Friday, October 27, 2006

It's a bird! It's a plane...it's a lovely Cloud!!

kw: book reviews, nonfiction, clouds, cloudspotting

Clouds are the Rorschach inkblots of the sky. Seen from above, or upside-down while lying flat below with your head tipped back, they are fantasy landscapes. Sunrise or sunset in a cloud-wracked sky is the most soothing of experiences.

It didn't surprise me to find that there is a well-established taxonomy of clouds, with ten genera, about thirty species, many named varieties—all in Latin—and lists of diagnostic criteria. The Cloudspotter's Guide: the Science, History, and Culture of Clouds by Gavin Pretor-Pinney begins with a one-page taxonomic summary, and each of his first ten chapters begins with a detailed page about each genus, including explanatory images. The author is founder of the Cloud Appreciation Society, which is certainly worth a look.

The real value of the book is the narrative: great stories, as of Lt. Rankins's near-miraculous descent through a powerful thunderstorm in 1959, during which he rose and fell with the hail for a half hour or more, or the author's own (succesful) quest to view the unique Morning Glory roll cloud in northern Australia; cloud-inspired poetry, folklore, and lyric prose from sundry cultures; historical vignettes from the entire range of literate time; and the author's own experiences as someone still enthralled, amazed, and captivated by seeing clouds.

Did you ever look out the window of an airplane, and spot the shadow of the plane on clouds below? If you did, there's better than half a chance it was surrounded by a bright rainbow halo. This is a "glory", and from a mountain, with the sun at your back, above the right kind of cloud, you'll see a similar glory around the shadow of your head. The bodily shadow is called a Brocken Specter, from a famous German mountain where it is frequently seen. The specter plus glory probably provided the inspiration for the around-the-head haloes in much medieval religious art.

Do you love sunbeams cast through broken clouds, as I do? These specular rays are an effect of perspective, but knowing this doesn't blunt their beauty to me. Knowing the geometry of the hexagonal ice crystals that produce the big halo about sun or moon, or the light pillars one might see above bright lights on sharp winter evenings, doesn't diminish my pleasure and wonder.

And sunsets. Pretor-Pinney writes, "What, after all, is a sunset without the clouds? A bright ball disappearing behind a line, that's what." Sunsets are among nature's most beautiful displays. They are useful also. Most weather systems move from West to East. If the sunset has a good mix of cloud and open sky, chances are the next day or two will be pleasant. If instead, it is obscured or overcast, expect rain. Several layers of cloud, lit by the sun's differently-colored rays, sorted red below, yellow between, to white above, indicate a front on the way, with windy or unsettled weather.

My father is a painter. I saw a book at the library, some forty years ago, titled Look at the Sky and Tell the Weather by painter Eric Sloane (Amazon.com informs me it can still be found). I promptly got a copy for my father. I was much impressed that Sloane wrote that he strives to have the minimum amount of blue sky in his paintings, in favor of the greater beauty and drama of cloudscapes. My father's landscapes improved also.

Each of the book's first ten chapters discusses one genus of clouds, classified by height at their base, from Stratus (including ground fog) up to Cirrus at the top of the Troposphere. An eleventh chapter covers "accessories", such as Tuba, which Midwesterners call a funnel cloud, a tornado "seed"; or Virga, the rain or snow that doesn't reach the ground, but makes a cloud look more like a jellyfish. The twelfth is on Contrails, the new, human-caused clouds of the jetways, which are probably contributing to climate change. The author urges us to adopt a Pascalian philosophy, which I'll summarize.

Pascal stated that believing in God is a one-sided bet: if you believe wrongly, you lose nothing, but if you disbelieve yet God is real, you lose everything. Believing is the only rational stance. In the same way, it may be that jet contrails won't have much effect on climate. If we take steps to reduce their prevalence, there is at most a minor economic impact. But if they do have a major impact, as many climate scientists now believe, and we do nothing to reduce it, we could lose a very great deal. We won't go to hell, of course, but we may find we've come close! Taking the economic hit is the more rational choice. Sad to say, my experience leads me to believe few people are rational, either about God or about economics.

Finally, the thirteenth chapter narrates the author's quest to view the Morning Glory, a truly enormous roll cloud that forms over the Gulf of Carpenteria off the Cape York Peninsula of Australia. It shows clearly on satellite photos, being about the size of the California coast from San Diego to Eureka. Fortunately, unlike many quests, his was rewarded, not just with a look at the cloud, but a ride above it with a Cessna pilot.

You may wonder why I've included only one photo. I'd prefer you begin by clicking here, where you'll get better pix than I could legally acquire on short order. Not only is this Guide a fantastic book, it reminds me to look up more.

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