The photographer Manolis Thravalos captured a rare meteorological phenomenon called Solar Halo.
In Meteorology, Halo is called the optical phenomenon produced by solar or lunar light interacting with ice crystals suspended in the atmosphere, resulting in a wide variety of colored rings or arcs in the sky.
Therefore there are two kinds of Halo, solar and lunar. Because the basic precondition is the existence of ice crystals, the clouds that can cause this phenomenon stand as high as 6.000 meters and above. Such clouds are called upper or cirrostratus.
The term “Halo” refers to several imperfect phenomena, but the main image of Halo is the one seen as a great circle in a distance (radius) from 22° to 46° from the center of the source (sun or moon). In the first case the circle is white, but when the phenomenon is intense then is red inside with different color shades inwardly (orange, yellow and rarely green). Even more rarely a blue outer halo is observed.
In meteorology “Solar Halo” is symbolized by a circle in which the vertical and the horizontal diameters are shown as a cross, while the “Lunar Halo” is symbolized by an upper semicircle with a horizontal diameter and a vertical radius (i.e. half the symbol of the Solar Halo).
In general, this phenomenon belongs to the so-called “deterioration” situations i.e. when weather deterioration is expected, even though this should not be considered as a safe criterion for weather forecasting, though usually the phenomenon is followed by storms.
However, in the latitudes such as of Greece (about 35°-41°) this phenomenon is rather unusual but not rare, especially during summer and in February.
Such a rare phenomenon was captured by photographer Manolis Thravalos last Saturday in Samos.