Thursday, August 16, 2007

Elliptical halos over Deventer

14 August 2007 - At the edge of a large, smooth-structured Altocumulus bank, elliptic halos appeared at 1100, and from 1113 to 1120 UTC. In the first stage, the halo was complete and quite bright, although hardly coloured. It remainded too short to get the camera ready. In the second stage, the halo was quite bright as well, and uncoloured, and sometimes partly covered by the continuously passing-over Altocumulus edge.

Several photographs were able to be made (Nikon D80, AF-S Nikkor justed on 45mm). At 1113 UTC there were sections of two different elliptic halos visible. The inner remainded visible and was complete, even shining through the Altocumulus. The Altocumulus became increasingly dense and halos disappeared at 1120 UTC. Solar elevations from 51,7 to 51,9degs.

Peter-Paul Hattinga Verschure, Deventer The Netherlands

Wednesday, August 15, 2007

Pyramidal halos 8-14-07

After weeks of seeing no nice halo displays I was at work today on breaktime and I saw 22 halo and upper 22 deg tangent arc. I put my sunglasses on and I soon realized I had an odd radius display at hand. In all there was 9 deg. halo 18 deg halo and the outer halo who knows it could be 22 or 23 or a combo of both. The upper arc is convincing it looks sharp and I think it might be 22deg upper column arc but not sure. One photo is an original and the other has USM applied to make the halos stand out better. This is a good odd radius display for me but I know there is a lot better.