This is the personal blog of greenygrey

I took the swans and sunset on the Aire photos at Kirkstall Abbey, and was also treated to a wonderful light show after sunset. There were clouds on the horizon above the sunset, and then more above that after a clear gap, creating a kind of dome or arch effect.

Then the sky under the higher cloud turned translucent sea-green, turquoise, sky-blue and pink. After it faded away, the sky started to redden, and there was a conventional sunset which filled half the sky.

I think I saw the translucent colours before, but was half asleep on a train, and wasn't sure if I was seeing things. This second time suggested it was happening, so I asked on Yahoo answers, and got a couple of ideas:

1. It might have been Noctilucent clouds. They are the highest clouds in the Earth's atmosphere, located in the mesosphere at altitudes of around 76 to 85 kilometers (47 to 53 mi). They are normally too faint to be seen, and are visible only when illuminated by sunlight from below the horizon while the lower layers of the atmosphere are in the Earth's shadow.

2. Diffraction. This is similar to the effect light has when passed through a prism. The light is split into it's constituent components (wavelengths), and depending on your viewing angle, you will see different colors.

Have any of you seen this, or know what it is. Cheers.