Bright Tricker arcs in Prichovice

On 10 January 2009, Jan Smejkal observed a complex display in Prichovice, in which some rarer halo forms - such as the anthelion brightened by crossing Tricker arcs - were in action, too. The more frequent halo arcs included suncave and sunvex Parrys, Wegener, a faint helic, upper Tape arcs and subhelic arc ( 1 – 2 – 3 – 4 – 5 – 6 – 7 ). The photos also show a weak Liljequist parhelion ( 8 ).

Jan Smejkal described the weather during the complex halo in the following way: "On 10 January 2009, Prichovice was slightly above inversion, and time to time some very thin clouds crossed the sun. The display was observed at different intesities from around 9:00 until 11:30UTC when the sun got covered by clouds."

More information on the Czech diamond dust displays can be found in some articles at the following site: ( 9 ).

Text: Martin Popek and Matej Grek

Bottlinger's rings from a Beijing - Singapore flight

The photo on the right, and another one ( 1 ) were taken on an airplane from Beijing to Singapore on 3 January. The Bottlinger Rings appeared two times in total, when the plane flew above patches of dissipating AC clouds. I only managed to capture the first appearance. When the rings appeared, the subsun was glaring, and I got a feeling of the ring swelling and shrinking as the cloud moved, but I guessed it was only an illusion.

Text: Jia Hao

Elliptical halo from the Czech Republic

On 17 January, I (Matej Grek) went to Malenovice near Lysa hora in the Beskydy mountains to "hunt" halos in diamond dust, because humidity was near 98% and temperature below zero. However, as the temperature was still not low enough, they stopped operating the snow guns, so I went back to the train stop, and on the way, I noticed Altocumulus Virga clouds. They started to disintegrate into ice crystals ... so this was the chance to see my first ellipse ever. I looked through sunglasses and there was something that looked like a sun pillar. I blocked the sun with a chimney and started taking photos. In the train I looked at them, and noticed an elliptical shape. Back at home, I stacked the images, and Marko Riikonen also helped me by creating an animation ( 1 ). It has proved to be clearly an elliptical halo - my first one.

Text: Matej Grek

Halo display in Himos on the night of 9/10 January

The display developed soon after the snow guns were started at 21:30 and began vanishing no earlier than 05 in the morning when Ac clouds rolled over. It was an unusually stable display, the swarm stayed in the same location and there were no much changes in the halo composition.

Jari Luomanen ( 1 ) and Mika Aho ( 2 ) photographed the display and took videos in the spotlight beam. I sampled crystals ( 3 - 4 - 5 ). Wegener arcs were full and both lower Parrys were visible.

Diamond dust halos were observed also in Sievi by Marko Mikkilä ( 6 ) and in Hyvinkää by Jukka Ruoskanen ( 7 ).

Diamond dust displays in Sudelfeld Pass

The new year started with two nice diamond dust displays on 3 and 7 January. The weather situation was similar: above the Inn valley there was a low stratus layer with an upper limit of ca. 1000-1200m. The passable Sudelfeld Pass is situated in this level, where I've already seen several diamond dust haloes. In the afternoon the clouds dissipated and desintegrated into ice crystals.

On 3 January columns dominated. The 22° parhelia, the upper tangent arc with convex Parry arc and the colourful supra- and infralateral arcs appeared in –6°C ( 1 ).

The haloes on 7 January (see image above) were produced at a temperature of –8°C and consisted mainly of plates. The appearance of the phenomena changed at seconds intervals. We observed 22° halo with parhelia, upper and lower sun pillar, CZA, 46° halo, subsun, sub parhelia, parhelic circle with 120° parhelia and anthelion, heliac arc, Wegener's arc and Moilanen arc ( 2 ).

Text: Claudia Hinz

Divergent light curiosities

In the image above the two photos in rigth hand column represent intense pillarforests with superparhelia rising from nearby lamps. The sight is very impressive as tens of lamps around the observer create pillars. Furthermore, one can see a long circumzenith arc, as all the lamps contribute to it ( 1 ).

Some interesting halo geometries come about when one approaches a spotlight and the light rays become ever more divergent. In the leftmost column there are two examples of that. In the upper photo both car headlights are the light source, and peculiar arcs are formed each side of the lamps. A strong feeling is that these are superparhelia-related. In the lower photo the camera is only 5 meters from the spotlight and almost outside the strongest beam. The shape of the subparhelia gets distorted in a funny way. That effect can also be seen in Jari Luomanen's photo ( 2 ).

So far we have no definite answer to the origin of these halos, but surely they are a result of quite complex geometries involved in divergent light scattering and represent distorted images of ordinary haloforms. These photos are important in correctness evaluation of divergent light simulation code. Should anyone reading this want to shoot similar images, I suggest that the relative distances are carefully noted so that comparison with simulations can be done.

During the night between 2nd and 3rd January the divergent-light 120° parhelion was seen as well ( 3 ) and some crystals were collected and photographed at the same time ( 4 - 5 ).

Spotlight sub-Kern in diamond dust in Hyvinkää

Sub-Kern, although already documented by Riikonen ( 1 ), was in the back of my mind when the plate crystal swarm got better in the night between 1st and 2nd January 2008. I was forced to photograph in a light-polluted parking lot, but immediately when lying on my back I could see something encircling the zenith. Pretty soon it came to me: sub-Kern and circumnadirarc. Despite the poor contrast conditions the halo shows up well in the photos, as expected since it could be seen visually as well.

Next evening (2.-3.1.2008) the plate crystal swarm was very impressive again, and this time it lasted for several tens of minutes, but unfortunately the diamond dust cloud did not spread very far. I did not even consider phtographing with the spotlight due to the surrounding streetlights. I did take one photo of the subKern on a dark field in the edge of the crystal area where the crystal density had decreased significantly ( 2 ).

All photos from these two nights are in their own galleries ( 3 - 4 ).