Category Archives: meeting

Two Days of Diamond Dust Halos in Boži Dar (CZ) Nov. 27th/28th, 2015

The attempt of a group of pictures. Photo: Andreas Zeiske

About half of the participants under a diamond dust halo. Photo: Andreas Zeiske

The 13th meeting of German halo observers was a quite bountiful one as it presented halos on two of the three days. The location at the top of the western Ore Mountains, which straddle the German-Czech border with peaks surpassing 1200 m is well known for complex displays as documented by the organizers Claudia and Wolfgang Hinz. [e.g. 1234]

Although this area was being readied for the skiing season, ice crystals from snow guns were not the dominant source for the observed halo phenomena. Rather, the local winter weather can make fog from the often persistent huge mass of cold air in the Czech/Bohemian basin ascending toward the mountain ridge, where it can precipitate as diamond dust. Claudia Hinz has also observed that it does not need to be below -10oC for good halo displays.

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The Mt. Keilberg in a diamond dust cloud. Taken from Mt. Fichtelberg by Andre März.

As a case in point, during the meeting, the temperatures were between -2oC und -5oC only. However, clouds and fog were not coming from the South this time, but rather slowly from the Northwest. The photo taken on the evening of Nov. 27th, 2015, shows a hood composed of this ice fog covering Mt. Klínovec (Mt. Keilberg, 1244 m) as seen from Mt. Fichtelberg (1215 m) a few kilometers to the west. These two mountains are the highest peaks of the range, and both were accessed in less than 10 minute by car from our meeting place in the cosy winter resort Boži Dar (Gottesgab).

On that very night, the ice fog at Klínovec unfolded a wide array of lamp and lunar halos, namely the plainly visible 22°-ring, upper and lower tangent arcs, Parry arc, 46°-ring (or supralateral arc)  parts of the parhelic circle, and just bordering at visual detection Tape arcs, helic arc (from the Moon, however) and Moilanen arcs, as well as Minnaert’s cigar.

But there were daylight halos too, and it all started unexpectedly on the same day’s morning, when murky morning weather all of a sudden made room for ice fog precipitating into clear Southeastern skies. This also happened at the road toward and on the summit of Klínovec. Although being seasoned observers, most participants of the meeting had never stood in diamond dust and its halos. So, this day proved to be a spectacular experience for all senses, of course starting with the three-dimensional flickering of otherwise well-known halos up to the sounds and sights of ice crystals falling on their jackets like fine semolina.

Actually, one of the group, Reinhard Nitze, often refrained of looking at the halos, but rather collected and photographed the fallen crystals. These proved to be almost exclusively needles. This is compatible with the observed halos, comprising once again strong tangent arcs, a weaker 22o ring, and later then an occasional display of the suncave Parry arc and parts of the 46°-ring (or supralateral arc) and traces of the helic arc, outlined by individual glistening crystals in the zenith only .

The next display came to happen after a late lunch on Fichtelberg. In it, halos of the 22o family were nicely contrasted against a blue sky, with the upper tangent arc assuming a huge “longhorn steer like” appearance at times. Due to rapid variations in the thin drifting ice fog, many halos “pulsated” in 3D between a couple of meters distance and maybe 50 to 100 m. Not farther away than a few arm lengths, one could see both a weak 22o ring as well as a snow surface halo from the just fallen crystals. The whole display was ending with a blindingly bright pillar of light around the sun.

The second day (Nov. 28th, 2015) eventually saw a westerly snow and rain front drawing in, but in the early morning  there were halos, once again on Fichtelberg (22° ring, UTA, and 46o ring und mehr?).

For the subsequent interesting talks and demonstrations by Elmar Schmidt, Alexander Haußmann, Claudia Hinz, Michael Theusner, Georg Dittié, Kevin Förster, Reinhard Nitze, Michael Großmann, Thomas Klein, and Richard Löwenherz, which formed the other major part and reason of the meeting, the reader should refer to the German language publications [1].

Before leaving for their respective homes, on Sunday, Nov. 29th, 2015 the group was given a tour of the Fichtelberg active mountain top weather station which by now was surrounded by a thick ground cover of snow.

 

Author: Dr. Elmar Schmidt, Bad Schönborn, Germany

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Dawn of the Sudelfeld monsters (AKM Halo meeting in January 2012)

Observers and interested people of atmospheric phenomena convened on the first weekend in 2012 to the annual meeting on the Sudelfeld. Actually, the mountain saddle at an altitude of approximately 1200m acts as a predestinate location for halo observations, but the continuous snowfall buried all hopes – like most cars too, by the way.

But the “hydro-meteors” with its radians at the zenith also gave benefits, because the dancing snowflakes optimally served as a canvas for uncounted Sudelfeld monsters and angels, which were surrounded by glories and fog bows partially. Furthermore, we were initiated in the secrets of shooting photographs of snowflakes by Reinhard Nitze.

At our domicile, the Sudelfeld youth hostel, we could rewarm ourselves after nocturnal ghost hunting as well as listen to very interesting articles about light and colors in nature, phenomena in twilight, lamp halos, the three-dimensional appearance of ice crystal halos, bagel-like raindrops and spiderweb-halos. Also fascinating colorful pictures were shown in a great number.

However, the highlight of the meeting was Michaels Großmann’s crazy experimental stuff. He did not even show his first and second edition of the “Halomator”, (23animation), but also performs numerous experiments to illustrate the reason for blue-colored sky, the development of Quételet-rings (2), and the simulation of  higher order rainbows (2).

The next meeting is already being planned. It will take place in Davos/Switzerland on the weekend of 22nd to 25th November 2012. Davos is located at an altitude of 1600m and very popular in winter sports. There are many snow guns, that should support the looked-for halo activity. The meeting will be in German language. Interested persons are welcome and can register here.

Halo Meeting of the “Arbeitskreis Meteore e.V. / FG Atmosphärische Erscheinungen der VdS e.V.“ at the Sudelfeld (Upper Bavaria), January 08 – 10, 2010

Winter halos in nearby ice crystals are quite a rare sighting in most parts of Germany. However, there are few special places where the chances for such displays are much higher, such as the Alps mountains. To benefit from this, 14 halo enthusiasts met at the Sudelfeld Youth hostel near Bayrischzell in the vicinity of the Wendelstein (1838 m) during the second weekend of January. Already on Thursday (January 07) a very impressive halo phenomenon at the sun could be observed by Reinhard Nitze. Unfortunately, throughout the meeting a complete cover of low-level clouds blocked the sun so that halo observations were restricted to artificial light sources during night time. The highest halo activity was noticed at late Friday evening, involving light pillars (or superlamps), upper and lower 22° tangent arcs (“champagne glasses”), parhelic circles (visible for only few seconds), and superparhelia (not photographed due to fleeting appearance). The phenomena showed remarkable dynamics, lasting for about 10 minutes and being followed by intervals of 30-60 minutes without halos. The influence of snow blowers was discussed as well, since there were some of them running the whole night, approximately 500 m apart from the observation place.

During the second evening only weak light pillars were seen for short times, eventually being replaced by fog bows due to rising temperatures and the transition from ice crystal to water droplet fog. Great fun were the shadow plays using a floodlight in the back of the people what finally led to photos of the “Sudelfeld monster”.Apart from the actual observations, the participants joined a workshop program containing slideshows from Michael Großmann, Claudia Hinz, Reinhard Nitze, and Andreas Zeiske as well as talks dedicated to special topics such as halo image stacking by Georg Dittié, high dynamic range image processing by Claudia Hinz, high precision measurements of the moon’s opposition effect by Elmar Schmidt, microphotography of snow and ice crystals by Reinhard Nitze, and artificial dew bows as well as stereo photography by Alexander Haußmann. The following experimental demonstration of glass bead bows in divergent light was received with great interest and triggered a high amount of photographic activity. Furthermore, an excursion to the nearby Tatzlwurm waterfall (named after some kind of dragon) was organized at Saturday afternoon and revealed a great winter landscape containing a large number of worthwhile photo subjects.

More pictures are here.

Author: Alexander Haußmann, Hörlitz, Germany