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Author Kocifaj, M.; Solano Lamphar, H.A. url  doi
openurl 
  Title Quantitative analysis of night skyglow amplification under cloudy conditions Type Journal Article
  Year 2014 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal Monthly Notices of the Royal Astronomical Society  
  Volume (down) 443 Issue 4 Pages 3665-3674  
  Keywords Skyglow; radiative transfer; scattering; atmospheric effects; light pollution; methods: numerical  
  Abstract The radiance produced by artificial light is a major source of nighttime over-illumination. It can, however, be treated experimentally using ground-based and satellite data. These two types of data complement each other and together have a high information content. For instance, the satellite data enable upward light emissions to be normalized, and this in turn allows skyglow levels at the ground to be modelled under cloudy or overcast conditions. Excessive night lighting imposes an unacceptable burden on nature, humans and professional astronomy. For this reason, there is a pressing need to determine the total amount of downwelling diffuse radiation. Undoubtedly, cloudy periods can cause a significant increase in skyglow as a result of amplification owing to diffuse reflection from clouds. While it is recognized that the amplification factor (AF) varies with cloud cover, the effects of different types of clouds, of atmospheric turbidity and of the geometrical relationships between the positions of an individual observer, the cloud layer, and the light source are in general poorly known. In this paper the AF is quantitatively analysed considering different aerosol optical depths (AODs), urban layout sizes and cloud types with specific albedos and altitudes. The computational results show that the AF peaks near the edges of a city rather than at its centre. In addition, the AF appears to be a decreasing function of AOD, which is particularly important when modelling the skyglow in regions with apparent temporal or seasonal variability of atmospheric turbidity. The findings in this paper will be useful to those designing engineering applications or modelling light pollution, as well as to astronomers and environmental scientists who aim to predict the amplification of skyglow caused by clouds. In addition, the semi-analytical formulae can be used to estimate the AF levels, especially in densely populated metropolitan regions for which detailed computations may be CPU-intensive. These new results are of theoretical and experimental significance as they will motivate experimentalists to collect data from various regions to build an overall picture of the AF, and will encourage modellers to test the consistency with theoretical predictions.  
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  ISSN 0035-8711 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ christopher.kyba @ Serial 538  
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Author Kyba, C.C.M.; Ruhtz, T.; Fischer, J.; Hölker, F. url  doi
openurl 
  Title Red is the new black: how the colour of urban skyglow varies with cloud cover Type Journal Article
  Year 2012 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal Monthly Notices of the Royal Astronomical Society  
  Volume (down) 425 Issue 1 Pages 701-708  
  Keywords Keywords: skyglow; radiative transfer; atmospheric effects; instrumentation: detectors; light pollution  
  Abstract The development of street lamps based on solid-state lighting technology is likely to introduce a major change in the colour of urban skyglow (one form of light pollution). We demonstrate the need for long-term monitoring of this trend by reviewing the influences it is likely to have on disparate fields. We describe a prototype detector which is able to monitor these changes, and could be produced at a cost low enough to allow extremely widespread use. Using the detector, we observed the differences in skyglow radiance in red, green and blue channels. We find that clouds increase the radiance of red light by a factor of 17.6, which is much larger than that for blue (7.1). We also find that the gradual decrease in sky radiance observed on clear nights in Berlin appears to be most pronounced at longer wavelengths.  
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  ISSN 0035-8711 ISBN Medium  
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  Notes Approved no  
  Call Number IDA @ john @ Serial 272  
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Author Kocifaj, M.; Aubé, M.; Kohút, I. url  doi
openurl 
  Title The effect of spatial and spectral heterogeneity of ground-based light sources on night-sky radiances: Light pollution for heterogeneous sources Type Journal Article
  Year 2010 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal  
  Volume (down) 409 Issue 3 Pages 1203-1212  
  Keywords light pollution; scattering; atmospheric effects; methods: numerical  
  Abstract Nowadays, light pollution is a permanent problem at many observatories around the world. Elimination of excessive lighting during the night is not only about reduction of the total luminous power of ground-based light sources, but also involves experimenting with the spectral features of single lamps. Astronomical photometry is typically made at specific wavelengths, and thus the analysis of the spectral effects of light pollution is highly important. Nevertheless, studies on the spectral behaviour of night light are quite rare. Instead, broad-band or integral quantities (such as sky luminance) are preferentially measured and modelled. The knowledge of night-light spectra is necessary for the proper interpretation of narrow-band photometry data. In this paper, the night-sky radiances in the nominal spectral lines of the B (445 nm) and V (551 nm) filters are determined numerically under clear-sky conditions. Simultaneously, the corresponding sky-luminance patterns are computed and compared against the spectral radiances. It is shown that spectra, patterns and distances of the most important light sources (towns) surrounding an observatory are essential for determining the light pollution levels. In addition, the optical characteristics of the local atmosphere can change the angular behaviour of the sky radiance or luminance. All these effects are evaluated for two Slovakian observatories: Stará Lesná and Vartovka.  
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  ISSN 0035-8711 ISBN Medium  
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  Notes Approved no  
  Call Number IDA @ john @ Serial 259  
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Author Quinn, G.E.; Shin, C.H.; Maguire, M.G.; Stone, R.A. url  doi
openurl 
  Title Myopia and ambient lighting at night Type Journal Article
  Year 1999 Publication Nature Abbreviated Journal Nature  
  Volume (down) 399 Issue 6732 Pages 113-114  
  Keywords Human Health  
  Abstract Myopia, or short-sightedness, occurs when the image of distant objects, focused by the cornea and lens, falls in front of the retina. It commonly arises from excessive postnatal eye growth, particularly in the vitreous cavity. Its prevalence is increasing and now reaches 70-90% in some Asian populations1,2. As well as requiring optical correction, myopia is a leading risk factor for acquired blindness in adults because it predisposes individuals to retinal detachment, retinal degeneration and glaucoma. It typically develops in the early school years but can manifest into early adulthood2. Its aetiology is poorly understood but may involve genetic and environmental factors1,2, such as viewing close objects, although how this stimulates eye growth is not known3. We have looked at the effects of light exposure on vision, and find a strong association between myopia and night-time ambient light exposure during sleep in children before they reach two years of age.  
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  Language English Summary Language Original Title  
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  ISSN 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:10335839 Approved no  
  Call Number GFZ @ kyba @ Serial 2550  
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Author Wang, X.; Liu, G.; Coscieme, L.; Giannetti, B.F.; Hao, Y.; Zhang, Y.; Brown, M.T. url  doi
openurl 
  Title Study on the emergy-based thermodynamic geography of the Jing-Jin-Ji region: Combined multivariate statistical data with DMSP-OLS nighttime lights data Type Journal Article
  Year 2019 Publication Ecological Modelling Abbreviated Journal Ecological Modelling  
  Volume (down) 397 Issue Pages 1-15  
  Keywords Remote Sensing  
  Abstract Emergy analysis is one of the ecological thermodynamics methods. With a specific set of indicators, it is proved to be highly informative for sustainability assessment of national/regional economies. However, a large amount of data needed for its calculation are from official statistical data by administrative divisions. The spatialization of emergy in early researches were limited to the administrative boundaries. The emergy inside an administrative boundary renders a single value, which hides plenty of information for more precise regional planning.

This study develops a new methodology for mapping the spatial distribution of emergy density of a region. The renewable resource distribution can be mapped based on latest geospatial datasets and GIS technology, instead of solely relying on statistics and yearbooks data. Besides, a new spatialization method of non-renewable emergy based on DMSP-OLS nighttime lights data is proposed. Combined with the radiation calibration data, the problem of light saturation of DMSP-OLS nighttime lights data was solved to improve the emergy spatial detail of city centers. With a case study of Jing-Jin-Ji region, results showed that this method could generate a high-resolution map of emergy use, and depict human disturbance to the environment in a more precise manner. This may provide supportive information for more precise land use planning, strategic layout and policy regulation, and is helpful for regional sustainable development.
 
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  ISSN 0304-3800 ISBN Medium  
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  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2192  
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