Circumscribed Halo

Earlier in the day extensive cirrus passed through but around local noon much thinner patchy cirrus appeared. The halo formed by this was more irregular but showed more colour.

This was probably caused by the tangent arc components rather than the normal 22 degree halo seen earlier in the day.

Solar altitude was 61 degrees.

For brief periods the lower part of the halo was quite bright and showed distinct colour.

(The prismatic colours halfway between the sun and the arc are caused by an internal lens reflection.)



At bottom right part of a weak circumhorizon arc can be seen


Canon EOS 20D   4th June 2006
Wiltshire, England

Other Halo Topics