Blog Archives

Shadows in sunward direction

Every day one can see shadows pointing away from the sun, but in rare cases there are also shadows visible in sunward direction. These shadows are projected against the sky. Seeing those spooky phenomena requires a low sun elevation, a high object which seems to tower above the sun, and a transparent “screen” of fog between the observer and the object. In the morning of September 11, 2013, Ulf Köhler observed such a phenomenon on the Hoher Peißenberg (998m). The shadow of the dome of the Mariä Himmelfahrt Pilgrimage Church appeared in passing wafts of mist. When Ulf Köhler changed his position within the shadow of the steeple, the shadow of the dome also changed its appearance. (12).

Another article on this topic: “Düsseldorf Leaning Tower and other Shadow Plays”

Advertisements

Double Contrail Shadows

Condensation trails are a common feature in the sky. But those which Richard Henkes saw on June 13, 2013, in Rheinstetten, are really unusual. A number of parallel contrails do not only cast their shadows onto the screen of high cirrus clouds, but also onto a narrow bank of stratocumulus clouds (12). Due to the different altitude of the two cloud layers, the angle of vision is different for each of the layers. This is why the shadows do not appear parallel to the contrails. Also their shadows in the atmosphere appear under a different angle as these are cast downwards. So they “stand” in the air, and their angle corresponds to the sun elevation at the moment the photo was taken. The shadows on the low clouds, however, are flat or only a little tilted according to the shape of the clouds. Both shadows, the one in the atmosphere as well as the one on the clouds, are seen laterally, which makes a sharp bend appear. And not all contrails and shadows are parallel because the airplanes which caused the contrails did not all fly parallely.

Authors: Peter Krämer und Claudia Hinz

Dark ring around the sun

“On the afternoon of 16th November I noticed a dark ring around the sun outside of an aureole. However, the effect could be catched better with the naked eye than the photographs assume.” (2)

“I took some picture in close succession, but none of them shows the ring. Conspicuously, the ring was distinguished by high regularity and evenness. Subsequent enhancing of the contrast let the dark ring become visible clearly on these pictures.”

Quite often, you can spot clouds moving in front of the sun. With a little luck and a cloud layer, that isn’t too thick, beautiful halation and aureoles can be seen at these conditions.

Since a cloud act as an obstacle, it causes a shadow. Apriori, this shadow is invisible to the observer. But if the shadow is projected onto a lower layer of haze, the shadow gets visible in the haze.

Hence, the example above generates a dark ring around the sun, induced by altocumulus cloud shadows on the hazes below.

Time : 16 November 2011
DSLR Camera : Nikon D 3100
Exposure : 1/500 sec, f/22#18mm, F/11, ISO 100

Author: Alec Jones, Bolton/Lancashire, United Kingdom; Michael Großmann, Kämpfelbach, Germany

Alpenglow and Crepuscular Rays from above

In the morning of November 11, 2010, Anke Morbitzer from Gladbeck, Germany could enjoy the alpenglow from above during a flight from Milan over the Bern and Pennine Alps. Especially impressive were the shadows of the mountains being projected upward into the haze. Just before, also the upcoming twilight with its impressive colours had been very exciting.

Duplicated cloud shadow

Sometimes it may happen that there are several cirrus layers above a building thunderstorm cloud. Only when the cumulus cloud has grown to a high level breaking through these cirrus layers, its top casts a shadow upon the cirrus layer.

If there are several cirrus layers, this multiple projection is caused by the perspective effect.

Also this photograph is rather old, it is still very impressive.

Camera: Nikon D40x; focus lenght: 55mm; exposure-time: 1/500 sec.; aperture: F/11; Date: 05.09.2009

Author: Michael Großmann, Kämpfelbach, Germany

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

Thunderstorm shadows

In the evening of June 29, 2009, several thunderstorms formed unexpectedly over northwestern Germany, from the Ruhr area northward to southern Lower Saxony. They brought rainfalls up to 30 liters per square meter.

As the sun was almost setting, the shadows of the storm clouds reached a length of several hundred kilometers. The satellite picture taken at 19.15 UTC = 21.15 CEST shows the shadows extending even up to Thuringia and northern Bavaria.

Unfortunately, there are no reports on crepuscular rays from the area southeast of the thunderstorms.

Author: Peter Krämer, Bochum, Germany
Satellite image with kind permission of DWD (German Weather Office)

Shadows casting shadows

In the late afternoon of February 10, 2008, my friend and I went to a little pond on a field in Bochum, Germany, to take a few landscape photographs. It was a sunny day with a cloudless sky and no wind, so that the sun could be reflected very well from the smooth surface of the pond.

When we went along the pond, our shadows fell upon the water. As the sun was very low – it was about one hour before sunset – our shadows extended over the whole width of the pond, with the heads just beneath a bush positioned on the other side of the pond. Suddenly I noticed two fainter shadows just above the heads of our shadows, moving over the bush. When we stopped, these additional shadows appeared only as two faint stripes extending upwards across the bush from the heads of our shadows, as it can be seen in the wide-angle picture.

But when we moved, the phenomenon became quite obvious. So I did not only take a few photographs, but also made a short video with my digital camera. The video can be watched here.

What caused these additional shadows? First I thought that they were just the reflections of our shadows on the water, but when I later thought about my observation, I realized that it was a little bit more complicated:
The sun was shining on the water, and the sunlight was reflected from the smooth water surface. From the other side of the pond there could be seen a reflected picture of the sun in the water. This picture – or, better said – the reflected sunlight fell upon the bush, together of course with the direct sunlight. So the bush received direct light from the sun and also reflected light from the water surface.

When our shadows fell upon the water, the shadowed parts of the water could not reflect any more sunlight, so that the areas above the shadows received only the direct sunlight. So the parts of the bush which did not get the additional reflected light appeared less bright than the rest of it forming two slightly darker stripes extending upward from our shadows. So, what we saw were two secondary shadows, the shadows of our shadows. For a visual explanation of the phenomenon, I also drew a skech of the situation.

Never before I had thought that a shadow could also cast a shadow, and this observation was only possible because it was absolutely calm that afternoon. The slightest wind would have caused ripples on the water and thus blurred those secondary shadows.

Author: Peter Krämer, Bochum, Germany

Shadow Rays above Pithead Rig

In the morning of December 21, 2007, a beam of shadow rays appeared above the pithead rig of the German Minery Museum in Bochum, Germany.

The picture was taken at about 10 a.m., one hour after sunrise. As the sun elevation was still very low, the shadow of the pithead rig was projected upwards and became visible as a beam of shadow rays in a thin layer of mist near the ground. A similar phenomenon can sometimes be seen above a pylon or tower, but there only one single dark ray appears. The shape of the pithead rig, however, made a beam of four shadow rays appear.

Author: Peter Krämer, Bochum, Germany

Fog shadow of TV tower in San Francisco

These fascinating shadows look odd since humans are not used to seeing shadows in three dimensions. The thin fog was just dense enough to be illuminated by the light that passed through the gaps in a structure or in a tree. As a result, the path of an object shadow through the “fog” appears darkened. In a sense, these shadow lanes are similar to crepuscular rays, which are caused by cloud shadows, but here, they’re caused by an object shadows.

Author: Mila Zinkova