Increase in Circumzenithal Arcs (upside down rainbows)

[Lizziespreparetogovegan]

I've just returned from a 5 rhythms dance class where a couple of the attendees where raving about seeing an upside down rainbow about 10 minutes before the class started. I didn't see it myself but they had pictures on their phones.

Anyway, not sure if there's anything in this as such but it certainly seems that these are VERY rare and are usually only seen in colder climates. Here's an article from SOTT from 2010:

http://www.sott.net/article/213830-UK-Rare-Sighting-of-Inverted-Rainbow-Causes-a-Stir

Excerpt

The phenomenon, which rarely occurs in non-Arctic conditions, is caused by sunlight bending when it hits crystals of ice floating five miles above the Earth

It seems that despite the references of upside rainbows or 'circumzenithal arcs' being extremely rare, this one above Hastings this evening seems to be at least the third in the last month or so in the UK. There's two others here:

_http://www.bbc.co.uk/news/uk-england-wiltshire-27466519/ 17th May

_http://www.theweathernetwork.com/photos/view/beautiful-weather/upside-rainbow/19189304 6th June

I don't really understand the science and behaviour of the levels of the atmosphere but it would seem that this phenomenon is certainly connected with ice crystals at about 20,000 feet and these circumzenithal arcs are on the increase here in England. Perhaps someone with more knowledge could chime and suggest whether this necessarily means an increase in Ice in the upper layer of the atmosphere or something else?

 

[Chad]

I can't comment on the above as such, but just to jump on the back of it since you are talking about England. A friend of mine took the attached photo, today, and called it 'Inverted Sky'. It sounds like the effect could be due to similar conditions, but like you, i don't know. I would also note that Bangor and i think the Isle of Wight had recent incidents of Noctilucent clouds - but they are 'expected' for this time of year so it may not be related.