Anybody else see this on Monday or know what caused the red, green blue in the clouds..many people were taking photos.Would love to know what it was...obviously not Northern Lights...seen from Warorot Market.

Atmospheric optics. That is, light absorption and reflection variations.

Some explanation here - http://optics.kulgun.net/Cloud-Colour/

http://optics.kulgun.net/GreenClouds/green_clouds.shtml

Here is an extreme version for the conspiracists.

I saw very similar on Tuesday at around 5.30am, also from Wororot market area. Before sunrise, just as the sky starts to turn yellowy purple-ish on the bottom of the horizon. I was quite transfixed by it and gazed, in my own little world, for about 30 minutes, until the sun was actually visible and hurting my eyes.

An amazing sight. Didn't mention it to anyone as they probably would have thought 'Crazy woman', but it's something I'd never noticed before. I'm going to look for it in future when I'm able to see the sun rising. I'll follow up with a post after the weekend either saying same again or nothing happening.

I took the following two pictures of a rainbow from the Maya shopping mall, but on Tuesday. It's probably the same phenomena at work.

Post #2 answered it.

Post #2 answered it.

Yup - ice crystals in the clouds. They also cause the 'double rainbow' effect and rarely, a 'moonbow', when light from a full moon shines through ice crystals.

Cumulonimbus calvus are the towering cotton-wool-like clouds such as we've seen most of the past week. They contain enormous amounts of water [vapour] and eventually become rain-bearing thunderstorms. Depending on altitude reached, the tops may change into ice crystals giving a blurred effect, thus turning into cumulonimbus incas [from memory] which reflect colour much like a rainbow.

re

Yup - ice crystals in the clouds. They also cause the 'double rainbow' effect

like this double one over the meridien last year ?

dave2

I no longer feel compelled to take pictures of cloud iridescence but I do take a moment to enjoy the colors, like I did while walking the dog yesterday. Here are a couple of old photos I took in the Chiang Rai area.

Cumulonimbus calvus are the towering cotton-wool-like clouds such as we've seen most of the past week. They contain enormous amounts of water [vapour] and eventually become rain-bearing thunderstorms. Depending on altitude reached, the tops may change into ice crystals giving a blurred effect, thus turning into cumulonimbus incas [from memory] which reflect colour much like a rainbow.

That's very impressive kaptainrob; I have a commercial pilot/instrument rating and had never heard of either one of those cloud sub-types before! I guess from your nic you are a professional.

I've taken gliders up inside the base of cumulus clouds several times and encountered snowflakes there once even though it was 40C on the ground below.

Whatever their names the clouds certainly have been spectacular recently. Typically November is the peak month for beautiful sunsets in Pai.

Awesome pics VF

http://en.wikipedia.org/wiki/Noctilucent_cloud

I saw sun dogs a few times over the years here. They are really amazing.

^^^ Can't see the phenomena in either of them 2 photographs they would be better served in the photography and the arts subforum, sunsets thread.

I also saw some Iridescent clouds a couple years ago just south of Doi Suthep. I only had a phone camera with me at the time so no great shots.