SKY PATTERNS

Over the rim of the mountains summer clouds came sailing. Almost every day late in June came loose white puff-balls, the fair weather clouds with deep blue sky around them. A few days behind them came the huge white galleons, moving with majesty, their billowing sails spread before the wind, their flat bottoms seeming to float on a steady current of air. One after another they came until the sky was filled with great armadas.

We lay in the shade of yuccas and watched the clouds come sailing. They meant that rain was coming and soon there would be no need herding cattle into dry and thinning grass lands. Every day we made a new search for pasture. While the horses browsed on stubble we lay on our backs and watched the sky galleonssailing from far horizons-wondering where they came from. Every wind that circles the globe from arctic seas and tropic oceans, from everywhere on earth, helps to bring a precious cycle of water.

Water vapor travels invisible, as clear as blue sky. Clouds form when mountains turn the winds upward, vapor cools and changes into droplets, very small droplets that shine with rays of sunlight. Reflecting every ray of light the clouds turn white as snowbanks. Every shade of gray is formed by deeper masses, shaded from the sun rays. The bases grow dark and heavy, stretching out in long flat bottoms. Rain streamers form and drop like curtains. Often they hang in mid air, their frayed ends trailing above the landscape, a dry layer of ground air absorbing every drop of water and no rain is falling.

Another day and new armadas join the battle. Thunder rolls and lightning flashes from cloud to cloud and from cloud to earth. Dust flies when a bolt makes ground contact. Evening brings the scarlet sunset, red lightning streaks from purple cloud ships and they disperse under cover of darkness.

The storm may carry over with cloud layers to screen a summer sunrise but often it will be clear and cloudless. Bright blue sky all morning and then by noon a line of cloud ships circles the valley, rising on the crest of the mountains, advancing in mass formation with all the sky arranged for battle. The flat bottoms stretching in long columns appear in stepped formation but some"... one after another they came until the sky was filled with great armadas.."

are near and some are far away and they all sail on the same flowing current.

Rain streamers form in different places, showers come and move onward. The big cloud ships go into action, the sky grows darker and a general downpour covers half the valley. An hour of rain will soak the earth, another may come an hour later. A rising current may carry raindrops upward and a new cloud moves under, the rising drops lose momentum and falling backward start a new downpour. The double broadside comes in torrents and the ground is covered with sheets of water.

The white faced calves leap and play like rabbits. The older cattle, gaunt and thin, smelling better pasture, toss their heads and try to gallop. Within days the land will be green and growing. Grass will spring up like magic and cattle start to fatten.

The ranchers hope for rainy summers. Spring will bring a short burst of pasture that soon turns dry and yellow but the rains of summer bring the real growing season. Gramina grass and blue stem must grow tall before seeding. If summer rains should fail them the winter is a time of problems.

The Navajo people say the sky is a warp of yellow twilight, the rain god weaves a pattern of white and gray clouds. And the Navajo weavers draw from nature's patterns, they weave designs of clouds and rain and mountains, of sun and wind and lightning. Most Navajo blankets are made with sky patterns. A legend tells about the rain god and his way of hanging curtains to hide him from the westwind. It was an old trick and it seldom worked, for the sun and storm gods were soon annoyed with curtains. The storm god rolled his thunder drums and cracked his lightning whip, the sun burst out with fury and tore away the curtains. And from these battles came the flash floods running in the washes.

At school we had a special book, of clouds and wind

"... every wind that circles the globe... helps to bring precious cycles of water..."

and weather. In this book of science we learned that summer clouds are cumulus-the ones that we called galleons. The low layered clouds are stratus and the high flying feather clouds are called cirrus. The cloud from which rain is falling is nimbus. These are soon multiplied into a broad field of combinations but these are the basic patterns from which all skies are painted. An endless change of patterns can be woven with a few threads of cotton. A few chunks of water vapor and a warp of westwind. The cumulus are the heaped-up, wool-pack clouds, A mass of warm air slowly rises and, growing colder, starts condensing. The temperature inside the cloud is warmer than the air outside and the air-lift rolls gently upward, molding the cloud into rounded puff-ball patterns. The winds sculpture it into many forms and figures. The bottoms form at condensation level. On hot days the clouds boil up from mountain tops like active volcanoes and the ranchers call them thunderheads. Warm air holds more vapor, cold air but little. Millions of droplets form a raindrop when cooling air reaches the point of saturation, the cloud turns to nimbus. Cumulus grow miles high, may reach an altitude of freezing temperature, droplets change to crystals, a million forming a snowflake. When the crest is round and smoothly edged the cloud holds water droplets, but if the edge is fraying, like the ravel of a piece of cotton, snowflakes are flying. These may form in summer, melt in falling and reach the earth as raindrops. The stratus are the layered clouds, hanging in the sky like ribbons. They appear to drop low on the far horizon but in the sky near us they seem to reach upward toward the zenith. Stratus in the western sky may screen the sun before sunset, producing both upward rays and those that flow downward. The cirrus clouds are thin and waving, flying in the

NOTES FOR PHOTOGRAPHERS OPPOSITE PAGE

"SUMMER AFTERNOON-MOUND'S PARK" BY ESTHER HENDERSON. 5x7 Deardorff View camera; Kodachrome; f.32 at 1 sec.; Goerz Dagor lens; July, late afternoon; 100 Weston meter reading; ASA rating 12. Photo taken at Mound's Park (also called Mund's Park) about seventeen miles south of Flagstaff toward Oak Creek Canyon on the old Schnebly Hill road. Just to left of pond is the Foxboro Ranch. Photographer says: "Interesting point is this: during rainy summer season this meadow fills with water and becomes pond with meandering stream winding into foreground. At other seasons it is just a meadow and unrecognizable from this summer scene. Very lovely location; high (6500-7000 feet) timbered (ponderosa); off the beaten track. Road: O.K. but muddy during rains."

CENTER PANEL

"PANORAMA-CHIRICAHUA NATIONAL MONUMENT" BY WILLIAM D. BLEDSOE. Linhof Technika 4x5 camera; Ektachrome, daylight type; f.16 at 4th sec.; Schneider Angulon 120mm. lens; August, bright sunlight, mid-afternoon; 400 Weston meter reading; ASA rating 8. The scene was taken near the Heart O' Rocks Trail, a one mile loop which covers the "showplace" of the Chiricahua National Monument in Cochise County. The viewpoint is found on the back trail which leads from Massai Point to the Heart O' Rocks area. One high point on the trail affords the hiker a view of the distant valley and the Dos Cabezas Mountains over the top of the Wonderland of Rocks. The use of a polarizing filter is very helpful, as in this scene, to partially penetrate the distant haze, and accentuate the clouds by darkening the blue sky, and also to give greater color saturation of the rocks and green foliage. Due to the density of this filter, about 1½ stops greater exposure should be allowed. Cloud formations in this area are spectacular in August when summer storms come in from the south.

OPPOSITE PAGE

"MARSHALL LAKE" BY ESTHER HENDERSON. 5x7 Deardorff View camera; Kodachrome; f.32 at 1½ sec.; Ektar lens; midJuly; bright sunny afternoon with scattered clouds; 200 Weston meter reading; ASA rating 12. This is Marshall Lake-more duck pond than lake, but shown as lake on map, three miles off the Lake Mary road about eight miles southeast of Flagstaff. The photographer says: "Albeit not a very 'lakey' lake, thought it would be good for ducks in fall. Some years later arrived here in early October and a cloud of mallards arose from water as we approached. In the words of TV script: Don't have gun but Will travel! This time no gun-only camera-but hundreds of ducks. Maybe thousands."

"ON THE RIM OF THE PAINTED DESERT" BY ESTHER HENDERSON. 5x7 Deardorff View camera; Kodachrome; f.29 atth sec.; Goerz Dagor lens; July; stormy sunset about 6 P.M.; 400 Weston meter reading; ASA rating 12. Taken from rim of Painted Desert some twenty miles east of Holbrook. The photographer explains: "We camped at this spot on the rim for five days waiting for clouds and rain. No rain-some clouds-not as dramatic as we would wish. Nights cool and lovely; days dadblasted hot. Shade condition: None unless you can sit under the bottom branch of a scrub juniper tree! Finally on the fourth day in afternoon this effect a promise of rain, coolness, picture. Development: No rain, some coolness, some picture. Not as interesting as wished for but after such a long wait, a must. A vast and lonely expanse. Tourists stop by on U.S. 66, jump out of car, look, jump back in-hurry away. Day after day-only our family remains! Felt as permanent as a petrified log myself! One time wind blew so hard thought we were going to be blown into valley but no!-still here!"

high wind like veils of lace. They are the highest clouds and are always made of ice crystals. In the upper atmosphere they form the haloes we see around the sun and moon.

Sometimes a banner cloud will form on the leeward side of a mountain peak, a streamer flying in the wind. Often it is a streamlined oval that seemingly defies the wind. It evaporates rates in dry air at the trailing end and is constantly renewed by vapor from the windward side. In a similar way the top of a cumulus may rise to colder regions and the high wind along the crest will carry away a flying plume of crystals.

Sun power and water vapor cause all our weather, all that happens in our atmosphere. The steady flow of sun power has a mighty force-a square mile of earth surface receives sun power equal to the energy of Hoover Dam. Some of this sun power warms the earth and some warms our atmosphere but almost half of it is turned away unused. If all of it were captured the world might well operate on this constant flow of power.

Falling rain releases energy and thunderstorms develop huge amounts of power. This is sun energy changing the temperature of air and water. The steam train that streaks across the valley-drawing a long line of coaches -derives its power from the same principle of changing temperature. The force of a thunderstorm may be imagined when we compare its over-all dimensions with the boiler of the locomotive. This great force expends itself in the roll of thunder and flash of lightning but not quite all is lost. Instead it sends a flood of nitrogen from the sky to earth with falling raindrops. The energy is transformed to plants, and grass shoots up by inches.

The day begins with sky patterns. First comes a faint glow of yellow twilight. The starlight curtain rises and morning brings a prelude to the changing scene. Sometimes the clouds are opal-fringed with tinted haloes. Once before sunrise we saw a flock of fleecy little clouds trailing from horizon to the zenith and they were white and sparkling. Lighted by the sun that was still below the skyline they were marching like so many sheep on their eager way to pasture.

The day may bring the thunderheads but storms usually move from west to east, and by evening when the west is breaking clear the eastern sky may be full of raindrops. Then is the time to look for rainbows. The sun is now behind you and the long slanting rays strike the crystal raindrops, being transformed there like magic and reflected in a blending arc of color. The rainbow has the red outside and runs through yellow and green to blue-violet. The arc is always the same and is almost but not quite a half circle, for the center of the circleis as far below the skyline as the sun is above it. Sometimes the rays are reflected twice and a second bow forms a larger arc with the colors reversed from red inside to blue-violet outside and the bow is always fainter.

A thunderstorm in daytime is always thrilling and a thunderstorm at night has suspense and mystery, but when lightning flashes in a sunset sky there is a striking beauty. The mauve and purple clouds grow slowly darker. The orange flashes bring a sudden brightness and the rain curtain is rent again and again by sharp bursts of lightning. For an interval the dark shapes of mountains show clearly on the skyline. The storm drifts far away and the flashes light a wide backdrop. Thunder fades to faint echoes. Blue-white lightning is close at hand, a mile away it is yellow. A long way off it has an orange flicker and in the farthest distance there will be no flash at all but only a waving glow of purple.

Lightning itself is a sort of chain reaction that starts with something small and simple as a splitting raindrop. Each raindrop has a small charge of current, a billion build up to something very complex and release tremendous power. The flash may cover a great distance, branch and waver for one brief moment and then it is gone. The flash is white hot and the air it touches expands violently with heat. Concussion waves from near and far strike upon the eardrums, thunder claps and rolls away, reverberates across the wide curtain of the sky.

At sunset the sky becomes a color palette. If the evening is cloudless the sky may be a flowing tone from orange skyline to purple zenith. A cloudscape is just the opposite. The top of the tall thunderhead will hold the slanting rays long after the sun has left the mesa. It will show a yellow tint on the rounded crest grading downward through tones of pink to lavender. But when the sky is full of clouds of many forms and patterns the rays will bring a symphony of colors. The cumulus will turn to red and gold, the stratus interwoven bands of orange and purple. The flying cirrus will show in flaming tones of lace.

Once we saw a cloud of stratus flying like a giant eagle with its fluted red wings spread wide across the mountain. Once a tumbled mass of cumulus seemed to roll with pink and gold horses drawing a pink and gold chariot over red hot embers.

There are no limitations to the fantasy of a sunset, nature never lacks imagination. Her paints are flowing rays of light and every form and color has dynamic rhythm. Night comes quickly in a cloudless sky but in a cloudscape the afterglow is lingering.

Sun and cloud and star dust are elements of weather. The air most always carries microscopic dust, some of it has earth origin and some of it comes from outer space, literally star dust. Water vapor condenses on dust particles as dew will form on cooler solids. Every raindrop then and every snowflake is born by seeding with microscopic dust. Every wind brings weather. And history goes the way of weather. Man has often been its beneficiary and sometimes its victim, for seldom has the weather been ideal. But the drum and the rain dance have been discarded. At long last we read the patterns in the sky, but there we have much to know and there is man's great challenge. The atmosphere is a world-wide river, it must be understood and be controlled. A cloudscape is not just a world of fancy. The rain god must not weave a whimsy pattern. The river in the cloudscape will show the way that life must follow on the land.

Echo Cliffs

Look out!... Ye ancient, ruddy, gripping forms The Maurader is coming!

The geiger stick there in his hand A price for you is summing.

And now how will the echo ring Against your sullen height?

So different from the ancient drums Once called across the night.

"The children of your shadow beg For food, for peace, for rain God of all the God's look down And rob our nest of pain!

Deep within the mother-pouch Some by-gone yesterday Our fathers rose and moved about Thus moulded from your clay.

A fire, feathered by our gift, To Pachamama's handReturns his blood to earth again No redder than the sand."

The fire lies in cold arrayUpon a floorless cave As tick-tick-tick, the geiger stick Ascends toward the grave.

A cairn now rises here to claim This trampled ancient mound Once altar stones... they are the same The mountain God's look down!