> i've seen sundogs in nice summer weather. a pair of them only, though. it's > conditions up in the stratosphere that matter. > > Herb...
True. The best season for all halo phenomena here in Finland is springtime (around April). It's the temperature and humidity in the lower atmosphere (troposphere) which matters (at the level of about 6-10km, where the halos normally originate in the ice crystals usually found in the Cirrus clouds). I would not use the word stratosphere here (too high altitude). During the really cold ground level temperatures you will get really intense halos sometimes when the conditions are right (then the ice crystals will be all around you at "ground level"). Then you can even catch the ice crystals and make pictures or 3d footprint models of them, thus identifying which crystal form make which type of halo phenomena. Best conditions for this kind of research can be found on the Antarctica (and a couple of guys I know have been there just because of this). Antti-Pekka ________________________________________ Antti-Pekka Virjonen Estera Oy Turku www.estera.fi www.computec.fi
