Sundogs big ones or little ones?

Question

what is a sundog and can a sundog tell the weather or feature weather

Answer 1

Sundogs are similar to rainbows in being a optical arc, but usually in pairs on either side of the sun The inner part of the arc is red. They are formed by light passing through ice crystals, thus in cold weather with moisture in the air.


Sundogs (parhelia, mock suns) are, with the 22º halo, the most frequent of the halos. Look for them, especially when the sun is low, at each side and about 22° away. This is the same distance or more** than the common circular halo.

Sundogs reveal that the clouds are hosting horizontal plate crystals. These plates drift slowly downwards like leaves with their large faces almost horizontal.

Sundogs are formed when light passes through crystal side faces inclined at 60° to each other. The rays, like those of the 22° halo, are deviated by up to 50° but those near to the minimum deviation condition of near** to 22° are the most numerous and they form the very bright sundog inner edges. Sundogs are often brightly coloured because the crystals refract each colour by a different amount.