What makes a spectacular sunset

The blues could be somewhere over the West Coast, leaving a disproportionate amount of oranges and reds as that beam of light hits the East Coast.

So the same ray of sunlight is hitting people in both the Rockies and the Appalachians? Basically, the East gets the West's leftovers at sunset? Yes, I think a lot of people don't realize that. Everything is connected. And as humans, we like to think color is concrete: "Oh, that's a blue sky," or "That's a brown table. Absolutes don't really exist in color perception. It's rather disquieting when really you start thinking about it! No, you often hear that, but—assuming you mean typical pollution in the lower atmosphere—it's a myth.

It's actually the opposite: Large particles in the lower atmosphere tend to mute and muddy the colors because they absorb more light and scatter all the wavelengths more or less equally, so you don't get that dramatic filtering effect.

In areas with a lot of haze, you don't typically see the types of sunsets that are likely to appear on a wall calendar— or in, say, National Geographic. You see bright ones in the fall and winter particularly, especially in the East, because the air along the path of the ray of sunlight tends to be dryer and cleaner. I grew up in Baltimore, and this is part of why I got interested in weather.

I would wonder: Why is the sunset so pretty tonight? And there weren't answers to questions like this in standard weather books, because it's more about physics than forecasting. Speaking of forecasting, what about the saying: "Red sky at night, sailor's delight; red sky in morning, sailors take warning. Those spectrally pure colors are telling you there's a sizable swath of clear air off to your west that's likely to be over you the next day.

Yeah, you can forecast them to a certain degree. I guess it's a question of who cares—maybe filmmakers or photographers would find that information useful, but most people just want to know if it's going to rain or not.

There's often a slanting band of clouds on the back side of the departing weather system, and that can act as a sort of projection screen for the low-sun colors, better than a horizontal band would. The slant means it captures more of the orange and red light, and if the cloud is thin enough, it will reflect those colors down to you.

Also, storms wash a lot of the big particles out of the air. Yes, true sunset occurs a minute or so before you see the sun disappear. What you see is a kind of mirage; the light is getting bent around the horizon by the effect of refraction. Our eyes are sensitive to a very tiny part of the spectrum of the sun's wavelengths, and that's responsible for the way we see our environment. Other creatures seem able to see the ultraviolet area of the spectrum. We can only see a tiny part of what's going on.

So a butterfly or a reindeer , which can perceive ultraviolet light, might be seeing a different, perhaps more colorful sunset than we do? The more you look at things, the more you realize how unique your own experience is as a human on this planet, at this particular place and time. All rights reserved. In simple terms, what makes a good sunset happen? Do dust and air pollution make sunsets more dramatic?

Of course. Beauty is subjective. Sunset colors are created by a phenomenon called Rayleigh scattering. Sunlight contains all the colors of the rainbow. But not all the colors reach the ground in the same concentration. Nitrogen and oxygen molecules in our atmosphere act as little mirrors for blue and violet light, in particular. That means not as much blue or violet light reaches the ground.

At sunset, light has to travel through a greater distance of atmosphere to reach our eyes — so even more blue light, and even some green and yellow light, gets filtered out. But why are they seemingly more saturated during the colder months? But the explanation for why low humidity produces better sunsets is a bit indirect.

These can be chemicals naturally produced by trees, they can be from the wind kicking up dirt and dust into the atmosphere, or they can be from man-made pollution sources. When these aerosols attract water vapor, they swell. That is, they block the view. Also: Some people just might like the gauzier sunsets produced by occluded air. As we approach the winter solstice, the time the sun takes to set lengthens, due to the angle the sun takes in setting into the ground.

During the equinoxes, the sun pretty much sinks into the ground at a degree angle. Nearer the winter solstice, the sun sets on more of an angle, drawing out the time it takes to set. Which is to say: Sunset colors linger closer to the winter solstice, which allows us to enjoy them for longer.

One last thing: The clouds may be more conducive to beautiful sunsets in the winter. After a day or two of clouds, or rain, or snow, and these weather systems move westward, they set up conditions for stunning sunsets draped by clouds.

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