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Author Aubé, M.
Title Physical behaviour of anthropogenic light propagation into the nocturnal environment Type Journal Article
Year 2015 Publication Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences Abbreviated Journal Philos Trans R Soc Lond B Biol Sci
Volume 370 Issue Pages 20140117
Keywords (down) Skyglow; artificial light at night; light pollution; radiative transfer; atmospheric effects; scattering; methods; numerical; sensitivity analysis
Abstract Propagation of artificial light at night (ALAN) in the environment is now known to have non negligible consequences on fauna, flora and human health. These consequences depend on light levels and their spectral power distributions, which in turn rely on the efficiency of various physical processes involved in the radiative transfer of this light into the atmosphere and its interactions with the built and natural environment. ALAN can affect the living organisms by direct lighting and indirect lighting (scattered by the sky and clouds and/or reflected by local surfaces). This paper mainly focuses on the behaviour of the indirect light scattered under clear sky conditions. Various interaction processes between anthropogenic light sources and the natural environment are discussed. This work mostly relies on a sensitivity analysis conducted with the light pollution radiative transfer model, Illumina (Aubé et al. 2005: Light pollution modelling and detection in a heterogeneous environment: toward a night-time aerosol optical depth retrieval method. In Proc. SPIE 2005, vol. 5890, San Diego, California, USA). More specifically, the impact of (i) the molecular and aerosol scattering and absorption, (ii) the second order of scattering, (iii) the topography and obstacle blocking, (iv) the ground reflectance and (v) the spectrum of light devices and their angular emission functions are examined. This analysis considers different behaviour as a function of the distance from the city centre, along with different zenith viewing angles in the principal plane.
Address Département de physique, Cégep de Sherbrooke, Sherbrooke, Quebec, Canada
Corporate Author Thesis
Publisher Royal Society Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title The biological impacts of artificial light at night: from molecules to communities Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1115
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Author Bará, S.; Tilve, V.; Nievas, M.; Sanchez de Miguel, A.; Zamorano, J.
Title Zernike power spectra of clear and cloudy light-polluted urban night skies Type Journal Article
Year 2015 Publication Applied Optics Abbreviated Journal Appl. Opt.
Volume 54 Issue 13 Pages 4120-4129
Keywords (down) Skyglow; artificial ligh at night; light pollution; Zernike; power spectrum; atmospheric optics; imaging systems; image analysis
Abstract The Zernike power spectra of the all-sky night brightness distributions of clear and cloudy nights are computed using a modal projection approach. The results obtained in the B, V and R Johnson-Cousins' photometric bands during a one-year campaign of observations at a light-polluted urban site show that these spectra can be described by simple power laws with exponents close to -3 for clear nights and -2 for cloudy ones. The second-moment matrices of the Zernike coefficients show relevant correlations between modes. The multiplicative role of the cloud cover, that contributes to a significant increase of the brightness of the urban night sky in comparison with the values obtained in clear nights, is described in the Zernike space.
Address Area de Optica, Dept. Fisica Aplicada. Facultade de Fisica / Facultade de Optica e Optometría Universidade de Santiago de Compostela Campus Sur, E-15782 Santiago de Compostela, Galicia, Spain; salva.bara@usc.es
Corporate Author Thesis
Publisher Optical Society of America Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1156
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Author Wallner, S.; Kocifaj, M.
Title Impacts of surface albedo variations on the night sky brightness – A numerical and experimental analysis 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 106648
Keywords (down) Skyglow; albedo; surface albedo; Sky Quality Meter; Austria; Europe
Abstract The aim of this paper is to analyze surface albedo impacts on artificial night sky brightness at zenith. The way in which these parameters correlate with each other is analyzed numerically and then experimentally by Sky Quality Meters (SQMs) in the city of Linz, Austria between 2016 and 2018. Three SQMs are located in city areas that differ in ground type, while other two are installed outside but near the city. To eliminate systematic errors of different SQMs or a missing inter-calibration of all devices, we examine relative change in zenithal brightness instead of its absolute values. However, the ground albedo not only depends on the ground type, but also shows seasonal variation most often driven by vegetation and environmental change. To understand these changes, we use SkyGlow simulator to perform numerical experiments on four different albedo models. The results have proven that seasonal variations are clearly visible as green city parts become darker around autumn and ratios to urban located SQMs increase. We show that there is a major difference in simulation results if either conducting city parts with various surface albedos or using only one averaged value over the whole city. The latter produces worse fit to the observed SQM data, implying that a use of various surface albedos is a need when modelling zenithal brightness in artificially lit areas of a city or town. Also, the seasonal changes of surface albedo cannot be neglected and the parameter itself must be included in the modelling tools.
Address Department of Astrophysics, University of Vienna, Türkenschanzstrasse 17, 1180 Vienna, Austria; stefan.wallner(at)univie.ac.at
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language English 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 2675
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Author Aubé, M.; Franchomme-Fossé, L.; Robert-Staehler, P.; Houle, V.
Title Light pollution modeling and detection in a heterogeneous environment: toward a night time aerosol optical depth retrieval method. Type Journal Article
Year 2005 Publication Proceedings of SPIE 2005 -- Volume 5890, San Diego, California, USA. Abbreviated Journal
Volume 5890 Issue Pages
Keywords (down) Skyglow; aerosol optical depth;  remote sensing; light pollution; artificial skyglow
Abstract Tracking the Aerosol Optical Depth (AOD) is of particular importance in monitoring aerosol contributions to global radiative forcing. Until now, the two standard techniques used for retrieving AOD were; (i) sun photometry, and (ii) satellite based approaches, such as based DDV (Dense Dark Vegetation) inversion algorithms. These methods are only available for use during daylight time since they are based on direct or indirect observation of sunlight. Few attempts have been made to measure AOD behaviour at night. One such method uses spectrally ­ calibrated stars as reference targets but the number of available stars is limited. This is especially true for urban sites where artificial lighting hides most  of these stars. In this research, we  attempt  to provide an alternate method, one  which exploits artificial sky glow or light pollution. This methodology links a 3D light pollution model with in situ light pollution measurements. The basic idea is to adjust an AOD value into the model in order to fit measured light pollution. This method requires an accurate model that includes spatial heterogeneity in lighting angular geometry, in lighting spectral dependence, in ground spectral reflectance and in topography. This model, named ILLUMINA, computes 1st and 2nd order molecular and aerosol scattering, as well as aerosol absorption. These model features represent major improvements to previous light pollution models. Therefore, new possibilities for light pollution studies will arise, many of which are of particular interest to the astronomical community. In this paper we will present a first sensitive study applied to the ILLUMINA model.
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Call Number LoNNe @ kagoburian @ Serial 554
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Author Sánchez, S. F.; Aceituno, J.; Thiele, U.; Pérez-Ramírez, D.; Alves, J.
Title The Night Sky at the Calar Alto Observatory Type Journal Article
Year 2007 Publication Publications of the Astronomical Society of the Pacific Abbreviated Journal Publ Astron Soc Pac
Volume 119 Issue 860 Pages 1186-1200
Keywords (down) Skyglow, Darkness
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ISSN 0004-6280 ISBN Medium
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Notes Approved no
Call Number LoNNe @ christopher.kyba @ Serial 1131
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