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   46 Radius Halo 

 
Ray trace simulation by HaloSim.  Halos are: (a) 46°, (b) faint supralateral arc, (c) faint infralateral arc, (d) parhelic circle (e) 22°, (f) parhelia, (g) tangent arc (h) Suncave Parry and (j) circumzenithal arc. Crystals were: random 54%, columns 20%, Parry 4% and plates 22%. Oriented crystals were given fairly large wobbles.

    





Antarctic halo display at Halley 5, Brunt Ice Shelf, Coats Land captured with a fisheye lens by Jon Oldroyd (site). The large outer circular halo is (partly) the rare 46° halo. Several other halos are present - see the simulation. Image ©Jon Oldroyd.





The 46° halo is rare and huge. Two outspread hands from the sun, it spreads across the sky.

Its colours are also well spread. They are pastel with red on the inside and no real greens or blues.

But - If you see a fragment of a very large coloured halo twice as far from the sun as the everyday 22°, it may not be a 46° halo!

Supralateral and infralateral arcs lie in a similar position and are often mistaken for the rarer 46°.

See how to distinguish between the two halos.