Nature Matters – Article and Photos by Shirley Woods

This article first appeared in Around Here Magazine, Spring 2026 issue.

In the previous Nature Matters, I mentioned that I would continue on about  phenomena in air, everywhere including around here. Researching an outdoor observation is, for me, like jumping in to a vast river of information, taking me swirling around bends, into deep pools, then, sometimes, flinging me out over a waterfall of current science, which is constantly being tested and modified, moving into unknown territory.

Our atmosphere has been divided into layers based on temperature and altitude. Also, there is the ionosphere, which is categorized separately, due to its electrically charged particles. Closest to outer space, furthest from Earth’s surface, is the exosphere, 375 miles to 6,200 miles above Earth. Satellites orbit here. Next closest is the thermosphere, 53 miles to 375 miles from Earth, where the International Space Station travels and auroras dance. Thirty one miles to 53 miles above us is the mesosphere, where gases are thick enough to slow down and usually burn up meteors, evidenced by their flaming tails that we might be fortunate to see. Four to 12 miles on up to 31 miles above Earth is the stratosphere. Temperatures increase with altitude in this layer because of absorption of solar ultraviolet radiation by the ozone layer, keeping us safe from harmful radiation. And finally, where our weather takes place, where we see clouds, is our troposphere. Its height varies from 11 to 12 miles above the equator to under four miles above Earth at the poles. (Distances are approximate.)

A weather front is the boundary between warm and cold air. Molecules of nitrogen and oxygen in colder air move slower, taking up less space, therefore making colder air denser than warmer air. In warmer air the same type of molecules move faster, and take up more space, therefore warmer air is less dense than cold air. Colder air pushing under warmer air can create clouds and storms. The greater the temperature difference the greater the storm’s intensity.

In 1803, Luke Howard created a classification of clouds based on shape, appearance, thickness and height at which they form. Today, we use this way of classifying clouds. There are more than three dozen types with names. I especially enjoy seeing lenticular clouds over the mountains, at times, looking like stacked plates of soft fuzzy material, sometimes called UFO clouds.

Within a thunder cloud, called cumulonimbus, warmer air is rising, cooling at the top of the cloud, then sinking and warming as it goes to the bottom of the cloud. This repeating motion causes the top of the cloud to acquire a positive electrical charge and the bottom of the cloud to have a negative charge because every drop of water has a tiny charge of electricity. Billions of drops in a cloud create a powerful charge. Static electrical charge builds up until it sparks– lightning. Lightning releases a huge amount of heat in a fraction of a second so that the air around the flash quickly heats and expands creating an explosive shock wave that we call thunder. Sometimes we see lightning flash between clouds or from cloud to ground or suspended in the air. Lightning shows are exciting; remember to stay safe. Check out: weather.gov/safety/lightning

In rainy weather, we may be lucky to spy a rainbow.  Rainbows exhibit seven main color wavelengths- red, orange, yellow, green, blue, indigo, violet. Water drops act as prisms. Sun’s white light enters a raindrop. Acting as a prism, the drop of water bends the light, called refraction. As the light waves come out of the droplet they are organized by wavelength. Red light waves bend the least and have the lowest frequency or longest distance between waves; violet is bent the greatest because violet wavelength has the shortest distance between waves, or the highest frequency. As millions of raindrops direct the various light waves at the same angle, a circular pattern is created, the curve of a miraculous rainbow.

On a mid-morning without rain, I was looking for the waning gibbous moon.  As I looked up I saw something I’d never seen before. I called it an upside down rainbow. I learned that it is a circumzenithal arc formed by refraction of sunlight by hexagonal ice crystals. In order for them to occur, Sun needs to be 15 to 25 degrees above the horizon with high, nearly transparent cirrus clouds present that don’t block the sunlight. Since it is an inverted arc the violet color is the inner most part and the red is the arc closest to Earth. To see a circumzenital arc one is looking in the direction of the sun with the cirrus clouds between them and the sun. To see a rainbow, one needs to have their back to low angled sunlight, not blocked by clouds, looking through, or towards, raindrops falling.

Now for auroras. They occur in the thermosphere and the overlapping ionosphere. Storms on the sun cause solar winds that are loaded with bits of Sun’s energy and they are drawn to Earth’s magnetic poles, interacting with gases. Different gases are responsible for displaying different colors when they come into contact with solar energy. Auroras are known for their curtain-like appearance as they ripple and float in the sky. They are happening year round, simultaneously at the North and South Poles, and sometimes can be viewed at lower latitudes depending on their intensity and the darkness of the night. Last year for the first time in my life, I was thrilled to see, from my house in El Dorado County, the mesmerizing wispy veils of green, light green and white swaying about on the northeast horizon. The show lasted about ten minutes and has become an indelible memory.

I hope you enjoyed learning about some events in our atmosphere. Thank you for reading.

Shirley Woods enjoys being nature-centric, a part of nature in El Dorado County

Nature Tending Tips

Look up; behold revealed wonders in the sky;

Conscious curiosity can be cultivated.