Pollen Corona Observed

FMims fmims at aol.com
Wed Mar 5 17:44:35 EST 1997


On 29 December 1996, I observed in a
very clear sky a corona around the Sun
consisting of 3 concentric rings. This
phenomenon increased the optical depth 
of the atmosphere by about 0.03 at 1020 nm.
I am located in South Central Texas.

Knowing the diameter of the innermost ring, it 
is possible to estimate the size of the particles
causing the corona at about 60 microns. I therefore 
assume that the corona was caused  by pollen from 
the dense stands of "mountain cedars" (actually junipers) in
the Texas Hill Country. I would very much appreciate 
receiving information about the diameter of pollen
grains from this tree. Thank you.

Forrest M. Mims III
Sun Photometer Atmospheric Network (SPAN)





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