The Alderney UFO sighting

[Eburacum]

The report by Baure, Clarke, Fuller and Shough came up with a list of explanations of varying plausibilities, but one good explanation in that list is a reflection from Alderney's greenhouses onto a thin layer of haze in the air. If the sunlight from the greenhouses was particularly intense, the layer of haze could have emitted light in all directions by scattering, appearing like a long thin glowing shape. A hazy cloud illuminated from below would be a particularly unusual phenomenon, so Cap Bowyer may not have been familiar with it.

https://martinshough.com/aerialphenomena/Report on Channel Islands UAPs 23.04.07.pdf

 

[flarkey]

The report by Baure, Clarke, Fuller and Shough came up with a list of explanations of varying plausibilities, but one good explanation in that list is a reflection from Alderney's greenhouses onto a thin layer of haze in the air. If the sunlight from the greenhouses was particularly intense, the layer of haze could have emitted light in all directions by scattering, appearing like a long thin glowing shape. A hazy cloud illuminated from below would be a particularly unusual phenomenon, so Cap Bowyer may not have been familiar with it.

https://martinshough.com/aerialphenomena/Report on Channel Islands UAPs 23.04.07.pdf

Thats a nice theory that I haven't heard before, but the report says he was familiar with it...

 

[steviemac]

I have long suspected that this 'UFO' was actually a cross channel ferry reflecting the sunlight at a certain angle....and that the 'darker' region in the alleged disk of the UFO was simply where the letters 'P&O' ( or whatever ferry operator ) are painted on the side of the ship ( in blue in the case of P&O) about the same distance from the end of the UFO as the logo is from the end of a ferry. The sun would reflect more off the white paint of the ferry than the dark paint of the logo....giving the impression of a darker segment to the 'UFO'. In fact....the very fact that the logo is proportionally in the same place that the dark segment of the 'UFO' is located is precisely what makes me think channel ferry is the best explanation.

A channel ferry is a sizeable object....600-700 feet long, and is probably one of the few things that could be confused as 'a mile wide' if true distance was not known.

Question is...are there cross channel ferry logs from the time.

So let's take what you're saying.

Captain Boywer was an experienced pilot of 18 years. He had flown that route thousands of times and probably seen more ferries cross that route, than we have had hot dinners.

But yet suddenly, one day he can't identify a p&o ferry, despite having seen them probably thousands of times. He said the day was so clear he could see the island in the distance. He also watched the object through binoculars... And you're still saying this experienced pilot (and other passengers) suddenly couldn't identify a P &O ferry.

I have flown back and forwards to England, and the islands many times. I've looked down and seen many a ferry, I don't think I would ever I would mix up a ferry down below, with an object straight ahead, in the sky and in front of me - especially being viewed through binoculars.

and the fact something was picked up by radar and another pilot confirmed seeing a similar object in the same location... Well, sorry. I just find that all too much for coincidence.

So I find that explanation extremely implausible. I totally get that ships can be mistaken as in the air, by the average layperson - but that usually happens when viewing from standing on land, out towards the sea. It's highly unlikely to happen when you are piloting a plane.

 

[steviemac]

The report by Baure, Clarke, Fuller and Shough came up with a list of explanations of varying plausibilities, but one good explanation in that list is a reflection from Alderney's greenhouses onto a thin layer of haze in the air. If the sunlight from the greenhouses was particularly intense, the layer of haze could have emitted light in all directions by scattering, appearing like a long thin glowing shape. A hazy cloud illuminated from below would be a particularly unusual phenomenon, so Cap Bowyer may not have been familiar with it.

https://martinshough.com/aerialphenomena/Report on Channel Islands UAPs 23.04.07.pdf

He was an experienced pilot of 18 years and had flown that route thousands of times. He probably knew every inch of the islands. But suddenly one day he's confused by a reflection off greenhouses? So in all the years he had flown to that small island, there had never been a reflection off greenhouses before? That's implausible as well.

 

[Mendel]

Thats a nice theory that I haven't heard before, but the report says he was familiar with it...

Your quote talks about a direct reflection, while the hypothesis involves indirect lighting. Your quote at least suggests that the direction matches, and the phenomenon would certainly be out of the ordinary.

As would a superior mirage.

 

[flarkey]

Your quote talks about a direct reflection, while the hypothesis involves indirect lighting. Your quote at least suggests that the direction matches, and the phenomenon would certainly be out of the ordinary.

As would a superior mirage.

Ah, that is an important distinction. But where are these greenhouses? I've looked on Google Mps, and searched with OverpassTurbo but can only find one. Admittedly I accept that this was nearly 40 years ago, but we should be able to pin their location down.

 

[Easy Muffin]

I got these from the current OSM dataset.



I'll attach the KML file if you want to have a look around in Google Earth yourself. For completeness' sake it includes all of the greenhouses in the Channel Islands even though Guernsey is home to the vast majority of them.

 

[Eburacum]

Thats a nice theory that I haven't heard before, but the report says he was familiar with it...

Well, the quote you gave says he was familiar with direct reflection, which would have a critical angle for visibility. I'm talking about reflection onto a thin, hazy cloud, which would scatter light in all directions and have a much wider range of visibility. This possibility is mentioned in the report;

scattering of reflected light from surface sources by haze aerosol particles;

The scattered light would spread out in all directions, although there might be a preferred direction if Mie scattering is involved.

I suspect that there was a fairly thin, largely transparent layer of hazy stratus cloud at approximately the same height as the aircraft (or slightly lower), and this thin cloud was illuminated by direct reflection from greenhouses on the surface. Presumably these greenhouses were in direct sunlight, and sent a relatively constrained beam of reflected sunlight back towards the sky.

Since the phenomenon was seen to have a 'dark' band' in the middle of its length, perhaps there were two groups of greenhouses separated by some other feature, and each group of reflectors illuminated a different patch of sky.

A similar phenomenon can occur during a light show; the beams of light are largely invisible until they hit a bank of vapour from a generator.

 

[Z.W. Wolf]

Before I make my point we have to discuss what time of day it was.
The time of the sighting is reported as 14:09 GMT

Several questions:
-Is Guernsey time GMT +0? Yes
-Does Guernsey observe British Summer Time? Yes
-Was it British Summer Time at the time of the sighting? Yes
-How do you adjust GMT to British Summer Time? You add one hour.
-So what was the local time? 3:09 p.m. BST.
-Do I have Stellarium set to daylight saving time? Yes

This is what Stellarium says the witnesses would see at 1,200 meters altitude that day.



The Sun is at 43 degrees above the horizon. Not setting but westering. They we were heading south, so the sun was to their right, and should have been visible to both pilot and passengers in that small aircraft.


The two objects were described as sun colored. The witnesses couldn't decide how far away or how big they were, which indicates they were featureless. The pilot reports that he looked at them through binoculars and they weren't too bright to look at comfortably. They were thought to possibly be reflections of the Sun, so we can say they were Sun-like in general. They were described as oval shaped.

Man, I'm surprised that no one up to now has suggested that these objects were sundogs, because everything fits.

Sundogs, sometimes called Sun Dogs, Parhelia or Mock Suns, are with the 22º halo, the most frequent of the ice halos. They are most easily seen when the sun is low. Look about 22° (outstretched hand at arm's length) to its left and right and at the same height. When the sun is higher they are further away. Each 'dog' is red coloured towards the sun and sometimes has greens and blues beyond. Sundogs can be blindingly bright, at other times they are a mere coloured smudge on the sky. They are visible all over the world and at any time of year regardless of the ground level temperature. In Europe and North America one will be seen on average twice a week if searched for.

Sundog colors

This close-up shows sundog colors well, although each sundog is differs slightly in its own way. The sunward edge is a tawny red progressing through orange, straws and smoky yellows to pastel greens and then a hint of blue. There are no pure spectrum colors. Plate crystals forming the 'dog' are in all rotational positions about near vertical axes. The sun's rays therefore impinge on each crystal at different angles of incidence and skew causing some color overlap that increases from red towards the blues.

The blues blend into the blue of the sky. The red/orange/yellow colors are more noticeable.

Bowyer said that the object was "the size of five or six battleships", and that it had been "a very sharply defined, solid, bright yellow-gold object with a couple of black bands on the side that were kind of shimmering".

John Russell, meanwhile, reported seeing "an orange light … like an elongated oval".

That sounds a lot like sun dogs... or any number of atmospheric optics phenomena.

If these object were sun dogs it wouldn't matter how many times the pilot had flown this particular route because they have nothing to do with ground features.

 

[Eburacum]

The Sundog explanation is also discussed in the Clarke/Shough report.

these rare paranthelia are faint elliptical blurs of light not much brighter than the parhelic arc they sit on, which would also usually be visible, and more importantly the elevation of the parhelic circle is that of the sun, i.e. in this case ~ 45°, whereas the UAP was observed at a
depression angle below the horizontal. This theory doesn't fit the pilot’s description of a "yellow/beige" oval in any particular.

It also mentions several different parhelia phenomenon, the 'subsun', and 3rd and 4th order rainbows. These are also largely ruled out. Perhaps a reflected sunbeam from the greenhouses might have caused a small arc rainbow, but this possibility is something that would need some complex geometry to assess.

 

[Eburacum]

The two objects were described as sun colored.

They were also described as hazy. This suggests to me that a solar reflection of some kind was involved, rather than refraction or diffraction, which could have produced a rainbow effect.

 

[Z.W. Wolf]

I've just been looking at that Clarke/Shough report.

Now that I have more information, I think it was more likely to be a lower tangent arc or a partial lower tangent arc. The object was described as below the sun, and as being a horizontal oval with another horizontal object appearing above(?) it or below(?) it.

https://atoptics.co.uk/halo/colsolat.htm#






The Sun in this photo below is high above the horizon, thus the lower tangent arc is almost "flat" of horizontal. This example best matches the position of the Sun in this case - 43 degrees above the horizon.

Do these witness descriptions match what we see here?

Bowyer said that the object was "the size of five or six battleships", and that it had been "a very sharply defined, solid, bright yellow-gold object with a couple of black bands on the side that were kind of shimmering".

John Russell, meanwhile, reported seeing "an orange light … like an elongated oval".

Or could it have been a lower tangent arc and a lower Parry sunvex arc below it? As shown in this simulation - on the far right. Note that as the Sun is higher in the sky both arcs are "flatter" or more horizontal. The Sun at the time of this sighting was at 43 degrees above the horizon.

https://atoptics.co.uk/halo/parry1.htm

The changing aspect of Parry arcs with solar altitude. Faint 22� halos and upper tangent arcs (UTA) are included for reference in these HaloSim simulations. At 0� a 'sunvex' Parry arc is almost coincident with the UTA. As the sun rises the sunvex arc separates upward and a 'suncave' Parry arc appears and approaches the UTA. Above 25� a lower sunvex arc becomes visible.

http://photos1.blogger.com/blogger/1639/2131/1600/sim_photo.0.jpg

... very rare Lower Parry sunvex arc in Antarctica.

The authors dismiss the sundog idea, in part, because another pilot described something similar in a direction that could not be a sundog because of the geometry.

My impression:
The other pilot had been listening to the chatter on the radio.
He was responding to questions from a controller who was asking if he saw something similar.

He searched the sky and saw something similar enough to report.

This seems to me to be the result of priming and of demand characteristics.

Demand characteristics are all the clues in an experiment that convey to the participant the purpose of the research. Demand characteristics can change the results of an experiment if participants change their behavior to conform to expectations.

He may have seen something similar enough to report as the same object. But was it the same object? Or did it have to

be a 120° sundog on the complete parhelic circle. [?]

The authors do not mention the possibility of a lower tangent arc. But would they also dismiss this because of the second pilot testimony? Perhaps, but I think that would be an equally weak argument. Why should we assume the second pilot sighting has anything to do with the primary sighting in this case? I think that's an awfully shaky idea. Maybe even biased.



Just to give an example of variation...

Subparhelia (sub-sundogs) are the reflected version of parhelia (sundogs) as seen from the air. In other words, they are the sundogs on the sides of the subsun instead of the real sun. Because ice crystals in clouds are often not perfectly horizontal, subparhelia may look 'taller' than normal sundogs. Note the occurance of subparhelia does not depend on parhelia: the former can appear without the latter.

BTW, most subparhelia are vertical, but this is a "horizontal" subparhelion. There's a lot of variation.


I think the authors are being too absolutist in many cases.

Here's a description of the case included in the report.

b) Blue Island 832 (BAe Jetstream 32) At approximately 1412Z Capt Bowyer asked Jersey Zone controller Paul Kelly if anyone else was seeing the object (at this time only UAP #1 was visible). Kelly replied that he had “nothing really in the area”, but called a BAe Jetstream 32 turboprop passenger aircraft of Blue Islands airways (BCI832, Sqk. 7770) cruising at about 250 knots SE-bound past Guernsey en route to Jersey from the Isle of Man.

In charge of this aircraft was Capt Patrick Patterson, a pilot with several thousand hours experience (in excess of 2500 hrs in the command seat) who had been flying routes in the Channel Islands area for approximately one year. Kelly asked: “. . . in your left, just behind 9 o'clock, can you see anything in that direction?” 8 Capt Bowyer states that he did not himself draw his passengers’ attention to the objects. They spotted them independently. 9 At first sight this is in conflict with Capt Bowyer’s observation that sightlines to both objects were to the right of the flight track. Alderney was at this time to the left of the flight track. The explanation for this is discussed in Section 3. 12 Report on Aerial Phenomena Observed near the Channel Islands Baure, Clarke, Fuller & Shough Capt. Patterson, who had overheard the previous exchanges, replied, “I‘m having a look, stand by.”

A minute later the pilot replied that he could see nothing at all in that position, and at 1413:24 Kelly handed off Blue Island 832 to Jersey Approach. However very soon after this at 1414:43 the pilot radioed Jersey Approach, explained the situation and stated that “I've got something about 8 o'clock resembling the description”. From a point close to the island of Sark (E of Guernsey)10 the Jetstream pilot looked back over his left shoulder towards Alderney and now saw in his 8 o'clock position what he described in a written report the following day (see Appendix A) as an object fitting Capt. Bowyer's description and having a "yellow/beige" colour, apparently 2000ft below him at about 1500 ft altitude a little to the W or NW of Alderney about 20 NM away.

Subsequent questioning (Appendix B) established that this object appeared “oval” or “oblong” and its outline was very hazy, just a patch of yellow coloration comparable to the paint colour of an Aurigny Trislander fuselage (a bright canary yellow) as seen in hazy conditions at distance. It appeared to be approximately 2 NM to the west of Alderney (visible in outline through haze together with nearby Burhou) and, by comparison with the island, would have had a maximum horizontal dimension of about 0.5 NM (900m; Alderney, in this perspective, would have subtended about 7° in width from 20NM range, indicating a maximum angular width of about 1.3° for the object, or more than twice the apparent diameter of the moon). It did not appear to move. Visibility was "fairly poor" due to the haze layer below his altitude but the pilot saw this object several times in between brief interruptions due to flight deck duties. After approximately 1 minute he looked back and had lost visual contact.

The reasoning behind rejecting the sundog idea

a) sundogs It is immediately noticeable that the visual LOSs to the UAPs from the Trislander were not far from the azimuth of the sun. This fact was indeed noted by the witnesses, two of whom also described the light as “sunlight” coloured.77 This coincidence invites speculation that the UAPs may have been caused by some kind of atmospheric-optical reflection or refraction effect.

Sundogs (or parhelia) became a favourite hypothesis of some public commentators within a very short time of the event.78 Sundogs are fuzzy patches of light caused by refraction of the sun’s rays through hexagonal platelet ice crystals above the observer. We were easily able to confirm the presence of ice clouds above the ~10,000ft freezing level (Fig.22 & Section 5), thus between the Trislander and the sun. But not below the Trislander (air temps >10°C) and so not on the observer’s LOS to the UAPs near the horizon. The optical geometry dictates that sundogs occur close to the 22° halo around the sun. They tend to be elongated with the major axis of symmetry lying vertically because of the way the ice plates lie in the atmosphere, but do sometimes show spectral “tails” extending radially away from the sun, to left and right, for a degree or two. But a pair of sundogs would bracket the sun at about 45° elevation above the horizon, about 22° either side of the disc79.

Two lights near the horizon, almost directly below the sun and just a few degrees apart, are not sundogs. We can be confident of this on the grounds of the gross geometry without going on to consider their “brilliance”, “extremely well-defined” outlines and curious internal detail. The common sundog is only one of an array of light halo phenomena that can be caused by ice crystals, but most of these are even fainter and consequently rarely seen. In rare conditions such as most often occur in polar skies a complete display can be seen with a whole complex of superimposed arcs and nodes of increasing fugitiveness at larger angular distances.

There is even 77 One of these nevertheless thought that the source was emissive, not reflective, and this witness along with one other mentioned “orange” hues, suggestive more of haze-scattered sunlight than direct light from a high sun. 78 On the basis of early newspaper stories a local author, Michael Maunder, published the sundog theory in the biweekly Alderney Journal, volume #873. A letter in response from Capt Bowyer appeared in #874. Mr. Maunder retracted the theory on the basis of information provided by Capt Bowyer and by the present authors. He appears to have reverted to a version of it in A Report on the Putative UFO Seen Over Alderney, Maunder/Speedybrews 2008. 79 In fact sundogs are bright nodes at the intersection of the rarely seen circumscribed halo and parhelic circle, and the higher the sun the further out the sundogs will appear.

In this case they would have moved out several degrees from the 22° halo along the parhelic arc, appearing subjectively even higher. 61 Report on Aerial Phenomena Observed near the Channel Islands Baure, Clarke, Fuller & Shough a faint secondary halo occurring at 46° from the sun, which could at least have intersected the horizon in this case (had there been ice crystals present at low level). But none of these phenomena resembles the UAPs reported. [Appearances can vary. The absolutist certainty expressed here seems biased.] It would be possible - given the presence of a layer of ice crystals below the observers - for a brilliant terrestrial source (such as a reflection of the sun from the sea) to generate a 22° ice halo and also to appear flanked by a pair of “sundogs” ~44° apart.

But the reflection geometry, like that of a rainbow, is always fixed in relation to the positions of the observer and of the source, and the internal angles between the nodes and arcs of the halo do not change, whereas our UAPs (which were of course neither 44° apart nor each 22° from any visible bright source) moved laterally relative to one another by several degrees. [They were reported to move. That's a different thing than moved. Also, the movement could be due to seeing partial displays. The partial displays may seem to move because they are becoming more or less complete. Also, tangent arcs and Parry arcs change shape as the Sun reaches a different altitude. Once again, I'm seeing too much absolutist certainty when dealing with a dynamic phenomenon.]

Fig.22. Brest radiosonde ascent, noon, April 23 2007, showing freezing level ~3200m. The frost point is the temperature (slightly warmer than the dew point) at which saturated air begins to condense preferentially over ice particles. (graph courtesy Dr. Robin Hogan. Reading U.) The sundog hypothesis is also not very useful to explain the Jetstream pilot’s observation on a near reciprocal line of sight, looking away from the sun. The only remote possibility for explaining an object on this bearing as an ice halo would be a 120° sundog on the complete parhelic circle. [Is it? Why would that be the only explanation?]

In a very well developed parhelic display there are in principle two of these paranthelia , 60° either side of the anthelion (a faint patch on the parhelic circle opposite the sun), 62 Report on Aerial Phenomena Observed near the Channel Islands Baure, Clarke, Fuller & Shough therefore at 345° and 105° azimuth. It seems possible to reconcile a 345° azimuth with the pilot's 8 o'clock LOS within 10° or so. However these rare paranthelia are faint elliptical blurs of light not much brighter than the parhelic arc they sit on, which would also usually be visible, and more importantly the elevation of the parhelic circle is that of the sun, i.e. in this case ~ 45°, whereas the UAP was observed at a depression angle below the horizontal. This theory doesn't fit the pilot’s description of a "yellow/beige" oval in any particular. Plausibility (0 - 5): 0

 

[Ann K]

But where are these greenhouses? I've looked on Google Mps, and searched with OverpassTurbo but can only find one. Admittedly I accept that this was nearly 40 years ago, but we should be able to pin their location down.

I found this article on Guernsey history:

Greenhouses were already dotted around Guernsey at that time for grape-growing, but Peter (historian Peter Brehaut) said it was not until the 1880s that people were building greenhouses specifically for growing tomatoes.

By the start of the 20th century, the tomato industry was taking over from the grape growing industry. Carpenters and boat builders also turned their skills to greenhouse building as the ship building industry started to decline.

In the late 1960s nearly half a billion tomatoes were picked and exported to England. Each one of those had to be handpicked, packed and shipped out.

The cost of production increased when the price of oil went up, and it became cheaper for England to import tomatoes from Holland. Subsequently tomato growing in Guernsey became more or less unsustainable and many growers tried turning to other fruit and vegetables.

Peter said some turned back to flower growing, but it was not long before many greenhouses all around the island became derelict.​

Peter said he believed the days of growing tomatoes in Guernsey were long gone.

Content from External Source

https://www.bbc.co.uk/guernsey/content/articles/2009/03/18/tomato_growing_feature.shtml

 

[Ann K]

Man, I'm surprised that no one up to now has suggested that these objects were sundogs, because everything fits.

Do they fit? I'd expect a sundog to be described in terms of height rather than length. Perhaps a portion of a circumzenithal arc would fit the description better, because it's (largely) horizontal rather than vertical.

 

[Eburacum]

Curiously, most of the sundogs I've seen have been longer than they are tall, perhaps due to stratification in the clouds they appear in.

Circumzenithal arcs appear almost directly overhead, so they don't fit this sighting at all.

 

[Ann K]

Curiously, most of the sundogs I've seen have been longer than they are tall, perhaps due to stratification in the clouds they appear in.

Circumzenithal arcs appear almost directly overhead, so they don't fit this sighting at all.

Perhaps I'm misnaming it, but a nearly horizontal phenomenon would sound more likely to me. (Nevertheless, I'm leaning toward the greenhouse-reflection-on-cloud-layer concept, from @Eburacum) Here's a picture:

 

[Eburacum]

I have been requested by the moderator to post a quote from the link I posted earlier, to highlight the section of the Baure/Clarke report I was referring to.

Here is the quote;

We score two other theories as “somewhat plausible” because they seem to have potential to explain the lateral apparent motion as well as at least some, perhaps a majority, of the other significant features. These are:
1/ Secondary scattering, by a haze layer, of specular sunray reflections from greenhouse glass on Guernsey
2/ Earthquake light

The first explanation is the one I find most plausible. If there were two, separate banks of greenhouses in direct sunlight with windows at a 45 degree angle (or thereabouts), they could have projected two beams of sunlight upwards towards a thin, hazy cloud somewhere above them. This would cause the haze to glow and emit light in all directions (secondary scattering) and this source of light could have been seen by Capt Bowyer, his passengers, and even by Capt Patterson in the other aircraft.

I should note that I do not kind the 'Earthquake light' explanation plausible at all. Even very strong earthquakes do not seem to produce consistently observable lights, although sometimes there are electrical flashovers from damaged transmission equipment.

 

[Z.W. Wolf]

Earthquake lights is a non-starter.

The idea that these lights were caused by "secondary scattering, by a haze layer, of specular sunray reflections from greenhouse glass" seems naïve to me.

You can see ground lights reflected off of (or scattered by) low clouds at night.


But it doesn't seem credible to me that this kind of scattered light from water droplets would be this bright in contrast to the daylight sky. Would reflected sunlight add that much brightness to a cloud, or a hazy sky, that was already scattering direct sunlight? Is there anything in the literature about seeing scattered light from ground lights in the daytime? I can't find anything like that.

Whatever these lights were, I think it's far more likely they were due to refraction.

The observers were looking toward the Sun. Bright displays that are partially due to internal reflections in water droplets occur when the Sun is behind the observer. Rainbows.

Displays that are caused by reflections off of ice crystals don't seem credible to me either. There could be two sources of light.

-Specular reflections from the greenhouses.
-Specular reflections from the surface of the ocean.

In both cases the lights would be a species of light pillar. They would be perceived as horizontal bands of light because the light sources were broad bands of light rather than point sources such as street light.s

I think this scenario is very doubtful, because light pillars are dependent on ice crystals that are between the light source and the observer and above the observer. I don't think the geometry is right for an observer at 1,200 meters altitude in an aircraft to see light pillars just above the horizon. It seems to me that the light pillars in this scenario would seem, to the observer, to be visible far above the horizon.





I'm going to stick with a lower tangent arc, or a lower tangent arc plus a lower Parry sunvex arc below it as the most credible cause. Something the authors of the study don't even mention as a possibility. I have to conclude that this omission was due to ignorance of the existence of this kind of display.


If the Sun were a little lower in the sky than it is here in this photo, the lower tangent arc would appear just above the horizon. This kind of display is rare but is well represented in the literature. In other words, it's a known type of display.

Not a wholly speculative kind of thing such as ground lights scattered by water droplets in a hazy sky or light pillars in the daytime. The lower tangent arc is caused by refraction in ice crystals between the observer and the Sun. A much more credible scenario.

Note that there are two zones of brightness in the lower tangent arc in this photo. Could these be perceived as two different lights that are very close, one above the other?

The lateral shift can be explained more convincingly by:
- Purely optical effect involving atmospheric optics and moving observers. For example, it's well known that rainbows move relatively quickly with the observer while the distant landscape moves more slowly. This type of refractive display would "move" in much the same way.
- Purely optical effects involving atmospheric optics. But because the display was dynamic and became more or less "complete" over short periods of time. That could explain the two lights appearing to shift relative to one another. This is the one I favor.
- Illusory perceived motion due to observers traveling at speed in an aircraft, with additional pitch, roll and yaw movements. An optical illusion in other words.

 

[Ann K]

But it doesn't seem credible to me that this kind of scattered light from water droplets would be this bright in contrast to the daylight sky

Would it be in contrast to a bright sky? This was seen from the air, so it might well have been in contrast to the water, to land, or to dark clouds at a distance. (It's possible that the direct reflection was also in line with a haze layer that obscured the shape, but that wouldn't square with the reported several minutes of sighting.)

Anecdote: I recall being in my office at work when suddenly the entire room (already illuminated by artificial light) glowed brilliantly. That was the reflection in my window from one single car window (a jeep, with a flat windshield) in a parking lot at a distance of well over a hundred yards, as the sun reached just the right position. If the island once had acres of glassed greenhouses, such a display seems plausible to me.

 

[Z.W. Wolf]

Would it be in contrast to a bright sky?

Yes, the lights were described as just above the horizon.

Anecdote: I recall being in my office at work when suddenly the entire room (already illuminated by artificial light) glowed brilliantly. That was the reflection in my window from one single car window (a jeep, with a flat windshield) in a parking lot at a distance of well over a hundred yards, as the sun reached just the right position.

That was a direct specular reflection

If the island once had acres of glassed greenhouses, such a display seems plausible to me.

Again, that would be a direct specular reflection.

This was not described as a direct specular reflection, but as something happening in the atmosphere.

The UFOlogists are indeed insisting that it couldn't be simple specular reflections from these green houses because of how familiar this pilot was with this area.

In my scenario, the landscape is irrelevant. This was a matter of atmospheric optics that could happen anywhere, and is rare to boot. So it's not surprising the pilot was unfamiliar with this rather striking kind of display.

 

[Eburacum]

Secondary scattering from a haze layer could have increased the brightness of that haze layer significantly, and would be sufficiently unusual to have puzzled even the most experienced observer. Reflected sunlight shining onto a surface often looks unusual and unfamiliar - this would be a kind of caustic, an optical effect most people don't notice but it is unmistakable when seen. Locally bright patches often appear on surfaces due to true reflection, near buildings with large glass windows, and can make very peculiar effects when they do.

However I am quite taken with the Lower Tangent Arc explanation. This could easily be much brighter than secondary scattering, However a Lower Tangent Arc appears directly below the Sun, so was the Sun directly above the sighting?

 

[Eburacum]

But it doesn't seem credible to me that this kind of scattered light from water droplets would be this bright in contrast to the daylight sky. Would reflected sunlight add that much brightness to clouds that were already scattering direct sunlight? Is there anything in the literature about seeing scattered light from ground lights in the daytime? I can't find anything like that.

One phenomenon which involves secondary scattering from clouds due to reflected sunlight in daylight is iceblink, which involves light reflected off distant ice onto clouds. This phenomenon can be used by arctic explorers to detect ice over the apparent horizon, so is quite a useful effect.

 

[Z.W. Wolf]

Secondary scattering from a haze layer could have increased the brightness of that haze layer significantly, and would be sufficiently unusual to have puzzled even the most experienced observer.

You'll have to show me something in the literature to back this up, otherwise this is just empty speculation. I've never seen anything like this in my 66 years, nor seen anything like it in the scientific literature.

The one ground source I can think off that might be bright enough to produce this kind of effect, is this kind of solar power plant.

Solar One
Solar thermal power project
Barstow, California, 1993


I saw this in real life. A number of times. A very odd and spectacular sight. A magically bright light. But I didn't see anything in the atmosphere. A dry atmosphere, admittedly.

 

[Eburacum]

(see post #62 about iceblink for an example of bright, and easily visible, secondary scattering).

Note that iceblink involves two different instances of diffuse reflection, first from the snow, and second from the cloud layer. The secondary scattering that may have happened above Alderney would have involved one instance of scattering, from the cloud, and one instance of regular, specular reflection, which reflects light in one particular direction. So it could potentially be brighter than iceblink.

 

[Ann K]

One phenomenon which involves secondary scattering from clouds due to reflected sunlight in daylight is iceblink, which involves light reflected off distant ice onto clouds. This phenomenon can be used by arctic explorers to detect ice over the apparent horizon, so is quite a useful effect.

OT: a green reflection can appear in clouds from an atoll in the ocean, and has been used in the past by Polynesians navigating their craft over long distances in the Pacific.

 

[Eburacum]

Yes, I've heard of that.
Another manifestation of the secondary scattering phenomenon is the opposite of iceblink, known as water sky; an observer standing on a continuous ice sheet can sometimes find open water by observing a darkening of the cloud layer, since reflected light from open water is much lower than reflection from ice. This is due to a difference in albedo between ice and open water.

 

[Giddierone]

While driving today I saw what I think is a radius halo (going off the link Z.W provided above https://atoptics.co.uk/halo/46hal.htm). The effect was visible for a long time and there were faint traces of the sundog almost two hours later at sunset. Location: driving North towards Scotland, just below Carlisle. Video clip is shot looking almost vertically up by a passenger. The luminous horizontal parts were very large and bright and there were two of them above the sun.

 

[Z.W. Wolf]

What you've got there is a nice upper tangent arc and a 22 degree halo. No sundog visible in this frame.

Was the Sun behind some heavier clouds?

https://atoptics.co.uk/halo/column.htm

upper tangent arc. The gull winged arc always touches the 22º halo at a point directly above the sun. Its wings open and then droop as the sun climbs.

The best tangent arcs wing outwards from where they touch the 22º halo directly above and below the sun. Their colours are bright yet delicate. Red is sunward. On less favourable days they can be just local brightenings of the 22� halo.

The upper and lower arcs change shape considerably between sunrise and noon. Look at their variations in the animation.

When the sun climbs above 29º both arcs join into a single halo wrapped right around the sun - the "circumscribed halo".

Tangent arcs form when cirrus clouds have well developed columnar ice crystals drifting with their long axes almost horizontal. These are called "singly oriented columns" because having their long axes horizontal is their only orientation constraint. They can take up any rotational position around their long axis and a vertical axis. This crystal orientation is a common one and produces a number of different halos.

The rays of tangent arcs enter a side face and leave directly through another inclined 60º to the first. As in the rays forming the 22º halo, a deflection of 22º after the two refractions is the angle of minimum deviation but larger ray deviations occur as well. Thus the tangent arcs touch the 22º halo but rays deviated through larger angles (including skew rays) form its 'wings'.

Red light is refracted less strongly than other colours and so the halo edge closest to the sun is red. The halo's colours are much more apparent when seen directly, photographs rarely do them justice.

Tangent arc rays pass through the same crystal faces as those of the 22º halo and sundogs. The essential difference in the formation of the three halos is the orientation of their crystals.

 

[Eburacum]

Yes; I think that the parhelia you have captured here are an upper tangent arc, a 22º halo and a circumzenithal arc. The last one is uppermost in your clip, and is sometimes called 'the smile in the sky'.

 

[Giddierone]

Yes, exactly, the sun was behind the trees for that 2 second video, so the labels above are correct. It was interesting because the sundogs were visible for a good couple of hours (the arcs we saw for about half an hour). Here's another shot where you can see more of the elements in the diagram above - the Circumzenithal arc and Upper Tangent arcs, and a shot about 10 mins before sunset (two hours later) where you can still just about make out two sundogs. Most of these elements were visible for a long time as we travelled North along a motorway where our relation to it changed somewhat due to the gentle turns in the road.

Two hours later and 50km further North: the 22 degree halo is just about visible as are the sundogs.

 

[Giddierone]

Since it was described by Bowyer as below the sun I wonder if he was observing some part of a subhorizon arc, parallel to the parhelic arc, given an "eliptical blur" shape by cloud / haze.

The sighting took place when they were flying in an evelope of clear visibility between haze layer below and cloud cover above.

"there was a layer of thin haze below the aircraft at approximately 2000ft" (p.79)
"Cloud overcast at about 8,000 feet." (p.132)
"Visibility was estimated by Capt Bowyer at 100nmi above the haze" (p.86).

Sun “was behind clouds but virtually straight ahead” (p.133)

Object was slightly to the right and “same height as the aircraft” (p.134)

In dismissing the sundog hypothesis the NICAP report (p.60) says:

Two lights near the horizon, almost directly below the sun and just a few degrees apart, are not sundogs.

But could they have been subsun dogs, or some part of the subhorizion arc visible in the haze layer below them? [assuming the subsun itself was obscured by the body of the aircraft]

A rough approximation using Bowyers illustration (p.9) of what he saw and the subhorizon arc diagram overlaid from https://atoptics.co.uk/halo/subhor.htm.

The "dark area"​

“these two objects were both to the same side of the sun“ (p.151)
“The dark areas were darker than the yellow part of the object and lighter than the background (haze/ground). The dark was a “graphite grey” colour. The dark bands oscillated on both objects. “ (p.144)

Could the "dark area" in Bowyers drawing be the intersection between the parhelic arc and halo?

Because of the cloud above they may not have noticed the halo or even the whole complex array of atmospheric effects that Mike Maunders suggested the conditions were right to provide.

Atmospheric phenomenon (sundogs/subsun) are put way down on the list of possibilities (p.111), apparently only because of the description of the objects moving in relation to each other. (but again it's not clear where that description comes from).
However no movemnt is described in the interviews with Bowyer, his passenger Kate Russell or the pilot in the other plane Capt Patterson.

Bowyer says the objects “appeared stationary” and “always appeared stationary” (p.123 & 125, 126).

In his interview he says:
“Only due to the relative position of my aircraft did the second object appear to 'move' left” (p.149)

Capt Patterson says there was “No apparent motion” of the object (p.156)

Yet the report includes this claim:​

"during the course of 6 minutes Capt Bowyer observed the two UAPs steadily cross each other from left to right, horizontally, over an arc of a few degrees.” (p.113)

I can’t find anywhere where bowyer says this on the record, it's not in his TV interviews or the interviews he gave for the NICAP report: that the objects moved in this way, or even moved in relation to one another at all!

Discrepancies in eyewitness accounts.​

Bowyer could see the sea horizon and there was cloud cover above. (but when asked if he could see any ships says “Cannot recall seeing any but it was very hazy below the aircraft” (p.137).

Yet his passenger Kate Russell says “whilst I was watching the second time I could clearly see a little fishing boat on the sea below” (p.150)

Bowyer “The objects were seen against both the sea and the Islands.” (p.145)
“The horizon was visible at all times. The haze layer itself forms a horizon as it disappears off to the horizon! The sea and the haze layer merge at the horizon. At 2000 ft items or objects at or on the top of the haze layer are shrouded by the dirt in the air.“ (p.149)

Yet Capt Patterson says when asked “Was the horizon clearly discernable despite any haze/cloud?

Says, "No" (p.156)

While Bowyer describes the object as "very sharply defined" Patterson describes the object as a just “hazy patch” (p.156)

“At the time of last sighting both objects were visible on the horizon i.e. the haze horizon which coincides with the actual horizon. Both objects disappeared from my view simultaneously at 2000 ft.” (p.149)

This suggests a link between the objects and the haze layer - it seems necessary for the observation - and since the objects were not seen from the ground and didn't apparently move perhaps the atmospheric phenomenon hypothesis deserves another look.

[all quotes and page numbers above are from the NICAP report http://www.nicap.org/reports/070423channel_islands.pdf]