Weather 101: Why are sunsets red when it's smoky outside? - Tucson News Now

Weather 101: Why are sunsets red when it's smoky outside?

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Have you ever noticed how red sunrises and sunsets are when there is a wildfire in the area?

Here's why!

When the sun is directly overhead, there is not as much atmosphere for sunlight to go through before reaching our eyes as there is when the sun is low on the horizon.

When the sun is directly overhead, there is not much atmosphere for sunlight to go through before reaching our eyes as there is when the sun is low on the horizon.</

Figure 1: Less atmosphere is between us and the sun when the sun is high in the sky.

So, when the sun is overhead, the effect is minimal.

When it's on the horizon and when there is smoke in the air, the beauty shines through!

When the sun is low on the horizon sunlight has to travel through more of the atmosphere, allowing for more interference from smoke in the air.

Figure 2: When the sun is low on the horizon sunlight has to travel through more of the atmosphere, allowing for more interference from smoke in the air.

The sun's light is made up of all the colors of the rainbow. Each of those colors has a different wavelength.

Wavelength is the distance between peaks of a wave.

Figure 3: Wavelength is the distance between peaks of a wave.

Smoke particles are just the right size for the red color to bump into. Then, the red gets scattered out of the rest of the sunlight. There you have it! A red sunrise or sunset!

Red has just the right wavelength to bump into smoke particles, resulting in scattering of the red light, making it visible to us.

Figure 4: Red has just the right wavelength to bump into smoke particles, resulting in scattering of the red light, making it visible to us.

Enjoy!

Chuck

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