I have a fondness for what meteorologists call fair-weather cumulus clouds, which sometimes form "cloud streets" -- clouds on a string stretching for hundreds of miles, clouds following each other like ducklings. Cloud streets are parallel to the wind's direction and to one another. In photos from space, they resemble the map of a well-ordered city. Over the ocean, cumulus clouds sometimes create massive cellular patterns, polygons arranged in a rough honeycomb design.
Typically, cumulus clouds are formed as the sun heats the earth, and a packet of warm air rises from the ground, cools, and condenses. The cloud's flat base forms at the level where condensation begins, and as the rest of the packet continues to rise and condense, puffy cotton balls take shape. Such a cloud is diurnal. It is usually low, perhaps a mile high, and small, perhaps a city block. It may live for five minutes or half an hour. Too often, we look up to that cloud-tossed sky, the shifting shapes and play of light, and then quickly look away. We think of something else -- our job, our errands -- unprepared for so much grandeur.
My father was a test pilot, and in a job that takes bravery for granted, he was known for being brave. In 1956 he tested the X-2 rocket plane and set a speed record, climbing high into the stratosphere, high above the clouds, moving three times the speed of sound. In the descent, the plane went out of control, and my father died in the crash. I was two years old.
But parents have a mythic as well as a physical presence. Though my father's death created a great physical emptiness, I was left with the sustaining myth of his bravery and buoyancy, his unwillingness to be bound to the earth, his love of flying through the sky's landscape.
Where I live in New Mexico, the landscape of the sky is often tumultuous. Fair-weather cumulus clouds are also known as "stable weather" clouds, and in less stable conditions, when a packet of warm air moves up through dropping temperatures, a cumulus cloud will rise higher and develop more vertically, with peaks and towering cliff walls. Inside the cloud, there is further rising and falling, condensation, coalescence, until water droplets become heavy enough to fall. In cloud language, the word nimbus means "rain"; a cumulus cloud becomes a cumulonimbus by virtue of raining. A large cumulonimbus cloud may be seven miles in height and several miles wide. High-altitude winds shear its top, the "anvil," from which cirrus clouds or trails of ice crystals spin out like mare's tails. Electrical energy builds up as water and ice particles are repeatedly split and separated. Suddenly there is a flash in the sky, a terrible brightness, cracks, and rumbles. Over the duration of a single thunderstorm, the explosive force of 10 Hiroshima-sized bombs can be released. Are we wrong to imagine the battling of gods?
As a college professor, I teach writing skills to freshmen. I teach simile: "I saw a cloud like a great castle." I teach metaphor: "I saw a great castle in the sky." I am also a writer, drawn to nature and science, and as part of that job I have learned that I cannot live in nature or understand science without simile and metaphor. (Scientists themselves classify certain cumulus clouds as castellanus, or clouds with turrets.) We are storytelling animals, and we bring our stories to the world as naturally as water vapor condenses and rain falls.
I bring to clouds a particular story of heroism and love. But everyone's story is different. I love clouds, in part, because they are democratic. You don't need to live in a high-rise with a view. You don't need to travel. You can simply slow down and look up. The landscape is ephemeral, forever on the verge of change. In that sense, this sky and this moment are meant only for you. The grandeur is free. You bring the story.