A Cloud A Day E-Book

Gavin Pretor-Pinney

• Herausgeber: Batsford
• Kategorie: Wissenschaft und neue Technologien
• Serie: A Day
• Sprache: Englisch

Seitenzahl: 204

Veröffentlichungsjahr: 2019

Beschreibung

'This charming volume reminds us that self-care is as available as a glance out the window' – The New York Times 'A confident celebration of our ever-changing skies... I defy anyone who reads it not to start taking furtive peeks out the window.'– Robert Leigh-Pemberton, The Daily Telegraph 'A gorgeous celebration of the wonder of clouds' – The People's Friend It's more important than ever to engage with the natural world. The sky is the most dramatic and evocative aspect of nature and looking up at the clouds is always good for the soul. Ever-changing and ephemeral, clouds reflect the shifting moods of the atmosphere in limitless compositions and combinations. Gavin Pretor-Pinney started the Cloud Appreciation Society in 2005. Since then, he's been encouraging people to 'look up, marvel at the ephemeral beauty, and always remember to live life with your head in the clouds.' Membership to the Society now includes over 50k cloudspotters. Together, they capture and share the most remarkable skies, from sublime thunderstorms and perfect sunsets to hilarious object shaped clouds. A Cloud A Day is a beautifully illustrated book containing 365 skies selected by the Cloud Appreciation Society. There are photographs by sky enthusiasts around the world, satellite images and photographs of clouds in space, as well as skies depicted by great artists over the centuries. The clouds are accompanied by enlightening explanations, fascinating snippets of cloud science, poetry and uplifting quotations. The perfect dip-in-and-out book for anyone who wants to de-stress and reconnect with nature, A Cloud A Day will inspire you to open your eyes to the everyday beauty above and to spend a moment each day with your head in the clouds.

Leseprobe

A CloudA Day

A CloudA Day

Gavin Pretor-Pinney

Contents

Introduction

The clouds

Picture credits

Index

A Cloud A Day

IT IS EASY TO FORGET that you live in the sky – not beneath it, but within it. Our atmosphere is an enormous ocean, and you inhabit it. This ocean is made up of the gases of air rather than liquid water, but it is as much of an ocean as the Atlantic or the Pacific. You may think of yourself as living on the ground, but all that means is that you are a creature of the ocean bed. You still inhabit the atmosphere like a sea creature does the water.

‘It is a strange thing how little in general people know about the sky,’ wrote the Victorian art critic John Ruskin (see here). Strange indeed, given how important it is to us. One reason for this might be that the sky is always there. It is the ever-present backdrop to our lives, and anything as ubiquitous as this is easily missed because it hides in plain sight.

We at the Cloud Appreciation Society believe that you would do well to pay more attention to the sky. Having your head in the clouds, even for just a few moments each day, is good for your mind, good for your body and good for your soul. This book aims to show you why.

‘The first step to wisdom’, as the biologist E.O. Wilson noted (see here), ‘is getting things by their right names.’ Learning the names for a few of the different cloud types is a good way to start a new relationship with the sky. Every cloud is unique, but we humans love to put things into groups and so we gather their chaotic forms according to ten main types, known as cloud genera. You might have learned some of them at school – names like Cumulus, Stratus and Cirrus. There are also many sub-categories of cloud. These cloud species and varieties and cloud features crop up here and there among the main types. Some of them are rare and fleeting, and you have to really pay attention to the sky to be able to spot them. To start getting used to which cloud is which, you can navigate your way through the notable examples using the Cloud Types map.

The Latin names sound formal, but they are mostly just based on how the clouds look – on their shapes – and you certainly don’t need to remember Latin terms to enjoy finding shapes in the clouds. You might remember doing this when you were young. Back when you had time on your hands, when the only deadline was bedtime, and your imagination could float free.

Finding shapes in the clouds is how most of us first become interested in the sky. There is an aimless pleasure to this side of cloudspotting, one that feels nostalgic. The early age at which this relationship with clouds is first forged might explain why our feelings about clouds and the sky run deep. But once we have grown up, this aimless pleasure of youth feels frivolous. We’ve no time to sit around gazing at clouds.

So why when you speak to someone who, for whatever reason, knows their days on Earth are numbered, do you often find them saying that the sky, the transient, ephemeral, ever-changing clouds, feel more worthy of their attentions than most of the stuff we spend our days worrying about? Just because something is aimless doesn’t mean that it is pointless.

So find the time, every now and then, ‘to make the shifting clouds be what you please,’ as the poet Samuel Taylor Coleridge put it (see here). You will be engaging the idle mode of your brain – a mode that has been effectively eradicated from our daily lives by device culture – because cloudspotting legitimises doing nothing. You’ll be freeing your imagination and reminding yourself to stay lighthearted. The spottings in this book by members of the Cloud Appreciation Society will help get you in the mood. Use the Clouds that Look Like Things map to find them.

We all know clouds can have a profound effect on our moods. No wonder, then, that they are the tool artists use to introduce feeling to a landscape painting. The nineteenth-century Romantic painter John Constable argued (see here) that in any landscape painting the sky is the ‘chief organ of sentiment’, the ‘key note’. You can map our changing attitudes towards nature through a history of how we depict the sky in art. Until the last 200 years or so, the sky was treated in Western art less as the key note and more as a footnote. When clouds did appear, they were little more than background decoration, compositional space-fillers, at best cartoon cushions for deities to recline on. They rarely played a major role. But there were exceptions, and you can navigate these alongside more modern artistic explorations of the atmosphere with the Art of the Sky map.

To tune into the sky is to slow down. Clouds may be in a state of perpetual change, but it is one that, more often than not, appears gradual. They might in fact be moving quite fast – ice crystals in the high, sweeping streaks known as Cirrus can blow along at speeds approaching 300 km (200 miles) per hour – but they appear to change gradually because they are a long way away. So you can treat cloudspotting like a moment of meditation, a meditation on the sky, which differs from other forms in one important regard: what you are concentrating on, the sky, is beyond your control. You cannot plan your cloudspotting for a specific duration, schedule it for a certain moment in the day. Cloudspotting is a frame of mind more than a planned activity. When the sky puts on a show, you just have to be prepared to pause what you are doing and engage with it for a few moments.

Clouds are the embodiment of chaos and complexity. Why do they change so unpredictably? What accounts for their dynamic, ever-shifting forms? The answer is a simple one. Clouds change appearance so much because of the unique qualities of water. It is the only substance on our planet that is found naturally in the three states of solid, liquid and gas. Nothing else on Earth (or above it) shifts between these states with such ease, ushered along by just the slightest changes in temperature. And one of the three, the gas state of water, is invisible. It is known as water vapour, and it is transparent. So a subtle warming or cooling of the air can be enough to choreograph the magical dance of water from invisible to visible; from transparent gas to a solid-looking array of droplets or a translucent streak of ice crystals.

We see clouds because their particles reflect and scatter the sunlight. And sometimes when they do so, if their droplets or ice crystals are just the right sizes, shapes and orientations, they can bend and separate the light to form a whole range of arcs, rings, bands and spots of colour. Journey through these light phenomena of the atmosphere with the help of the Optical Effects map.

Each of the 365 clouds in this book, no matter whether it was spotted by an astronaut aboard the International Space Station, an old master of the Dutch Golden Age or a member of the Cloud Appreciation Society from their back yard, should be thought of as a reminder. Each cloud is a tap on your shoulder, prompting you to look up, take a breath and unfetter your thoughts from earthbound concerns. It is there to remind you to look around you, look above you and appreciate this ever-changing ocean of air that we all inhabit and share.

Gavin Pretor-Pinney

I am very grateful to all the members and friends of the Cloud Appreciation Society who contributed images to the book. I would personally like to thank the following members whose words and ideas featured in the Cloud-a-Days: Yoav Daniel Bar-Ness (Member 10,389), Sheila Brooke (Member 32,250), Shelley Collins (Member 9,733), Elliot Davies (Member 7,143), Kym Druitt (Member 19,908), William A. Edmundson (Member 5,218), Jeanne Hatfield (Member 36,420), Richard Joosse (Member 32,314), Andrew Pothecary (Member 3,769) and Judith Strawser (Member 32,075). In particular, Elliot Chandler (Member 16, 353) has been instrumental in helping write and develop much of the content, for which I am especially grateful.

Cirrocumulus lenticularis clouds contorted by turbulence in the lee of the Sierra Nevada mountains, California, US, spotted by Stephen Ingram (Member 7,328).

One way to open your eyes to unnoticed beauty is to ask yourself, ‘What if I had never seen this before? What if I knew I would never see it again?’

From The Sense of Wonder (1956) by Rachel Carson.

Cloudy Mountains (before 1200) by Mi Youren. Handscroll, ink on paper.

WHEN DID REALISTIC CLOUDS first appear in pictures? It was most likely in 12th-century Chinese art. This detail shows Stratus fractus clouds on the slopes of mountains in an ink drawing by the Chinese artist Mi Youren, created sometime before the year 1200. In another of his several Cloudy Mountains drawings the artist included an inscription:

Innumerable are the wonderful mountain peaks

which join the end of the sky,

Clear or cloudy, day or night, the misty atmosphere is lovely.

Altocumulus lenticularis, spotted by Ian Boyd Young over the east end of the French Pyrenees mountain range, near the border with Spain.

THE LENTICULARIS CLOUD, which has a distinctive disc shape and forms in the vicinity of mountains, is named after the Latin for a lentil. This is because no one could think of the Latin for a flying saucer.

Cloud iridescence appearing in Cirrostratus, spotted above Cumulus over North Elmham, Norfolk, England, by Danielle Malone (Member 35,276).

BANDS OF PASTEL COLOURS sometimes appear spread across high clouds like this Cirrostratus. They’re caused by the sunlight bending as it passes around the tiny particles of the cloud. The optical effect is known as diffraction, and the different wavelengths that make up sunlight bend by different amounts. This has the effect of separating out the wavelengths, which in isolation appear coloured. The colours only show when a cloud’s droplets or ice crystals have a very consistent size and are very small – each one around a thousandth of the width of a human hair.

A rainbow spotted in the spray by Sarah Jameson, standing around a waterfall in Skogar, Southern Region, Iceland.

It was a hard thing to undo this knot. / The rainbow shines, but only in the thought / Of him that looks. Yet not in that alone, / For who makes rainbows by invention? / And many standing round a waterfall / See one bow each, yet not the same to all, / But each a hand’s breadth further than the next. / The sun on falling waters writes the text / Which yet is in the eye or in the thought. / It was a hard thing to undo this knot.

Unfinished poem, dated 1864, by Gerard Manley Hopkins.

Fluctus clouds curling like peaks of meringue over the Green Mountains near Starksboro, Vermont, US, spotted by Keith Edmunds (Member 41,937).

FLUCTUS CLOUDS are also known as Kelvin-Helmholtz wave clouds, after 19th-century scientists Lord Kelvin and Hermann von Helmholtz, who studied turbulence at the boundary between moving fluids. A difference in velocity between two airstreams, known as wind shear, results in unstable vortices that can lead to this rare and fleeting formation.

Pileus forming above towering Cumulus clouds, spotted over Kentucky, US, by Frank Leferink (Member 41,121).

APILEUSWAS A BRIMLESS FELT HAT worn by the Ancient Greeks and later the Romans. It is also the name of this smooth cap of cloud that can appear over the top of a towering Cumulus as it builds rapidly upwards through the atmosphere. The formation is caused by airstreams passing above being cooled as they are lifted by the violent rising air currents within the convection cloud below. For Romans, the pileus was a symbol of freedom. It was given to slaves when they were released from servitude.

A cat stalks headlights in Ashtead, Surrey, England. Luckily, the alarm has been raised as this cat wears a bell. Spotted by Debbie Whatt (Member 43,013) and known also as Cumulonimbus capillatus.

Cirrus uncinus, spotted over Gevninge, Zealand, Denmark by Søren Hauge (Member 33,981).

The cloud-capp’d tow’rs, the gorgeous palaces,

The solemn temples, the great globe itself,

Yea, all which it inherit, shall dissolve,

And, like this insubstantial pageant faded,

Leave not a rack behind. We are such stuff

As dreams are made on; and our little life

Is rounded with a sleep.

From The Tempest (1623), Act IV, Scene 1, by William Shakespeare.

The cloud pattern known as Saturn’s Hexagon, spotted in 2016 over the planet’s north pole by NASA’s Cassini spacecraft.

ON SATURN, A RING OF CLOUDS EXISTS with a distinctly angular form that has not changed for 30 years. This hexagon of clouds at the planet’s north pole is so large that each side is about the diameter of Earth. The formation was first observed in the early 1980s. While it is understood that the shape results from the path of a jet stream, there is yet to be any clear consensus on what causes it to have such a regular pattern. Whatever the explanation, Saturn’s hexagon is a rare example of order emerging from the chaos of clouds.

New Mexico Recollection #12 (1922–1923) by Marsden Hartley. Spotted by Minnie Biggs (Member 4,330).

THIS PAINTING, CALLEDNew Mexico Recollection #12, is by the American modernist painter Marsden Hartley. The artist produced it in the early 1920s, when he was living in Berlin. It is one of a series based on his memories of the arid landscape of New Mexico, which he described as ‘essentially a sculptural country’. Above the stylized terrain, Hartley depicted what appear to be stacked lenticularis clouds. This is a formation that looks like discs of cloud, layered one on top of another. Such a cloud type would have made complete sense as it is one of the most memorable and, without a doubt, the most sculptural of all the cloud formations.

Clouds at sunrise over the coast of Guatemala, as viewed from directly above by astronauts aboard the International Space Station.

THE COLOUR OF CLOUDS depends greatly on the colour of the direct sunlight striking them. The colour of sunlight depends greatly on the journey it has travelled through our atmosphere, which scatters out the blue end of its spectrum more than the red. Here, the lower Cumulus and Stratocumulus clouds look pink, while the high tops of the Cumulonimbus clouds look white. The sunrise lit the low clouds by shining at a shallow angle through the denser, lower atmosphere. Its bluer wavelengths having been scattered away along the journey, the light reached the low clouds with peachy, salmon hues. The light shining onto the towering summits of Cumulonimbus travelled through the less dense, higher atmosphere. Its spectrum remained largely intact, and it lit the lofty cloud peaks in pure, brilliant white.

A wandering Cumulus, spotted by Rauwerd Roosen over the Soiern Mountains, Upper Bavaria, Germany.

I look about; and should the guide I choose / Be nothing better than a wandering cloud / I cannot miss my way.

From The Prelude (1850), Book One, by William Wordsworth.

A Von Kármán vortex street in marine Cumulus downwind of Isla Socorro, 500 kilometres (just over 300 miles) off the Pacific coast of Mexico, spotted by NASA’s Aqua satellite.

THIS SWIRLING PATTERN appeared in the marine Cumulus clouds downwind of Isla Socorro, a volcanic island in the Pacific Ocean. It is known as a Von Kármán vortex street, named after the Hungarian-American mathematician and physicist Theodore von Kármán, who explained in the 1910s how alternating oscillations can develop as a fluid flows around a blunt obstacle. This is the phenomenon that causes overhead cables to hum a note in the wind. And it is how a solitary volcano jutting up from the ocean’s surface can send the clouds into a spin.

A fragment of a rainbow, spotted in a shower over the Sierra Almijara mountains, Andalucia, Spain by Rodney Jones (Member 15,695).

SOMETIMES A SHOWER just doesn’t cover enough of the sky to form a proper rainbow. The colour in this evening downpour might better be described as a ‘rainsquare’.

Altocumulus stratiformis perlucidus, spotted over Dorset, England, by Poppy Jenkinson (Member 39,335).

HERE IS HOW THE NAME FOR A CLOUD like this Altocumulus stratiformis perlucidus is constructed. ‘Altocumulus’ is the genus. A genus is one of ten main types into which most clouds can be classified. The Altocumulus genus refers to a clumpy cloud, up at the mid-level of the troposphere. ‘Stratiformis’ is the species. It means that the layer of clumps extends over a large region of the sky. ‘Perlucidus’ is the variety. It refers to when the clumps have gaps between them, rather than being joined into a more continuous layer. In other words, it means ‘those nice little puffy ones that spread across the sky’, but in Latin, to make it sound official.

Eight of the 14 Cloud Studies by John Constable within the collection of the Yale Center for British Art, New Haven, Connecticut, US, spotted by Mark Richardson (Member 42,827).

FROM 1820 TO 1822, the English Romantic landscape artist John Constable dispensed with painting the land altogether and concentrated solely on the sky. During this period, he produced numerous Cloud Studies – fast sketches of the sky, never intended for exhibition. These small canvases, far more loose and free than his famous landscapes, were Constable’s experiments in depicting the moods of the sky. Through this ‘skying’, as he called it, Constable strove to become a master of clouds. As he wrote in a letter to his friend John Fisher in 1821, Constable considered the sky to be ‘the chief Organ of Sentiment’ in any landscape painting – the ‘key note’, which brings emotion and drama to the scene.

Altocumulus radiatus, spotted over Prospect Park, New York, US, by Elise Bloustein (Member 41,703).

RADIATUS CLOUDS ARE WHERE PARALLEL LINES or rolls extend so far across the sky that they appear to fan out from a point on the horizon. This is just an aerial version of that perspective effect in which train tracks appear to converge in the distance when you look down the length of them.

Mamma clouds, spotted over Cap Ferret, Aquitaine, France, by Katalin Vancsura (Member 30,830).

THESE POUCH-LIKE LOBES of cloud are known as mamma, from the Latin for ‘udder’ or ‘breast’. The exact mechanism for their formation is not fully understood. It might relate to air cooling within the cloud layer above – perhaps as ice crystals in the cloud melt. As it cooled, the air would become denser and sink below, arranging itself into pockets of descending air.

Spotted by Ram Broekaert over Enghien, Hainaut Province, Belgium.

Spotted from the aircraft cockpit on an approach to Geneva Airport by Richard Ghorbal (Member 5,117).

A GLORY IS AN OPTICAL EFFECT that can appear when sunlight shines from behind the viewer onto a layer of cloud. Coloured rings appear around the observer’s shadow due to the sunlight being diffracted as it is reflected by the droplets of the cloud. The effect is also known as a Brocken spectre by mountain climbers, who sometimes see it as they climb above a cloud layer. The most common place to see a glory these days is from the window of an aircraft. Look for it when your plane’s shadow is cast down onto a cloud layer below. The laws of optics decree that the circle of colours is centred on your position within the aircraft. For this reason, you can tell from a photograph of an aircraft glory where the cloudspotter was sitting – here, just behind the wing in the top image, and in the cockpit, flying the plane, in the lower image.

An arcus cloud feature at the base of a Cumulonimbus, spotted by Ebony Willson approaching Moreton Bay, Queensland, Australia.

THIS STORM SYSTEM came barrelling in over the coast of Queensland, Australia. The upper left part of the image shows the spreading canopy up at the top of the Cumulonimbus storm cloud. The low edge of cloud, looking like the skirt of a hovercraft, is a feature called arcus, which is also known as a shelf cloud. This is where cool air dragged down to the land or sea surface by all the storm’s precipitation, visible off in the distance, splays outwards and burrows beneath the warmer, moister, less dense air ahead of the storm. As this lifts, it forms a low, menacing base extending from the front of the storm, heralding the downpours to come.

Dust devil tracks spotted on the surface of Mars by the HiRISE camera on board NASA’s Mars Reconnaissance Orbiter.

NO, THIS ISN’T A CLOSE-UP of someone’s belly tattoos. It is an image of the meandering trails inked on the surface of Mars by dust devils. Growing kilometres high and metres wide, these Martian whirlwinds dwarf their terrestrial cousins. They spin dust and sand at such velocities that they produce miniature lightning bolts. One such ‘Martian devil’ did such a good job of cleaning the solar panels on Spirit, the Mars Exploration Rover, that power levels dramatically increased after the encounter.

Asperitas clouds depicted in Seashore by Moonlight (c. 1835–36) by Caspar David Friedrich.

WHEN THE ASPERITAS CLOUD was accepted as a new classification in 2017 by the World Meteorological Organisation (WMO), everyone asked if the formation itself was new or just the name. When we first proposed it as a new classification, we argued that the formation, though rare, had always been around. Smartphones just meant anyone could capture a cloud and send it in to us, so we had spotted a pattern previously missed. German artist Caspar David Friedrich spotted an asperitas back in 1835. With no smartphone to hand, he’d depicted it in his painting Seashore by Moonlight. We like to think that had the Society existed in 1835 Friedrich too would have sent his asperitas spotting in to us. Would be worth a lot of money for the Society today. Unless, of course, we’d been dumb enough to forward it on to the WMO.

Nacreous clouds, spotted over The Curragh, County Kildare, Ireland by Kelly Hamilton (Member 15,098).

MID-WINTER IS THE TIME OF YEAR to spot nacreous clouds. Also known as polar stratospheric clouds, these form higher than the normal, weather clouds, at altitudes of 10–25 kilometres (9–16 miles), which is inside the stratosphere. They are generally only observed from latitudes of more than 50 degrees. Being so high, nacreous clouds can catch the light when the Sun is below the horizon, and they look brightest against the darkened sky within an hour or two before sunrise or after sunset. This is when the lower part of the sky (the troposphere) is in shadow. The cloud’s particles, which can consist of different combinations of acid and water, diffract the sunlight and separate it into beautiful bands of pastel colours. No wonder these formations also go by the name of ‘mother-of-pearl clouds’.

Cirrus uncinus, spotted by Sarah Nicholson over Kommetjie, Cape Town, South Africa.

It is a strange thing how little in general people know about the sky. It is the part of creation in which nature has done more for the sake of pleasing man, more, for the sole and evident purpose of talking to him and teaching him, than in any other of her works, and it is just the part in which we least attend to her.

From Modern Painters (1843), Volume I, Section III, by John Ruskin.

Enhanced-colour view of Jupiter’s cloud tops processed by Bjorn Jonsson using data from the JunoCam instrument on NASA’s Juno spacecraft.

THE GIANT PLANET JUPITER has the largest atmosphere in the solar system. It is perpetually covered with clouds of ammonia crystals. There may also be a thin layer of water clouds hidden beneath. The clouds are arranged into bands of lighter-hued ‘zones’ and darker ‘belts’, which rotate around the planet in opposing directions at speeds of around 360 kilometres per hour (220 miles per hour). The interaction between these conflicting circulation patterns results in turbulence which can develop into massive storm systems. Jupiter’s most famous storm is known as the Great Red Spot, but the planet also has many lesser, unnamed storms. These appear as brown or white ovals within the ever-shifting swirls and eddies of cloud. Some Jovian storms last a few hours; others persist for centuries.

Advection fog over Hong Kong, spotted by David Law from the Pok Fu Lam Reservoir Trail.

The fog comes

on little cat feet.

It sits looking