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Author (up) Aubé, M.; Kocifaj, M.
Title Using two light-pollution models to investigate artificial sky radiances at Canary Islands observatories: Light-pollution models and artificial sky radiances Type Journal Article
Year 2012 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 422 Issue 1 Pages 819-830
Keywords Keywords: radiative transfer; atmospheric effects; light pollution; methods: observational; site testing
Abstract Astronomical observations are increasingly limited by light pollution, which is a product of the over-illumination of the night sky. To predict both the angular distribution of scattered light and the ground-reaching radiative fluxes, a set of models has been introduced in recent decades. Two distinct numerical tools, MSNsRAu and ILLUMINA, are compared in this paper, with the aim of identifying their strengths and weaknesses. The numerical experiment comprises the simulation of spectral radiances in the region of the Canary Islands. In particular, the light fields near the Roque de los Muchachos and Teide observatories are computed under various turbidity conditions. It is shown that ILLUMINA has enhanced accuracy at low elevation angles. However, ILLUMINA is time-consuming because of the two scattering orders incorporated into the calculation scheme. Under low-turbidity conditions and for zenith angles smaller than 70° the two models agree well, and thus can be successfully applied to typical cloudless situations at the majority of observatories. MSNsRAu is well optimized for large-scale simulations. In particular, the grid size is adapted dynamically depending on the distance between a light source and a hypothetical observer. This enables rapid numerical modelling for large territories. MSNsRAu is also well suited for the mass modelling of night-sky radiances after ground-based light sources are hypothetically changed. This enables an optimum design of public lighting systems and a time-efficient evaluation of the optical effects related to different lamp spectra or different lamp distributions. ILLUMINA provides two diagnostic geographical maps to help local authorities concerned about light-pollution control. The first map allows the identification of the relative contribution of each ground element to the observed sky radiance at a given viewing angle, while the second map gives the sensitivity, basically saying how each ground element contributes per lumen installed.
Address
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 256
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Author (up) Aubé, M.; Kocifaj, M.
Title Editorial: Special issue on remote sensing of light pollution Type Journal Article
Year 2016 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume 181 Issue Pages 1
Keywords Commentary
Abstract
Address
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 0022-4073 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1441
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Author (up) Aubé, M.; Kocifaj, M.; Zamorano, J.; Solano Lamphar, H.A.; Sanchez de Miguel, A.
Title The spectral amplification effect of clouds to the night sky radiance in Madrid Type Journal Article
Year 2016 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume 181 Issue Pages 11-23
Keywords Skyglow; Madrid; Spain; Europe; artificial light at night; light pollution; clouds; amplification
Abstract Artificial Light at Night (ALAN) may have various environmental impacts ranging from compromising the visibility of astronomical objects to the perturbation of circadian cycles in animals and humans. In the past much research has been carried out to study the impact of ALAN on the radiance of the night sky during clear sky conditions. This was mainly justified by the need for a better understanding of the behavior of ALAN propagation into the environment in order to protect world-class astronomical facilities. More recently, alongside to the threat to the natural starry sky, many issues have emerged from the biological science community. It has been shown that, nearby or inside cities, the presence of cloud cover generally acts as an amplifier for artificial sky radiance while clouds behave as attenuators for remote observers. In this paper we show the spectral behavior of the zenith sky radiance amplification factor exerted by clouds inside a city. We compare in-situ measurements made with the spectrometer SAND-4 with a numerical model applied to the specific geographical context of the Universidad Complutense de Madrid in Spain.
Address Cégep de Sherbrooke, 475 rue du Cégep, Sherbrooke, Canada J1E 4K1; aubema(at)gmail.com
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 IDA @ john @ Serial 1351
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Author (up) Aubé, M.; Roby, J.
Title Sky brightness levels before and after the creation of the first International Dark Sky Reserve, Mont-Mégantic Observatory, Québec, Canada Type Journal Article
Year 2014 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal JQSRT
Volume 139 Issue Pages 52-63
Keywords Skyglow; measurements; metrology; Mont-Mégantic; Quebec; Canada; modelling; radiative transfer; sky quality; sky brightness
Abstract In 2007, the area around the Mont-Mégantic Observatory (MMO) was officially certified by the International Dark-Sky Association and the Royal Astronomy Association of Canada as the first International Dark Sky Reserve (IDSR). In order to be able to investigate the impact of Artificial Light at Night on night sky brightness before and after the establishment of the IDSR, we used a heterogeneous artificial sky brightness model including an implicit calculation of 2nd order scattering (ILLUMINA) developed by Martin Aubé's group. This model generates three kinds of outputs: the sky radiance at the given site, observing angle and wavelength and the corresponding contribution and sensitivity maps. The maps allow for the identification of the origin of the sky radiance according to each part of the surrounding territory. For summer clear sky conditions, the results show that replacing light fixtures within a 25 km radius around the MMO with cut-off High Pressure Sodium devices and reducing the total installed radiant power to ~40% of its initial level are very efficient ways of reducing artificial sky brightness. The artificial sky brightness reduction at zenith observed after the establishment of the IDSR was ~50% in the 546 nm mercury spectral line, while the reduction obtained in the 569 nm sodium line was ~30%. A large part of that reduction can be associated to the reduction in radiant power. The contribution and sensitivity maps highlight critical zones where any changes in the lighting infrastructure have the most important impact on sky brightness at the MMO. Contribution and sensitivity maps have been used to analyze the detailed origin of sky brightness reduction. The results of this study are intended to support authorities in the management of their lighting infrastructure with the goal of reducing sky brightness. The results have been shared with MMO officials and are being used as a tool to improve sky quality at the observatory.
Address Tel.: +1 819 564 6350x4146.
Corporate Author Thesis
Publisher ScienceDirect 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 IDA @ john @ Serial 1099
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Author (up) Aubé, M.; Roby, J.; Kocifaj, M.
Title Evaluating potential spectral impacts of various artificial lights on melatonin suppression, photosynthesis, and star visibility Type Journal Article
Year 2013 Publication PloS one Abbreviated Journal PLoS One
Volume 8 Issue 7 Pages e67798
Keywords Humans; *Light; Lighting/methods; Melatonin/*metabolism; Photosynthesis/*radiation effects; Plant Development/radiation effects; blue light; circadian disruption
Abstract Artificial light at night can be harmful to the environment, and interferes with fauna and flora, star visibility, and human health. To estimate the relative impact of a lighting device, its radiant power, angular photometry and detailed spectral power distribution have to be considered. In this paper we focus on the spectral power distribution. While specific spectral characteristics can be considered harmful during the night, they can be considered advantageous during the day. As an example, while blue-rich Metal Halide lamps can be problematic for human health, star visibility and vegetation photosynthesis during the night, they can be highly appropriate during the day for plant growth and light therapy. In this paper we propose three new indices to characterize lamp spectra. These indices have been designed to allow a quick estimation of the potential impact of a lamp spectrum on melatonin suppression, photosynthesis, and star visibility. We used these new indices to compare various lighting technologies objectively. We also considered the transformation of such indices according to the propagation of light into the atmosphere as a function of distance to the observer. Among other results, we found that low pressure sodium, phosphor-converted amber light emitting diodes (LED) and LED 2700 K lamps filtered with the new Ledtech's Equilib filter showed a lower or equivalent potential impact on melatonin suppression and star visibility in comparison to high pressure sodium lamps. Low pressure sodium, LED 5000 K-filtered and LED 2700 K-filtered lamps had a lower impact on photosynthesis than did high pressure sodium lamps. Finally, we propose these indices as new standards for the lighting industry to be used in characterizing their lighting technologies. We hope that their use will favor the design of new environmentally and health-friendly lighting technologies.
Address Departement de physique, Cegep de Sherbrooke, Sherbrooke, Quebec, Canada. martin.aube@cegepsherbrooke.qc.ca
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 1932-6203 ISBN Medium
Area Expedition Conference
Notes PMID:23861808; PMCID:PMC3702543 Approved no
Call Number IDA @ john @ Serial 282
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