A FUNDAMENTAL STUDY ON SKY UV-B RADIANCE DISTRIBUTION AND ULTRAVIOLET DAYLIGHT FACTOR OF CLEAR SKY

A clear-sky radiance archive from Meteosat ”water vapor” observations

Ultraviolet Sky Radiance Distributions of Translucent Overcast Skies

The diffuse sky radiation component in the ultraviolet wavelengths is often at least 50% of the global irradiance under clear skies, and is the dominant component of ultraviolet global radiation under translucent overcast skies. The distribution of sky radiance was measured in a rural area and modeled for wavelength bands of ultraviolet-B (UVB, 280-320 nm) and ultraviolet-A (UVA, 320-400 nm). S...

Digital imaging of clear-sky polarization.

If digital images of clear daytime or twilight skies are acquired through a linear polarizing filter, they can be combined to produce high-resolution maps of skylight polarization. Here polarization P and normalized Stokes parameter Q are measured near sunset at one inland and two coastal sites. Maps that include the principal plane consistently show that the familiar Arago and Babinet neutral ...

Polarization singularities in the clear sky

Ideas from singularity theory provide a simple account of the pattern of polarization directions in daylight. The singularities (two near the Sun and two near the anti-Sun) are points in the sky where the polarization line pattern has index +1/2 and the intensity of polarization is zero. The singularities are caused by multiple scattering that splits into two each of the unstable index +1 singu...

On the angular effect of residual clouds and aerosols in clear-sky infrared window radiance observations: Sensitivity analyses

[1] Accurate environmental satellite observations and calculations of top-of-atmosphere infrared (IR) spectral radiances are required for the accurate retrieval of environmental data records (EDRs), including atmospheric vertical temperature and moisture profiles. For this reason it is important that systematic differences between observations and calculations under well-characterized condition...