Lower Pillar, Arctic Russia

A spectacular pillar extends downwards from the sun. There is a hint too of a subsun. Imaged by Boris Borisovich ( journal ) at the Big Wood ski resort in the Khibiny mountains.

 All images ©Boris Borisovich, shown with permission

Subsun

The subsun is formed exactly the same way as pillars except that the mirror-like crystals are aligned much better with their upper and lower hexagonal faces almost perfectly horizontal.

Here the 'subsun' is a slightly elongated brightening in the pillar the same distance below the horizon (marked by the distant cloud deck) as the sun is above it. The crystals making it had small wobbles and were not precisely aligned horizontal.

 
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Lower Sun Pillar

Sunlight reflects from the mirror-like surfaces of wobbly hexagonal plate crystals.  Large crystals wobble most and the greater the wobble from their equilibrium horizontal orientation the longer is the pillar.

It is surprising that crystals wobbling in all directions produce a sharp pillar. It is not easy to visualize but ray tracing computations confirm that it is so.