Les Cowley wrote: > > When cirrus clouds weaken sundial shadows it is well worth looking > sunward. Atmospheric halos, formed by refraction > and reflection of light through cloud ice crystals, are surprisingly > frequent. They are beautiful and tell us a great deal about > cloud crystals. The familiar circular halo around the sun or > moon is an example - the rarer forms that often span the sky > are well worth looking for.
In Brazil old farmers will always tell you that when there is a halo close to the moon, that means it will not rain any time soon; when the halo is far from the moon, that means it is about to rain. I've never had the time or opportunity to check this popular belief. I wonder if there is some similar believes in other countries. - fernando > We have a new Windows program that simulates halos. It can be > freely downloaded from > http://dspace.dial.pipex.com/lc/halo/halosim.htm > The site describes halos, has photographs and example > simulations. There's a puzzle for the halonically challenged. > > Les Cowley > Michael Schroeder
