I have heard artists talk about the unique quality of light near the sea, and now I live near the coast I want to know if there's any truth in it. Does being near the ocean affect light inland?

I'm in the UK, where it's not usually clear blue skies; it's cloudy or partially cloudy (clouds may have an effect?).

I've lived in a flattish region in the centre of the UK, and at the coast. I think it's brighter here, but I can't figure out if it's a real difference. And Google is silent.

I've come up with possible explanations:

  • It's purely psychological
  • It's a side-effect of the big horizons making places feel lighter because more sky is visible
  • Sunlight reflects off the sea, and the clouds scatter it back onto the land

Is this real? If so, what's the mechanism and how far inland does the light penetrate?

  • $\begingroup$ Apart from obvious things like horizons and so forth, I wonder whether levels or types of haze in the air are different. $\endgroup$ – Semidiurnal Simon Aug 8 '17 at 12:56

At the coast the horizon facing the ocean is unobstructed, so a larger part of the sky is visible than inland, where trees, buildings, etc., block the view of the horizon. Also, the horizon sky is brighter than the overhead sky. At or near the horizon the sky appears lighter blue than at the zenith, or even whitish. Looking vertically at the zenith is looking through one air mass; looking horizontally at the horizon is looking through 40 air masses. Although the atmosphere scatters short wavelengths at the violet end of the spectrum most effectively, 40 air masses scatters enough of even the longer red wavelengths that the horizon sky appears very light blue or even whitish. 40 air masses is enough to scatter all of the light. Greater scattering of light causes the near-horizon sky to be brighter. (Even the zenith sky appears blue rather than violet because the Sun emits more blue light than violet and the eye is more sensitive to blue light than violet.)

  • $\begingroup$ So how about locations in, for example, the US Plain States, where the horizon is generally almost equally unobstructed... are you suggesting they will be comparable to this coastal environment? $\endgroup$ – JeopardyTempest Aug 9 '17 at 14:57
  • $\begingroup$ There could be other factors as well. One possible other factor: Near the ocean salt particles predominate; in the Plains states soil particles predominate. The type of suspended particulate matter could also be a factor. Consider Mars, whose typically butterscotch-colored skies are due to suspended dust. If the dust were to settle, the Martian sky would be a very deep dark blue, like than on Earth in the stratosphere. $\endgroup$ – Jack Denur Aug 10 '17 at 3:09

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