Sun dog

This photo shows both a parhelion commonly known as a mock sun or sun dog at the left hand side of the sun and a partial 22° halo on top of the sun formed out of the reflection from cirriform ice crystals. A mock sun is defined by the WMO as bright, coloured spots (parhelia) that appear to the right and left of the Sun, and at the same elevation above the horizon. In this case, the cirrus cloud was too thick on the right to produce the right counterpart. It is noticed that such halo phenomena could only occur when the sun is low on the horizon such as nearing sunrise or sunset and a full solar halo occurs when the sun is higher on the sky such as the solar halo on the second thumbnail taken some days later on the 9th. The first thumbnail is a close-up view of the parhelia near to the church showing rainbow-like colours. The third thumbnail is the weather sounding showing very high clouds whose temperature was particularly cold at below -30°C enabling such halo phenomena similar to what is seen in the polar regions of the Earth at much lower levels. This cloud formation followed the retreat of an unseasonable polar outbreak over the Central Mediterranean. This meant that the air may have been particularly clean for this phenomena to be observed at ground level. This high-cloud mass was visible through the satellite imagery.

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