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Author (up) Baddiley, C.
Title Light pollution modelling, and measurements at Malvern Hills AONB, of county conversion to blue rich LEDs Type Journal Article
Year 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume 219 Issue Pages 142-173
Keywords Skyglow
Abstract The introduction of blue rich colour, Correlated-Colour-Temperature (CCT) 6000K road lighting could increase skyglow significantly compared with CCT 3000K types, if the blue content reaches the sky.

Highways England have a policy for lighting specification on motorways advised by the author's work. This is a categorised environmental impact point system of summed brightness as a function of angle from vertically down to the cut off angle; but with no CCT limitation.

Modelling was done for Malvern-Hills Area-of-Outstanding-Natural-Beauty (MHAONB), for the nighttime environmental impact of the LED replacement of Low-Pressure-Sodium throughout Herefordshire. The study was extended to include High-Pressure-Sodium and to LEDs at several CCTs, for the same Photopic ground illuminance.

Dark-Sky-Survey geographic location results for the MHAONB (2012) are described. Near-Zenith sky brightness photometry became continuous from 2016 at 2 minute intervals in all weathers, not just clear nights, with a networked calibrated Unihedron Lensed Sky Quality Meter (LSQM). Samples were also taken of all-sky camera images, corrected for vignetting and near-Zenith calibrated with the LSQM, to study weather effects, Milky Way contribution, and Herefordshire lighting conversion to blue-rich LEDs (2013-15), compared with the less converted Severn valley direction.

Time-plots and histogram analysis showed a small reduction in brightness (2012-2018), 0.1 mag.arcsec−2. Most variation is from increased sampling of distant cloud cover effects. Mist or low cloud on the horizon obscures light sources beyond reducing local skyglow, while high cloud reflects, increasing clear sky brightness. The Milky Way is critically 20% above background. Darkest periods near Zenith reach 21.1 mag.arcsec−2, to 21.2 after rain or surrounding low-cloud or poor-visibility. Clear-sky brightness decreases into early hours (∼0.03 mag.arcsec−2/hr); dimming effects were not seen.

The Zenith brightness is still set by distant cities, while towards the horizon, commercial and private uncontrolled non-directional LED lighting is increasing, negating the improvements in road lighting.
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 GFZ @ kyba @ Serial 1914
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Author (up) Bagan, H.; Borjigin, H.; Yamagata, Y.
Title Assessing nighttime lights for mapping the urban areas of 50 cities across the globe Type Journal Article
Year 2018 Publication Environment and Planning B: Urban Analytics and City Science Abbreviated Journal Environment and Planning B: Urban Analytics and City Science
Volume Issue Pages 2399808317752926
Keywords Remote Sensing
Abstract Nighttime data from the Defense Meteorological Satellite Program Operational Linescan System have been widely used to map urban/built-up areas (hereafter referred to as “built-up area”), but to date there has not been a geographically comprehensive evaluation of the effectiveness of using nighttime lights data to map urban areas. We created accurate, convenient, and scalable grid cells based on Defense Meteorological Satellite Program/Operational Linescan System nighttime light pixels. We then calculated the density of Landsat-derived built-up areas within each grid cell. We explored the relationship between Defense Meteorological Satellite Program/Operational Linescan System nighttime lights data and the density of built-up areas to assess the utility of nighttime lights for mapping urban areas in 50 cities across the globe. We found that the brightness of nighttime lights was only in moderate agreement with the density of built-up areas; moreover, correlations between nighttime lights and Landsat-derived built-up areas were weak. Even in relatively sparsely populated urban regions (where the density of the built-up area is less than 20%), the highest correlation coefficient (R2) was only 0.4. Furthermore, nighttime lights showed lighted areas that extended beyond the area of large cities, and nighttime lights reduced the area of small cities. The results suggest that it is difficult to use the regression model to calibrate the Defense Meteorological Satellite Program/Operational Linescan System nighttime lights to fit urban built up areas.
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 2399-8083 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @; GFZ @ kyba @ Serial 1795
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Author (up) Bailey, L.A.; Brigham, R.M.; Bohn, S.J.; Boyles, J.G.; Smit, B.
Title An experimental test of the allotonic frequency hypothesis to isolate the effects of light pollution on bat prey selection Type Journal Article
Year 2019 Publication Oecologia Abbreviated Journal Oecologia
Volume in press Issue Pages
Keywords Animals; Ecology
Abstract Artificial lights may be altering interactions between bats and moth prey. According to the allotonic frequency hypothesis (AFH), eared moths are generally unavailable as prey for syntonic bats (i.e., bats that use echolocation frequencies between 20 and 50 kHz within the hearing range of eared moths) due to the moths' ability to detect syntonic bat echolocation. Syntonic bats therefore feed mainly on beetles, flies, true bugs, and non-eared moths. The AFH is expected to be violated around lights where eared moths are susceptible to exploitation by syntonic bats because moths' evasive strategies become less effective. The hypothesis has been tested to date almost exclusively in areas with permanent lighting, where the effects of lights on bat diets are confounded with other aspects of human habitat alteration. We undertook diet analysis in areas with short-term, localized artificial lighting to isolate the effects of artificial lighting and determine if syntonic and allotonic bats (i.e., bats that use echolocation frequencies outside the hearing range of eared moths) consumed more moths under conditions of artificial lights than in natural darkness. We found that syntonic bats increased their consumption of moth prey under experimentally lit conditions, likely owing to a reduction in the ability of eared moths to evade the bats. Eared moths may increase in diets of generalist syntonic bats foraging around artificial light sources, as opposed to allotonic species and syntonic species with a more specialized diet.
Address Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown, 6140, South Africa. b.smit@ru.ac.za
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 0029-8549 ISBN Medium
Area Expedition Conference
Notes PMID:31139944 Approved no
Call Number GFZ @ kyba @ Serial 2511
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Author (up) Bapary, M.A.J.; Takano, J.-I.; Soma, S.; Sankai, T.
Title Effect of blue LED light and antioxidants potential in a somatic cell Type Journal Article
Year 2019 Publication Cell Biology International Abbreviated Journal Cell Biol Int
Volume in press Issue Pages
Keywords Cells; Biology
Abstract Light is an indispensable part of routine laboratory works in which conventional light is generally used. Light-emitting diodes (LEDs) have come to replace the conventional light thus could be a potent target in biomedical studies. Since blue light is a major component of visible light wavelength, in this study, using a somatic cell from African green monkey kidney, we assessed the possible consequences of blue spectra of LED light in future animal experiments and proposed a potent mitigation against light induced damages. COS-7 cells were exposed to blue LED light (450 nm) and the growth and DNA damage were assessed at different exposure times. A higher suppression in cell growth and viability was observed under a longer period of blue LED light exposure. The number of apoptotic cells increased as light exposure time was prolonged. Reactive oxygen species generation was also elevated in accordance to the extension of light exposure times. A comparison to dark-maintained cells revealed that the upregulation of ROS by blue LED light plays a significant role in causing cellular dysfunction in DNA in a time-dependent manner. In turn, antioxidant treatment has shown to improve the cell growth and viability under blue LED light conditions. This indicates that antioxidants are potential against blue LED light-induced somatic cell damage. It is expected that this study will contribute to the understanding of the basic mechanism of somatic cell death under visible light and to maximize the beneficial use of LED light in future animal experiments. This article is protected by copyright. All rights reserved.
Address Tsukuba Primate Research Center, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Japan
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 1065-6995 ISBN Medium
Area Expedition Conference
Notes PMID:30958611 Approved no
Call Number GFZ @ kyba @ Serial 2328
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Author (up) Bará, S.
Title Black-body luminance and magnitudes per square arcsecond in the Johnson-Cousins BVR photometric bands Type Journal Article
Year 2019 Publication Photonics Letters of Poland Abbreviated Journal Photon. Lett. Pl.
Volume 11 Issue 3 Pages 63
Keywords Skyglow; night sky brightness; luminance; photometric
Abstract A relevant amount of light pollution studies deal with the unwanted visual effects of artificial light at night, including the anthropogenic luminance of the sky that hinders the observation of the celestial bodies which are a main target of ground-based astrophysical research, and a key asset of the intangible heritage of humankind. Most quantitative measurements and numerical models, however, evaluate the anthropogenic sky radiance in any of the standard Johnson-Cousins UBVRI photometric bands, generally in the V one. Since the Johnson-Cousins V band is not identical with the visual CIE V-lambda used to assess luminance, the conversion between these two photometric systems turns out to be spectrum-dependent. Given its interest for practical applications, in this Letter we provide the framework to perform this conversion and the transformation constants for black-body spectra of different absolute temperatures.
Address Dept. Física Aplicada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia
Corporate Author Thesis
Publisher Photonics Society of Poland Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2080-2242 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2685
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