Optical and atmospheric phenomena

The strong Foehn winds today have been able to generate perturbations in the atmosphere that brought some moisture in the stratosphere. The result is this amazing view after sunset with tiny ice crystals reflecting and breaking down light from the sun. The city below the clouds with the 2 towers is La Morra, Italy.

Clouds do not normally form in the stratosphere.
Cirrus clouds, the highest 'standard' clouds, form around 12 km above the sea level. Measuring the height of the cloud (12° above the horizon) and using the height of the sun at the time the cloud was not lightened by the sun anymore (-6° at my location) I estimated the height of the cloud to be about 20-25 km above the sea level and 100 km away from me (near Colle di Tenda). This, in addition to the morphology of the clouds itself, seems to confirm that these are not the more common iridescent cirrus clouds.

Even the solar disk can be warped by mirages! When at sunset or sunrise there are conditions for the occurrence of inferior mirages, the solar disk can appear with a characteristic Omega (Ω) shape. The pedestal is due to the reflection of the bottom part of the solar disk in the low atmosphere. In the first image a distant bird passes in front of the solar disk, while in the second image the time evolution of the phenomenon is visible.

After sunsets and before sunrises is possible to see, in good atmospheric conditions, what is called the Belt of Venus: this phenomenon is visible above the antisolar point and it's formed by backscattered reddened sunlight. The light is reflected by atmospheric particles. In this shot is easily noticeable the curvature of the belt.Under the Belt of Venus there is a darker band: this is the shadow of the earth projected into the sky. This is the zone where direct sunlight is not yet arrived (at sunrise) or is already gone away (at sunset). I took this photos the morning of the Lunar eclipse, near Pisa (Italy) some minutes after moonset. So, in the same morning I saw two different reddening effects of our atmosphere in the sky!!

The green flash is a optical phenomenon visible on the sun (and other solar system bodies) when they are near the horizon. In some favorable conditions, due to atmospheric dispersion, it is possible to admire the last part of the setting sun of an intense green color before it disappear. After looking for him without success a couple of times in the previous months, I finally managed to catch this phenomenon in this picture. It is truly a wonderful phenomenon and I hope to be able to return to resuming it soon, now with some more awareness. A special thanks for this shot goes to Marco Meniero that let me know this phenomenon, through his book "Luci e colori del cielo".

The "mock mirage" is a complex system of mirages that form when there are several layers of thermal inversion above the horizon. In these conditions, the visible elements on the horizon may appear strongly distorted and various images of the same object may appear. In this picture the sun a few minutes before sunset appears very elongated and distorted due to this effect.

In this photo, an inferior mirage is visible on the island of Gorgona from Marina di Pisa, during the settlement of an anticyclone on Italy. You can also notice the mirage on the sailboat next to the isle.

Lunar halo of 22° caused by moonlight. The colors were invisible to the naked eye but easy to view in photos

This is a photo taken with a longer focal length to see the nuances of the nightlife clouds above the town of Roddi. The complexity of the structure of these clouds is typical.

After the tasting at the the summer solstice, on 5 July the noctilucent clouds reappeared. This time they were in all their magnificence.This is a wide field picture one hour and ten minutes after sunset. Above the clouds, the constellation of Cassiopea is visible despite Caph it was cut off from the photo

An hour and a quarter after sunset, strange blue clouds appeared in the north-west sky. A pinch of trigonometry confirms that these are not cirrus but the rarer (especially in our latitudes) noctilucent clouds. You can observe the typical complex structure of these clouds. Further down dark clouds are visible because they are no longer illuminated by sunlight. The noctilucent clouds are thin clouds which origin is still uncertain.They form in the Mesosphere between 75 and 85 km of altitude (much higher than the classic clouds which reach about 12km in height from the ground). They are visible in the summer months in latitudes between 50° and 70°.

A sun halo among cirrus clouds, which aren't uniformly modeled by the wind.

A small but intense supercell stands out on the Langhe's landscape. The aquamarine color visible in the clouds is a symptom of hail.

The vertical trails of the intense rain formed under a cumulonimbus during a summer storm.

A strange black line in heaven seems to converge towards the Library of Riga (Latvia). The black line is the shadow projected on the atmosphere below of contrails formed by a plane. Normally this shadow is not visible because the atmosphere absorbs little light and the difference in brightness is not visible. However, if the observer finds himself in certain positions, the layers of air in the shade are aligned and the darker area becomes visible

Although weak, this sun halo at dawn has interesting details: you can see the two sun dog, a weak upper tangent arc and a very weak sun pillar. Everything sit above the hilly hazed landscape of the Langhe in winter

Just as the train tracks seem to converge, thus alternating areas of shadow and light produced by a cloud in front of the sun, seem to converge in the opposite direction to the sun. In fact, this picture is taken towards East while the sun was setting (so it was near West)

A pillar of light above the sun caused by the reflection of sunlight by ice particles suspended in the high clouds

This phenomenon is similar to the sun halo with the sun dogs, but in this case is rarer because formed by moonlight

Even without any halo, this is a photo of a single sun dog caused by a cirrus which was in the right place at the right time.

Just as the train tracks seem to converge, thus alternating areas of shadow and light produced by a cloud in front of the sun, seem to converge in the opposite direction to the sun. In fact, this picture is taken towards East while the sun was setting (so it was near West)

It seems that I was on the last flight before the retirement of the pilot. So, he did not want to risk landing at an airport immersed in the fog. In this way, the plane first dropped and then raised. During these strange maneuvers we could see our shadow on the fog surrounded by a beautiful glory.

Solar halo and circumscribed halo. Due to the height of the sun above the horizon, the upper and lower tangent arc close in a ring that circumscribes the main halo