User Comments
Never seen an upside-down rainbow before!
col3 - 03/Feb/12
Photo must be upside down.
Fiend - 03/Feb/12
Looks like a circumzenithal arc and a supralateral. Very nice catch!
cado - 03/Feb/12
Definitely upside down, saw it with my own eyes! Besides, there are two, one the right way up and the other upside-down. And thanks :)
col3 - 03/Feb/12
Very unusual - well captured!
Paul Evans - 03/Feb/12
Saw the bottom half of a rainbow up the valley from high on Gob on Carnmor.
Geoff Monaghan - 06/Feb/12
Nice picture.
These things are generally caused by refraction through high altitude ice crystals. I did some simulation work to model these things back in the day when I was at uni. Could bore you for hours...
d_b - 08/Feb/12
These things are generally caused by refraction through high altitude ice crystals. I did some simulation work to model these things back in the day when I was at uni. Could bore you for hours...
The upside down one seen from Gob was the actual bottom half of a rainbow, which I had not really ever visualised as being perfect circles in the right circumstances.
Geoff Monaghan - 08/Feb/12
Thanks, that's really cool that it's probably caused by ice crystals. Makes sense as there was a low freezing level that day! I would love to see a whole rainbow circle someday.
col3 - 08/Feb/12
A lot of these crystals are shaped like little pencils, and tend to line up vertically as they fall through the air. That results in 2 bright spots to the left and right of the sun.
You only get the full halo if they are aligned randomly, which tends to happen more with shorter, fatter crystals.
d_b - 10/Feb/12
You only get the full halo if they are aligned randomly, which tends to happen more with shorter, fatter crystals.