Article 25591 of rec.aviation.ifr: Path: matra.meer.net!news1.best.com!newsxfer3.itd.umich.edu!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!ais.net!newsfeed.concentric.net!news-master!news From: Dave Butler Newsgroups: rec.aviation.misc,rec.aviation.piloting,rec.aviation.ifr Subject: Re: Rainbow on cloud tops Date: Sat, 06 Sep 1997 16:14:44 -0400 Organization: Concentric Internet Services Lines: 27 Message-ID: <3411B9B4.3243@concentric.net> References: <341063EB.609A@sdrc.com> <3410CB2F.2AE172C2@compuserve.com> Reply-To: flypa28@concentric.net NNTP-Posting-Host: ts001d13.ral-nc.concentric.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.0Gold (Win95; U) Xref: matra.meer.net rec.aviation.misc:65645 rec.aviation.piloting:56096 rec.aviation.ifr:25591 Elizabeth A. Wood's excellent book "Science from your Airplane Window" has much to say about the glory, including this: "The center of the glory is the point where a line drawn from the sun through your head meets the cloud. The rays of colored light from the glory circle to your eye form a cone of rays, with your eye at the apex of the cone. All this is also true of the rainbow, but,... the angle of the cone of the rainbow is always the same ..., whereas that of the glory is not. The angle of the glory varies inversely with the size of the droplets causing it... Indeed, you may sometimes see one part of a glory bulge or shrink a bit as a cloud with finer or coarser droplets takes part in its formation." Ed Williams wrote: > > Tom Cleland wrote: > > > > Has anyone ever noticed the rainbow pattern around the shadow of an > > aircraft that appears on cloud tops? I noticed this phenomena on my last > > commercial flight. Any ideas of the physics involved here? Is it just > > the same principle as other rainbows? > > It's called a "glory". It comes from light back-scattered from the > spherical water drops. It's more diffraction than refraction. > > One thing it tells you is that the cloud tops have a lot of liquid > moisture content- icy if it's below freezing.