Getting up to grab a glass a water at 3:30am this morning I popped my head out the window to hear the dawn chorus. I’m glad I did, as it gave me my first sight of noctilucent clouds this year. These ‘night-shining’ clouds appear to glow as the rising or setting Sun scatters off tiny ice particles within them.
Noctilucent cloud patterns at dawn. Credit: WillGater.com
They are found much higher in the atmosphere than ‘normal’ clouds, typically around 80km or so. You can often see them in the summer months about an hour after sunset and before sunrise. They shine whiteish blue and don’t appear silhouetted against the bright dawn or twilight sky like lower clouds tend to be (some high cirrus clouds can often look similar to them though). Sometimes they show beautifully intricate glowing patterns and other times simple swirls.
Type II NLCs towards the bottom of the image. Credit: WillGater.com
To find out more about NLCs there is some excellent information on Les Cowley’s great site and more on the different forms of NLC here. I’ve put two pictures I captured of this morning’s impressive display in the post above. So if you are up early or are enjoying a twilight walk, keep an eye out for these impressive and ethereal clouds.