2006. december 13., szerda

Diamond dust haloes in the German Alps

On 11th of december 2006 I saw a wonderful diamond dust phenomenon in the Wendelstein area in the altitude of ca. 1100m. It was the best in my life! I was a part of it and around me floated ice crystals with different white and coloured arcs. Directly over my head was formed an aura, the upper tangent arc I could touch and on the opposite side of the sun were some white arcs crossed in three-dimensional space.

The origin of ice crystals were definitely natural. The clouds came from the very cold Inn valley and creeped up the mountain sattle. The sun elevation was 18 to 20 degrees.

I've seen with naked eye the following haloes: : 22° halo, upper and lower tangent arc (extremely bright!), complete sun pillar, 46°halo (very faint lower part), complete parhelic circle, anthelion, 120deg parhelia, infra- and supralateral arcs, Wegeners anthelic arc (one of the cross bows), Tricker's and diffuse anthelic arcs, heliac arc, subhelic arcs and Moilanen arc.

More pictures are here.

2006. december 6., szerda

Diamond dust halos over open sea

It is not so often to see diamond dust halos over the open sea, like here in the photograph of Pasi Snellman, taken on 5 November in Porvoo, Southern Finland. The display occurred only above the sea indicating that the open water was the moisture source for ice crystal growth. A couple of of kilometers upwind from the bridge is a small ski center, and according to Snellman snow making was under way there.

This may have provided the nuclei for the ice crystal formation. Snellman also tells that the air temperature was -7° C and sea +5° C.

On 5 November good diamond dust was seen also in Jämsä and Lahti, the latter of which is not reported here in Haloreports.

2006. november 21., kedd

Halo phenomena at 09/12/2006 in Mongolia

Richard Löwenherz made a cycle tour across Mongolia and while in Bajantes he witnessed a wonderful halo display. Up to 15 different types of halo (here the German halo key) were simultaneously visible. Unfortunately there are no photos because on the 10th day of the 6-week cycle tour the camera failed. However, I think, the sketch give a no less beautiful impression of the multiplicity of the kinds of halo which he could all see with the naked eye! Apart from this spectacular event, hardly any other halos were seen in Mongolia.

2006. november 13., hétfő

Lunar display in Switzerland

On Nov/11/2006 I observed a nice high moon halo display in Switzerland. Visible was a bright circumscribed halo and a infralateral or circumhorizon arc.

2006. november 8., szerda

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.

Diamond dust display in Jämsä

To fill the weekend of diamond dust halos in Finland, Simo Romo sent photographs of a display that was seen on sunday 5. November in Jämsä. The location is not far from Himos ski center where previous night and day Mika Aho photographed good displays, so it's probable that this one also originated from snow machines.

In addition to photographed halos there was also something else to be seen: "I was heading east and in the north-easten sky there was as if a brighter column of fog. Probably it was part of the phenomenon", writes Simo. Most likely he was looking at a diffuse anthelic arc.

The upper photograph is a panorama made of several individual images. The process has not been completely successful and that's why on the left side of upper tangent arc is an artefact.

2006. november 6., hétfő

Lunar display in France with 9° halo and Lowitz arcs

On the evening of 30 October 2006, I saw this lunar display in the west of France, close to Nantes. The photos were taken between 18h and 21h UT, the moon elevation was between 19 and 24 degrees.

A lot of halos were visible, including 9° halo, upper and lower Lowitz arc and a bright upper suncave Parry arc.

The orange colour of the sky is due to a strong light pollution. The images have been processed to reduce this effect and unsharp mask has been applied to enhance the halos. I got also nice displays the 2 previous days.

More images of the display here: 1, 2, 3.

Diamond dust from Himos snow guns

Mika Aho was also on the halo move on Saturday 4. November. He headed for the Himos ski centre, where some 30 snow guns were operational. The trip was worthwhile. From skiing flanks spread an ice crystal cloud that, even though a bit unclean in appearance, presented some of the rarest halos.

These rare halos are best shown in the photo on the left where several white arcs are seen crossing the sky. Wegener, helic, subhelic, subanthelic and Tricker arcs are all present. Outside Antarctica subanthelic arc has been observed reliably only twice before, both times in Finland. Now Aho's photos add the third observation.

More of the display is to be found here. Like Oksanen, also Aho got halos in moonlight the following night. These photos are under the same link.

Diamond dust from Riihivuori snow guns

Towards the last weekend tension was rising among Finnish halo observers. It was going to be clear skies with sinking temperatures and full moon. Most of the ski centers had their snow guns running, so anticipation for diamond dust was high.

On Saturday, 4 November, Arto Oksanen drove to check the sitation at Riihivuori ski center. There was indeed a column crystal dominated display with upper sunvex Parry, as shown in the photo on the left.

Next night Arto did not have to go anywhere, since wind carried the ice clouds straight to his doorsteps, to Muurame town. It was Parry-time again, and now in addition to normal upper suncave there was also the much less commonly seen lower sunvex Parry (photo on the right). Untill the last winter the latter has been considered as an extreme rarity, but now reports have increased, thanks mainly to ski centers' snow guns and active observers around them. The display contained also other halos of interest, like Wegener anthelic arc and anthelion. See also Juha Oksa photos from Muurame the same night.

2006. november 3., péntek

Diamond dust season opened in Finland

On October 26 the pupils of the Särkijärvi school near the small northern Finland town of Muonio stopped suddenly their indoor activities and rushed out - somebody had noticed a halo wonder in the sky.

At the school were also excursionists from University of Lapland. Among them, Päivi Linnansaari happened to have a camera handy and took several photos of which a selection is presented here.

The display had all the basic flavourings of a great diamond dust display, including the helic arc, circular Lowitz arc and diffuse anthelic arc - the latter of which is seen faintly in the lower left image. But then there is also a new halo: the 46° contact arcs. Theoretically it has been known for quite a while, but no convincing photographs have come up untill now. The halo shows up in the upper right image as three arcs below the circumzenith arc. Probably a comparison with simulation is needed to get a proper grip of it.

The halo display made it also to local newspaper. Couple of kilometres from the location there is a ski center, so the halos may likely have originated from snow guns.

2006. november 1., szerda

High sun halo display in Bolivia

Louise Emmons sent these two photos of a halo display seen on 9 October, in Noel Kempff national Park North-Eastern Bolivia. The halos are a bright circumscribed halo, a probable 46° infralateral arc and parhelic circle.

"It was one of the most amazing phenomena that I have seen in my life, together with a total solar eclipse with ground waves and an immense fireball", writes Emmons.

The display lasted at least for half an hour. In about 6-8 h it was followed by a strong rain front.

Rare halos in Czech rep. Oct. 30 and 31

On October 30 in Prague was observed rare halos. Stepanka Kosova had Lowitz arcs and 120 deg. parhelia (title photo). Lukas Shrbeny had nice 120 deg. parhelia too. I observed rare halos in two last days. On October 30 I saw: 9°, 20° halos and Parry suncave arc. On October 31 I seen: Parry suncave arc , upper and lower Lowitz arcs and probably circular Lowitz arc too. M.Popek and R.Manak seen 9° halos in Lunar displays.

2006. október 29., vasárnap

Parry sunvex and suncave arcs

On October 28 in Czech Republic I and Lukas Kosarek observed Parry arcs. I saw sunvex arc too (you see title photo) and Lukas take photos of Suncave arc. We saw a nice supralateral arc also.

2006. október 22., vasárnap

Parry and Lowitz arcs in Czech rep

On October 20 and 21 I and Roman Manak saw an upper suncave Parry arc. On October 21 I also observed Lowitz arcs too. On photo is nice Parry arc by Roman. My Parry arc and my Lowitz arcs.

2006. október 18., szerda

Circular circumscribed halo

This high sun picture by Dorothé Trompert was taken in Alice Springs, Australia, on 15 Nov 2005 13:17 LT. The solar height was 75°. Although the halo is almost circular, it is probably not the 22° halo itself. Instead, the strong peak in its intensity near the halo angle and its vivid colors indicates that it is a circumscribed halo. This observation supports my conjecture that in many of the historic reports of widely noticed 22° halos the presence of a bright circumscribed halo contributed to its visibility. This happened, among other cases, with the so-called 'Chernobyl-halo' in 1986 and with Emperor Augustus's halo in 44BC.

2006. október 15., vasárnap

Lunar display with Lowitz arcs

Martin Jankovic and Lukas Kosarek from Brno (Czech Rep.) observed nice lunar display with bright parhelia at October 9. On photos was found clear upper and lower components of Lowitz arcs. More photos of this display are here.

Unidentified halo display in Romania

Attila Kosa-Kiss from Salonta, Romania observed on 29th September 2006 a very interesting halo display at a sun elevation of 12°. Unfortunately, there were no photos but there is a sketch. The most probable explanation is the existence of suncave [H] and sunvex [G] Parry arcs, as shown by the simulation from Les Cowley. Other possibilities would be an circular Lowitz arc [F], as seen on the simulation with HALOET (random: 0.5, plates: 0.5, columns: 0.5, parry: 0.5, Lowitz: 4.0, number of rays=150000). On the same day was observed several time in Germany and Czech the upper part of Lowitz arcs. But Romania was influenced by another weather front (with another cirrus clouds) like the middle European area. Further comments and ideas are very welcome!

2006. október 14., szombat

Tricker arc in Prague

Very rare Tricker anthelic arc was observed in Prague by Stepanka Kosova. Stepanka seen bright anthelion with "small X". This image is stacking of three photos. It is part of nice halo display with Parry arc and 120 parhelia at October 12 2006.

Czechoslovakia Lowitz arcs

This photo show nice circular Lowitz arc. Photo was taken by Michal Nagy from Slovakia at September 29 2006. My photo possible all components of Lowitz arcs was taken in Holesov (Czech rep.) at October 12 2006.

2006. október 12., csütörtök

Circular Lowitz arc in Germany

At the end of September weather fronts from an ex-hurricane reached Germany. In the leading cirrus, Lowitz arcs were observed over two days. Hartmut Bretschneider in Schneeberg (Saxony) made the first sighting on 28th September. He first saw a parhelion with a Lowitz arc emanating from the parhelion when the sun was at an elevation of 14 deg. Later when the sun was higher there was a very bright Parry arc and an upper Lowitz arc (right photo). On evening of the following day Werner Krell saw a solitary upper Lowitz arc at Wersau (Hessen). His photo was taken at a sun elevation of 11 deg. [2, 3]

More rare halos in Czechoslovakia

Today was day of halos for all observers. I was seen: Parry arc, Infralateral arc. Martin Jankovic: Parry arc, 120 parhelia. Milan Cerny: Parry arc. Stepanka Kosova: Parry arc, 120 parhelia. Roman Manak: Parry arc and Martin Popek: 120 parhelia. For discussion: Lukas Shrbeny from Ondrejov had maybe Lowitz arc. You see his link.

2006. október 10., kedd

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

2006. október 8., vasárnap

9° column arcs in Prague

Today Ondrej Vlach seen nice Lunar display in Prague, Czech. Halo, upper tangent arc and rare 9 column arcs. Ondrej say: "Left side of 9 halo was very bright and I was took some photos at 22:40 UT. I use Registax for photo stacking."

2006. október 4., szerda

Lower Parry arc in Antarctica region

Joe MacGregor observed very rare Lower Parry sunvex arc in Antarctica. Joe say: "The photo was taken about January 19, 2006 somewhere within ~100 km of 79S, 117W. It was taken with a point-and-shoot Canon S230." More photos halos are here. Simulation is made with Halosim by Les Cowley and Michael Schroeder. This Sun display with Lower Parry sunvex arc is probably second case of the World.

2006. október 2., hétfő

Low sun Parry in Helsinki

October is probably the worst halo month in Finland. The last chances for good high cloud displays are gone with September and diamond dust is not swarming in until November. So it was nice to see today a low sun Parry starting to develop in the sky upon returning from grocery store. Grabbed pocket camera and tripod from my room and rushed to nearby parking lot.

The two images are stacked from series of 15 and 16 shots. The time span is two minutes in both stacks.

Earlier I had seen low sun Parry's only on two occasions. These were in high arctic Canada during diamond dust conditions. It took 22 years of observing to get one in high clouds.

2006. szeptember 29., péntek

Wegener arcs in Czechoslovakia again

Today (9:00 - 11:30 UT) was next nice day. Sky in Holesov showed clear and coloured Wegener arc and other arcs (common halos and upper Parry suncave arc, lower Lowitz arc and infralateral arc).

Display was photographed also by others. Here are the photos by Martin Jankovic from Brno.

[text: Patrik Trncak]

2006. szeptember 24., vasárnap

From archives: odd radius column arcs in 2001

I saw this display in Oulu on 17 September 2001. Because the photos have not been around in the internet, I dare to make posting even though the event is not so recent.

The display has all the odd radius column arcs except the 23° arc. Images are stacked from 3-8 individual images. The one on the lower right is also flipped horizontally to get a bit more definition. For the upper left and lower images, simulations of the pyramid column arcs give crystals as in the figure. Also shown is similarly shaped real crystal, photographed during a weak odd radius column arc display at South Pole in 1999.

From pyramid plate crystals there is the 23° plate arc in all photos, and lower 9° and 24° plate arcs in the upper right photo. The display was discussed in more detail in September 2003 number of journal Weather. It also appears in the book "Atmospheric halos and the search for angle x" by Tape and Moilanen.

2006. szeptember 18., hétfő

Lowitz arcs in Czech

Martin Popek observed this display with Lowitz acrs on 16. September. Interesting feature is the lower Lowitz component extension above parhelion. In the simulation there is something like that, but it's very, very ghostly. The main body of the lower component below parhelion looks as if it were just a patch of 22° halo - the extension towards parhelion is missing. Same goes with the upper component. This is quite typical way of Lowitz arcs showing up. Circular component is seen only above parhelion.

I was given sun elevation of 39° for this display but somewhat lower elevation gave a bit better simulation results. This is for 33°. The projection in the simulation is clearly not the same as in camera and this may have caused some of the broblems. Simulation is made with Halosim by Les Cowley and Michael Schroeder.

Be the sun elevation 39° or 33°, it does not change much anything fundamentally. Several question could be raised about this display with lenghty discussions. It seems we still have a long way to understanding Lowitz arcs.

V-shaped Parry and Tape's arc in Germany

On August 31, 2006, clouds moved in destroying all hopes for meteor observations in the night. The halo display in the high clouds close to sunset (1725 UT, Sun elevation approximately 3 deg) observed by Jürgen Rendtel from Marquardt (west of Berlin, 13.0 deg E, 52.5 deg N) included intense V-shaped upper tangent and Parry arcs. Another bright coloured 'spot' of about 3 deg apparent size was found to be part of the supralateral arc and Tape's halo. The image processing by Claudia Hinz using unsharp masking also revealed the convex Parry arc.

2006. szeptember 16., szombat

Circumscribed halo and pyramid halos in Sardinia

This display was captured by Jan Drahokoupil in Sardinia on 6. September. The 22° halo is surrounded by elliptical circumscribed halo. The small halo around the sun is 9° halo or 9° column arc (or both together). Simulations could give better clue. Later on the display changed and there were also 18° plate arcs.

More photos here.

2006. szeptember 14., csütörtök

A fine circumhorizontal arc from Italy

Circumhorizontal arc more than 100° wide above the horizon, very brilliant, for about 25 minutes. The best I have seen from Italy!

Equipment :Canon EOS D30.

A collage of 3 images with a 35mm lens at f/8 and 1/1000 sec. 

31 May 2006 12,20 LT (+2h) Viterbo - Italy

2006. szeptember 9., szombat

Odd radii in Czech

During the Czech halo observers meeting in Kuncice, high clouds created some good displays. This odd radius halo complex was seen on 14. August. It shows 9,° 18°, 20°, 22-24° and 35° halos. Judging from the non-uniform intensity distribution of some of the halos (9° and 20° halos being brightest on the sides), this display was caused by poorly oriented columnar pyramid crystals. It's also interesting that 20° halo is brighter than 18° halo. This type of occurence is uncommon.

This is stacked image processed by Roman Manak and Patrik Trncak. Original photos were taken by Martin Popek.

2006. augusztus 16., szerda

HOP meeting 13 - 16 August 2006

Meeting of Halo Observation Project members was in Kuncice pod Ondrejnikem (Czech republic) - beautiful landscape of hills and woods. We had very nice observations of some rare halos: Parry suncave arc, 9 halos and 18 halos, on the high clouds. See PHOTO from Martin Popek. On photo from left to right: Vladimir Odvarka, Roman Manak, Lukas Kosarek, Jan Kondziolka, Martin Jankovic, Martin Popek and me. Photo was taken on meteorological station, Lysa hora.

2006. augusztus 14., hétfő

Subhorizon diffuse arcs with Liljequist subparhelia

Francesco De Comité took this great photo from an airplane between Brussels and Madrid in 7 August 2006 at 19h31. Unfortunately no more additional photos are available from this display.

There is really well developed diffuse anthelic arcs crossing subparhelic circle. Subanthelion point is illuminated by these arcs. In this case it is clear that there is no subanthelion, since bright spot on subanthelion point has clearly square shape caused by diffuse arcs. Column ice crystals have to have good orientation.

Other very rare halo shown in this photo is broader segments on parhelic circle on both sides on subanthelion point. Unfortunately these broader segments are not very clear and they are cutted by edges of the photo. These broader brightenings are so called Liljequist subparhelia caused by plate ice crystals. Liljequist subparhelia have been photographed earlier at least by Walter Tape (see Tape's book Atmospheric Halos in page 71). Tape's display is very similar than this Francesco's display.

Since Francesco's display has rare halo made by plate ice crystals, it would be a really good case to look for still undocumented 120° subparhelia. Hunt for 120° subparhelia is still going on...

2006. július 23., vasárnap

Subparhelic circle

On June/3/2006 at 20:20 CEST Susanne Danßmann observed a subparhelic circle on a flight from Berlin to Zurich. The elongated spot of light in the center of the image is likely a subanthelion. The shadow on the winglet suggests the photo was taken in direction of the antisolar point. There is no shadow of the airplane in the center of the subanthelion, because the airplane was high above the clouds.

2006. július 17., hétfő

Halo Meeting in Finland 14-16 July 2006

Nearly thirty halo enthusiasts from all around the world gathered to Artjärvi, Finland for a weekend of avid halo discussion. Apart from Finland there were participants from the USA, Japan, Germany, Sweden, Czech Republic and Netherlands. The meeting took place in URSA Astronomical Association's new observation centre. The programme for the meeting consisted of five sessions that included 14 presentations. The topics spanned from halo theory and simulation to photography and observation techniques as well as national observation networks and great historical displays. Slideshows of the very best photographs took place in the evenings and everybody feasted their eyes on literally hundreds of gorgeous halo images.

The event was well organised and everybody appeared to be having a good time. The exciting presentations, friendly atmosphere and the evening gatherings around the campfire all added to a great experience of shared enthusiasm. And to top it all of, beautiful NLC displays illuminated the skies on both nights.

We are all indebted to the people who dealt with the groundwork: Veikko, Marko and Jukka worked hard on all the arrangements while Krista and Aikku prepared the delicious meals. As soon as the gathering came to an end the plans for a new meeting had already started brewing among the participants.

2006. június 9., péntek

Wegener anthelic arcs in Ondrejov

Two days (8.6.2006 and 9.6.2006) in Prague and near neighbourhood was very good for halos. The best halo display had Martin Nekola in Ondrejov, he was seen nice Wegener arcs in high Sun elevation (approximately 55 degrees) as big X on anthelion side of Sun. Web site of some next Martin´s halo photos is here.

2006. május 19., péntek

World database of rare halos

For all rare halos of the world is database now. The most contribution to database is from Finnish, Czech and German observing networks, and from acouple of active observers from USA. You can search the database in four ways: all observations, name of observer, country of observation and name of halo.

You visit: http://www.halo.astronomie.cz/database.php

Bottlinger's rings from airplane

To help overcome our dearth of haloes, here is another archive picture. It was taken in the morning over Iberian Peninsula in April 1997 by Frank Wächter using a 35mm lens. It shows elliptical haloes around the subsun called Bottlinger's rings.

2006. május 18., csütörtök

A halo caused by light reflected from water surface

This subsun-like pillar on front of dark cloud was photographed by Jenni Elina Holopainen on 18. May 2006 in Pyytivaara, Finland. The position of the pillar is apparently the same as that of the Sun's behind the cloud, which is better revealed by the cloud rays in another photo.

So how this is possible? The explanation must be a reflection of sun light from still water body and further reflection of this light from ice crystals that are precipitating from the Altocumulus clouds seen in the picture. Thus we are looking here - not at the subsun - but at "supersun".

The best sun pillars are usually seen in the icy virga of the Altocumulus clouds. This is because virga can consist of very big plate crystals that have plenty of horizontal surface to reflect sun light. Thus it would be expected that if this phenomenon were to occur, it would be Ac virga if anything. In high clouds it's impossible to see this, becase there is nothing behind the crystals to block the Sun. And when diamond dust occurs, waters are usually frozen. Thus ice crystals precipitating from middle level clouds is perhaps the only possible formation for the phenomenon Holopainen photographed. In yet another photo taken by Holopainen, a curved Ac virga can be seen in the middle of the picture above the lake. This is the lake that most likely was responsible for the reflection.

Actually this is not the first observation we have of this kind of phenomenon. In the end of 90's in Oulu a pillar of light (with no distinct subsun like appearance) was observed in a similar manner.

2006. május 14., vasárnap

odd radius plate arcs

35° plate arc in lower center, 24° plate arc above it and slightly to the right, and faint infralateral arc (?) at far left. The angular distances from the sun still need to be measured, however. Dalton Highway, northern Alaska, April 17, 2006. The photo has not been manipulated. Copyright Walt Tape.

A wider angle photo of the same display is here. A photo of another display, about 20 minutes earlier and ten miles further south on the highway is here; (then at "on assignment: arctic Alaska").

2006. május 13., szombat

Doubled Halos?

This image was taken in Fukushima pref. in Japan, by Mr. Tasan (handle), May 5, 2006. There are two halos -- the lower one seems a 22 degree halo, but what is the upper one? I think it can be a 24 (or 23?) degree halo, a circular Lowitz arc or a 23 degree plate arc. What are your opinions?

2006. május 10., szerda

Unknown halo in Germany

This archive picture photographed Dieter Klatt on october 25th, 1996 in Oldenburg (North Germany). It shows an upper unknown arc with faint 22° halo, right parhelia and a eft fragment of parhelic circle.

2006. május 9., kedd

Lower 23 degree plate arc observed in Ohio USA 5-9-06

While on break time at work I decided to check the sky and saw a 22d halo with a rather suspicious brightening that encircled the lower half of the halo. As the cloud moved on a rather bright arc appeared and I thought circuscribed halo no it was a lower 23 degree plate arc!! I could tell because there was no circumscribed halo which goes all the way around while lower 23 degree plate arc tails off away from the circular halo. weak 18 degree halo was also observed. The photo has been given an unshap mask to show the halo better. You can clearly see the arc tailing away from the halo while diminishing in intensity

2006. május 7., vasárnap

Odd radius halos in Finland

Yesterday, 6 May 2006, odd radius halos were observed in a large area in Eastern and Central Finland. Odd radius halos observed during the day were mainly circular halos and plate arcs.

I photographed the display in Vaala, were it lasted for 3 hours. Photo shown here is made by stacking 24 photos which were taken during 10 minutes time. Unsharp mask has been used to show halo better. Visually halos of the display were not as clear as in this stacked photo, but all halos shown in this photo were also observed visually, except 35° halo which can be seen faintly on left. More photos are here.

Jenni Holopainen in Joensuu probably got best odd radius halos during the day. Her photos can be seen here and here. Marko Mikkilä observed odd radius halos in Nivala, Teemu Öhman in Äänekoski and Eero Savolainen in Kuusankoski. Photos by Mikkilä and Savolainen can be found also here.

2006. május 3., szerda

Ice Crystals

"Atmospheric Optics" has a newly updated section about halo forming ice crystals - check under "What's New". Plate, column and pyramidal crystals are illustrated with their orientations and resulting halos.

2006. május 2., kedd

Off topic - A new Atmospheric Phenomena blog

Following the idea of Halo reports blog, a new Atmospheric Phenomena blog has been opened by Claudia Hinz. There will be reports of of recently observed interesting atmospheric phenomena around the World. Reports will cover all other atmospheric phenomena except Halos. Halos will be reported here in Halo reports blog.

Atmospheric Phenomena blog can be found here.

2006. május 1., hétfő

Diamond Dust Halo in Austria

This picture was taken on December 10, 2005 by Wolfgang Gurgiser at the summit of the Hohe Salve (1829 m, Kitzbühler Alps, Austria) at a temperature of about -7°C. Contrary to what is usual, this halo was not caused by cirrus clouds, but by diamond dust which had direct contact to the ground. This diamond dust consisted of needle-shaped ice crystals smaller than 1 cm.

Besides the 22°-halo, the picture also shows a V-shaped upper tangent arc and Parry arc, the arc of Moilanen which is also V-shaped and situated at 11° above the sun, and – emanating from the sun – the heliac arc.