New images of noctilucent clouds taken by a NASA spacecraft may help solve a few mysteries…

A seasonal cloud-lookalike has made the headlines in a New Zealand newspaper.

A beach on the Lincolnshire coast, will soon have its own official cloudspotting area…

Society founder gives Martha Stewart membership to the society…

Member’s photograph on the cover of the Weather Watcher’s 3-Year Log Book, published by the Royal Meteorological Society…

Margaret Nelson’s photo of cirrus and
cumulus clouds in a cross wind

Most of us look up and marvel at clouds at least once a day – that is what makes us cloudspotters.

But chances are very few of us bother to keep a daily diary of what we have seen, unless we happen to be professional meteorologists.

Margaret Nelson (member 2812) is a keen amateur and records what she has seen near her Suffolk home in her online cloud journal. Her daily updates usually inlcude photographs, like the one shown here.

Lightning in Lincolnshire, taken by
our photo gallery editor Ian Loxley

A striking picture taken by our photo gallery editor Ian Loxley features in a new book about extreme weather.

Storm Force, by TV weathermen Michael Fish, Ian McCaskill and Paul Hudson, was published last month to mark the twentieth anniversary of the October 1987 hurricane, which flattened much of south-eastern England.

It uses pictures and news reports from national and regional archives to recall the most amazing episodes of weather that have left trails of death and destruction across the UK.

The book includes Ian’s photograph of lightning, which has also featured on the front cover of the International Journal of Meteorology.

Society founder Gavin Pretor-Pinney will be giving a talk on cloudspotting on Monday, November 12 as part of the Bridport Literary Festival.

If you live in or near Dorset, then for the Eype Centre for the Arts at St Peter’s Church, where you will be able to hear Gavin extol the virtues of cloudspotting in person.

His illustrated talk starts at 2.30pm and you can download a copy of the festival brochure here.

3D cloud image taken
by Ben Orona

If you click on the cloud photograph to the right and think perhaps it is time you wore glasses, you are right.

But your eyesight is probably fine – it is the picture that is playing tricks. It is an anaglyph image, which creates a stereoscopic 3D effect when viewed with two-colour glasses, usually cyan and red. Anaglyph images are made up of two colour layers, superimposed, but offset with respect to each other to produce a depth effect.

This example is part of a series of cloud pictures taken by Ben Orona. He says the two photographs which make up each 3D image were taken hundreds of feet apart, which helps give them their depth.

However, you will need a pair of anaglyph cyan-red glasses to see the 3D effect. You can buy them online – here, for example – but all the sites we found sold them in packs of five or ten. You may be able to buy them singly on eBay.

Lenticular clouds near Mt Adams
photographed by Darlisa Black

Amateur photographer Darlisa Black has written to tell us about a beautiful series of pictures she took of lenticular clouds near Mount Adams in the Pacific Northwest of the USA.

She was walking in the hills near her home in Washington State when she spotted the formation and spent nearly two hours capturing its changing shapes in the fading light.

“As with many volcanoes, certain weather conditions bring about lenticular
formations, and all my life I have witnessed many ‘caps’ on the nearby Mt.
Adams and Mt. Hood in Oregon.

“On November 6, I was fortunate to be up in the hills on my day off,
taking photos and enjoying the day. I could see a small lenticular formation near the mountain, so I decided to drive up 10 miles above Trout Lake, Washington, to a viewpoint I knew of with a great view of Mt. Adams.

‘I was so excited, and hiked along the edge of the cliff edged road for a mile, taking well over a hundred photos over the next hour and a half. Every time I started to quit and get in the truck, the colors and form would change again becoming even more amazing! I finally quit when all color was gone and it was getting dark.

“Every few minutes, the formation would change significantly. I loved it right at the end when it seemed the layers were lifting up away from the lowest layer, until there was a complete separation between the bottom two layers.”

The result is an absolutely stunning slideshow, which you can see here.

Celestial, a film by member Esther Johnson

Society founder Gavin Pretor-Pinney features in a new film about the sky by one of our members, Esther Johnson.

Celestial takes the form of an experimental portrait, exploring the poetry of the sky, which is seen as a space of fascination and contemplation.

It features interviews with weather experts, scientists and cloud
lovers, focusing on their perceptions and thoughts about the sky. In the film, Gavin describes looking at clouds as a form of meteorological meditation.

Snippets of dialogue from the interviews are spliced with visuals, including time-lapse footage of the sky, cloud formations, aerial views and people cloudspotting. The film also uses sounds from weather monitoring equipment and noises created from the weather itself.

Celestial premiered a few weeks ago at the Urban Screens Conference in Manchester but there are a few more screenings coming up which members might like to try and attend: Urban Screens Conference Manchester, 02/11/07;
Aurora, Norwich, 10/11/07; 21st Leeds International Film Festival, 17-24/11/07; Site Gallery Sheffield, 03/08.

You can find out more about Celestial on Esther’s website, www.blanchepictures.com, and watch an extract of the film here: www.biggerpictureuk.net

Wheat Fields by
Jacob van Ruisdael,
c 1670

Franz Ossing (member 9648) has drawn our attention to a lively debate in the art history world about whether the Dutch 17th-century masters painted realistic clouds.

There is no doubt the landscape artists of the Dutch “Golden Age”, like Jacob van Ruisdael, painted clouds beautifully. The question is whether the clouds in their paintings were meteorologically accurate.

Some art historians claim to be able to find the complete World Meteorological Organisation cloud atlas reproduced in landscapes from that period. Others argue that cloud forms were distorted to fit compositions and certain types of clouds that are typical for Holland did not appear in the paintings.

Read more about this here.

Weather Watcher’s
3-Year Log Book

Anthea Howard (member 9169) is Membership Secretary of the Royal Meteorological Society and has sent us a copy of their Weather Watcher’s 3-Year Log Book.

Cloudspotters have more than a passing interest in the weather, so you may want to add this handsome book to your collection.

It is crammed with fascinating facts, including information on how to identify different cloud types and what weather they portend.

It gives explanations of weather forecasts and how to understand them and features stunning images of the weather in all its power and glory. You can even learn how to make simple weather measuring apparatus.

You can find out more and order a copy on the RMS website.

The remains of an
ironbark eucalyptus
hit by lightning

We get sent a lot of pictures of fierce clouds but Bruce Sharp (member 3979) has emailed us an impressive shot of the aftermath of a storm in Australia.

This is what was left of an ironbark eucalyptus, one of the hardest of timbers, after it was hit by lightning. Fence post-sized chunks were hurled up to 50 yards and the stump was lifted out of the ground.

The picture was taken by Col Coulson near Kingaroy in central Queensland.

Have you ever wished you could watch clouds from the comfort of your own home, without even having to look out of the window?

DVDs might be the answer, but American artist Georgie Friedman has come up with an intriguing, all-round experience.

Her Cloud Room is a four-channel, high-definition video installation with cloth walls, each with a cloud video on a loop. Find out more about it here.

Scottish writer David Cunningham has written to tell us about his fantasy novel set on a planet divided by a permanent layer of clouds.

CloudWorld, an old-fashioned adventure story about a son’s search for his missing father, is aimed at young adult readers but might appeal to fans of Dune, with its citadels above the layer, ruling families, weird flying machines and fear of the world below.

You can find out more about it here: www.cloudworld.org

Seeing shapes in the sky and letting your imagination run riot is the fun side of cloudspotting.

Our new book of cloud-lookalikes, A Pig with Six Legs and other Clouds, is proof that our members are not only extremely handy with cameras but also enjoy being playful.

So we think you might get a few laughs from SKYplay, a series of visual jokes using the sky and clouds as a backdrop.

Our thanks to Dave Hall for sending us the link.

At last – something to listen to as you discuss the finer points of cloud formation with the rest of the family.

Our middle-aged American members may remember a series of educational children’s songs dating from the late 1950s called Ballads for the Age of Science by Lou Singer and Hy Zaret. Zaret is best known as the co-author of the 1955 hit Unchained Melody, one of the most recorded songs of the 20th century.

The six-album set included one of weather songs featuring such gems as How Clouds are Formed, Stratus and Cumulus, and Where is the Stratosphere? Here is a flavour of the lyrics, sung to a folksy guitar accompaniment:

“Clouds that are formed without any up and down movement – this information’s the latest,
“Cooled without rising and sheet-like or layered, sheet-like or layered, they’re stratus (pronounced stray-tus).”

The records were quite successful and the song Why Does the Sun Shine? (aka The Sun is a Mass of Incandescent Gas) was even covered by quirky alt-rockers They Might Be Giants in 1994.

An American called Jef Poskanzer has thoughtfully uploaded the songs as MP3 files onto his website and you can listen to them here. Our thanks to Jeff Waddell for telling us where to find them.

John Peña is an artist who likes to give clouds a run for their money.

He has also been known to put clouds into small packages and send them all over the world.

John, who lives in Washington State in north-west USA, describes himself as a cloud artist. “Although my art is a bit less traditional, I am devoted to the glory of clouds.”

One of his projects was to try and outrun clouds, a futile exercise but fun to watch. You can see the video of this one-sided race here.

The idea to put a a cloud in the post was inspired by a walk in the hills near his home in Ellensburg. “I saw a cloud come so close to touching the ground that I was convinced it was going to get caught in the top of a tree and anchor itself. I thought how amazing it would be to run over and capture a part of that cloud and send it to a friend.

“This is exactly what I did and my friend greatly enjoyed it. I then thought how beautiful it would be to try and package an entire Ellensburg cloud and have the people of Ellensburg help me send it around the country and around the world.”

Find more about John’s cloud art on his website: www.johnpena.net

Avid readers may remember a recent piece about a Canadian professor who invented The Cloud Harp, an instrument that creates music from the shape of the clouds above it.

On a similar theme, English composer Richard Garrett has written to tell us how he makes music from the changing patterns of the weather as recorded by an electronic weather station.

You can hear some of the music and find out more about Richard’s Weathersongs project by visiting his website: www.weathersongs.org

Astronomers are still struggling to understand a bizarre, six-sided cloud formation spotted circling Saturn’s north pole.

No one has seen anything like it anywhere else in the solar system. Unlike some of our individual clouds which look like a hexagon, the Saturn cloud pattern appears to have six well-defined sides of nearly equal length. Even stranger, it maintains its structure while rotating (see it spin). It is also huge: four Earths could fit inside it.

Originally discovered during NASA’s Voyager fly-bys in the 1980s, the recent infrared image taken by the Saturn-orbiting Cassini spacecraft, above, shows this cloud pattern is remarkably stable and may continue to baffle scientists for some time to come. Read more about it here.

It is a cloud-crazy world out there.

First we were horrified to read on the US satirical news website, The Onion, that Senator John Edwards was vowing to ban clouds. Imagine our relief to learn, therefore, that one of his presidential campaign opponents, Rudolph Giuliani, had rallied to their defence.

Now the website reports that scientists from the University of Chicago are theorising about what would happen if they touched a cloud. Read about it here.

Have you taken a photograph of a cloud that you are particularly proud of? Then you could win a digital camera.

Member Mark Humpage is running a competition to mark the launch of Cloud, a new natural-world photo agency, and has invited society members to take part.

The theme of the competition is the natural world, which includes the weather, the elements and, of course, clouds. The lucky winner will walk away with a top-of-the-range Olympus E510 professional digital SLR camera complete with 14-42mm lens, like the one pictured right.

Mark, who contributed one of the photographs in the 2008 Cloud Calendar, said: “With so many great ‘Natural’ photos on CAS I thought it may be a good opportunity for CAS members to dig out some and enter.”

You can see all the competition details and prizes here: www.cloudnews.co.uk

The closing date is December 31, so make it snappy.

Society founder, Gavin Pretor-Pinney, was asked by Tate Britain (London) to come to the gallery and discuss the clouds in some of the paintings in their collection. Amongst others, he mentioned cloud painting masters such as Constable and Turner as well as a painting that looks like it should be on the side of a Harley Davidson…

To watch Gavin’s cloudspotter’s tour of the Tate Gallery, go here and click on the image:
http://www.tate.org.uk/tateshots/episode.jsp?item=11569

At the end of July, the Cloud Appreciation Society put on a free exhibition of a selection of the photographs from our new book ‘A Pig with Six Legs and other clouds from The Cloud Appreciation Society’ at the Port Eliot Literary Festival in Cornwall, UK.

During the festival we set a competition for festival goers to take photographs of clouds in the shape of things during the weekend. The results were judged and awarded prizes at a star-studded, Oscars-like ceremony at the end of the weekend. Society founder, Gavin Pretor-Pinney, presented the gold and silver cloudspotting award trophies (see right). Luckily the recipients didn’t realize until they had returned to their seats that these were in fact made out of rubber toilet plungers, sprayed with sparkly paint.

Winner: ‘Laughing Man‘ by Gregory Wade.
Runner-up: ‘Duck of the Devil‘ by Bianca Daniels.

Click on the thumbnails below to see them full size.

Society founder, Gavin Pretor-Pinney, is presenting some short TV segments on cloudspotting to be shown on UK television at the beginning of August. There are five 3-minute pieces, which will appear in BBC1’s The One Show (BBC1, weekdays, 7pm) on the dates shown below. Each one focuses on a different cloud type, starting with Cumulus and ending with Noctilucent clouds.

Cloudspotters in the UK who are interested should watch The One Show on these days:

Thursday 2 August, BBC 1, 7pm Watch Part 1 here…
Monday 6 August, BBC 1, 7pm Watch Part 2 here…
Tuesday 14 August, BBC 1, 7pm Watch Part 3 here…
Tuesday 21 August, BBC 1, 7pm Watch Part 4 here…
Thursday 30 August, BBC 1, 7pm Watch Part 5 here…

For more information about the The One Show, see:
http://www.bbc.co.uk/theoneshow/

It is not everyday that you’ll find The Cloud Appreciation Society petitioning for FEWER clouds, but that is exactly what we have just done on a UK Government website.

We signed up to a petition urging the Prime Minister to take positive action to counter the increasing proliferation of aircraft condensation trails – the long man-made clouds that form behind high altitude planes.

There is a growing body of evidence to suggest that contrails result in increased levels of high cloud, which tend to trap in the sun’s heat, increasing surface temperatures in the regions they cover. Lower clouds have the opposite effect – of reflecting away much of the sun’s radiation. Indeed, the effect of all cloud types taken as a whole, seems to be a cooling one. The tendency of contrails to spread out and lead to increased levels of high, ‘cirriform’ clouds is in danger of distorting this effect.

Aircraft do not always need to fly at contrail-producing altitudes. It might be possible to limit cruising altitudes with air-traffic ceilings based on the atmospheric conditions, in order to reduce the effects of cloud formation without overly increasing fuel consumption. Organised by Shabra Dowson, the petition states:

“We, the undersigned, petition the Prime Minister to seriously consider using air-traffic management to keep European aircraft outside of contrail-forming regions of the atmosphere. Reducing contrails would bring an immediate reduction in high clouds with a corresponding immediate decrease in global warming.”

We encourage any members and visitors who are UK citizens to add their names to the petition and call for measures to reduce these man-made clouds. Over 200 names on the list by October 2007, and the govenrment will have to give a response.

For more info, see: http://petitions.pm.gov.uk/ContrailCutback/

Many of our members have been in touch to tell us about Ewa Wisnierska, the German paragliding champion, who had the misfortune of being sucked up into the heart of an enormous Cumulonimbus storm cloud. They all pointed out that the incident had much in common with that of Colonel William Rankin in the 1950s, described in The Cloudspotter’s Guide, in which he had to eject from his jet as he was flying over the top of a storm cloud, only to have the horrific experience of falling down through the middle of it.

Wisnierska’s ordeal happend near Manilla, in Australia’s New South Wales, on 14 February 2007, while she was training for the upcoming Paragliding World Championships. She was sucked towards the enormous Cumulonimbus by the strong air currents that flow up the centre of these storm clouds, and lost consciousness as she disappeared into the middle of it, rising at a rate of 20 meters per second. Her equipment recorded that she was sucked up to an altitude of 32,612ft, higher than Mount Everest.

Wisnierska was unconscious in the cloud for more than 40 minutes, during which time she was battered by hailstones the size of oranges and subjected to temperatures of -40 to -50 ˚C.

He Zhongpin, a Chinese paraglider, was also sucked into the cloud and, tragically, was found frozen to death 75 kilometers from his launch location.

Suffering from severe frostbite, Wisnierska nearly lost her ears in the ordeal. “From the theory, I knew the chances to survive are almost zero,” she later told the press, “I knew I can only have luck, I can’t do anything – and I got it.”

Read an article on the incident from The Age newspaper:
www.theage.com.au

We have often wondered about the particular way that clouds form in the Cantabrian Mountains of Northern Spain. So we were very pleased to receive an email from a Franco Ferro, of Italy, to tell us that they are in fact made by ‘El Nubero’.
He is a character, described in the folklore of the Asturian region of Spain, who is responsible for making the clouds.
We were amazed and impressed that Franco was able to capture this rare snapshot of El Nubero.

On 25th April 2007, NASA launched a satellite to study the Earth’s highest clouds. Now orbiting at an altitude of 375 miles, the AIM satellite (which stands for ‘Aeronomy of Ice in the Mesosphere’) is the first to be dedicated to the observation of the most mysterious of all the cloud types: Noctilucent clouds.

These clouds typically form at altitudes of between 30 and 50 miles, in a region of the atmosphere called the mesosphere (the one above the stratosphere). They are therefore way higher than most clouds, which tend to form in the lower 10 miles of the atmosphere. Being so far up, Noctilucent clouds catch the sunlight well after sunset, and so can shine bright against the darkening sky. They tend to be bluish-white, with a beautiful rippled texture. Their name is Latin for ‘night-shining’.

We know very little about how and why Noctilucent clouds form and scientists are keen to find out more since. Traditionally seen only towards the poles, they are now being observed at lower latitudes and more frequently than ever before. This has led some scientists to speculate that they are indicators of global climate change. Hence the AIM satellite mission.

Short NASA video about the mission:
http://www.youtube.com/watch?v=i9_8_2nL6Vo

Video of the AIM launch:
http://www.youtube.com/watch?v=xnWnur5KxPM&NR=1

More about the AIM launch to study Noctilucent clouds:
http://spaceflightnow.com/pegasus/aim/

The Noctilucent Cloud Observers Homepage:
http://www.kersland.plus.com/

Richard Parnell, Member 7750, has written to tell us of evidence of cloudspotting amongst western lowland gorillas that he observed during a three-year field trip to study them in Congo, Africa.

Richard was observing gorillas from a hide next to a jungle clearing. A family emerged from the foliage and began to make their way across the clearing. After just a few steps out out into the treeless swamp, one juvenile gorilla happened to look up. She suddenly cringed and raced back into the jungle. A few moments later she reemerged, only to look up again and show exactly the same startled reaction.

“I half expected to see a large eagle circling,” Richard told us, “but stepping out from under my tarpaulin canopy, I was rewarded with this fabulous sky, which was undoubtedly the cause of the young gorilla’s alarm.”

Clearly, the incident points towards a remarkable evolutionary development for the gorilla species: their ability to react emotionally to cloudscapes. This gorilla’s reaction may not have been quite the one we’d have hoped for, but it is perhaps forgivable. No doubt, if you were the first of your species to behold the drama and beauty of the Cirrocumulus undulatus cloud, you too would be in a state of shock.

Are you a teacher who would like to make more use of the sky in your classes? ‘For Spacious Skies’ is a US organisation set up to encourage the use of the sky as an educational resource.

They produce an activity pack, with vaulable ideas and resources for teaching sky awareness to children. We think this is a very worthwhile endeavour. According to a study by Harvard’s Graduate School of Education, the incorporation of the guide into educational programs has been shown to increase visual arts and literary skills.

Jack Borden, the founder of For Spacious Skies, argues that people who are sky-aware have five advantages: they are environmentally protective; aesthetically sensitized to the world; spiritual, having more of a sense of wonder about them; mellower, and more receptive to information related to the atmosphere. Who can argue with that?

If you would like to get a copy of the For Spacous Skies Activity Pack, as well as their cloud formations chart, visit:
http://www.forspaciousskies.com/chart.html
or email Jack Borden at: jjborden@webtv.net

‘Hole punch clouds’, also known as ‘fallstreak holes’, occur when patches of high cloud freeze and fall as ice crystals, leaving a dramatic gap behind. You can see examples of fallstreak holes in our cloud photography gallery.

The formations only appear in cloud layers consisting largely of ‘supercooled’ water droplets. These remain liquid even though temperatures are often well below freezing point. They are unable to freeze without airbourne particles, known as ‘freezing nuclei’, on which to get started. Sometimes there just aren’t enough of these particles floating around in the atmosphere for droplets to turn into ice crystals. In these situations, the introduction of suitable nuclei into a region of supercooled cloud can make it freeze and fall below. The particles in airline exhausts can serve as freezing nuclei, as can ice crystals themselves, falling from Cirrus clouds above.

Peter Roper, Cloud Appreciation Society Member No. 5840, alerted us to this NASA image of hole punch clouds photographed from space. The lines are caused by aircraft flying near to the cloud. The holes are probably due to Cirrus falling from above.

Hole punch clouds from NASA’s Terra satellite:
http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17539

NASA’s Mars Expolration Rover turns out to be a robot with a penchant for cloudspotting. In October 2006, during a routine communications pass, it filmed some of the red planet’s clouds and gave us a glimpse at how cloudscapes on Mars compare to those on Earth.
The formation that it photographed looks much like the patches of ice crystals that we call ‘Cirrocumulus’. We have yet to learn the Klingon translation.

See the NASA web page about these martian clouds:
http://photojournal.jpl.nasa.gov/catalog/PIA09170

Ancient Hindus and Bhuddists believed that elephants are the spiritual cousins of clouds and possess the power to encourage the clouds to form and bring rain. We have always thought that this is why so many people seem to see elephant-shaped clouds.
However, scientists at the Georgia Institute of Technology have found evidence to suggest that, rather than elephants, it is microscopic phytoplankton that actually posses the power to bring clouds. They found that increases in cloud cover over the Southern Ocean, around Antarctica, corresponded to a large bloom in the population of the sea organisms. It seems that the phytoplankton emit chemicals which find their way up into the atmosphere and act as microscopic nuclei onto which the cloud droplets can form.
If you want to know more:
http://www.gatech.edu/news-room/release.php?id=1183

On 28th April 2006, two NASA satellites, called CloudSat and CALIPSO, were launched into orbit 438 miles above the Earth to get a better view of the clouds. Whilst this may sound like a rather expensive indulgence for the cloudspotters of the science world, it begins to make more sense when you learn that clouds are the wildcards in climate change.
Will a warming planet lead to more or less cloud cover? Will any changes in the amount and type of cloud contribute to, or lessen, global warming? The new satellites should help scientists’ quest for answers.
CloudSat will profile the clouds with an extremely sensitive radar to determine how much water they contain and whether this is in the form of droplets or ice crystals. It will help clarify basic questions about how clouds form rain and snow, as well as how they affect the Earth’s climate. CALIPSO will provide data about the amount of microscopic ‘aerosols’ in the atmosphere, such as man-made pollution, volcanic ash and mineral particles. These affect how the Sun warms the planet and also play a cruical role in cloud formation.
Finally, we might learn how clouds react to a warming planet.
To read more about CloudSat:
http://cloudsat.atmos.colostate.edu/home
To watch videos of the launch:
http://www.nasa.gov/mission_pages/cloudsat/launch/calipsocloudsat-allvideos.html

He was one of Britain’s best cloud painters, and described the sky in his landscape painting as ‘the keynote… the chief organ of sentiment’. This means that the new John Constable exhibition opening at the Tate Britain, in London, is a must see for any cloudspotters finding themselves in the capital. The show brings together, for the very first time, all of the artist’s six-foot landscape canvases and includes 65 works in total.
Constable: The Great Landscapes is showing at Tate Britain from 1 June till 28 August 2006:
http://www.tate.org.uk/britain/exhibitions/constable/

Stretching over 12,000 square kilometers, the Salar de Uyuni in Bolivia is the largest salt lake on the planet. It is also one of the best places in the world to go cloudspotting. For brief periods during the rainy season, the salt lake becomes flooded with a layer of water just a few centimeters deep. This turns it into an enormous mirror of the sky, reflecting the clouds above to make you feel like you are suspended in the mid-heavens.
Argentinian artist, Tomas Saraceno, used an array of 32 cameras to film a panoramic view of this cloudtopia. His film is currently being projected along the eighty-meter wall of the Curve Gallery in London’s Barbican Centre.
Now we know what heaven looks like.
Visit The Barbian to see Tomas Saraceno’s art installation (until 16th July):
http://www.barbican.org.uk/artgallery/event-detail.asp?ID=4107

We always love a cloud with a name. This thunderstorm complex is well known by scientists interested in tropical meteorology, as it forms on a daily basis at certain times of year over the Tiwi Islands, off the north coast of Australia.
It forms on almost a daily basis during the transitional months of Nov-Dec and Feb-March, which makes it a perfect subject for meteorologists studying the development of Cumulonimbus clouds.
Mighty thunderclouds like this are estimated to harness the power of ten Hiroshima-sized bombs. Stretching up to 20km into the atmosphere, it is clearly visible from Darwin, over 100km away. We are very pleased that such an awe-inspiring and ferocious a monster as this has been christened by the locals with a name like Hector.
Many thanks to Tim Garrett for sending the photos in.

Conscious of increasingly frequent and wide-spread observations of Noctilucent clouds (see May’s Cloud of the Month), scientists have speculated as to whether this extremely high ice cloud is an aerial indicator of our contribution to climate change. Forming at altitudes of between 30 and 50 miles up, these clouds might be appearing more often due to increased levels of greenhouse gasses. But until we know how these mysterious clouds form and why they appear to be more common, all scientists can do is speculate.
That is about to change, however. NASA’s ‘AIM’ satellite, due to be launched later this year, should shed new light on this beguiling cloud formation.
More info about the AIM mission:
http://aim.hamptonu.edu/
More info about Noctilucent clouds:
http://science.nasa.gov/headlines/y2003/19feb_nlc.htm