On 10 January 2009, Jan Smejkal observed a complex display in Prichovice, in which some rarer halo forms – such as the anthelion brightened by crossing Tricker arcs – were in action, too. The more frequent halo arcs included suncave and sunvex Parrys, Wegener, a faint helic, upper Tape arcs and subhelic arc ( 1 – 2 – 3 – 4 – 5 – 6 – 7 ). The photos also show a weak Liljequist parhelion ( 8 ).
Jan Smejkal described the weather during the complex halo in the following way: “On 10 January 2009, Prichovice was slightly above inversion, and time to time some very thin clouds crossed the sun. The display was observed at different intesities from around 9:00 until 11:30UTC when the sun got covered by clouds.”
More information on the Czech diamond dust displays can be found in some articles at the following site: ( 9 ).
Text: Martin Popek and Matej Grek