Results 221 to 230 of about 30,314 (256)

From spectral clear sky emissivity to total clear sky emissivity

Solar & Wind Technology, 1989
Abstract From standard and observed atmospheric profiles a simple model to compute the spectral sky emissivity has been built, and compared with Lowtran-6 code calculations. In the present paper, it is analytically integrated. The relations expressing the total emissivity point out a small effect of hygrometry.
X. Berger, J. Bathiebo
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An Analytical Model for the Clear-Sky Longwave Feedback

Journal of the Atmospheric Sciences, 2022
Estimates of Earth’s clear-sky longwave feedback from climate models and observations robustly give a value of approximately -2 W/m^2/K, suggesting that this feedback can be estimated from first principles. Here we derive an analytical model for Earth’s clear-sky longwave feedback based on a novel spectral decomposition that splits the feedback into ...
Daniel DB Koll, Nadir Jeevanjee, Nicholas J Lutsko   +2 more
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Twilight and Daytime Colors of the Clear Sky

Light and Color in the Open Air, 1993
Several years ago Bohren and Fraser1 asked “How can anyone have the audacity to write about colors of the sky in the year 1985?” Nearly a decade later, writing about sky colors is no less audacious — and no less necessary.
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Color and luminance asymmetries in the clear sky

Applied Optics, 2003
A long-standing assumption about the clear sky is that its colors and luminances are distributed symmetrically about the principal plane. As useful as this approximation is, our digital-image analyses show that clear-sky color and luminance routinely depart perceptibly from exact symmetry.
Javier, Hernández-Andrés, Raymond L, Lee, Javier, Romero   +2 more
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Qualifying IMG tropical spectra for clear sky

Journal of Quantitative Spectroscopy and Radiative Transfer, 2003
The problem of cloud detection for the Interferometric Monitoring of Greenhouse Gases spectrometer has been addressed by considering a set of thresholding tests which takes full advantage of the high spectral resolution of the sensor. The methodology has been applied to a case study consisting of spectra recorded in the tropics on sea surface, although
MASIELLO, Guido, SERIO, Carmine, SHIMODA H.   +2 more
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Digital imaging of clear-sky polarization

Applied Optics, 1998
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.
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Standard distributions of clear sky radiance

Quarterly Journal of the Royal Meteorological Society, 1977
AbstractDiffuse radiation from cloudless skies varies with solar height and atmospheric turbidity but its angular distribution remains generally characteristic of single scattering. It was found that when sky radiance measurements, N, were normalized with respect to horizontal diffuse irradiance, Sd, the angular distributions of N/Sd were remarkably ...
Michael D. Steven, M. H. Unsworth
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Analytic Formula for the Clear‐sky UV Index

Photochemistry and Photobiology, 2007
AbstractAn approximate formula for the UV Index (UVI) under cloud‐free, unpolluted, low surface albedo conditions is: image where μo is the cosine of the solar zenith angle and Ω is the total vertical ozone column (in Dobson Units, DU). The dependence on μo and Ω is based on a simple physical model of biologically weighted atmospheric transmission in
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Nice colors and a clear sky

Acta Obstetricia et Gynecologica Scandinavica, 2011
Torbjørn Moe, Eggebø, Reynir Tómas, Geirsson   +1 more
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Thunderbolt from a Clear Sky

2018
This chapter deals with the outbreak of war in 1914, which exposed the poor quality and high geographical concentration of the acceptance business of some firms. The inconsistent and, in some cases, inequitable treatment of firms of foreign origin by the City establishment is examined.
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