Cirrus
And higher, higher yet the vapors roll: Triumph is the noblest impulse of the soul! Then like a lamb whose silvery robes are shed, The fleecy piles dissolved in dew drops spread; Or gently waft to the realms of rest, Find a sweet welcome in the Father’s breast.
— Johannes Wolfgang von Goethe
Gauzy, wispy, and ethereal, clouds hang in the heavens, slowly moving across the sky, changing shape and form. Billowy, fluffy, full and fat with rain, snow, hail, or lightening, clouds also charge through the atmosphere changing from an innocent white to dark gray and hosting violent weather within minutes. They inspire art and science like no other part of creation, and for many Christians, they inspire prayerfulness and anticipation.
Composed of visible liquid droplets or frozen crystals of water and chemicals as small as one millionth of a millimeter, clouds are made of such small particles spread out for miles that they don’t have the velocity to fall down. They float.
Yet their beauty is so commonplace, perhaps sometimes people don’t even notice them unless they get in the way of the sun. Cloudy skies are a metaphor for looming bad news or a state of depression. And yet there is good news in the clouds. As Christ ascended into heaven, 40 days after his resurrection, he was taken up into a cloud (Acts 1:9–11), and on the clouds he will return to gather his saints.
Here are five awesome things you may not have known about clouds:
1. Luke Howard loved clouds so much he named them. At the turn of the 1800s, Howard, a pharmacist and Quaker turned Plymouth Brethren, proposed an international system for naming clouds modeled after Carl Linnaeus’s taxonomy. Using Latin, Howard named the three principal categories of clouds: cumulus, stratus, and cirrus. The system is used for clouds in the troposphere, which is the lowest layer of the earth’s atmosphere and the site of most weather.
Howard humbly considered himself to be nothing more than a “man of domestic habits,” but Johann Wolfgang von Goethe, one of Europe’s most celebrated intellects of the time, convinced him to write an autobiography of his work. Goethe wrote a series of poems about Howard’s categories of clouds and even wrote about Howard: “In truth nothing more pleasant could have happened to me than to see the tender religious soul of such an excellent man opened out to me in such a way that he has been able to lay bare for me the story of his destiny and development as well as his innermost convictions.”
2. Clouds play a vital role in ecosystems. Want to know where a species lives? Look up, say scientists from the University at Buffalo in New York. The clouds are a map of all the species on earth, according to a study just published in PLoS Biology. Cloud cover patterns vary geographically over the surface of the earth, affecting the climate of ecosystems; chief among climatic observations, of course, is sunlight. Using NASA satellite images taken between 2000 and 2014, the scientists mapped the clouds and found that one could more accurately predict where a species lived based on the clouds than on any on-the-ground observations.
“Sunlight drives almost every aspect of ecology,” study author Adam Wilson told New Scientist. “So when you put something in between the sun and plants, that is going to have implications on the amount of energy they are receiving, soil moisture, leaf wetness, and humidity—almost everything that is important.”
3. On a winter evening, as twilight edges toward darkness, iridescent clouds known as nacreous clouds hang and shift slowly in the stratosphere just above the troposphere. The scattered end-of-day sunlight paints a pearly white cloud while particles within the clouds diffract the light to create an interference of colors, making the frozen droplets gleam with iridescence like a pearl. The clouds can also form at dawn, but are only visible in northern regions like Canada and Scandinavia. Less vivid iridescent clouds do also live at lower elevations and have wider visibility around the globe, but nacreous clouds are unforgettable to those who have seen them.
4. Even higher in the sky, shimmery, wispy clouds known as noctilucent clouds float about 47 to 53 miles above the Earth in the mesosphere. Shining in the summer, these colorless clouds can be seen between 50 and 65 degrees latitude north and south of the equator—that’s farther south than nacreous clouds. Normally they are too faint to be seen, and are rare. The mesosphere contains one hundred millionth the amount of moisture that exists in the air of the Sahara Desert, and because the air is so thin, ice crystals can only form at -187 degrees Fahrenheit.
Keep your eyes trained upward: Noctilucent season is almost here. It began last year on May 19.
5. Other planets have clouds, too. Clouds are not unique to Earth, but other clouds so far observed on other planets don’t seem to be made of water. Jupiter has clouds made of ammonia. Venus has thick sulfuric acid clouds in its atmosphere that make it the bright “morning star” visible from Earth. On the other hand, the reddish color of Mars is due to its lack of clouds.
Whether Jesus will return through luminescent nacreous clouds, tumultuous cumulonimbus clouds, or a “great cloud of witnesses” (Heb. 12:1), the clouds will usher in his return. “Then will appear the sign of the Son of Man in heaven. And then all the peoples of the earth will mourn when they see the Son of Man coming on the clouds of heaven, with power and great glory. And he will send his angels with a loud trumpet call, and they will gather his elect from the four winds, from one end of the heavens to the other” (Matt. 24:30–31).
An old hymn promises “a home where no storm clouds rise, O they tell me of an unclouded day.” But it is awesome clouded skies that Christians look forward to, not a wholly blue one.
Rebecca Randall is The Behemoth’s science editor.
