Showing posts with label 120° parhelion. Show all posts
Showing posts with label 120° parhelion. Show all posts

Friday, 21 April 2023

Sharp Lowitz & Parry display, in short time [2023-04-04]

Here are some nice ice halos at the passage of a particular layer of clouds, during a clear sky day (2023-04-04, from near Dole, Jura, France). This clouds layers gave an extraodinary sharp looking display of ice halos, as I rarely saw in 15 years of watching. I was then in the good spot at the right time, for this one. While I was taking care of my lawn, during a clear sky day, I saw some high altitude clouds coming from the north, and decided to take the bet I will have some ice halos, but I did not epected that kind of sharp halos. In all the below images, clouds are coming from the left (North-East).
On this first stack image, you can see the Wegener arc, with almost the part crossing the parhelic circle. There is also the 120° parhelion with reddish edge as well as on the circle.
Process is (as an example of how I do usually, for the image shown above,
named 2023-04-04-[14h57to15h37]-bw-[4-2]-UsM(11)-5s5-notrack-UsM.bmp):
→ B-R ( -bw ) rendering of all the images of the sequence ( -[14h57to15h37] ),
→ 11th stack ( (11) ) of the sequence with 4 images ( -[4 ),
→ then Unsharp mask on this stack ( -UsM ),
→ then a new stack (with Registax, without the track on the sun ( -notrack ))
→ of 5 ( -5s5 ) of last stacks (those ones taken every 2 images ( -2] ))
→ then one more Unsharp filter ( -UsM ) to end it.
Later, like 5-6 minutes later, the layer of clouds enter the 46° FoV from the sun, which gave the most impressive part of the display to me.
Here is one single image, with just B-R rendering (no UsM or what so ever).
Then 2 stack versions witht this image along with some before and after, to see more clearly the Lowitz & Parry display, (on the above one, we can see parts of 46° halo, but not in whiole, because of the hole in the clouds crossing the view... I guess)
and with the images when the clouds are on the side of the sun from my point of view. I even manage to watch clearly the circumscribed halo while i was cutting my lawn.
You can also see the left part of lower Parry arc tangent with the circumscribed halo.
A last part of the display, with clouds on the bottom left of the sun, to see the extension of the lower Lowitz and the extension of the left part of the Lower Parry, tangent to the circumscribed halo.
For this stack, a "min" function is applied during the stacking process, in order to keep the minimum value of each pixel while stacking, and try to make the black forms therefore the colored halos more visible.
A crop on the left sundog, to see the Lowitz crossing and the 2 Parry arcs.

I have not presented any colored versions, because of the heterogeneous form of the clouds mask the halos for this display.

Finally, a time-lapse of the display is available here, which a compilation of differents time-lapses (one for each processing type). From those images are extracted the previous posted here :
www.flickr.com/photos/gaukouphoto/52808574767/in/dateposted/

All images are taken with Canon EoS 6D + 8mm Samyang lens from my roof windows, South-South-East side.
Settings: 1/1000s, ISO100, f/9,4, 1 image every 12s.
Sun mean height is 47° at the time of the sequence.

Google Drive folder shared, with all the images presented here, and the time-lapse.
I still have all the raws of the sequence if needed too.


Monday, 19 February 2018

Halo Complex 2-18-18

Seems like the rare halos keep coming. While visiting my brother and his family I was outside his house watching this halo complex evolve. In terms of rare halos I got parry, 120d parhelia, Wegener arcs, blue on parhelic circle. While enhancing pics and I saw it in pics afterwards an inverted V shaped arc outside the parhelic circle. Could this be hi-sun Tricker arc?

Marko Riikonen what do you think?






Saturday, 16 September 2017

Finnish Display 2nd September 2017

Kimmo Laitinen captured a nice display with Wegener arcs and a really strong lower tangent arc on the 2nd September 2017. I'll let Kimmo describe his observation in greater detail in his own words. 

He says, "we drove from Siilinjarvi to our summer house in Leppavirta via Kuopio. In Siilinjarvi the weather was sunny but before Kuopio a thin uniform layer of high clouds covered the sun and we spotted the first halos as we passed the city centre of Kuopio about 11.45.... At this point the 22 deg lower tangent arc was not so impressive and only a short section of the parhelic circle could be seen. Then we went on southward to the Puutossalmi cable ferry.... In Puutossalmi the 22 deg lower tangent arc was the most impressive and reflected nicely from the lake. After the ferry the 22 deg lower tangent arc disappeared but the parhelic circle became all the time longer and a very faint Wegener arc was seen by the naked eye. After driving a few km more southward the low clouds disappeared from the northern sky and the parhelic circle became complete about 12.30 in the village of Lansi-Saamainen in Leppävirta. The 120 deg parhelia were clearly visible and the intersection of the Wegener arcs with the parhelic circle was revealed from the images. After this the display got dimmer but still lasted for a few hours.



All images used by permission. © Kimmo Laitinen. 


Friday, 14 April 2017

Recent displays from St Petersburg, Russia

In this post, I'm including the most interesting displays observed during the last month.

14th March 2017


On that day, halos appeared in the morning in separate cirrus clouds. Their arrival was not predicted by the meteogram. When I looked out from the window, I saw a bright CZA, but when I came down, it had disappeared. Nevertheless, I could see the weak supralateral arc. Half an hour later, I also saw a nice infralateral arc, when the cirrus cloud reached the horizon.

29th March 2017


In the evening bright parhelion was detected, and then a little while later also the wide circumzenithal arc. The halos were produced by the anvil of a convection cell.

1st April 2017


In the morning, at 10-00, the sky was clear. But in the south-west direction, low over the horizon a lot of cirrus clouds were visible. Their arrival was extended for an hour and a half. When a border of a front of cirrus clouds started to arrive, I noticed that it was weak and almost transparent. When these weak clouds reached the sun, at first I did not notice any halos. But soon, some markers of sub-visual odd radius display appeared.

It was broad and undefined halo in 22° area, with pretty obvious upper 23° plate arc in some moments. In the reflection of my sunglasses these things were visible a lot better. These weak odd radius halos were visible for around a half of hour, or even more while the area of weak cirrus crossed the sun.

Then, on the right-hand side pretty bright 22° halo started to appear. It was the arrival of main part of cirrus. In that area clouds were common and solid. After few minutes both bright tangent arcs appeared. Lower tangent arc was brighter than upper. I also noticed big infralateral arc on the right-hand side. It was pretty weak, but well coloured. I could see the arc better when I used peripheral vision.

This peak of the display was rather lengthy, and during its course I also watched both 120° parhelia, parhelic circle (it was easily seen within 22° ring), and the top part of 46° halo (likely it was the combination of supralateral arc and 46 halo. Although both were weak, together they became visually visible).
The peak was interrupted when middle-level cloud started to arrive. Then I saw a couple times only bright 22° halo

7th April 2017


The display looked quite ordinary, so I was glad I detected pyramidal halos such as upper 23° plate arc and 9° column arc.

9th April 2017


On that day, there was only a weak 22° halo. But the stack discovered also 18° halo/18° plate arc

10th April 2017


It was the weak display, which lasted most of the day. There was no suspicion that there may be pyramidal halos. But still I got upper 23° plate, 18° plate arc and 9° halo in the stacks.

Sunday, 2 April 2017

Subvisual odd radius halos in the UK

In the afternoon of 26 March, 2017, I was spending time outdoors with my family and wasn't too well equipped for serious observing. Of course, I had paid some attention to cirrostratus clouds drifting in the sky, but most of the time I struggled to see any significant halos. There were just occasional patches of 22° halo: or at least that's what I thought they were. But then the upper suncave Parry arc appeared so I had no choice but to start photographing immediately. After all, you don't get Parry every week, and in fact this was my first such encounter in 2017. During the next 20 minutes or so, I took a decent set of photos, but then gave up as it appeared that the display had become insignificant again.

My hope was to find a few more halos in the post-processing, and stacking did a good job indeed. The stack shown above is from the first 50 frames and covers a total of 196 seconds. On the left the unsharp mask is applied on individual frames before stacking. The version in the middle is a gradient-subtracted average stack, which is further processed by using the blue-minus-red subtraction technique on the right. In addition to the usual stuff and the Parry arc, we can identify upper and middle Lowitz arcs as well as a short piece of helic arc to the left from the circumzenith arc. But that's not all - there are also odd radius circular halos.

For comparison, the stack below is from the last set of 30 frames that I took more than 30 minutes after the last signs of the Parry arc had disappeared. This stack covers a total of 174 seconds. I didn't really expect to find anything special at this point, but took the photos anyway out of curiosity. Apparently the odd radius stuff is still in play. My feeling is that it had been there all the time, possibly long before I noticed the Parry for the first time and also long after I had got indoors to celebrate the Mother's day dinner.

What is shown below is an attempt to make the scene as clear as possible by combining photos from two different series into one stack. 100 frames are included, covering 13 minutes in time but missing about six minutes in the middle. My interpretation is that the relatively typical pattern of 9°, 18°, 24°, and 35° halos is complemented by the exotic 13° halo. But I'm not sure and it would be great to hear what readers might think of the case. Whether the 20° halo is missing altogether or masked behind the suspiciously wide 18° halo, I am not sure of that either.

Sunday, 26 March 2017

Halo Phenomena in Olaus Magnus’s Historia de Gentibus Septentrionalibus (Part 2)



Halo phenomena in Historia de Gentibus Septentrionalibus, Bk. 1, Ch, 14. Image from www.avrosys.nu

The Swedish Olaus Magnus’s 16th century Historia de Gentibus Septentrionalibus (History of the Nordic Peoples) has several chapters and woodcuts dedicated to halos. The first part of our series introduced this medieval best-selling work, and concentrated on parhelia and paraselenae as described by Olaus. This time the halos of Book 1, Chapter 14 are to be introduced, which is the very first section of his work where he deals with halo phenomena. 

We don’t  know whether Olaus saw any halos in his life, though in Chapter 17, he notes that there were three suns and moons in the sky at the time of his birth. Besides classical natural historical authorities like Pliny the Elder, his information comes most probably from accounts collected during his journeys, which he later recorded according to his own understanding and imagination. He introduces halos as seasonal phenomena, which are connected to early spring and hardly last longer than two and a half hours. He does not even start the list of halo forms with the most frequent ones: the first halos that he describes are the parhelic circle and three patches on it which could be interpreted as the 120° parhelia and the anthelion.

“Up in the north when deep snow covers the earth round about the vernal equinox, circles sometimes appear with the following formation and position. The most spacious circle, spread over the horizon is entirely white, as also are three small circles, each hanging separately from its circumference; towards the east, however, these are distinguished by their yellow colour, as if they are trying to resemble the sun (…)”

Olaus then continues his presentation with the more frequent forms. The 22° halo, the parhelia and the upper tangent arc are easily recognizable, and so is the circumzenith arc. But what comes afterwards (a blackish rainbow and a dusky but colourful one) is more difficult to interpret. We could deduce from their position in the woodcut that he may be talking about supra- and infralateral arcs, but since the depiction and the description are not obvious and they contradict to what such arcs look like in reality, we should not draw further conclusions from them. Olaus’s description is typical of similar accounts: he presents events which took place over a longer stretch of time, disregarding the changes in halo forms as time passes, what is more, he probably never witnessed such halos in the sky.

“(…) and even the body of the sun can be surrounded by a corona or halo of rainbow hues, and has reddish likenesses of itself attached on either side. From these likenesses, or if you wish, from these two suns,  two semicircles, like bows, rise to intersect each other; eventually, after expanding as halos do, they vanish. Around the navel or centre of the most spacious of these circles can be seen an inverted rainbow, which gleams in a cloud of fine vapour. Next there appears another blackish rainbow, opposite to the first in colour and position. Afterwards this bow, dusky but ever varying in colour, as is customary with the celestial arc or rainbow, extends towards the south, crossing through the most spacious of the circles.” 

Vädersolstavlan by Jacob Heinrich Elbfas. Image from Wikipedia

The woodcut illustrating his chapter might look familiar to people interested in historical displays. It bears resemblance to Vädersolstavlan, an oil-on-panel painting by another Swedish man, Jacob Heinrich Elbfas. The painting is the 17th century copy of the now lost original ordered by the Swedish reformer Olaus Petri, and created by Urban Målare. It shows the halos that appeared over Stockholm on 20 April 1535, 20 years before Olaus Magnus’s book was published. The country at this time was turning to the Lutheran faith, and religious reformation fuelled serious conflicts and controversies between the ruthless reformer king Gustav Vasa, and more moderate Protestants like Olaus Petri. Both parties saw a celestial sign in the appearance of this halo phenomenon, and we can easily deduce that the Catholic Church was also prone to interpreting the halo as a divine premonition. Olaus Magnus himself was the last Catholic archbishop of Uppsala, who had to live in exile for the rest of his life after Sweden had turned to the new religion. Although he does not mention the ominous 1535 Stockholm halo and its contemporary reception, but the striking similarity between the woodcut and Vädersolstavlan might indicate a conscious choice for deciding to start his description of halos in Historia de Gentibus Septentrionalibus with this very emblematic appearance.

Either influenced by his own fate, or due to contemporary superstitions, Olaus attributes bad omens to such halos. Much of his chapter elaborates on what misery they may bring. As he claims, they “always cause, either by their own nature or for some other, hidden reason, the worst consequences in the time immediately following them: for example, ominous thunderings and thunderbolts which throw houses and animals to the ground; capturing and killing of nobles and common folk, and pillaging of the people in that region, not to speak of enemy fleets, pirate raids, and acts of arson; and when the circles disappear at the end of spring, grains of suphur commonly rain down in a stinking mist.”

By Ágnes Kiricsi


English translation by Peter Fisher and Humphrey Higgens from: Olaus Magnus, A Description of the Northern Peoples, 1555, Vol. 1. Ed.: Peter Foote, Hakluyt Society, 1996.

Friday, 3 March 2017

The great 24 February 2017 halo display in Pskov region of Russia

In the evening, I looked at meteoblue's meteogram (like I do everyday), and saw on it plenty of high-level clouds, but at the same time together with middle-level clouds. At 09-30 I woke up that to check whether middle clouds would not allow observing halos.

I came out and saw that the sky indeed was pretty dirty and contained not only cirrus but also low and middle clouds. But above the sun were the central part of UTA and diffuse pillar. I could leisurely to prepare my camera before halos became brighter.

After a few minutes, UTA became seen pretty well. Viewing the sky I was very surprised to detect the supralateral arc to the left of the sun. The arc was not bright but it was clearly visible. It was weird to see such good halos in such dense clouds. Clouds from different levels merged with each other. So at first, I did not understand that it was a big display that penetrated through the gaps of the lower clouds.

After 10-15 minutes came a big gap in those clouds and I saw the full Supralateral arc which was noticeably brighter than previously. I already was very glad because the arc in this form I saw only on my screen when I processed stacks. And at the moment I saw it in the sky with my own eyes. However, this was only a prelude of what was to come.

Wegener arc, subhelic arc, and blue spot on parhelic circle


Around 11-00 the sky started to clear and above the supralateral arc and a nice circumzenithal arc appeared. In that moment I noticed to the west a bright fragment of the parhelic circle which was low over trees. Cirrus arrived from this direction. While I changed the direction of my camera's field of view, I noticed also the anthelion. High clouds arrived quickly, and they were very uniform and smooth. The brightness of halos quick started to accrue. I ran in my home in order to show the current display to my father, and during this couple of minutes the brightness of halos increased even more. I ran back to my camera, and in this moment halos became extremely bright! The upper tangent arc was very perfect and sharp. The supralateral arc was brighter than a common primary rainbow! Probably it reached such extreme brightness not only because crystals were perfect, but also because the sun elevation was almost optimal. The parhelic circle was also incredible and looked like jets of light. Wegener arc was visually visible as well. Its oblique wide lines pointed out on far and weak anthelion. Around anthelion from time to time X-shaped arc was visible.

Near sun there are 9° halo together 9° column arcs
All sky view. Near anthelion there is Tricker arc
Anthelion and some of diffuse anthelic arcs
Upper tangent arc with diffuse upper 23° plate arc and sharp 24° column arcs. Thanks to M.Riikonen for the confirmation
Halos lasted in this bright form around 45 minutes. After the brightness of complex a few decreased, but all details continued were visually visible. I remember that I saw well crossing of Supra/Infra-lateral arcs on the parhelic circle. Also from time to time appeared 120° parhelia.

On the left there is 120° parhelion
At 13-10 was the end of this great display, only halos near the sun remained. Parhelia were most bright in this moment and seemed to me that near them were Lowitz arcs. But stacks showed that is not true.

Saturday, 11 February 2017

Complex Halo January 21st 2017

On January 21st, after a long stretch of not getting any significant halos and not too long after observers in Hungary got a spectacular display, I observed a nice display here in the USA. The highlights of this one were the nice upper tangent arc and the 46 supralateral arc. I also got 120° parhelion too.

Monday, 3 December 2007

More results from the latest display in Rovaniemi


Here is some more material from the diamond dust in Rovaniemi three nights ago. After the heaviest Parry-crystal bombarding was over, Moilanen arc appeared, as shown in the photo on the left. Moon gives the beauty spot.


I have crystal photos from this stage, but as usual, they give no clue to Moilanen arc. In the earlier Parry-stage there was no indication of Moilanen arc whatsoever, but I did not manage to get the crystals. This bugs, because comparing the samples might have pushed us forward in solving the mystery.

The upper left image shows parhelia from streetlamp - the stripes that are parallel to the electric lines. Then there are also arcs extending slightly obliquely downwards. While visually parhelia curved towards me, these other arcs curved away and around me. As far as I understand from looking at divergent light simulations by Lars Gislen et. al, this effect is a 120° parhelion. In the photo only the brightest part of 120° parhelia is seen, visually the crystal glitter extented much further. Also a full parhelic circle was seen visually.

The lower left photo shows what was seen around the half moon at its best. For long time there was hardly no moon halo, although in the beam of the halogen torch a great display was present. Some indication of Lowitz arcs is present in the moon photo. The crystal sample may be representative of this stage, but I am not sure. Crystal photos of Lowitz displays are also very welcome

By Marko Riikonen

Wednesday, 17 October 2007

Halo Complex 15th October 2007












After over 90 days of above 90 degree temps and no halos this half-way decent display shows itsself in high clouds. Upon leaving work, I got quite a few photos. In all I got 22d halo, parhelia, upper tangent arc, bits of parhelic circle, infralateral arcs, 120d parhelia, and an upper suncave parry arc. While on the road I observed a rather bright 120d parhelion on the left side. As the patch of cloud shifted to the north the blue spot appeared and got several photos of it. When enhanced, the bluespot shows green, blue and purple and possible red but can't be sure. The one photo showing the Parry has ugly power lines but could not help that because I was shooting out the car window. If you wondering if I was driving at the time I wasn't because one should not drive and take photos at the same time. During those halo free days the temps were breaking records even in October and it was nice to see halos again.
 
by Michael Ellestad