over the geographic
> horizon.

But this is "normal refraction", I mean very large, but "in the normal direction": The light ray is curved in the same direction as the
Earth surface. This sort of refraction would require NEGATIVE
correction to compensate it. In our case, the refraction had to be
in the opposite direction: the ray had to be curved on the opposite
direction to the Earth surface.

This means that the remote toll bioldings whose tops are normally visible
would be unvisible in these conditions.

Alex.

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