More results from the latest display in Rovaniemi

Here is some more material from the diamond dust in Rovaniemi three nights ago. After the heaviest Parry-crystal bombarding was over, Moilanen arc appeared, as shown in the photo on the left. Moon gives the beauty spot.

I have crystal photos from this stage, but as usual, they give no clue to Moilanen arc. In the earlier Parry-stage there was no indication of Moilanen arc whatsoever, but I did not manage to get the crystals. This bugs, because comparing the samples might have pushed us forward in solving the mystery.

The upper left image shows parhelia from streetlamp - the stripes that are parallel to the electric lines. Then there are also arcs extending slightly obliquely downwards. While visually parhelia curved towards me, these other arcs curved away and around me. As far as I understand from looking at divergent light simulations by Lars Gislen et. al, this effect is a 120° parhelion. In the photo only the brightest part of 120° parhelia is seen, visually the crystal glitter extented much further. Also a full parhelic circle was seen visually.

The lower left photo shows what was seen around the half moon at its best. For long time there was hardly no moon halo, although in the beam of the halogen torch a great display was present. Some indication of Lowitz arcs is present in the moon photo. The crystal sample may be representative of this stage, but I am not sure.

Halo Complex 15th October 2007

After over 90 days of above 90 degree temps and no halos this half-way decent display shows itsself in high clouds. Upon leaving work, I got quite a few photos. In all I got 22d halo, parhelia, upper tangent arc, bits of parhelic circle, infralateral arcs, 120d parhelia, and an upper suncave parry arc. While on the road I observed a rather bright 120d parhelion on the left side. As the patch of cloud shifted to the north the blue spot appeared and got several photos of it. When enhanced, the bluespot shows green, blue and purple and possible red but can't be sure. The one photo showing the Parry has ugly power lines but could not help that because I was shooting out the car window. If you wondering if I was driving at the time I wasn't because one should not drive and take photos at the same time. During those halo free days the temps were breaking records even in October and it was nice to see halos again.

Concave and convex Parry arc in Germany

When Stefan Danner was driving home in the evening of September 12th, he saw a pair of very beautiful sundogs. After having reached home, he noticed that there were two more halos – a very rare combination of a concave and a convex Parry arc. He could watch the two arcs getting brighter and brighter by the time. The impressive phenomenon lasted about 10 minutes before it ended showing a bright sundog.

Later, when he looked at the “raw pictures” closely, disenchantment followed: there was not a lot to see for the eyes of a layman. Only after having processed the pictures a little more or less, the effect of the halos in the pictures was like he felt it. (He saw them better than visible in the “raw pictures”, but not as intensive as they look after the processing.)

More pictures

Anthelic arcs in Finland

On August 28th anthelic arcs appeared in the northern part of Finland. My coffee break was suddenly halted as watching from the window I noticed several arcs. Once outside my eye was first caught by well developed parhelic circle. Then, looking up I noticed a colourful Wegener arc. Colours were red on the bottom and blue on the upper part. In the later stage of the display I noticed faint X at the anthelion indicative of the diffuse/Tricker arcs. I had no camera but my friend borrowed his camera equipped cellphone. Image quality is quite poor, but halos are still recognizable. Also Parry arc and 120 parhelia were present. Other halos were 22halo, parhelia, 22 upper tangent arc, parhelic circle, circumzenith arc, infralateral arc and supralateral arc. The display was noticed over large areas in Finland. More photos is here. Also see the photos by Arto Oksanen and Panu Lahtinen

Diamond dust display in the Spanish Pyrenees

On January 26, 2007, Claudio Martinez watched and photographed a complex diamond dust halo display at the Baqueira Ski Station in the Spanish Pyrenees. Baqueira is situated at an altitude of 1850m. At about 5.30 pm CET the display showed the 22°-halo with sundogs, anextremely bright upper tangent arc, upper and lower sun pillar and the parhelic circle. Part of these was also visible in front of a mountain ridge. In the upper sun pillar there also appeared the Moilanen arc. Nearby floating ice crystals are also visible as bright sparks in the pictures.

There is also a video existing. You can see it here.

Reflected Lowitz arcs in Finland

On 30th January 2007 I found that local district heating plant was causing a nice diamond dust display. Temperature was -22 C and the steam crystallized immediately. Only a few hundreds meters from the plant was already a plenty of crystals, but the best was about 2 km from the plant.

There I drove to a small road and got out and saw a display like never before. Parhelia were very bright, like fireballs. Also circumzenith arc was bright, but 22 halo was quite weak. Almost full parhelic circle was present with faint 120 parhelia, that looked more like pillars than fuzzy balls.

I had a film camera and eventually run out of film. The only choice was to drive home to get digital camera and fisheye lenses. On returning back the display had lost intensity and the 120 parhelia were completely gone. Anyway, I took about 80 photos with digital and later stacking of those photos revealed faint reflected Lowitz arcs rising up from the parhelia (marked in the photos with arrows). More photos of display is here. The looks of the display is quite similar to the one that was observed by Jari Luomanen a year ago. See photo here.

Lunar Diamond Dust Display in Pälkäne, Finland

In the evening of 4 November this lunar display graced the sky soon after sunset. Among the halo forms observed are the rare heliac arc, Tape arcs and Moilanen arc. The Moon elevation is ca. 16°.

In the image the entire length of the heliac arc is visible as a beautiful loop encircling the zenith. The Moilanen arc is very intensive and appears to extend beyond the 22 degree halo. Tape arcs can be seen as diffuse brightenings on the supralateral arc.

In the beams of the passing cars a bright pillar, parhelia, upper tangent arc and Moilanen arc were clearly visible. These proved difficult to photograph though. At the local ski resort the snow guns were operating during the display and the crystal swarm was a by-product of this activity. The temperature was below -15 °C.

Lowitz arc in Prague

Upper part of Upper Lowitz arc was observed yesterday (9.10.) in Prague, Czech by Milan Cerny. Milan seen nice parhelia, upper tangent arc and Parry suncave arc. Red arrow show Lowitz arc. Here is second photo