Mysterious Light Pillars from Latvia

Even two leading experts in atmospheric optics can't quite figure them out: "These pillars are mysterious," say Les Cowley and Marko Riikonen. "They have unexplained curved tops and even curved arcs coming from their base.
http://spaceweather.com

Light pillars are a known phenomenon, but they usually look like this:



The Cause
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Columns of light apparently beaming directly upwards from unshielded (and wastefully polluting) lights are sometimes visible during very cold weather. Plate shaped ice crystals, normally only present in high clouds, float in the air close to the ground and their horizontal facets reflect light back downwards.
http://www.atoptics.co.uk/halo/lpil.htm