The Science of Sunsets

Golden sunsets bring to mind picture-perfect vacation photos and romantic walks along the beach.

Dramatic sunsets aren’t by chance. For each beautiful sunset, there’s a bit of science at work: Sunlight only appears white. It’s actually made up of all the colors of a rainbow (red, orange, yellow, green and blue). During the day, the sun is overhead. Air molecules in the atmosphere scatter the beams of sunlight and make our sky appear blue on clear days.

Credit: T Williams, Bedford PA - via WeatherBug Photos

Credit: T Williams, Bedford PA
via WeatherBug Photos

As the sun sets, the sun is lower in our sky. Sunlight must pass through more of our atmosphere. These beams then hit the tiny oxygen and nitrogen molecules in the air we breathe. At this angle, the beams of light are scattered into reds and oranges – and make for some pretty fabulous sunsets.

Credit: Doreen, Anna Maria Island, FL - via WeatherBug Photos

Credit: Doreen, Anna Maria Island, FL
via WeatherBug Photos

Pollution doesn’t typically create or enhance sunsets. That’s because bigger particles scatter the reds and the purples and can dull the colors.

Long before TV, the internet and smartphone apps brought weather information and forecasts to our fingertips, people used firsthand observations and proverbs as guides to predict the weather.

Credit: Scott Nygaard, Fort Myers, FL - via WeatherBug photos

Credit: Scott Nygaard, Fort Myers, FL
via WeatherBug photos

One proverb relating to sunsets that you might be familiar with is “Red sky at night, sailor’s delight. Red sky in morning, sailors take warning.” And there is some truth to it.

Credit: Adrian Olivera, Denton, Nebraska - via WeatherBug photos

Credit: Adrian Olivera, Denton, Nebraska
via WeatherBug photos

Wind and weather come from the west in most parts of the world. A red sky at sunset generally means that there’s high pressure in the atmosphere, so the approaching air from the west is dry and good for sailing. A red sky sunrise generally means that high pressure has already moved east, and that there is low pressure and bad weather on the way. Morning red skies also indicate a high level of moisture in the air, which could mean that rain and showers are possible.

Credit: Sara An Justin. Depoe Bay, Oregon - via WeatherBug photos

Credit: Sara An Justin. Depoe Bay, Oregon
via WeatherBug photos

Share your favorite photos of spectacular sunsets at http://photos.weatherbug.com/photos

 

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This entry was posted in General, Phenomenon, WeatherBug Photos.