The art of clouds: What causes certain cloud formations

Published: Jan. 12, 2021 at 5:25 PM AKST
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ANCHORAGE, Alaska (KTUU) - From billowing waves in the sky to characteristics of a UFO, clouds come in all shapes and sizes. One could describe them as some of the more beautiful things that Mother Nature puts on display for us. After all, for many of us, clouds captured our attention at a young age. We likely spent a multitude of days in our youth gazing at the sky, calling out shapes and animals as if a storybook were playing out right in front of us. What we may not have realized at that age, is that a story was actually occurring. However, not in the way we usually picture, as this was a story being written by our atmosphere in a way that lets us know the current state of the weather and what is to come.

Here in the Last Frontier, we get to experience all types of weather and thanks to viewer-submitted photos we get to relay the story of Mother Nature in a unique and informative way. Before we begin let’s tell the story of cloud formations and how they were named, we’ll call it a prequel to the art of clouds in the 49th state.

In 1772, a young man by the name of Luke Howard was born in London. Much like most future meteorologists, he was fascinated with the weather at a young age. Though he had a career as a chemical manufacturer, his desire and passion for weather led him to create his own weather station so that he could study the weather. One way he did that was through clouds. At that time, clouds were thought to be just a moment in time and existence and unclassifiable, but Howard set out to change that. He used the method of Linnaeus to classify the clouds, which is a hierarchical classification system. Through his work, he presented his Essay on the Modification of Clouds to the Askesian Society - a debating club for scientific thinkers in London - in 1802. The essay which was published a year later divided clouds into three categories; cirrus, cumulus, and stratus. It’s through his work and fascination with clouds that the first International Cloud Atlas was published in 1896, which has remained in print ever since.

We have come to understand and learn about many of those clouds today and while we are constantly identifying new clouds, if it weren’t for Howard we wouldn’t have the classification system we use now. And it certainly comes in handy with the multitude of clouds we see in Alaska. Because of the topography, Alaska has some unique weather and with that comes some rare cloud types that help tell our story of the atmosphere in the current state and what’s to come.

One such cloud is the Kelvin-Helmholtz, a rare cloud that is more common in mountainous regions.

Clouds breaking (Kelvin-Helmholtz) as pictured by Martha Foster in Twin Hills
Clouds breaking (Kelvin-Helmholtz) as pictured by Martha Foster in Twin Hills(Martha Foster)

Like waves breaking in the sky, Kelvin-Helmholtz shows the fluidity of the atmosphere and the ocean of air that surrounds us. The clouds which are named after Lord Kelvin and Hermann von Helmholtz form when there is strong wind shear between two air streams. Basically what is happening is that winds in the upper atmosphere are blowing faster than winds in the lower levels. This creates a billowing effect of the clouds in the sky and is a visual example of turbulence in the atmosphere. You’ll usually find these clouds on windy days. As a side note, it’s believed that these clouds might have been the inspiration for Van Gogh’s famous painting ‘Starry Night’.

Anticrepuscular Rays in Anchorage as pictured by Kori Marchowsky
Anticrepuscular Rays in Anchorage as pictured by Kori Marchowsky(Kori Marchowsky)

Clouds can also set the stage for unique light shows that commonly look like light pillars in the sky. You’ve likely seen this as rain showers move out of a region and the clouds slowly break away. As they do, rays of light (Crepuscular Rays) shine down through the clouds creating a visual artwork that many have come to know as “Angel rays” or “God rays”. A lesser-known example of this occurs during sunset and takes some effort on your part to be able to distinguish them. More often than not as the sun is setting we fixate our gaze on the beautiful colors that illuminate the sky, but we never turn our back to the sun. In doing so, you’ll be able to see Anticrepuscular Rays, a unique optical phenomenon that lights up the sky. The rays of the sun appear to converge at the anti-solar point, which is the point in the sky directly opposite of the sun. It takes on a unique appearance because the sun’s light is shining through gaps in the clouds and/or mountains. So the next time you are out and happen to catch a sunset, turn your back to the sky and you may be surprised to see the other side of a sunset.

Do you have some cloud shapes you would like identified and explained? Email them to us here at the station and we’ll do our best to tell you the story of our atmosphere.