The cloud with no name: Meteorologists campaign to classify unique 'Asperatus' clouds seen across the world
Whipped into fantastical shapes, these clouds hang over the darkening landscape like the harbingers of a mighty storm.
But despite their stunning and frequent appearances, the formations have yet to be officially recognised with a name.
They have been seen all over Britain in different forms - from Snowdonia to the Scottish Highlands - and in other parts of the world such as New Zealand, but usually break up without producing a storm.
Stunning but undefined: The clouds loom over the skies of New Zealand - but unfortunately words can't describe this dramatic vision from the heavens
And some experts believe the stormy weather phenomenon deserves its very own classification.
Experts at the Royal Meteorological Society are now attempting to make it official by naming it 'Asperatus' after the Latin word for 'rough'.
If they are successful, it would be the first variety of cloud formation to be given a new label in over half a century
'It is a bit like looking at the surface of a choppy sea from below,' said Gavin Pretor-Pinney, founder of the Cloud Appreciation Society, who identified the cloud from photographs sent in by members.
Dramatic: The ribbons across the sky look like a 'choppy sea viewed from below'
'We try to identify and classify all of the images of clouds we get in, but there were some that just didn't seem to fit in any of the other categories, so I began to think it might be a unique type of cloud.'
He added: 'The underside of the clouds are quite rough and choppy. It looks very stormy, but some of the reports we have been getting suggest that they tend to break up without actually turning into a storm.'
The Royal Meteorological Society is now gathering detailed information for the days and locations where the asperatus clouds have been seen in an attempt to understand exactly what is causing them.
Officials will then apply to the UN's World Meteorological Organisation in Geneva to have the new cloud type considered for addition into the International Cloud Atlas, the system used by meteorologists across the globe.
Professor Paul Hardaker, Chief Executive of the RMS, said: 'There would probably need to be quite a lot of heat around to produce the energy needed to generate such dramatic cloud formations.
'They are quite dark structures so there must be a lot of water vapour condensing in the cloud.'
Cloudy skies: If 'Asperatus' sticks, it could be the first such classification in half a century
Skies over Scotland: This scene from Perthshire could help confirm the new 'Asperatus' classification
Last edited by peter griffin on Wed Jun 03, 2009 4:28 pm; edited 1 time in total
New type of cloud found
An unusual type of storm cloud could become the first new variety of cloud to be officially identified in more than half a century.
By Richard Gray, Science Correspondent
Published: 9:00PM BST 30 May 2009
Meteorologists believe they have discovered a new classification of cloud after the unique formation has been spotted in skies around the world.
Experts at the Royal Meteorological Society are now attempting to have the new cloud type, which has been named "Asperatus" after the Latin word for rough, officially added to the international nomenclature scheme used by forecasters to identify clouds.
If successful, it will be the first variety of cloud to be classified since 1953.
The new type of cloud forms a dark, lumpy blanket across the sky and has been sighted in locations all over the world, including above the hills of the Scottish Highlands and above Snowdonia, Wales.
"It is a bit like looking at the surface of a choppy sea from below," said Gavin Pretor-Pinney, founder of the Cloud Appreciation Society, who first identified the asperatus cloud from photographs that were being sent in by members of the society.
"We try to identify and classify all of the images of clouds we get in, but there were some that just didn't seem to fit in any of the other categories, so I began to think it might be a unique type of cloud.
"The underside of the clouds are quite rough and choppy. It looks very stormy, but some of the reports we have been getting suggest that they tend to break up without actually turning into a storm."
The Royal Meteorological Society is now gathering detailed weather data for the days and locations where the asperatus clouds have been seen in an attempt to understand exactly what is causing them.
Among the worldwide locations where asperatus clouds have been spotted are above the flat plains of Iowa and Australia and also over the arctic sea just off the coast of Greenland.
The undulating and lumpy underside, however, is thought to be caused by warm and cold air meeting a the boundary between the lower and middle atmosphere creating a transition effect similar to those seen when oil and vinegar mix.
Officials will then apply to the UN's World Meteorological Organisation in Geneva to have the new cloud type considered for addition into the International Cloud Atlas, which is used as the worldwide standard for meteorologists.
Professor Paul Hardaker, the Chief Executive of the Royal Meteorological Society, said: "The process is a long and convoluted one to get through, but we believe there is a good case for this cloud to be added.
"There would probably need to be quite a lot of heat around to produce the energy needed to generate such dramatic cloud formations. They are quite dark structures so there must be a lot of water vapour condensing in the cloud."
Clouds are classified in an internationally recognised way that identifies where in the atmosphere they form, the amount of moisture they hold, their shape and appearance.
Luke Howard, a British pharmacist, first proposed a nomenclature system for clouds at the start of the 19th century, which was adopted as the standardised way of categorising cloud types.
The system, which is governed by the WMO, uses three layers of classification and was developed to help forecasters predict oncoming weather conditions from the cloud cover in the sky.
There are 10 basic cloud forms, or genera, that describe where in the sky they form and their approximate appearance, including stratus, cumulus and cirrus clouds.
The genres are subdivided into cloud species, which describe shape and internal structure, and cloud variety, which describes the transparency and arrangement of clouds.
Mr Pretor-Pinney is to publish a new book, The Cloudspotter's Guide, next week which provides detailed descriptions and photographs of all the different cloud types. It comes at a time when clouds are taking on a new importance in meteorological work after falling out of fashion as forecasters used satellite images and radar to help their predications rather than using cloud formations.
Professor Hardaker said: "Clouds are very important in the Earth's climate as depending where they are in the atmosphere they will either reflect heat or absorb and trap heat. We are only just starting to understand that role."
The Met Office is also to release another book later in the month, called Extraordinary Clouds, which features dramatic photographs of clouds.
Richard Hamblyn, from the environmental institute at University College London and author of the Met Office book, added: "Clouds are beautiful things that have volume, form and shadow, yet they float in the sky.
"There can't be many people who have not wondered at some point how they stay up there, as nothing else in our world behaves in that way."
Professor Paul Hardaker, Chief Executive of the RMS, said: 'There would probably need to be quite a lot of heat around to produce the energy needed to generate such dramatic cloud formations.
A cloudspotter from Somerset believes he has identified a new type of cloud.
Gavin Pretor-Pinney, from Somerton, who also founded the Cloud Appreciation Society, wants recognition for what he has named the asperatus cloud.
He said: "It looks quite violent - as if you are looking up from underneath the turbulent surface of the sea."
Weather forecaster Michael Fish told the BBC Radio 4 programme he thinks it is caused by a mixing of two air masses or the underneath of a storm cloud.
Pictures 'amazing'
Mr Pretor-Pinney, who wrote the Cloudspotter's Guide which featured in the Sunday Times non-fiction bestseller list, asked his cousin - who is a Latin teacher - for a word that means choppy or turbulent that is used to describe the sea to name the cloud after.
"Asperatus comes from the Latin verb aspero meaning 'to roughen up' or 'agitate'," he said.
"It was used by the poet Virgil to describe the surface of a choppy sea."
Mr Fish said he was "quite amazed" by pictures showing clouds fitting Mr Pretor-Pinney's asperatus description.
“ There has been no change to the classifications of clouds since 1953 and maybe this should be considered now ”
Gavin Pretor-Pinney
He said: "I can offer two explanations - they are either the mixing of two air masses - very warm humid air and and very cold dry air and it is like oil and water - it doesn't mix.
"These clouds could be formed at the boundary of these two air masses.
"Or, I have just spent several weeks chasing tornado-type storms in the Mid West they could be the turbulent underbelly of one of the huge thunder clouds.
"The only way to find out for sure is to look at the meteorological observations in the area at the time," Mr Fish added.
Mr Pretor-Pinney said the pictures were sent in by cloud society members from all over the world and some of them said there was no storm activity or heavy precipitation in the area at the time.
Expert committee
He said: "We need to look into this some more and I am speaking with the Royal Meteorological Society to do that.
"There has been no change to the classifications of clouds since 1953 and maybe this should be considered now."
Clouds are classified by a committee of experts from the World Meteorological Organization (WMO) based in Switzerland.
For them to consider Mr Pretor-Pinney's suggestion the WMO would have to be lobbied by a professional body such as the Royal Meteorological Society or the Meteorological Office.
Any decision on whether it is a new classification, or regarded as a sub-classification, is likely to be a two to three-year process.
Quote:
Mr Pretor-Pinney said the pictures were sent in by cloud society members from all over the world and some of them said there was no storm activity or heavy precipitation in the area at the time.
My wife and I saw one of these just the other day so I was stunned when I saw the article on it. These clouds are unbelievable, and odd colors with bright spots, sometimes in a pattern. I find this quote quite interesting:
Quote:
Professor Paul Hardaker, Chief Executive of the RMS, said: 'There would probably need to be quite a lot of heat around to produce the energy needed to generate such dramatic cloud formations.
Mr Pretor-Pinney said the pictures were sent in by cloud society members from all over the world and some of them said there was no storm activity or heavy precipitation in the area at the time.
This is true of the cloud I saw, no storm what so ever, not a drop of rain. And I think it's notable that half of the cloud was very bright, as if light was shining through it, but also sort of dull orange in color, while the surrounding clouds were dark blue. It was truly one of the strangest things I've ever seen.
