Category Archives: air mirages
In clear air, the Alps are visible from Munich. In the morning of October 18, 2012, Frank Sievers observed this superior mirage of the Alps from the roof of a house behind the Perlach heat and power station. It was probably caused by layers of air of different temperature generated by the power station, which refract the light at different angles to the observer´s eye.
At sunrise during the transit of Venus on June 6, 2012, there were not only distortions of Sun and Venus visible as well as the Green Flash, but there were also several observations of the so called Etruscan Vase.
As weather forecasts for Germany´s sunniest island, Fehmarn in the Baltic Sea, were most favorable for that day, Jens Hackmann flew there from the bad weather of his home town Bad Mergentheim. Just after sunrise at 4.41 hours, he observed the mirage effects mentioned above not only on Sun and Venus, but also on a passing ship. And only a few moments later the Etruscan Vase phenomenon appeared, an upside-down mirage of the sun which appears in most cases above a water surface (more pics and film).
Thomas Stemmler photographed the transit of Venus at beach on the Baltic Sea near Dahme and could shot mirage effects and the phenomena of Etruscian vase also.
This strange effect is caused by the refraction of sunlight together with a lower mirage and appears when a layer of cold air is positioned over a warm water surface. The lowermost air layer, which is heated up by the warm water, has a lower refraction index than the air at the level of the eyes of the observer. Sunrays hitting this layer in a very sharp angle can be reflected totally. So the observer does not only see light coming directly from the sun, but also light that had been reflected by the warmer and less dense layer of air directly above the water. The rays coming directly from the sun let the sun appear totally normal. But as our brains are not programmed for totally reflected sunrays, they extrapolate them lineally. This makes us see an upside-down reflection of the sun beneath the real sun which changes due to the angle of incidence of the light and thus with the sun elevation.
This phenomenon reminded the science-fiction-author Jules Verne of a paunchy Etruscan Vase standing on a pedestal, so he coined this term for the phenomenon.
On June 06, 2012, the rare constellation of the planet Venus crossing through the solar disk could be observed from the day side of the earth.
When in Germany the sun rose, the Venus transit was already in its final stage. Where the sun passed through differently dense air layers during its rise, the mirage phenomenon was visible, i.e. the sun as well as Venus appeared distorted or as a combination of multiple images. These effects are due to the different bending of the light waves at air layers of varying density. Moreover, an incident ray of light will be reflected at the interface between cool and warm air. When there are more than one of these interfaces, multiple reflection might occur.
Rico Hickmann could even observe the Green Flash during the Venus transit from Dresden: “I was incredible lucky with respect to the weather. Yesterday evening, it was still very cloudy, and after the end of the transit there were again clouds filling the sky. Before sunrise, a light pillar could be seen, that served as a pointer towards the sun. The sunrise over Dresden was spectacular, Green Flashes and disconnected segments… I’m still speechless.” Here are some more incredible pictures from this series: 1-2-3-4-5
Another spectacular image of a triple Venus was obtained by Frank Killich, who observed the Venus transit from the Wolfswarte in the Harz mountains (916 m / 0 °C). The image is a single frame from a HD video file.
Some more and equivalently wonderful observations were reported. Alexander Haussmann made a Video showing a triple Venus, green segments and distorted Venus passing through different air layers that were responsible for the green segments some seconds before. Further examples of impressive green flashes are the pictures of Andreas Möller, taken in Zinnowitz (photo and and animation as gif or MP4 [better quality]) and Hermann Koberger from Fornach, Austria (1-2-3).
On June 26, 2011, Laslo Segi could photographically record this nice moment. “It looked like a second sun rising from the sea, although the sun was just setting.”(1)
“Some time later I learned that it was a lower mirage, that means that the sky is reflected upwards by a thin layer of warm air above the ground.”
This is caused by air layers of different temperature. At the boundary surface, light is totally reflected causing these phenomena. This phenomenon, however, is called “Omega-sun”, because the shape of the sun is similar to the Greek letter omega.
Photo taken on 26.06.2011 in Croatia/Fazana
Author: Laslo Segi / Michael Großmann, Kämpfelbach, Germany
In December 2006, some very prominent inversions formed in Germany. On two days mirages were observed along these inversion layers.
In the morning of December 15, 2006, Rüdiger Manig could see the miraged Fichtelgebirge from the weather station at Neuhaus am Rennweg in Thuringia, which was situated directly above a sea of clouds when he made his observation. The distance between the Fichtelgebirge and Neuhaus am Rennweg is about 70 km. The photograph shows Mt Schneeberg (1053 m) on the left and Mt Ochsenkopf (1023 m) on the right.
On December 23, 2006, Stephan Rubach saw the Alps main ridge in a distance of more than a hundred km from Mt Grosser Arber (1456 m) in the Bavarian Forest. Also he stood above a sea of clouds when making his observation, and the layers of air of differnent temperatures let the peaks of the Alps grow upwards in an abstractly distorted way.
The image was taken by Timo Kuhmonen at last weekend, on Saturday 10th February 2007. Place is near to Helsinki / Finland (Lauttasaari).
Timo was outside on that day hiking and taking some winter weekend photos. He had seen the mirage above frozen sea, distant island was “floating” on the air.
Temperature on that morning at his house in Espoo was -20°C. At the place where photo was taken, temperature was higher. Propably there has been enough of temperature differences in the air layers to produce this “winter mirage”.
October 13th 2006 was a sunny and very warm autumn day, which we wanted to spend on a hike at the Königssee. However, we did not get very far because the scene over the very cold, deeply shielded mountain lake was entrancing. Ships flew over the water, islands floated in the air and aliens over the lake were hunted. It was really fascinating to pursue the fast changing mirages.
Author: Claudia Hinz, Brannenburg, Germany
On June 11, 2006, Thorsten Falke and his girlfriend Bärbel Wichmann decided to have a picnic at the south-beach of Düne, a one square kilometer little island in the North Sea and in the neighbourhood of Helgoland.
Even though the picnic basket contained several tasty titbits the sky was even more tempting with its unusual mirages. Ships passing Heligoland and Düne at a distance of 10 km or more appeared somehow “stretched”. They looked longer than they really were.
Thorsten and Bärbel are still wondering how this effect come about. The sun was shining the whole day and because there was almost no wind, a warm air layer probably lay above the water surface. They suggest that when a ship is on a course of 45° (for example) towards or away from the observer, the bow of the ship is closer/further to the observer than the stern. This, combined with the warm air layer, may cause the unusual extension/or sometimes shortening of the ship.
The two images are 15s apart. More mirage images here.
[Text: Thorsten Falke & Bärbel Wichmann]