November and December - the best time in year to travel Rovaniemi where the snow machines are in constant run generating the nuclei that helps to form the diamond dust.
6th November '08 - A new halo seen and photographed by Marko Riikonen. A new arc generated quite an excitement and discussion among the halo experts. Later the new halo explained by Walter Tape as the reflected lower sunvex Parry arc.
You can read more about it from ICH site - here and here. A detailed explanation is available on Atmospheric Optics.
7th December '08 - even more new halos by Marko Riikonen! In this time the new subhorizon halos: sub-120° parhelion, sub-Kern and subcircumnadiral arc formed by plate crystals. Also take a look on ICH site where Marko riikonen presenting the anthelion view of this display.