Two diamond dust displays in Finland

Miika Karppinen photographed this display in the town of Kajaani on 8 March this year. Upper sunvex Parry arc and 46° Parry arc are weakly present ( 1 ).

The other display occurred on 26 October 2006 in Salla ( 2 ). Photos were taken by Jani Päiväniemi. Under the circumzenith arc there is a patch of 46° halo, which could be indication of 46° contact arc. First convincing photos 46° contact arcs were taken three days later in Muonio ( 3 ).

Both Kajaani and Salla displays were captured with cell phone cameras.

Wegener Arcs in Finland

Long absence of rare high cloud halos in Tampere skies was brought to a sudden end by a complex display on 2 May 2008. Singly and Parry oriented columns played the key roles: among the more common halo forms the display featured an upper suncave Parry arc and Wegener arcs.

Sun elevation was ca. 27 degrees. Both photos are stacked images (no longer than 5 minutes' time period for each). Below them contrast enhanced versions are provided. Also, larger images are available online ( 1 ).

Complex displays in Eastern Europe

A series of complex halo displays occured in Eastern Europe between 27 March and 6 April. The first display was seen in Vecsés, Hungary (observer: Ágnes Kiricsi). On 27 March, after the appearance of a bright circumscribed halo, a growing stretch of the parhelic circle came to sight ( 1 ) and 120° parhelion showed up on the left ( 2 ). The parhelic circle was complete for about 5 minutes.

Close by in Budapest, a Tape arc was observed in the evening. Images were taken by Alexandra Farkas and Tibor Hollósy ( 3 and enhanced 4 ). They did not see other halos formed by Parry oriented crystals, but 7 km to the north of them and only 3 minutes earlier, Márk Laczkó had photographed an upper suncave Parry arc ( 5 - 6 ).

The next Hungarian observations of complex displays with complete or almost complete parhelic circles were on 1 April (Ágnes Kiricsi in Vecsés) and on 5 April (Alexandra Farkas, Tibor Hollósy in "Remete" Gorge).

On 2 April, Marko Krusel had an opportunity to observe a complex halo display in Estonia, nearby Keila (see image on top). Besides all the common halos, he got an upper suncave Parry arc, a full parhelic circle and 120° parhelia. A fragment of the infralateral arc was seen on left. The show ended with the parhelic circle and 120° parhelion as the latest leavers ( 7 ).

6 April was a favourable day for the Czech Republic and Poland. The Czech Matej Grek (Ostrava-Dubina) and Martin Popek (Nydek) both photographed complex displays with parhelic circles and bright circumscribed halos. A 46° halo was also visible ( 8 - 9 ). In southern Poland Jakub Marchewka observed a display with full parhelic circle in Chrzanów ( 10 - 11 ). From the photos he noticed a faint Wegener arc ( 12 and enhanced 13 ) and 46° halo ( 14 and enhanced 15 ).

It was a first observation of Wegener in Poland and one of the first of 46° halos. The latter was described by Johannes Hevelius on 20th February 1661 in Gdańsk, but it is likely that supralateral and infralateral arcs were the main contributors to the phenomenon.

Text: Marko Krusel, Jakub Marchewka and Ágnes Kiricsi

Subsuns from space

The publication of the Mars halo on this site stimulates me to dig in history. On 27 April 1975, I saw by change a picture of a subsun taken from space ( 1 ). It is here on the frontal system on the right of Greenland. It was taken by the satellite ESSA 8, which was the last weather satellite that took real pictures of the Earth rather than being a scanning platform. Only a few months later, ESSA 8 was lost, so I had been very lucky. The discovery of the subsun on a satellite picture gave me the same sensation as the discovery of the subsun on Mars, 31 years later.

In 1985, I got another subsun taken from space (see photo on top), taken by the Dutch astronaut Ockels from the Challenger space shuttle during its last flight before the crash. The subsun is visible over the Netherlands, viewed upside down. Interestingly, the astronaut had overlooked the subsun despite the fact that I had prepared him for this possibility. He only saw the thing when he gave a slide show and I put his attention to it. Note its white colour compared to the sun’s reflection in the sea. Contrary to the ESSA 8 subsun on which I wrote a short paper in Weather, I did not publish this one.

Text: Günther Können

An unknown halo and other displays by Jukka Ruoskanen

Jukka Ruoskanen has scanned his best halo slides ( 1 ). The material spans from year 1988 to 2005 and includes several displays of interest. Some cases are rather puzzling, like the one shown above, photographed on 23 December 2001. It contains strange pillars next to sun pillar. Explanation for these arcs is not known.

A halo on Mars and other papers by Gunther Können

Gunther Können, who has produced a decent number of halo papers, has put his works on-line. These are found in the atmospheric optics section of his web page ( 1 ). Among others, there is an article about subsun on Mars (right photo), as photographed in 2006 by Mars Global Surveyor (left photo). Also, the extensive work on halo systematics, "A general setting for halo theory" by Tape and Können, is available.

Image credits:
left - NASA/JPL-Caltech/Corby Waste
right - NASA/JPL/Malin Space Science Systems

Subsun and Bottlinger's ring

Dmitry Savvateev observed a subsun in 2006 in the Khibiny Mountains (Kola Peninsula, part of the Murmansk region). This subsun, however, seems to be accompanied by a much rarer halo: Bottlinger’s ring. Even though this case is a marginal one, the elliptical halo appearing around subsuns is so infrequent that the photo is worth showing here ( 1 ).

Just as elliptical halos formed around the Sun, Bottlinger’s rings can also be of one, two or three ellipses. The 1997 photo taken by Frank Wächter shows multiple rings ( 2 ), in the Khibiny picture, there is only one ellipse.