an almost circular rainbow?

Hi all,

On my way to Tullamore yesterday (19th), I saw something I am not sure was totally possible. I have heard about sun halo's, similar to Moon halo's, but I thought (and have seen) the sun halo was just a precursor to a sun pillar.

At 13:44, the sun was in front of me as I drove, and there was an almost circular rainbow around it. There was no rain, some light high-altitude cloud, and its (sun) elevation (I estimate) was about 35 degrees. It was visible for all my journey, with the window up or down (to eliminate possible slight condensation on my glass adding to the effect).

I know a rainbow can usually occur with the sun at 45 degrees or lower, and I thought with the observer usually between the sun and the seen rainbow. People in aircraft would see the rainbow as a circular phenomenon below them.

So what creates an almost circular rainbow halo round the sun in front of the observer?

Seanie.

hi seanie.

i knew straight away what you said about the halo around the sun.which had a rainbow around it...its to do with ice crystals checkout this site.

ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/opt/ice/halo/22.rxml

it will answer your question. if you havent already found out?

orion.

www.sunshinecoastdaily.com.au/storydispl...thesecondsubsection=

Better get out the umbrellas...

www.sundog.clara.co.uk/atoptics/phenom.htm

goes into all the wierd and wonderful atmospheric pheonomena

Seanie, pity you did'nt have a digital camera with you, I always carry a small one in the car just in case you happen to see something strange!, it happened to me months ago when i saw nearly the same thing, definitely ice crystals, as I awoke to a complete blanket of snow this morning!!!

Keith..

hi seanie.

i knew straight away what you said about the halo around the sun.which had a rainbow around it...its to do with ice crystals checkout this site.

ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/opt/ice/halo/22.rxml

it will answer your question. if you havent already found out?

orion.

Thanks Orion, that hit the spot! I always knew how sun (and moon) halos formed, just didn't realise that you can get a rainbow effect between you and the sun (when is usually behind you and the sun).

Thanks for the links guys.

And Keith, I sometimes do bring the camera with me. One of the few times I was in a bit of a hurry and didn't!

Seanie.