(WFRV) – Sunrises and sunsets often produce beautiful colors in the sky. These colors can range from bright reds to mellow yellows. The scientific term for this phenomenon to occur is known as scattering and is the reason for the vibrant colors produced at these times of the day.
Let’s start with the basics- why the sky is blue? As light waves produced by the sun enter the atmosphere, they scatter in all directions once atoms and molecules collide. This scattering is not equal across the visible spectrum and favors shorter wavelengths which equates to violet and bluer colors.
Violet colored wavelengths tend to scatter first towards the top of the atmosphere. Blue colored waves scatter next at roughly 4 times more the rate than red wavelengths. Therefore from the point of view of looking straight up from the surface, the sky appears blue.
At sunrise and sunset, the sun has to pass through more of the atmosphere than when it is directly overhead during the middle of the day, thus more scattering of molecules occurs. The longer distance of travel through the atmosphere causes more of the blue colored wavelengths to be scattered before reaching our eyes. This results in the atmosphere favoring longer wavelengths, like yellow, orange, and red, once the short blue wavelengths are scattered.
Human activity such as pollutants can also enhance the colors at sunrise and sunset. Larger amount of pollution higher up in the atmosphere increases the amount of scattering of particles.
Other weather phenomena, such as Saharan dust, volcanic chemicals, and wildfire smoke, also increase the number of particles available in the atmosphere. Similar to pollutants, the increase in particles can provide increased chances of scattering which could lead to more vivid sunrise and sunsets.
By the end of October, daylight shrinks by about 90 min compared to the end of September. Have an awesome sunrise or sunset picture? Share it with us: