Sunday 28 February 2010

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

5 comments:

  1. And Wegener arc!

    ReplyDelete
  2. marko riikonen1 March 2010 at 11:51

    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.

    ReplyDelete
  3. 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.

    ReplyDelete
  4. marko riikonen2 March 2010 at 11:20

    Ok, Karl, yes, I believe now! A great display!

    ReplyDelete
  5. 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

    ReplyDelete