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Halos & How to spot them

Images by Matt Hoskins in Berkshire, England on 16th January.

" While cleaning my car yesterday I noticed an odd rainbow effect in the paintwork and quickly realised it was actually the reflection of an ice halo above me. I rushed inside and grabbed my camera and took a few shots."

Images ©Matt Hoskins

A colour subtraction enhancement reveals a well shaped upper tangent arc and above it a faint upper suncave Parry arc.

Britain's skies are not renowned for halos but they are there if you care to search.

Keep the car bonnet clean!

Reflection from a dark (preferably convex) surface is a good way to spot halos, iridescent clouds or a corona. The glare is reduced, the view 'concentrated' and the head is at a more comfortable angle (we are not well evolved for halo observation). Sunglasses are helpful too. Shield the sun behind a pole or building.

The bright halo at left is the high overhead circumzenithal arc. Touching it and curving rightwards is a supralateral arc.

Scroll down for more halos of that day.

Below: Both paintwork and windscreen show halos.