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Registered Member #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
'Night-shining' clouds visible in UK skies for rest of the week
By NIALL FIRTH Daily Mail 20th July 2010
Rare 'night-shining' clouds will be visible in night skies across much of the UK for the rest of this week.
The eerie blue clouds become visible for a few weeks each Summer as the Earth tilts to allow the Sun to reflect off clouds in the upper reaches of the atmosphere.
They will be visible from between 11pm and 4am each night on a clear night, away from light pollution, between now and Friday.
Researchers expect them to be visible over the UK, northern Europe and North America between the latitudes 50 and 60 degrees North.
Noctilucent clouds should be visible across much of the UK between now and Friday
Last night saw good displays of noctilucent clouds across Cambridgeshire, in particular. Scientists expect the clouds to be particularly visible across Northern Ireland and Scotland.
The shimmering clouds form at an altitude of around 55 miles above sea level in an area known the mesosphere, the coldest region of the Earth's atmosphere at -150C.
Lying around 50 miles above the Earth's surface, this region is about 10 times higher than the troposphere, where weather clouds form.
They are made up of tiny ice droplets. Because they are so high up in the atmosphere the sun is able to illuminate the clouds from below the horizon.
Called 'noctilucent' clouds, which literally means 'night-shining' in Latin, they are normally spotted in polar regions during the summer months.
Despite the beauty of the clouds, scientists fear the clouds could be a sign of changes in the upper atmosphere because of global warming.
Rising methane levels from industry could also be producing more water vapour in the upper atmosphere.
Amateur scientist John Rowlands is studying the clouds for the BBC's Radio 4 Material World science programme.
He is working with Professor Nick Mitchell from the Centre for Space, Atmospheric and Oceanic Science at the University of Bath.
The team is asking members of the public who spot the clouds this week to let them know and to send in photos to their Facebook page.
Registered Member #1334
Joined: Tue Feb 19 2008, 04:37PM
Location: Nr. London, UK
Posts: 615
I've been looking for these for the last few nights - I live about 20 miles north of Proud Mary at about 50N, but my Northern horizon is plagued by lihgt pollution from London (about 30 miles away).
Its very clear at the moment, and I can see sheets of light to the North, but differentiating that from the normal light from London is difficult without a like-for-like comparison.
Registered Member #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
Kilham wrote ...
I managed to capture this in 2006 if it's any help.
One January, I saw the Northern Lights when I was camping at the Lairig Ghru in Cairngorm. These greenish veils of light were low in the northern sky, as if the flickering display itself was happening much further to the north, and I don't s'pose I'd have seen it at all were it not for my mountain vantage point.
But I've never see noctilucent clouds, though I've gone out into the garden in the middle of the night these few days past, without catching sight of them.
Registered Member #1334
Joined: Tue Feb 19 2008, 04:37PM
Location: Nr. London, UK
Posts: 615
IntraWinding wrote ...
Good map. I had a much better view when I lived in Shropshire, as it shows.
But a holiday on Lanzerote (canary Islands, well off the Western coast of Africa) totally blew my mind!
I always ask people who've been there if they saw the stars, hoping to share the life changing experience, and unerringly they say "No". Very sad
I used to do a lot of off-shore racing & cruising - I absolutely loved the night watches as there was almost (apart from the nav lights) no light except the phosphorescence from the wake and the darkest, clearest skies.
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