Noctilucent cloud season for the northern hemisphere kicked off in the first week of June. But poor weather and travelling meant that I only saw my first display of the year last night.
Here are a few pictures taken from Amble and Warkworth.
Noctilucent clouds (NLCs) might have a passing similarity to cirrus clouds but they are very different. They form about fifty miles above the ground in the mesosphere and are seeded by meteor smoke. I've written in more detail about them previously. The display last night was terrific and was still going when I got to bed at 1.30am.
It's empty. For the last few months the image has shown noctilucent cloud coverage over the poles. NLCs form in the summer months when, as strange as it sounds, the mesosphere is cold enough to allow it.
I saw these noctilucent clouds on lots of evenings over the past few months (and in most summers that I can recall). Some of the pictures I took can be found here, here and here.
I made a movie of all the daily daisies during this NLC season and assembled a short movie.
The data was assembled from the website of the AIM-CIPS instrument. You can see that the coverage increases from nothing in May, to a maximum in early July and then decreasing to nothing again in August.
As we approach the end of the summer the mesosphere begins to warm again the clouds disappear. No more NLCs until the next season begins sometime near the end of May 2014.
It's noctilucent cloud season again. In the northern hemisphere this lasts from roughly the end of May until the start of August each year.
Astronomers and clouds don’t generally get on. However, during summer in the northern hemisphere some mysterious and beautiful clouds may appear in the sky long after sunset. Known to astronomers as noctilucent clouds (NLC), these delicate and tenuous clouds are seen shining long after the ordinary clouds of the troposphere have darkened. NLC are the highest clouds in the atmosphere and form within the mesosphere at heights of 85km (about 52 miles) above the ground (which means you’ll hear scientists referring to them as Polar Mesospheric Clouds).
I was outside watching the planets and then much later for any sign of the aurora. I didn't see the northern lights but I did see some noctilucent clouds.
I took this picture near my home in Red Row overlooking the cemetary at about midnight last night. It wasn't the brightest display and the camera certainly captures the colour and structure more easily than the eye. But it's sign that NLC season, which lasts from about now until early august, has arrived again.
Dr Adrian Jannetta
Guitar strummin' explorer of the universe. Mild mannered maths teacher by day and astronomer by night.