Blog Archives
Valley rainbows
When working on a mountain top, one very soon breaks the habit of looking for rainbows only in the sky. Here rainbows can appear at all sun elevations, even when one really does not reckon with them. Last year I could watch rainbows at sun elevations of more than 60° on Mt. Wendelstein. The most beautiful ones appeared when several rain showers passed on May 31, 2010. The maximum sun elevation during this observation was 63.6°.
Later the same day (sun elevation now was “only” 41.8°) i had the rare opportunity to see a part of a rainbow on the left side of the mountain, while at the same time there was a fogbow on the right side, which soon was replaced by a glory. Unfortunately, it was impossible to look from the northeastern part of the mountain at the same time, so I could not see the transition from rainbow to fogbow.
On this day, rainbows appeared 6 times, the last one was a double reddish rainbow over the Inn valley.
Author: Claudia Hinz, Brannenburg, Germany
„Glorydescent Clouds“
In the morning of March 1st, 2010, I made my second observation of „glorydescent clouds“ (here the first). These are fragments of a glory which change very much in diameter due to the different size of the droplets towards the rim of a short-lasting foehn cloud.
This makes the sequence of the colours look asymmetrically.
The stratocumulus lenticularis cloud did not even last for 5 minutes and caused a bright and very changeable iridescence or “glorydescence” during this short period of time. When the colours reached their maximum, up to 4 systems of rings were visible, with the 4th one appearing in the cloud behind the glory.
The pictures were taken at 8.05 CET / 8.06 CET / 8.07 CET.
Author: Claudia Hinz
Shadows and lights of a flight
Many people find flights boring – but not all! If you are lucky to be seated by a window you can always find something interesting in the air beside or below the airplane. David Lukacs from Hungary took this picture on 2nd November 2009 on a flight from Rome to Budapest, about 15 minutes after the departure. A thin layer of haze was between the plane and the sea so the sun shining on the right side above the plane could cast radial shadows on the left below. The beams of shadow and light join at the antisolar point.
A bit later when the plane travelled above a cloud layer David also noticed a nice glory below them:
Even the shadow of the airplane appeared in the middle:
Posted by Noli
Effects in cloud bows caused by perspective
In the morning of December 12, 2008, I coud observe a cloud bow on a stratocumulus layer, which was kind of perspectively cracked. Due to the ruggedness of the cloud surface it seemed as if there was a deep horizontal notch on the left side of the cloud bow.
But also this moonlight cloud bow, taken on September 9, 2008, seems to have vertical indentations and also an elliptical shape caused by the horizontal projection upon an uneven surface.
Günther Können and I have written also an article to this topic.
Author: Claudia Hinz, Brannenburg, Germany
A strange kind of glory
I have often seen glories which appeared to be elliptical (and not circular) or vertically disrupted. This was always caused by the projection onto an uneven cloud cover. But on November 18, 2007, I could observe a “vaulted” glory from Mt Wendelstein (1835m) in the Bavarian Alps. The strange glory appeared in an isolated stratocumulus cloud which adapted to the shape of a mountain. Its colours ended irregularly on its outer fringe like those of a glory around the sun which pass over to cloud iridescence. There is no circular shape recognizable in the colours outside the inner glory rings. The pictures are taken using a polarization filter and the contrast has been increased.
Another observation which might be related to mine, has been made on January 01, 2007 by Stefan Rubach on Mt Großer Arber.
Author: Claudia Hinz, Brannenburg, Germany
Perspectively broken shadow
When there are swelling cloud parts on the surface of an unbroken cloud cover, it sometimes can happen that the shadow of a pole projected onto this cloud cover appears kind of broken. I could observe such a shadow broken perspectively on August 18, 2007, at 18.15 hours CET on the top of Mt. Wendelstein (1835m), when the shadow of the transmitting aerial of the Bavaria Broadcast fell upon such a cloud cover, surrounded by a glory which appeared three-dimensional.
Author: Claudia Hinz, Brannenburg, Germany
Divergent light fogbow
Observed at Tuula (Estonia) on 10th September at 00:30. The fog condition was perfect at the time for the glory””s rings merge into multiple supernumeraries. But the location was perfect as well which is surrounded by forest from east and west side generating the wind tunnel to blow the fog from the bog field in north or from the river in south. As long as I remember this location has been always very foggy and has been often flooded in spring-time. The light source I used was Johnlite-2940, which makes the car””s headlights a joke.
I also observed a very bright and colourful glory and took some close-ups.
at 43mm.
Here still photos with 24mm and 30mm.
Author: Marko Krusel
Tunnel Glory in Italy
Gerald Berthold spent the beginning of October in the South Tyrol, Italy. On 5th October 2006 he climbed the 2778m high Piccolo Lagazuio. The descent leads partly through tunnels dating to the First World War. Where they breakthrough the mountainside they give fantastic views of the Dolomites. On one of these galleries the sun shone along the tunnel through fog which developed because the humidity and lower temperature inside. In this formed a spectre of the Brocken with a spectacular multiple ringed glory (the camera is pointing away from the sunlight direction). The glory seemed almost graspable and was sensationally bright.
Polarized fogbow in car headlights
I spent the past summer at Langmuir Laboratory on the Magdalena Mountains, in southwest-central New Mexico (USA) at an elevation of 3.2 km. The purpose of this was thunderstorm research. The monsoon here was unusually wet and on several days and nights the mountain laboratory was actually foggy. This is relatively rare considering the New Mexico climate. I took this opportunity to view polarized fogbows in my car”s headlights, and on September 2nd, I was particularly successful.
When I programmed a Mie simulation algorithm late last year and plotted a polarized fogbow on my screen, I was surprised that the polarized bow looked as it did, with the typical Brewster”s angle ”gap” in the main bow for parallel polarization. How excited I was to see that the actual fogbow indeed looked like the simulation! I had never seen it before in nature.
I am sure this has been done before by someone else, but I thought I would post the images anyway.
I covered up one of the car”s headlamps as to not have a double bow. I positioned myself about 50 meters in front of the truck, which I had parked on a slight inclination so the bow would be better visible against a featureless sky and be more complete. The fisheye lens was equipped with a polarizer at the place in the lens where the rays go parallel.
The simulation I made earlier, for a 10 micrometer radius droplet. It looks sharper because I assumed a point light source, assumed a monodisperse droplet distribution, and it was not divergent light. It is not a perfect match either considering the placement of the supernumeraries: probably the droplets in the actual display were a bit smaller. Because of the divergent light source, and because I don”t know the distance to the truck accurately, I doubt I will ever be able to accurately tell the actual droplet radii in the display.
The polarized glory was also obvious, but my shadow was blocking most of the part that was most polarized. I am including the unpolarized glory here.
The close-ups of the polarized and unpolarized fogbow were made with a 24mm/2.8 lens. The camera was a Canon 300d (modified version – i.e. with IR filter removed). I did not need to adjust the brightness and contrast much to get the results as displayed here. The fogbow had good contrast by itself.
About 10 days later I documented a natural fogbow in sunlight from the laboratory, through a polarizer. I photographed that with film; I have not processed those photos yet.
[Posted by Harald Edens]
Brocken Spectre in sea fog
On March 24th 2005, Thorsten Gaulke was sailing homeward bound from Oslo to Kiel on a scarcely four month old ship called “Color Fantasy”. The ship entered an area of sea fog no higher than the ship formed by the cooling effect of the cold Baltic waters. With the sun to his back he was able to observe his Brocken Spectre surrounded by a bright glory. There is a trace of a much large glory-like phenomenon that might have resulted from much smaller droplets. Alternatively it could be a fragment of an inner supernumerary of the surrounding fogbow.
