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Author Barentine, J.C.; Walker, C.E.; Kocifaj, M.; Kundracik, F.; Juan, A.; Kanemoto, J.; Monrad, C.K.
Title Skyglow Changes Over Tucson, Arizona, Resulting From A Municipal LED Street Lighting Conversion Type Journal Article
Year 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume 212 Issue Pages 10-23
Keywords Skyglow; Tucson; Arizona; LED; modeling; radiative transfer; LED
Abstract The transition from earlier lighting technologies to white light-emitting diodes (LEDs) is a significant change in the use of artificial light at night. LEDs emit considerably more short-wavelength light into the environment than earlier technologies on a per-lumen basis. Radiative transfer models predict increased skyglow over cities transitioning to LED unless the total lumen output of new lighting systems is reduced. The City of Tucson, Arizona (U.S.), recently converted its municipal street lighting system from a mixture of fully shielded high- and low-pressure sodium (HPS/LPS) luminaires to fully shielded 3000 K white LED luminaires. The lighting design intended to minimize increases to skyglow in order to protect the sites of nearby astronomical observatories without compromising public safety. This involved the migration of over 445 million fully shielded HPS/LPS lumens to roughly 142 million fully shielded 3000 K white LED lumens and an expected concomitant reduction in the amount of visual skyglow over Tucson. SkyGlow Simulator models predict skyglow decreases on the order of 10-20% depending on whether fully shielded or partly shielded lights are in use. We tested this prediction using visual night sky brightness estimates and luminance-calibrated, panchromatic all-sky imagery at 15 locations in and near the city. Data were obtained in 2014, before the LED conversion began, and in mid-2017 after approximately 95% of  ~18,000 luminaires was converted. Skyglow differed marginally, and in all cases with valid data changed by  <±20%. Over the same period, the city’s upward-directed optical radiance detected from Earth orbit decreased by approximately 7%. While these results are not conclusive, they suggest that LED conversions paired with dimming can reduce skyglow over cities.
Address International Dark-Sky Association, 3223 N 1st Ave, Tucson, AZ, 85719 USA; john(at)darksky.org
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 (up) Conference
Notes Approved no
Call Number IDA @ john @ Serial 1819
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Author Aubé, M.; Simoneau, A.; Muñoz-Tuñón, C.; Díaz-Castro, J.; Serra-Ricart, M.
Title Restoring the night sky darkness at Observatorio del Teide: First application of the model Illumina version 2 Type Journal Article
Year 2020 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 497 Issue 3 Pages 2501-2516
Keywords Skyglow; Teide Observatory; Tenerife; Spain; modeling; Illumina; numerical methods
Abstract The propagation of artificial light into real environments is complex. To perform its numerical modelling with accuracy, one must consider hyperspectral properties of the lighting devices and their geographic positions, the hyperspectral properties of the ground reflectance, the size and distribution of small-scale obstacles, the blocking effect of topography, the lamps angular photometry and the atmospheric transfer function (aerosols and molecules). A detailed radiative transfer model can be used to evaluate how a particular change in the lighting infrastructure may affect the sky radiance. In this paper, we use the new version (v2) of the Illumina model to evaluate a night sky restoration plan for the Teide Observatory located on the island of Tenerife, Spain. In the past decades, the sky darkness was severely degraded by growing light pollution on the Tenerife Island. In this work, we use the contribution maps giving the effect of each pixel of the territory to the artificial sky radiance. We exploit the hyperspectral capabilities of Illumina v2 and show how the contribution maps can be integrated over regions or municipalities according to the Johnson–Cousins photometric bands spectral sensitivities. The sky brightness reductions per municipality after a complete shutdown and a conversion to light-emitting diodes are calculated in the Johnson–Cousins B, V, R bands. We found that the conversion of the lighting infrastructure of Tenerife with LED (1800 and 2700 K), according to the conversion strategy in force, would result in a zenith V-band sky brightness reduction of ≈0.3 mag arcsec−2.
Address Département de physique, Cégep de Sherbrooke, Sherbrooke, 475 rue du Cégep, Sherbrooke, Québec J1E 4K1, Canada; martin.aube ( at ) cegepsherbrooke.qc.ca
Corporate Author Thesis
Publisher Oxford Academic 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 (up) Conference
Notes Approved no
Call Number IDA @ john @ Serial 3406
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