Curious effect over commercial airplane wing. I suspect reflections from ice

Thank you, Mick and all!
I know "Atmospheric Optics" web site and "HaloSim" simulator.
I am interested in how HaloSim simulates and Les Cowley's opinion, if available...

I think that the flow around wings of a flying plane might have dissipative structure (dynamic equilibrium?), which is steady only when a certain input exists; and that the ice crystals there might align in a different way from the air which has not yet disturbed by the plane (perhaps, originally horizontal). That is, (this is my imagination), they are tumbling along an vortex, but their alignment and inclination distribution are steady if seen from a passenger moving with the airplane? The alignment of ice crystals around wings might not be realized in an air without aircraft.

As for aircraft strobe light, it was daytime and the glitter continued in 4.4 seconds at least, so at this time I do not think it as a reason...
 
And also...
I don't know the altitude, but, judging from the elapsed time, it might be still 7000-8000m (ca. 25000ft), and temperature might be about -20 degree C (ca. -10 F)?
 
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Really interesting video and story, thumbs up to Masayuki for being so accurate in his description of the event!

As you guys noticed, there's a vapor line on the winglet, this might be a clue that tells us that there's a source of moisture, therefore, if a cooling mechanism is at play here since the aircraft is already pretty high in the sky where colder temperature can be found (where temp meets the dew point), what we see in the video might just be moisture forming (or already formed) into ice crystals that just bounces off aircraft surfaces. In this (never seen before for me) case, it could be the leading edge of the starboard wing that created two vortices since these crystals seem to be well in focus and outside of the "blurfo zone".
 

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Christophe Isbert said:
Really interesting video and story, thumbs up to Masayuki for being so accurate in his description of the event!

As you guys noticed, there's a vapor line on the winglet, this might be a clue that tells us that there's a source of moisture, therefore, if a cooling mechanism is at play here since the aircraft is already pretty high in the sky where colder temperature can be found (where temp meets the dew point), what we see in the video might just be moisture forming (or already formed) into ice crystals that just bounces off aircraft surfaces. In this (never seen before for me) case, it could be the leading edge of the starboard wing that created two vortices since these crystals seem to be well in focus and outside of the "blurfo zone".
Click to expand...

There isn't time for crystals to grow to a size that gives a specular refection. See papers on aerodynamic contrails. Bounce speeds are likely to be much less than ~500 knots. The flashes are unrelated to streamlines, but are a locus of points where you can see a reflection of a light source by the crystals.
 
Masayuki SHIRAISHI said:
As for aircraft strobe light, it was daytime and the glitter continued in 4.4 seconds at least, so at this time I do not think it as a reason...
Click to expand...

I am trying to think of a good reason why the horizontal streaks would less than at least the angular width of the sun. Very fast rotation of the ice crystal could do it. If they rotate 60 deg. in 5 metres plane of travel at 250 m/s, it amounts to the image of the sun rotating across the camera at ~ 2*60*250/5 = 6000 degrees/second, which is almost fast enough. If the sun is 0.5 degrees dia. that is equivalent to a flash of 1/12 ms, in which time the plane travels ~250/12 mm... :-)
 
Christophe Isbert said:
Thanks for the info, I found a rather shot but interesting article about this kind of condensation trails:
http://www.dlr.de/pa/en/desktopdefault.aspx/tabid-2342/6725_read-16936/

So I decided to send an email to Pro.Dr. Bernd Kärcher of the German Aerospace Center Institute of Atmospheric Physics, Atmospheric trace gases.


Could vaporized fluids from a leak (oil, fuel, de-icing, hydraulic/lubricant) in the wing create crystals?
Click to expand...


Googling "Lidar horizontal orientation of ice crystals" will throw up some stuff on ice crystal plates.
 
Thank you, all.
And I'm looking forward to Pro.Dr. Bernd Kärcher's interpretation also.

As for Les Cowley, to tell the truth, I had contacted him last year after my submission to SpaceWeather by e-mail, too.
I received his response as follows:

Dear Masayuki Shiraishi,

Thanks for your note and pictures.

I have in fact already looked very carefully a day or so ago at your stacked image on Spaceweather and also studied the 4s video.

My first reaction was that the 'specks' were on the aircraft window. However, your depth of field arguments are rather convincing. You might want to check your conclusion by imaging a similar star-like pinpoint of light at the window distance using the same lens settings.

A vortex effect seems improbable because the glinting objects are probably ahead of the wing - unless they were very close.

If the glints were from ice crystals, they were not necessarily plates.

I thought about your image for some time. I am sorry to have to say that I cannot think of an atmospheric optics explanation.

The airflow around aircraft produces other effects. See for example this page: http://www.atoptics.co.uk/fz87.htm - unexplained.

You might want to send you image to my colleague Marko Riikonen in Finland ( riikonenmarko@yahoo.com ). He is an expert on halos and could have comments.

I'm sorry not to have been much help.
Best regards,
Les

Les Cowley
Atmospheric Optics - www.atoptics.co.uk
Optics Picture of the Day - www.atoptics.co.uk/opod.htm​

...So, at this time I may or may not obtain a new interpretation....
(I have no reply from Riikonen.)
But, by Mick's adequate questioning, I wish he gives us some hints.
 
Les Crowly says he does not know, but pointed to this on his site, possibly related:
http://www.atoptics.co.uk/fz87.htm
20171026-082801-mjztl.jpg

External Quote:
Subsun 'Tails'

Large images: Jerry Xiojin Zhu (site) near Chicago December '04. ©Jerry Xiojin Zhu, shown with permission.
Small image: Raymond L. Lee (site) during a descent into London, England June '97.©Raymond L. Lee, shown with permission.

In both cases the aircraft was quite low. Each photographer took several images.

Subsuns are produced by reflection from the near horizontal faces of plate shaped ice crystals. The curved tails below the subsuns are unusual. Window scratches can produce similar effects but that is not the case in these images.

A possibility is that the tails are produced by crystals tilted from horizontal in the aircraft airstream.

There is a problem! By measuring the angular length of the light streaks, knowing the camera shutter speed and estimating the airplane airspeed, the distance of the crystals producing the glints can be calculated. In these two separate cases they are 40-60m away. By comparison, the wingtip distance of a 737 (Lee's aircraft) is only 15m which somewhat rules out trailing wingtip vortices. The glinting crystals are well beyond the wingtips. The causes of the tails are uncertain.

Acknowledgements to Raymond Lee and Walter Tape for discussions and ideas.
 
Ric Werme said:
There's a curious image and brief video at http://spaceweathergallery.com/indiv_upload.php?upload_id=130105 showing an arc of something above the wing of a commercial flight. No flight details were reported.
External Quote:
Taken by Shiraishi on October 10, 2016 @ Over Japan Sea

Details:
73133c347e6e90c8afd227aace5bb8bc.gif

Something like diamond dusts glitter on plane.

I saw some glittering particles on a wing of my airplane.
They aligns along an arc.
I composited the frames from a movie, and I found 2 arcs on the wing.
I do not know whether there are actually 2 arcs of ice crystals or one can see 2 arcs due to the relationship among me and the crystals and the Sun.

Sony ILCE-7S digital camera; ISO 250, F10, 1/1000s exposure, f=30mm
A composite of 132 frame from a 4.4s movie.

Source: https://www.youtube.com/watch?v=j4JHVEig2Tw
Video description translated:
External Quote:

There was something glittering on the airplane wing.
Things such as diamond dust, have been sparkling along the arc-shaped. Arc-shaped Nanoha, what are lined up that way, I do not know whether this is so in relation to the sunlight.
Thumbnail is a stack of 132 sheets of the frame of this video.

5d0ccfaffdc352f08db1516c0a513596.jpg


I suggested elsewhere that the something are ice crystals, probably plates reflecting sunlight. The orientation may be due to vortexes, turbulence, or something else.

Have people here seen this phenomenon?

The video is important, the image is a composite of the whole video and is very different. Think time lapse photo.

[Mod: added frame grab from video, below]
View attachment 22123
Click to expand...
 
Mick West said:
There is a problem! By measuring the angular length of the light streaks, knowing the camera shutter speed and estimating the airplane airspeed, the distance of the crystals producing the glints can be calculated. In these two separate cases they are 40-60m away.
Click to expand...
Presumably this calculation is assuming that the ice crystals are essentially stationary with respect to the surrounding air. Is that necessarily the case though? If there is a vortex being set up and the crystals responsible are moving forward (ie in the same direction as the aircraft) then their relative speed as seen from the aircraft will be lower and the calculation will put them further away than they really are.
 
Airplane windows are usually made of polycarbonates which develop microscopic cracks over time. These can be aligned (like in a crystal) and refract/reflect light depending on the viewing angle.

I think this should be added to the list of possible explanations. There are usually at least two layers between passenger and the plane exterior.
 
JFDee said:
Airplane windows are usually made of polycarbonates which develop microscopic cracks over time. These can be aligned (like in a crystal) and refract/reflect light depending on the viewing angle.

I think this should be added to the list of possible explanations. There are usually at least two layers between passenger and the plane exterior.
Click to expand...
This has already been removed.
Anything on the two plane window panes can not be focused at the condition where the photos and movie were taken.
Even the exterior surface of the outer pane of double window is still too close to be in focus (in the depth of field).
It is quite difficult to take a pan-focused photo where both a thing of <20cm distance (window panes) and another thing of 25m distance (wing tip) are simultaneously in focus in F10. In order to take such a photo, at least "F number > 32" and "auto focused distance < 1m" are needed, but neither was realized.

And, there was nothing that lit the cracks on window panes. The right side was in shadow.

(In the first place, I found them (some glints) apparently outside of window, in the air, by naked eyes. At that time my eyes did not focus on the window pane, either. If they were on the window pane, I could recognize that "they are close!".)
 
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