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Author Kocifaj, M.; Kómar, L.
Title A role of aerosol particles in forming urban skyglow and skyglow from distant cities Type Journal Article
Year 2016 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS
Volume (down) 458 Issue 1 Pages 438-448
Keywords Skyglow; scattering; atmospheric effects; artificial light; numerical modeling; GIS-based modeling; light pollution
Abstract Aerosol particles may represent the largest uncertainty about skyglow change in many locations under clear sky conditions. This is because aerosols are ubiquitous in the atmosphere and influence the ground-reaching radiation in different ways depending on their concentrations, origins, shapes, sizes, and compositions. Large particles tend to scatter in Fraunhofer diffraction regime, while small particles can be treated in terms of Rayleigh formalism. However, the role of particle microphysics in forming the skyglow still remains poorly quantified. We have shown in this paper that the chemistry is somehow important for backscattering from large particles that otherwise work as efficient attenuators of light pollution if composed of absorbing materials. The contribution of large particles to the urban skyglow diminishes as they become more spherical in shape. The intensity of backscattering from non-absorbing particles is more-or-less linearly decreasing function of particle radius even if number size distribution is inversely proportional to the fourth power of particle radius. This is due to single particle backscattering that generally increases steeply as the particle radius approaches large values. Forward scattering depends on the particle shape but is independent of the material composition, thus allowing for a simplistic analytical model of skyglow from distant cities. The model we have developed is based on mean value theorem for integrals and incorporates the parametrizable Garstang's emission pattern, intensity decay along optical beam path, and near-forward scattering in an atmospheric environment. Such model can be used by modellers and experimentalists for rapid estimation of skyglow from distant light sources.
Address ICA, Slovak Academy of Sciences, Dúbravská Road 9, 845 03 Bratislava, Slovak Republic; kocifaj(at)savba.sk
Corporate Author Thesis
Publisher Oxford Journals Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1361
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Author Smith, M.
Title Time to turn off the lights Type Journal Article
Year 2009 Publication Nature Abbreviated Journal Nature
Volume (down) 457 Issue 7225 Pages 27
Keywords Editorial; Animal Migration/radiation effects; Animals; Astronomy/trends; Conservation of Energy Resources/economics/trends; *Darkness; Environmental Pollution/*adverse effects/economics/*prevention & control; Equipment Design/trends; Humans; Lighting/*adverse effects/economics
Abstract
Address Cerro Tololo Inter-American Observatory, Casilla 603, La Serena, Chile. msmith@ctio.noao.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-0836 ISBN Medium
Area Expedition Conference
Notes PMID:19122621 Approved no
Call Number LoNNe @ christopher.kyba @ Serial 466
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Author Kocifaj, M.; Solano Lamphar, H.A.; Kundracik, F.
Title Retrieval of Garstang's emission function from all-sky camera images Type Journal Article
Year 2015 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal Mon. Not. R. Astron. Soc.
Volume (down) 453 Issue 1 Pages 819-827
Keywords Skyglow; scattering; atmospheric effects; light pollution; methods: data analysis; methods: numerical methods: observational
Abstract The emission function from ground-based light sources predetermines the skyglow features to a large extent, while most mathematical models that are used to predict the night sky brightness require the information on this function. The radiant intensity distribution on a clear sky is experimentally determined as a function of zenith angle using the theoretical approach published only recently in MNRAS, 439, 3405–3413. We have made the experiments in two localities in Slovakia and Mexico by means of two digital single lens reflex professional cameras operating with different lenses that limit the system's field-of-view to either 180º or 167º. The purpose of using two cameras was to identify variances between two different apertures. Images are taken at different distances from an artificial light source (a city) with intention to determine the ratio of zenith radiance relative to horizontal irradiance. Subsequently, the information on the fraction of the light radiated directly into the upward hemisphere (F) is extracted. The results show that inexpensive devices can properly identify the upward emissions with adequate reliability as long as the clear sky radiance distribution is dominated by a largest ground-based light source. Highly unstable turbidity conditions can also make the parameter F difficult to find or even impossible to retrieve. The measurements at low elevation angles should be avoided due to a potentially parasitic effect of direct light emissions from luminaires surrounding the measuring site.
Address ICA, Slovak Academy of Sciences, Dúbravská Road 9, 845 03 Bratislava, Slovak Republic; kocifaj(at)savba.sk
Corporate Author Thesis
Publisher Oxford Journals Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1249
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Author Kocifaj, M.; Posch, T.; Solano Lamphar, H.A.
Title On the relation between zenith sky brightness and horizontal illuminance Type Journal Article
Year 2015 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS
Volume (down) 446 Issue Pages 2895–2901
Keywords Skyglow; scattering; atmospheric effects; light pollution; numerical methods
Abstract The effects of artificial light at night are an emergent research topic for astronomers, physicists, engineers and biologists around the world. This leads to a need for measurements of the night sky brightness (= diffuse luminance of the night sky) and nocturnal illuminance. Currently, the most sensitive light meters measure the zenith sky brightness in mag_V/arcsec^2 or – less frequently – in cd/m^2. However, the horizontal illuminance resulting only from the night sky is an important source of information that is difficult to obtain with common instruments. Here we present a set of approximations to convert the zenith luminance into horizontal illuminance. Three different approximations are presented for three idealized atmospheric conditions: homogeneous sky brightness, an isotropically scattering atmosphere and a turbid atmosphere. We also apply the resulting conversion formulae to experimental data on night sky luminance, obtained during the past three years.
Address Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska dolina, 842 48 Bratislava, Slovak Republic
Corporate Author Thesis
Publisher Royal Astronomical Society Place of Publication Editor
Language Summary Language 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 1076
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Author Sciezor, T.; Kubala, M.
Title Particulate matter as an amplifier for astronomical light pollution Type Journal Article
Year 2014 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal Monthly Notices of the Royal Astronomical Society
Volume (down) 444 Issue 3 Pages 2487-2493
Keywords atmospheric effects; light pollution; methods; data analysis; site testing
Abstract In this paper, we state that the main factor that influences seasonal changes in the brightness of the cloudless, moonless, light-polluted night sky is primarily particulate matter, emitted mainly from low-emission sources, especially in winter. This effect is particularly noticeable in Cracow and its surroundings, one of the places in Europe that is most polluted by particulate matter. Measurements taken over a period of one year have allowed us to show a linear relationship between the concentration of particulate matter and the brightness of the clear, cloudless night sky. We have also found similar correlations in other, industrialized areas of Poland, as well as at the Mount Suhora Astronomical Observatory. We believe that the factor described here should be taken into account when planning the construction of new astronomical observatories, especially those located near large urban areas.
Address Cracow University of Technology, Faculty of the Environmental Engineering, Warszawska 24, P-31-155 Kraków, Poland
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 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 366
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