Composite of two images. Only the one inner reddish ring is seen.
Tags: Corona red ring bishops ring solar corona
Common 22 degree halo, circumscribed halo both with colour and the faint parhelic circle is white, being formed by reflection from vertical end faces of hexagonal crystals falling horizontally. The usual display of a circumscribed halo (once or twice a year in the Bangkok area) occurs around noon and the circumscribed halo is circular with a 22 degree radius and overlaps the inner circular halo in this image. This event began at 9.00 am. and was more interesting with the circular halo and the circumscribed halo well separated because the sun was at a lower angle (around 50 degrees above the horizon). The inner circular halo is due to small randomly oriented hexagonal ice crystals and the outer circumscribed halo is formed by refractions in longer (pencil shaped) hexagonal crystals that naturally fall horizontally.
Common 22 degree halo, circumscribed halo both with colour and the faint parhelic circle is white, being formed by reflection from vertical end faces of hexagonal crystals falling horizontally. The usual display of a circumscribed halo (once or twice a year in the Bangkok area) occurs around noon and the circumscribed halo is circular with a 22 degree radius and overlaps the inner circular halo in this image. This event began at 9.00 am. and was more interesting with the circular halo and the circumscribed halo well separated because the sun was at a lower angle (around 50 degrees above the horizon). The inner circular halo is due to small randomly oriented hexagonal ice crystals and the outer circumscribed halo is formed by refractions in longer (pencil shaped) hexagonal crystals that naturally fall horizontally.
A thin uniform layer of ice cloud has produced the outer halo: a combination of a common 22 degree halo and a circumscribed halo due to hexagonal ice crystals, with an inner 9 degree halo due to rare pyramid shaped crystals.
Tags: nine degree halo 9 degree halo circumscribed halo cirrostratus cloud