46° halo in Czech Republic

The April 21st 2007 was undoubtely one of the best halo days in this year. Observers from all over the Czech Republic enjoyed very bright 22° halo with tangent arcs and infralateral arcs.

We probably observed Wegener arcs and 120° parhelia, but this cannot be proven, because even fotos from Registax didn’t help us to clearly identify them. Anyway, Martin Popek saw that day very nice 46° halo and he took these pictures which were stacked from 40 images in Registax.

As the Sun was setting down, more halos appeared. In the second picture you can see parhelion with a part of parhelic circle (parhelic tail), 22° halo, circumzenithal arc and probably supralateral arc.

Edit: It isn’t supralateral arc in the second photo, but 46° halo because there is no upper tangent arc. That signifies absence of horizontal oriented columns, which are necessary in order to make supralateral arc.

Odd radius halos in Czech Republic

On April 5th 2007 there was typical nice, but, dry“ cirrostratus in the sky without presence of halos. I was continuously checking the sky and after 10:00 I noticed very faint halo that had unusually wide upper part. That was very suspicious to me so I started to take photos which were after processed by Registax. You can see the result in the output picture. There are two separated halos which I later identified through the comparison with night sky, as 20° and 23° halos. Maybe there is also 35° halo, but it cant be certainly identified from the picture. The phenomenon could originate at 0,3-0,0-0,0 or 1,0-0,0-0,0 crystals.

I saw very similar displays with nice, "dry" cirrostratus and then with faint odd radius halos on June 22nd 2006 and August 26th 2006 so that is quite interesting.

Martin Popek

Odd radii in Southern Finland

A horrendously quiet April passed by without any noteworthy action (except Jarmo's fantastic bolide halo). Halo people were awakened from oblivion on 5th May, when a smooth cirrostratus veil crept in from west and offered plate crystals and odd radii halos. The display was seen and photographed by Ismo Luukkonen in Turku, Marko Riikonen in Helsinki (photo on the right by Marko) and Jukka Ruoskanen in Riihimäki.

Most likely all odd radius halos were on the sky, of which 9, 18, 20 and 35 degree halos were easily discernible. The 22-24 region may have consisted of all three possible rings. Also few of the odd radius plate arcs were present, although rather poorly.

Halo made by fireball observed in Finland

A fireball as bright as a full moon was observed in Finland 15 April 2007 at 00.13 local time. The fireball was also recorded by several fireball cameras in Finland.

In Vaala, a low-light video camera operating by Jarmo Moilanen got the whole event and also something extra: parhelion (A in image) and fragment of 22° halo (B) are following the fireball!

Image shown here is cropped from a single video frame. The fireball looks like a ball of light. In lower part of the image there is so called peak hold image from the fireball video showing the trace made by fireball during its 10 second existence.

Since fireballs are rare and sporadic events, halos made by fireballs are seldom reported. You can see the video here.

A spring-starter in Finland

On 25th March a relatively small high-cloud area swept over Southern Finland and produced a fine halo for observers in Helsinki, Espoo, Turku and Riihimaki. In Riihimaki the upper Lowitz arc was continuously in the sky for over three hours. In addition to Lowitz, there were also pyramidal crystal halos (9 halo/column arc?, 24 lower plate arcs, 18 plate arcs), helic arc and Wegener anthelic arc.

The photograph above is taken by Jukka Ruoskanen, and more photographs can be found here. In Helsinki the display was photographed by Marko Riikonen, in Espoo by Panu Lahtinen and Timo Kuhmonen and in Turku by Ismo Luukkonen

Wegener arc on webcam

On Mar/3/2007 I captured a halo display with a remote webcam in Oklahoma/USA. The camera image shows a bright parhelic circle, 120° parhelion and a rare Wegener arc forming a cross on the parhelic circle. A time lapse movie is available here: 

http://www.parhelia.de/storm/2007/flash/wegener.html (Flash)

Mid-elevation halo display with column crystals in control

Throughout my work day there were a number of halos that were coming and going. Around midday there was 22d halo, circumscribed halo, parhelic circle, and parhelia. Later on at break time I got 22 and circumscribed halos and there was a nice infralateral arc on the left and a possible lower suncave parry arc not sure on that need help to identify short piece of arc to the left of 22d halo. Before I left work I imaged an upper suncave parry arc. The final stage had nice upper tangent arc and a complete supralateral arc.