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Author Kocifaj, M.
Title Ground albedo impacts on higher-order scattering spectral radiances of night sky Type Journal Article
Year 2019 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume 239 Issue Pages 106670
Keywords (down) skyglow
Abstract The contribution from ground reflected light to the night sky radiance is of increased interest because of constant modernization of street lighting systems that now efficiently eliminate light emissions above the horizontal plane, so the appreciable fraction of artificial light directed upwards is from ground reflection. Diffuse light of a night sky shows a positive correlation with ground albedo (α), but it seems there is no linear trend between α and the night sky brightness (NSB), at least not for all sky elements, and, the mechanism of this relationship becomes even more complicated due to multiple scattering effects. The extent to which the ground reflectance influences the higher-order scattering radiance of night sky, and, the factors that initiate the crossover from single- to multiple-scattering dominance of the sky glow has been virtually unexplored until now.

We demonstrate here that albedo-induced effects in NSB exhibit an angular dependence, with amplitudes enhanced towards shorter wavelengths. For low values of ground reflectance and at short distances from a light source, the second-scattering radiance is found to be only a few percent of the first-order scattering radiance. However, the ratio of a higher- to the first-order scattering radiance gradually increases near horizon, specifically at the side opposite to the azimuthal position of the light source. Also the NSB in blue band has decreasing gradation tendency when increasing the altitude above sea level. The findings in this paper are significant in a proper incorporation of higher-order scattering in modeling the NSB under elevated reflectance conditions, and may be critical for saving computational time.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4073 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2679
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Author Fryc, I.; Tabaka, P.
Title Outdoor Areas Lighting with LEDs – the Competition Between Scotopic Efficacy and Light Pollution Type Journal Article
Year 2019 Publication Photonics Letters of Poland Abbreviated Journal Photon.Lett.PL
Volume 11 Issue 3 Pages 75
Keywords (down) Skyglow
Abstract In this paper the effect of spectral power distribution SPD

of typical outdoor LED lamps on star visibility index SVI was analyzed.

For those lamps the nearest color temperature CCT [K] and scotopic

efficacy lm/W] data are also provided. The SVI has been defined as a

ratio of its scotopic flux to scotopic flux created by full moon light. The

calculations show that there is a strong relation between CCT of LEDs

and SVI index. Low CCT of the lamps does not significantly affect their

SVI value. Unfortunately, those kind of lamps are less attractive in

applications because of their low .
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2080-2242 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2692
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Author Jechow, A.; Hölker, F.
Title Snowglow—The Amplification of Skyglow by Snow and Clouds can Exceed Full Moon Illuminance in Suburban Areas Type Journal Article
Year 2019 Publication Journal of Imaging Abbreviated Journal J. Imaging
Volume 5 Issue 8 Pages 69
Keywords (down) Skyglow
Abstract Artificial skyglow, the fraction of artificial light at night that is emitted upwards from Earth and subsequently scattered back within the atmosphere, depends on atmospheric conditions but also on the ground albedo. One effect that has not gained much attention so far is the amplification of skyglow by snow, particularly in combination with clouds. Snow, however, has a very high albedo and can become important when the direct upward emission is reduced when using shielded luminaires. In this work, first results of skyglow amplification by fresh snow and clouds measured with all-sky photometry in a suburban area are presented. Amplification factors for the zenith luminance of 188 for snow and clouds in combination and 33 for snow alone were found at this site. The maximum zenith luminance of nearly 250 mcd/m2 measured with snow and clouds is a factor of 1000 higher than the commonly used clear sky reference of 0.25 mcd/m2. Compared with our darkest zenith luminance of 0.07 mcd/m2 measured for overcast conditions in a very remote area, this leads to an overall amplification factor of ca. 3500. Horizontal illuminance measurements show values of up to 0.79 lx, exceeding maximum possible full-moon illuminance levels by more than a factor of two. Additional measurements near the Arctic Circle for clear and overcast conditions are presented and strategies for further studies are discussed. We propose the term “snowglow” to describe the amplification of skyglow by snow with and without clouds.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2313-433X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2699
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Author Wuchterl, G.; Reithofer, M.
Title Licht über Wien V Type Journal Article
Year 2017 Publication Abbreviated Journal
Volume Issue Pages
Keywords (down) Skyglow
Abstract Die hier präsentierte Studie gibt einen detaillierten Überblick zur Entwicklung derLichtverschmutzung über dem Stadtgebiet von Wien in den Jahren 2011 bis 2017 und bietet einePrognose bis 2020. Damit ist international erstmals eine Langzeitstudie über die Entwicklung derLichtverschmutzung einer Großstadt verfügbar. Im Rahmen der begleitenden Untersuchungen sindAussagen über die Verursacher und ihre spezifischen Anteile an der Lichtverschmutzung Wiensmöglich. Die aktuelle Umrüstung auf LED-Technik wird diskutiert und findet Eingang in diePrognose. Neue Messungen und Analysen von internationalen Teams werden kurz vorgestellt undbezüglich ihrer Relevanz vergleichend mit unserer Studie diskutiert.
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Publisher Place of Publication Editor
Language German Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2717
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Author Wuchterl, G.; Reithofer, M.
Title Licht über Wien VI Type Journal Article
Year 2018 Publication Abbreviated Journal
Volume Issue Pages
Keywords (down) Skyglow
Abstract Im Zentrum Wiens sättigt die Erhellung der Nacht, am Stadtrand sinken die jährlichen Zuwächse, wäh-rend im Abstand von 36 Kilometern (Großmugl) die Nächte um 10 % pro Jahr heller werden.Der Gesamtaufwand der Wiener Lichtglocke liegt 2018 bei 37 MW. Der Verlauf von 2011 bis 2018 zeigt ein deutliches Lichtmaximum um 2014 und 2015. Danach stellen wir einen allmählichen Rückgang fest.Der Verlauf der Lichtglocke und noch deutlicher jener der Einzelstationen zeigt signifikante Schwankun-gen von Jahr zu Jahr. Zur Aufklärung der Ursachen, die weder astronomisch noch meteorologisch sind, wur-den monatliche Analysen des Lichtmessnetzes mit Daten des Luftmessnetzes der Wiener MA 22 kombiniert. Die natürliche Variation über das Jahr wurde genutzt, um Zusammenhänge zwischen den Monatsmedianen von Luftfeuchtigkeit und Feinstaub mit jenen der Globalstrahlungsdaten zu suchen.Von 2016 bis 2018 korrelieren die Globalstrahlungswerte mit der relativen Luftfeuchtigkeit und den Feinstaubwerten (PM10 und PM2,5). Die engste Beziehung besteht auf der Kuffner-Sternwarte, wo eine Verdoppelung der Luftfeuchtigkeit statistisch von einer Verzehnfachung der Globalstrahlung begleitet wird. Die gefundenen Relationen sind über einen Faktor 100 in der Globalstrahlung äußerst robust und die Koeffizienten der Relationen sind an allen Stationen sehr homogen.Damit stehen gut bestimmte Zusammenhänge zwischen der Luftgüte und dem Zustand der klaren Atmo-sphäre zur Verfügung. Das wird es erlauben, Lichtmessnetze auf Standardatmosphären zu beziehen und damit eine wesentlich bessere Vergleichbarkeit der Daten zu unterschiedlichen Zeitpunkten herzustellen.- 130 Gigawattstunden Jahresaufwand für die Wiener Lichtglocke- 8 Jahre Vermessung der Lichtglocke zeigen Ansätze eines Rückgangs der Lichtflut- Mehr Feinstaub bewirkt überproportional mehr Lichtverschmutzung
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language German Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2718
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