Re: A Strange Rainbow

Dear Jackie, Rather more common are mock suns, or sun-dogs, which are either side of the sun. Some dramatic examples are in: https://en.wikipedia.org/wiki/Sun_dogs They are at 22º either side of the sun, and if you know when and where to look, and in t

Re: A Strange Rainbow

Would this be the same as a 'Sun Dog'? On 2016-08-17 10:36, Dave Bell wrote: Typically, this would indicate ice crystals in the upper atmosphere. A normal rainbow is formed by water droplets with two internal reflections, so the rainbow's light is projected back towards the sun. In this case,

Re: A Strange Rainbow

ards, John-- Dr J Davis Flowton Dials http://www.flowton-dials.co.uk/ BSS Editor http://sundialsoc.org.uk/publications/the-bss-bulletin/ From: Jackie Jones To: sundial@uni-koeln.de Sent: Wednesday, 17 August 2016, 15:24 Subject: A Strange Rainbow Dear Sundial  fol

Re: A Strange Rainbow

It’s called a circumzenithal arc. Unlike a normal rainbow, which is caused by total internal refraction within a (or, rather, millions of) water droplets, circumzenithal arcs are caused by light scattering in ice crystals in the upper atmosphere. They are generally only visible on very clear da

Re: A Strange Rainbow

Typically, this would indicate ice crystals in the upper atmosphere. A normal rainbow is formed by water droplets with two internal reflections, so the rainbow's light is projected back towards the sun. In this case, the light is passed forward through the crystals, at an angle determined by the