APOD: Ice Halos over Bavaria (2023 Dec 20)

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APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by APOD Robot » Wed Dec 20, 2023 5:08 am

Image Ice Halos over Bavaria

Explanation: What's causing those unusual sky arcs? Ice crystals. While crossing a field of fresh snow near Füssen, Bavaria, Germany, earlier this month, the photographer noticed that he had entered an ice fog. For suspended water to freeze into an ice fog requires quite cold temperatures, and indeed the air temperature on this day was measured at well below zero. The ice fog reflected light from the Sun setting behind St. Coleman Church. The result was one of the greatest spectacles the photographer has ever seen. First, the spots in the featured picture are not background stars but suspended ice and snow. Next, two prominent ice halos are visible: the 22-degree halo and the 46-degree halo. Multiple arcs are also visible, including, from top to bottom, antisolar (subsun), circumzenithal, Parry, tangent, and parhelic (horizontal). Finally, the balloon shaped curve connecting the top arc to the Sun is the rarest of all: it is the heliac arc, created by reflection from the sides of hexagonally shaped ice crystals suspended in a horizontal orientation.

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Ann
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Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by Ann » Wed Dec 20, 2023 5:26 am

Wow, that's a truly spectacular and fantastic image! :shock: :D


The heliac arc looks like a heart! 💙

APOD Robot wrote:

Finally, the balloon shaped curve connecting the top arc to the Sun is the rarest of all: it is the heliac arc, created by reflection from the sides of hexagonally shaped ice crystals suspended in a horizontal orientation.

Plates of ice.png

Are we talking about ice crystals like the fourth from left in the top row, the plates of ice, suspended in a horizontal orientation? These things?

Ann
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johnnydeep
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Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by johnnydeep » Wed Dec 20, 2023 8:35 pm

Very impressive panoply of "arcs"! If this doesn't set a record for the most arc types in a single event, it must be pretty close.
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}

Avalon

Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by Avalon » Thu Dec 21, 2023 3:53 am

Such a wonderful image and educational, as well. I would have made it my Christmas card!

Guest

Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by Guest » Fri Dec 22, 2023 4:55 am

Ann wrote: Wed Dec 20, 2023 5:26 am Wow, that's a truly spectacular and fantastic image! :shock: :D


The heliac arc looks like a heart! 💙

APOD Robot wrote:

Finally, the balloon shaped curve connecting the top arc to the Sun is the rarest of all: it is the heliac arc, created by reflection from the sides of hexagonally shaped ice crystals suspended in a horizontal orientation.

Plates of ice.png

Are we talking about ice crystals like the fourth from left in the top row, the plates of ice, suspended in a horizontal orientation? These things?

Ann
Which is most popular? I mean the shape of ice crystals?

Unely1965
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Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by Unely1965 » Fri Dec 22, 2023 4:56 am

Guest wrote: Fri Dec 22, 2023 4:55 am
Ann wrote: Wed Dec 20, 2023 5:26 am Wow, that's a truly spectacular and fantastic image! :shock: :D


The heliac arc looks like a heart! 💙

APOD Robot wrote:

Finally, the balloon shaped curve connecting the top arc to the Sun is the rarest of all: it is the heliac arc, created by reflection from the sides of hexagonally shaped ice crystals suspended in a horizontal orientation.

Plates of ice.png

Are we talking about ice crystals like the fourth from left in the top row, the plates of ice, suspended in a horizontal orientation? These things?

Ann
Which is most popular? I mean the shape of ice crystals?
Stellar dendrites?? Is that right?

sabnsy45

Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by sabnsy45 » Tue Dec 26, 2023 3:32 am

Ann wrote: Wed Dec 20, 2023 5:26 am Wow, that's a truly spectacular and fantastic image! :shock: :D


The heliac arc looks like a heart! 💙

APOD Robot wrote:

Finally, the balloon shaped curve connecting the top arc to the Sun is the rarest of all: it is the heliac arc, created by reflection from the sides of hexagonally shaped ice crystals suspended in a horizontal orientation.
geometry dash subzero

Plates of ice.png

Are we talking about ice crystals like the fourth from left in the top row, the plates of ice, suspended in a horizontal orientation? These things?

Ann
Is ice crystals the most popular?

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Ann
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Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by Ann » Tue Dec 26, 2023 2:32 pm

Unely1965 wrote: Fri Dec 22, 2023 4:56 am
Guest wrote: Fri Dec 22, 2023 4:55 am
Ann wrote: Wed Dec 20, 2023 5:26 am Wow, that's a truly spectacular and fantastic image! :shock: :D


The heliac arc looks like a heart! 💙





Plates of ice.png

Are we talking about ice crystals like the fourth from left in the top row, the plates of ice, suspended in a horizontal orientation? These things?

Ann
Which is most popular? I mean the shape of ice crystals?
Stellar dendrites?? Is that right?
Don't know, but I think that plates of ice are the most popular if you want to see ice halos! :D

Ann
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arabrockall
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Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by arabrockall » Tue Jan 09, 2024 3:45 am

sabnsy45 wrote: Tue Dec 26, 2023 3:32 am
Ann wrote: Wed Dec 20, 2023 5:26 am Wow, that's a truly spectacular and fantastic image! :shock: :D


The heliac arc looks like a heart! 💙

APOD Robot wrote:

Finally, the balloon shaped curve connecting the top arc to the Sun is the rarest of all: it is the heliac arc, created by reflection from the sides of hexagonally shaped ice crystals suspended in a horizontal orientation.
geometry dash
Plates of ice.png

Are we talking about ice crystals like the fourth from left in the top row, the plates of ice, suspended in a horizontal orientation? These things?

Ann
Is ice crystals the most popular?
No, I think the most common crystals are hexagonal plates

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johnnydeep
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Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by johnnydeep » Tue Jan 09, 2024 2:07 pm

arabrockall wrote: Tue Jan 09, 2024 3:45 am
sabnsy45 wrote: Tue Dec 26, 2023 3:32 am
Ann wrote: Wed Dec 20, 2023 5:26 am Wow, that's a truly spectacular and fantastic image! :shock: :D

The heliac arc looks like a heart! 💙
geometry dash
Plates of ice.png
Are we talking about ice crystals like the fourth from left in the top row, the plates of ice, suspended in a horizontal orientation? These things?

Ann
Is ice crystals the most popular?
No, I think the most common crystals are hexagonal plates
Umm, what's the difference between crystals 1 and 4 in that chart? It just looks like there are two of crystal 1 shown for "crystal" 4.
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}

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Chris Peterson
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Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by Chris Peterson » Tue Jan 09, 2024 2:31 pm

johnnydeep wrote: Tue Jan 09, 2024 2:07 pm
arabrockall wrote: Tue Jan 09, 2024 3:45 am
sabnsy45 wrote: Tue Dec 26, 2023 3:32 am
Is ice crystals the most popular?
No, I think the most common crystals are hexagonal plates
Umm, what's the difference between crystals 1 and 4 in that chart? It just looks like there are two of crystal 1 shown for "crystal" 4.
I think the crystal formations are identical, and the image is just emphasizing that a scattered cloud of them will result in different halo phenomena than you get in very still air where they will tend to align in horizontal alignment.
Chris

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johnnydeep
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Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by johnnydeep » Tue Jan 09, 2024 2:40 pm

Chris Peterson wrote: Tue Jan 09, 2024 2:31 pm
johnnydeep wrote: Tue Jan 09, 2024 2:07 pm
arabrockall wrote: Tue Jan 09, 2024 3:45 am

No, I think the most common crystals are hexagonal plates
Umm, what's the difference between crystals 1 and 4 in that chart? It just looks like there are two of crystal 1 shown for "crystal" 4.
I think the crystal formations are identical, and the image is just emphasizing that a scattered cloud of them will result in different halo phenomena than you get in very still air where they will tend to align in horizontal alignment.
Ok, so the difference between isolated hexagonal crystals and agglomerations of those same hexagons "aligned" together. Is actually joining together - or maybe forming joined in the first place - a possibility in the air?
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}

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Chris Peterson
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Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by Chris Peterson » Tue Jan 09, 2024 2:45 pm

johnnydeep wrote: Tue Jan 09, 2024 2:40 pm
Chris Peterson wrote: Tue Jan 09, 2024 2:31 pm
johnnydeep wrote: Tue Jan 09, 2024 2:07 pm

Umm, what's the difference between crystals 1 and 4 in that chart? It just looks like there are two of crystal 1 shown for "crystal" 4.
I think the crystal formations are identical, and the image is just emphasizing that a scattered cloud of them will result in different halo phenomena than you get in very still air where they will tend to align in horizontal alignment.
Ok, so the difference between isolated hexagonal crystals and agglomerations of those same hexagons "aligned" together. Is actually joining together - or maybe forming joined in the first place - a possibility in the air?
I don't think they join. It's just that in still air they orient themselves horizontally (like little parachutes), and in turbulent air their orientations are random.
Chris

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johnnydeep
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Re: APOD: Ice Halos over Bavaria (2023 Dec 20)

Post by johnnydeep » Tue Jan 09, 2024 2:46 pm

Chris Peterson wrote: Tue Jan 09, 2024 2:45 pm
johnnydeep wrote: Tue Jan 09, 2024 2:40 pm
Chris Peterson wrote: Tue Jan 09, 2024 2:31 pm
I think the crystal formations are identical, and the image is just emphasizing that a scattered cloud of them will result in different halo phenomena than you get in very still air where they will tend to align in horizontal alignment.
Ok, so the difference between isolated hexagonal crystals and agglomerations of those same hexagons "aligned" together. Is actually joining together - or maybe forming joined in the first place - a possibility in the air?
I don't think they join. It's just that in still air they orient themselves horizontally (like little parachutes), and in turbulent air their orientations are random.
✔️
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"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}