NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Fleming
Date: 2012 Mar 21, 09:17 -0700
My conclusion about terrestial refraction equaling refraction of the Suns LL is not justified. (It ignores further solar refraction that occurs beyond the horizon as the rays enter the atmosphere.)
Still the terrestial refraction of the horizon causes the horizon to appear higher than geometry would imply, ie the visible horizon is beyond the geometric horizon and rays are bent to follow somewhat the earths curvature.
With an enhanced air desity gradient due to cooling effects of the water this curvature is increased, the horizon is further lifted and the altitudes are less than expected.
Dave Fleming
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