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Author (up) Bará, S. url  doi
openurl 
  Title Anthropogenic disruption of the night sky darkness in urban and rural areas Type Journal Article
  Year 2016 Publication Royal Society Open Science Abbreviated Journal R. Soc. open sci.  
  Volume 3 Issue 10 Pages 160541  
  Keywords Skyglow  
  Abstract The growing emissions of artificial light to the atmosphere are producing, among other effects, a significant increase of the night sky brightness (NSB) above its expected natural values. A permanent sensor network has been deployed in Galicia (northwest of Iberian peninsula) to monitor the anthropogenic disruption of the night sky darkness in a countrywide area. The network is composed of 14 detectors integrated in automated weather stations of MeteoGalicia, the Galician public meteorological agency. Zenithal NSB readings are taken every minute and the results are openly available in real time for researchers, interested stakeholders and the public at large through a dedicated website. The measurements allow one to assess the extent of the loss of the natural night in urban, periurban, transition and dark rural sites, as well as its daily and monthly time courses. Two metrics are introduced here to characterize the disruption of the night darkness across the year: the significant magnitude (m1/3) and the moonlight modulation factor (γ). The significant magnitude shows that in clear and moonless nights the zenithal night sky in the analysed urban settings is typically 14–23 times brighter than expected from a nominal natural dark sky. This factor lies in the range 7–8 in periurban sites, 1.6–2.5 in transition regions and 0.8–1.6 in rural and mountain dark sky places. The presence of clouds in urban areas strongly enhances the amount of scattered light, easily reaching amplification factors in excess of 25, in comparison with the light scattered in the same places under clear sky conditions. The periodic NSB modulation due to the Moon, still clearly visible in transition and rural places, is barely notable at periurban locations and is practically lost at urban sites.  
  Address  
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  Series Volume Series Issue Edition  
  ISSN 2054-5703 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ kyba @ Serial 1544  
Permanent link to this record
 

 
Author (up) Bará, S. url  doi
openurl 
  Title Light pollution and solid-state lighting: reducing the carbon dioxide footprint is not enough Type Journal Article
  Year 2014 Publication Proc. SPIE 8785, 8th Iberoamerican Optics Meeting and 11th Latin American Meeting on Optics, Lasers, and Applications, 87852G, 2013 Abbreviated Journal Proc. SPIE 8785  
  Volume 8785 Issue Pages  
  Keywords *Lighting; LED; light emitting diode; outdoor lighting; artificial light at night; lighting policy; solid-state lighting; blue light  
  Abstract Public and private lighting account for a relevant share of the overall electric power consumption worldwide. The pressing need of reducing the carbon dioxide emissions as well as of lowering the lumen•hour price tag has fostered the search for alternative lighting technologies to substitute for the incandescent and gas-discharge based lamps. The most successful approach to date, solid-state lighting, is already finding its way into the public lighting market, very often helped by substantial public investments and support. LED-based sources have distinct advantages: under controlled conditions their efficacy equals or surpasses that of conventional solutions, their small source size allows for an efficient collimation of the lightbeam (delivering the photons where they are actually needed and reducing lightspill on the surrounding areas), and they can be switched and/or dimmed on demand at very high rates, thus allowing for a tailored schedule of lighting. However, energy savings and carbon dioxide reduction are not the only crucial issues faced by present day lighting. A growing body of research has shown the significance of the spectral composition of light when it comes to assess the detrimental effects of artificial light-at-night (ALAN). The potential ALAN blueshift associated to the deployment of LED-based lighting systems has raised sensible concerns about its scientific, cultural, ecological and public health consequences, which can be further amplified if an increased light consumption is produced due to the rebound effect. This contribution addresses some of the challenges that these issues pose to the Optics and Photonics community.  
  Address Univ. de Santiago de Compostela, Spain; salva.bara@usc.es  
  Corporate Author Thesis  
  Publisher SPIE Place of Publication Editor  
  Language English Summary Language English Original Title  
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  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 1135  
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Author (up) Bará, S. url  doi
openurl 
  Title Naked-eye astronomy: optics of the starry night skies Type Journal Article
  Year 2014 Publication Proc. SPIE 9289, 12th Education and Training in Optics and Photonics Conference, 2014 Abbreviated Journal Proc. SPIE 9289  
  Volume 9289 Issue Pages  
  Keywords Society; light pollution  
  Abstract The world at night offers a wealth of stimuli and opportunities as a resource for Optics education, at all age levels and from any (formal, non formal or informal) perspective. The starry sky and the urban nightscape provide a unique combination of pointlike sources with extremely different emission spectra and brightness levels on a generally darker, locally homogeneous background. This fact, combined with the particular characteristics of the human visual system under mesopic and scotopic conditions, provides a perfect setting for experiencing first-hand different optical phenomena of increasing levels of complexity: from the eye's point spread function to the luminance contrast threshold for source detection, from basic diffraction patterns to the intricate irradiance fluctuations due to atmospheric turbulence. Looking at the nightscape is also a perfect occasion to raise awareness on the increasing levels of light pollution associated to the misuse of public and private artificial light at night, to promote a sustainable use of lighting, and to take part in worldwide citizen science campaigns. Last but not least, night sky observing activities can be planned and developed following a very flexible schedule, allowing individual students to carry them out from home and sharing the results in the classroom as well as organizing social events and night star parties with the active engagement of families and groups of the local community. This contribution describes these possibilities and introduces some of the free resources available to put them in practice.  
  Address Univ. de Santiago de Compostela, Spain; salva.bara@usc.es  
  Corporate Author Thesis  
  Publisher SPIE 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 1134  
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Author (up) Bará, S., Lima, R.C. url  doi
openurl 
  Title Photons without borders: quantifying light pollution transfer between territories Type Journal Article
  Year 2018 Publication International Journal of Sustainable Lighting Abbreviated Journal  
  Volume 20 Issue 2 Pages 51-61  
  Keywords Skyglow  
  Abstract The light pollution levels experienced at any given site generally depend on a wide number of artificial light sources distributed throughout the surrounding territory. Since photons can travel long distances before being scattered by the atmosphere, any effective proposal for reducing local light pollution levels needs an accurate assessment of the relative weight of all intervening light sources, including those located tens or even hundreds of km away. In this paper we describe several ways of quantifying and visualizing these relative weights. Particular emphasis is made on the aggregate contribution of the municipalities, which are -in many regions of the world- the administrative bodies primarily responsible for the planning and maintenance of public outdoor lighting systems.  
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  Notes Approved no  
  Call Number NC @ ehyde3 @ Serial 2066  
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Author (up) Bará, S., Ulla, A. url  openurl
  Title Light Pollution in the Galician Atlantic Islands Maritime-Terrestrial National Park 2018 Report Type Report
  Year 2018 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Conservation; Spain; Galicia; Europe; national park  
  Abstract The Galician Atlantic Islands Maritime-Terrestrial National Park (PNMTIAG), with the exception of the island of Cortegada, still has night skies of acceptable quality. However, the PNMTIAG islands are under strong photic pressures, both internal and external, that hinder the preservation of the basic features of the natural night, and call for an immediate action of all concerned stakeholders  
  Address  
  Corporate Author Thesis  
  Publisher USC Tragsa Place of Publication Editor  
  Language Galician Summary Language Galician 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 2187  
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