diffuse sky radiation

For daytime situations, please see diffuse sky radiation and Rayleigh scattering.

See diffuse sky radiation for more details.

This includes direct sunlight, diffuse sky radiation, and (often) both of these reflected from the Earth and terrestrial objects.

There is essentially no direct sunlight under an overcast sky, so all light is then diffuse sky radiation.

In a 2006 study, the Bay of Islands was found to have the second Diffuse sky radiation in the world, after Rio de Janeiro.

There are three commonly detectable points of zero polarization of diffuse sky radiation (known as neutral points) lying along the vertical circle through the sun.

Diffuse sky radiation is solar radiation reaching the Earth's surface after having been scattered from the direct solar beam by molecules or suspensoids in the atmosphere.

Rayleigh scattering of sunlight in the atmosphere causes diffuse sky radiation, which is the reason for the blue color of the sky and the yellow tone of the sun itself.

Therefore, variations in both the quantity and quality of ultraviolet in both the direct solar beam and diffuse sky radiation are important factors in the design and evaluation of weathering tests.

Sunlight on Mars would be more or less like daylight on Earth wearing sunglasses, and as can be seen in the pictures taken by the rovers, there is enough diffuse sky radiation that shadows would not seem particularly dark.

Some models have polarized lenses, made of Polaroid polarized plastic sheeting, to reduce glare caused by light reflected from polarizing surfaces such as water (see Brewster's angle for how this works) as well as by polarized diffuse sky radiation (skylight).

Of the total light removed from the direct solar beam by scattering in the atmosphere (approximately 25% of the incident radiation when the sun is high in the sky, depending on the amount of dust and haze in the atmosphere), about two-thirds ultimately reaches the earth as diffuse sky radiation.