Sonnenhalo-Statistik Oktober 2023

[Carl Herzog]

Hier die Auswertung der im Oktober 2023 fotografisch bei mir in Idstein nachgewiesenen Halos an der Sonne (nach Häufigkeit sortiert):

21x 22°-Ring
17x Nebensonnen
12x 46°-Ring
12x Oberer Berührungsbogen
9x Zirkumzenitalbogen
8x Parrybogen
6x Horizontalkreis
5x Lowitzbögen
3x Supralateralbogen
2x 120°-Nebensonnen
1x Obere Lichtsäule
1x Untere Lichtsäule
1x Infralateralbogen
1x 46°-Berührungsbögen
1x Wegeners Gegensonnenbogen
1x Tapes Bögen

Pyramidale
9x 9°-Ring
7x 18°-Ring
5x 20°-Ring
4x 23°-Ring
6x 24°-Ring
8x 35°-Ring
2x 18°-Lateralbögen
2x 23°-Parryförmige Bögen
1x 24°-Lateralbögen

An 10 Tagen konnten keine Sonnenhalos nachgewiesen werden - zumeist wegen einer dichten tiefen Bewölkung. Allerdings waren an 6 dieser sonnenhalofreien Tage Mondhalos nachweisbar, so dass ohne die tiefe Bewölkung am Tag wahrscheinlich auch Sonnenhalos nachweisbar gewesen wären.

Soweit ich es in Erinnerung habe findet sich in bisherigen Studien die Feststellung, dass Halos nur zu ca. 25% bei hoher Bewölkung vorhanden sind. Im Oktober habe ich erstmalig die Wolkenhöhen mit notiert: insgesamt waren beim Vorhandensein von hohen Wolken immer Halos nachweisbar, sofern ganztägige tiefe Bewölkung den Nachweis nicht verhinderte.

Und eine Randnotiz, auch wenn die Mondhalos nicht in die obige Statistik reinfließen: der 22°-Ring am Mond konnte bis zu einer Mondbeleuchtung von 18% nachgewiesen werden, bei einer visuellen Mondhelligkeit von -8,39 Magnitude. Dies war am 10. Oktober zwischen 05:46 und 06:00 MESZ. Der Nachweis war bereits im Einzelbild per USM oder auch per B-R möglich.

Viele Grüße, Carl

[Nicolas Rossetto]

Congratulation on this statistic work, Carl!

Since you wrote that you are using your all sky camera in case you miss some halos, did you ever noticed, in cases you are using both set up, any differences between what you take with your Nikon and with your allsky camera (with the same regions of sky processed) ?

And second question, did you get any 9° circular halo with no other odd radius halo ?
(for exemple a complex display involving hexagonal crystals, and a 9° halo among all of those)

Nicolas

[Carl Herzog]

Hi Nicolas,

thanks.

From a pure detection perspective both ways work in most cases, but the images from the allsky-camera typically require more manual work for faint halos, specially because of the dome reflections and because only 1 image is recorded every 30 seconds. For sure the allsky-setup being a fixed setup isn't as flexible as the Nikon setup (specially for horizon work), but from a statistical point of view it's more complete, as it doesn't miss halos that where out-of-frame of when the Nikon was not setup at all. Probably the ideal statistical camera would be the allsky setup with a motorized sun blocker (this has already been done).

I'm not sure I got your question right regarding the 9° halos. When they are visible, I always also have some of the other pyramidals like the 18° halo, except when the halos are so weak, that I only can detect the 22° and the 9° halo. And when pyramidals are visible also complex displays with non-pyramidal halos are possible at the same time. See for example the last image under viewtopic.php?f=2&t=61598

Regards, Carl

[Nicolas Rossetto]

Thank you for your answers.

Indeed, for the odd radius halos, I can have with mixed pyramidal and non-pyramidal crystals too (last 17th October gave me a nice view too)

For the 9° halo quesiton, for my part, I often get 9° halo alone among other non-pyramidal halos, but the shape of the 9° halo is not the same.

It is rarely sharp with non-pyramidal halos:

It is sharper then when other pyramidal halos are there:

[Carl Herzog]

Hi Nicolas,

when looking at the link you provided, it seems that we had a very similar display with Wegener & co. by the 16th here and 17th at your location, with a little too busy sky. I also think I had something like the blue spot near one of the 120° parhelia, but as I have no reference for comparisson and I have never seen one before I was not sure. About the 28° halo there are also some hints in one or two of my stacks, but as the 24°, Lowitz and Parry are brightening up the surroundings quite strongly it is too difficult to tell. Is there a way to simulate the 28° halo?

I also think that in my combined pyramidals and non-pyramidals the pryramidals are quite weak, and therefore the 9° halo ends up being unsharp. Maybe the ice crystals are partially hollow or show other imperfections, or the pyramidal ice crystal concentration was just low. By the way, in the B-R image you posted here there seems also to be a hint of 20° halo near the left parhelia.

Cheers, Carl

[Elmar Schmidt]

Wow Carl,

yours is an impressive list of halos for October 2023. And it must have cost you a lot of work in image processing and analysis. Therefore I hesitate to prompt for continuation, although it certainly would put halo statistics on a more solid footing.

Some 30% of pyramidal halos are also unheard of so far and surely tell a story about the almost ever-presence of these crystals.

Regards, Elmar

[Nicolas Rossetto]

Hello there Carl,

indeed, there might be more to find in the pictures. Thank you for your hints.

Here is a shared folder of what I managed to render so far, but I am not finished yet.

For the blue spot, here is a explanation on what to look for when searching for it, if you don't already know this link.

For the 20° halo, this might be right. I could check the others pictures after this one, if the clouds coming give more odd radius halos.


I saw Marcel made a statistic work too, this is nice to read those.

Salutations météorologiques.
Nicolas