Such holes are formed when the water temperature in the clouds is below freezing but the water has not frozen yet due to the lack of ice nucleation particles (see supercooled water). When ice crystals do form it will set off a domino effect, due to the Bergeron process, causing the water droplets around the crystals to evaporate: this leaves a large, often circular, hole in the cloud.
It is believed that the introduction of large numbers of tiny ice crystals into the cloud layer sets off this domino effect of evaporation which creates the hole. The ice crystals can be formed by passing aircraft which often have a large reduction in pressure behind the wing- or propellor-tips. This cools the air very quickly, and can produce a ribbon of ice crystals trailing in the aircraft's wake. These ice crystals find themselves surrounded by droplets, grow quickly by the Begeron process, causing the droplets to evaporate and creating a hole with brush-like streaks of ice crystals below it.
Originally posted by Putyournamehere
I don't see a second sun or anything really unusual, just a nice picture.
Originally posted by Grimmley
FTR I am claiming Nibiru or anything like that, but it looked cool and daftly strange and figured I would share them with you all.
Originally posted by SeenAlot
I don't ever remember having seen these before until the last few months, or so. Someone on another thread claims these are HAARP related.
Then, on the same thread someone wrote that it is warm air above the cool air. The warm air "rains" onto the cool clouds creating the hole. While an interesting theory, one would think they'd be more prevalent, more common.
It is a stunning site. For me, they are mesmerizing. Circular holes in clouds aren't something I grew up with.
Sundogs are made commonly of plate-shaped hexagonal ice crystals in high and cold cirrus clouds or, during very cold weather, by ice crystals called diamond dust drifting in the air at low levels. These crystals act as prisms, bending the light rays passing through them with a minimum deflection of 22°. If the crystals are randomly oriented, a complete ring around the sun is seen — a halo. But often, as the crystals sink through the air they become vertically aligned, so sunlight is refracted horizontally — in this case, sundogs are seen.