Winter Sunrises and Sunsets Can be Better Compared to Summer
DULUTH, Minn — If you have watched a sunrise or sunset during the late fall or winter months and wondered if the colors were brighter and more intense compared to the summer, you would be correct.
There are a few things that influence the colors we see in the sky during a morning sunrise and evening sunset. The way sunlight interacts with particles in the air by scattering or reflecting will determine the color, brightness, and clarity of the horizon during the twilight hours.
Earth’s atmosphere is filled with tiny particles that affect incoming sunlight such as water vapor, dust, and pollution. These particles cause a portion of the sunlight to scatter while the rest is able to continue on.
Cooler colors such as blue and green have short wavelengths and are more likely to scatter. This makes it more difficult for them to get to us. The opposite is true for warmer colors. Red and orange have longer wavelengths and are able to travel farther without being scattered. When the sun is close to the horizon, light has to travel through more water vapor, dust, and pollution in our atmosphere before it reaches out eyes. So that is another factor filtering out the blues and greens, causing the sky to be illuminated with red and orange hues.
While these tiny particles in the air are what cause us to see more red and orange colors in the first place, too many particles can also lead to the colors being softened or dulled. This usually occurs during the summer when air circulation is poor. During the summer, stagnant air can cause pollution to build up leading to hazy conditions.
In the winter, better atmospheric circulation makes it more difficult for smog and haze to form. This allows for brighter and more distinct colors at twilight. Cold winter air is also less humid which means fewer water vapor particles in the air.
When the light has something to reflect off of such as ice crystals, it can make the twilight colors more expansive. The colder winter air makes ice crystals more abundant and so more light is reflecting and things are brighter.
There are some added benefits available to us only during the winter months. The angle the sun rises and sets during the winter keeps the sun near the horizon longer, increasing the amount of time we get to enjoy all the colors. We also do not have to wake up as early for a sunrise or stay up as late for a sunset during the shorter days of the year.