Pyramid Ice Crystal Halos Over Finland
			
		
		
			Credit & Copyright:  
Kari Nyman
		
		
			What if the atmosphere above you became one gigantic lens?
This actually happens when a nearly transparent sheet of 
pyramid shaped ice crystals 
falls from the sky in a common orientation.  
These ice-crystals act together like millions of miniature ice mirrors, with external and internal reflections from different faces creating 
arcs and halos of different radii.  
An amazing display of pyramid ice crystal halos was 
captured 
on June 5 above 
Tampere, 
Finland.  
Visible above are 
very unusual sun halos 
of 9, 18, 20, 23, and 24 degrees.
In contrast, thin and flat falling ice crystals will 
produce a halo of 
22 degrees only.  
The high clouds containing the ice crystals are faintly visible, as are some 
sundogs. 
The usual Sun image was covered behind a light post, 
and the above image was significantly digitally sharpened.  
It is not currently known how large areas of nearly uniform 
pyramidal ice crystals form.