Friday 18 December 2009

Liljequist parhelia in spotlight beam

One would think that such a demanding halo as Liljequist parhelia would need the best possible swarm to be seen. While that may be true in halo displays from natural light sources, with spotlight it is a different story. Here Liljequist parhelia - the two diffuse light areas both sides of the observers shadow - are visible despite the apparently crappy crystals that are filling the air.

Also visible are vague upwards curving extesions from Liljequist parhelia, which might have formed a complete half circle around subanthelic point if there was no cutting shadow. These are signs of the diffuse subanthelic halo that was photographed last winter in Rovaniemi ( 1 ). See also the lamp side of the display ( 2 ). The photo was taken by Marko Mikkilä in Sotkamo on 14th December. Click on the image to see a simulation.
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2 comments:

  1. marko riikonen18 December 2009 at 23:38

    Just remembered that should have made that simulation with crystals that have some random variation in the prism face ratios. This would have made the insides of the Liljequist parhelia / diffuse subanthelic halo more illuminated like in the photo. And also the blue circle would have disappeared. Yeah, I think that would have made quite perfect simulation, also could have tuned it to conform with lamp side.

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  2. Jari19 December 2009 at 11:27

    Mikkilä, what an interesting capture! This just goes to show that one must be ever alert even though it might first seem that nothing of particular interest is present.

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