Ice Crystal Halos

Tapes arc, helic arc and subhelic arc observed in Austria

Tapes arc, helic arc and subhelic arc observed in Austria

Last January, 27 th, I managed to get one of my best halodisplays during my long observation period of halos – I have observed these phaenomena more than 15 years already.

On my way home from work I observed 14 different haloforms within 1 and a half hour (14:15 – 15:45 CET). It started with a bright circumzenith arc, sundogs and a clearely vertically elongated left hand side 120° parhelion on a short parhelic circle. Later the 120° parhelion on the right hand side appeared. The highlight (about 15:15 CET) was the observation of the CZA, supralateral arc, 46° halo, suncave and sunvex Parry arcs, upper tangent arc, 22° halo with sundogs, Tape arc, helic arc, subhelic arc and a little bit later a small part of the left infralateral arc.

I run a simulation with Halosim from L. Cowley and M. Schroeder that shows the halos I have observed near the sun quite good. A report and many images can be seen by clicking the image above. I invite you to take a look at the site.

Karl Kaiser

7 comments

  • I have difficulties to figure out this display, especially the subhelic arc. Sometimes I think that it is just parhelic circle. The simulation is not much help. It is should be centered on the side, rather than on the sun.

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  • Thats just amazing Karl I like that tape arc and the subhelic arc. I’ve seen helic wegener arcs in cirrus back in 2006 but in 09 I got wegener three times and in the one display I got my first tricker arc.

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  • Dear Marko,

    Parhelic circle should be seen symmetrically in the images with vertical symmetryaxis. My camera was in a horizontal position as we see (look at the trees in the middle of my image – http://home.eduhi.at/member/nature/met/HALO/phaen2010-01-27/35komb.htm). In my pics subhelic arc stretches from right hand side up to left hand side down.
    I remember the height of the trees was much more than the elevation of the sun. In 2 hours, on my way to work, I check it out.

    Have a nice day.

    Best regards from Schlaegl,

    Karl

    Reply
  • I measured the height of the spruce you see in the image mentioned above – it´s about 22°. The subhelic arc was located much higher in the sky!

    Karl

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