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Author Solano Lamphar, H.A.; Kocifaj, M.
Title Urban night-sky luminance due to different cloud types: A numerical experiment Type Journal Article
Year 2015 Publication Lighting Research and Technology Abbreviated Journal Lighting Res. & Tech.
Volume 48 Issue 8 Pages 1017-1033
Keywords Skyglow; modeling; urban; clouds; radiative transfer
Abstract In this paper, we analyse theoretically and numerically the sky glow in urban and suburban areas, focusing on the zenith-normalised luminance of a cloudy sky. The results suggest that the altitude of a cloud imposes important changes in the luminance distribution. Peak values of sky luminance can be observed at a distance d = R + h tan (z), where R is the city radius, and h is the cloud altitude. Fluctuations of the zenith-normalised luminance over the city are dictated by three effects, specifically (i) extinction and backscatter in the undercloud atmosphere, (ii) the cloud properties and (iii) the radiant intensity function of the dominant ground-based light sources. For high clouds, the aerosol optical property is evident at moderate elevation angles. The light beams emitted from different parts of the city propagate along different inclined trajectories before they contribute to the elevated zenith luminance of low clouds. Then, multiple factors combine together to form the light field at the ground, city-size and city emission pattern being of specific importance.
Address Cátedras CONACYT, Instituto de investigaciones Dr José María Luis Mora, Programa Interdisciplinario de Estudios Metropolitanos (CentroMet), Plaza Valentín Gómez Farías #12 Col. San Juan Mixcoac, México D.F. C.P 03730. E-mail: lamphar(at)gmail.com
Corporate Author Thesis
Publisher SAGE Place of Publication Editor
Language English Summary Language (down) English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1477-0938 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1225
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Author Bará, S.; Ribas, S.; Kocifaj, M.
Title Modal evaluation of the anthropogenic night sky brightness at arbitrary distances from a light source Type Journal Article
Year 2015 Publication Journal of Optics Abbreviated Journal J. of Optics
Volume 17 Issue Pages 105607
Keywords Skyglow; light propagation, atmospheric optics, light pollution
Abstract The artificial emissions of light contribute to a high extent to the observed brightness of the night sky in many places of the world. Determining the all-sky radiance of anthropogenic origin requires solving the radiative transfer equation for ground-level light sources, generally resorting to a double-scattering approximation in order to account for the observed radiance patterns with a reasonable degree of accuracy. Since the all-sky radiance distribution produced by an elementary light source depends on the distance to the observer in a way that is not immediately obvious, the contributions of sources located at different distances have to be computed on an individual basis, solving for each one the corresponding scattering integrals. In this paper we show that these calculations may be significantly alleviated by using a modal approach, whereby the hemispheric night-sky radiance is expanded in terms of a convenient basis of two-dimensional (2D) orthogonal functions. Since the modal coefficients of this expansion do vary smoothly with the distance to the observer, the all-sky brightness distributions produced by light sources located at arbitrary intermediate distances can be efficiently estimated by interpolation, provided that the coefficients at a discrete set of distances are accurately determined beforehand.
Address Area de Optica, Universidade de Santiago de Compostela Campus Sur, E-15782, Santiago de Compostela, Spain; salva.bara(at)usc.es
Corporate Author Thesis
Publisher IOP Place of Publication Editor
Language English Summary Language (down) English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-8986 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1235
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Author Wakefield, A.; Stone, E.L.; Jones, G.; Harris, S.
Title Light-emitting diode street lights reduce last-ditch evasive manoeuvres by moths to bat echolocation calls Type Journal Article
Year 2015 Publication Royal Society Open Science Abbreviated Journal Roy. Soc. Open Sci.
Volume 2 Issue 8 Pages
Keywords Animals; artificial lighting; light-emitting diode; street lights; bats; moth predation; Nyctalus
Abstract The light-emitting diode (LED) street light market is expanding globally, and it is important to understand how LED lights affect wildlife populations. We compared evasive flight responses of moths to bat echolocation calls experimentally under LED-lit and -unlit conditions. Significantly, fewer moths performed ‘powerdive’ flight manoeuvres in response to bat calls (feeding buzz sequences from Nyctalus spp.) under an LED street light than in the dark. LED street lights reduce the anti-predator behaviour of moths, shifting the balance in favour of their predators, aerial hawking bats.
Address School of Biological Sciences, Life Sciences Building, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
Corporate Author Thesis
Publisher Royal Society Place of Publication Editor
Language English Summary Language (down) 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 1237
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Author Ouyang, J.Q; Maaike de Jong, M.H.; Visser, M.E.; van Grunsven, R.H.A.; Ouyang, J.Q
Title Stressful colours: corticosterone concentrations in a free-living songbird vary with the spectral composition of experimental illumination Type Journal Article
Year 2015 Publication Biology Letters Abbreviated Journal Biol. Lett.
Volume 11 Issue Pages 20150517
Keywords Animals; birds; corticosterone; stress; Parus major; great tit; artificial light; light spectra
Abstract Organisms have evolved under natural daily light/dark cycles for millions of years. These cycles have been disturbed as night-time darkness is increasingly replaced by artificial illumination. Investigating the physiological consequences of free-living organisms in artificially lit environments is crucial to determine whether nocturnal lighting disrupts circadian rhythms, changes behaviour, reduces fitness and ultimately affects population numbers. We make use of a unique, large-scale network of replicated field sites which were experimentally illuminated at night using lampposts emanating either red, green, white or no light to test effect on stress hormone concentrations (corticosterone) in a songbird, the great tit (Parus major). Adults nesting in white-light transects had higher corticosterone concentrations than in the other treatments. We also found a significant interaction between distance to the closest lamppost and treatment type: individuals in red light had higher corticosterone levels when they nested closer to the lamppost than individuals nesting farther away, a decline not observed in the green or dark treatment. Individuals with high corticosterone levels had fewer fledglings, irrespective of treatment. These results show that artificial light can induce changes in individual hormonal phenotype. As these effects vary considerably with light spectrum, it opens the possibility to mitigate these effects by selecting street lighting of specific spectra.
Address Department of Animal Ecology, The Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands; j.ouyang(at)nioo.knaw.nl
Corporate Author Thesis
Publisher Royal Society Place of Publication Editor
Language English Summary Language (down) 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 1248
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Author Bará, S.; Espey, B.; Falchi, F.; Kyba, C.C.M.; Nievas, M., Pescatori, P., Ribas, S.J., Sánchez de Miguel, A.; Staubmann, P., Tapia Ayuga, C.; Wuchterl, G., Zamorano, J.
Title Report of the 2014 LoNNe Intercomparison Campaign Type Report
Year 2015 Publication Abbreviated Journal
Volume Issue 32989 Pages
Keywords skyglow
Abstract The 2014 LoNNe (Loss of the Night Network) intercomparison campaign is the second of four campaigns planned during EU COST Action ES1204. The goal of these campaigns is to understand systematic uncertainty inherent in observations of skyglow (light pollution). An innovation of this year’s campaign was to take measurements with many of the nstruments at two sites: an urban location and a location far from artificial lights. This report summarizes the meeting, and also provides three recommendations for obtaining and analyzing handheld SQM observations.
Address
Corporate Author Thesis
Publisher Universidad Complutense Place of Publication Madrid Editor
Language English Summary Language (down) English Original Title
Series Editor Series Title e-prints Complutense Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1254
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