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Author Kocifaj, M.; Kundracik, F. url  doi
openurl 
  Title Multi-wavelength radiometry of aerosols designed for more accurate night sky brightness predictions Type Journal Article
  Year (down) 2020 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume 250 Issue Pages 106998  
  Keywords Skyglow; Remote Sensing  
  Abstract Scattering by aerosols and gases cause a certain fraction of artificial light emitted upwards is redirected to the ground. Of all atmospheric constituents just the aerosols are most important modulators of night-sky brightness under cloudless conditions. Unlike most of the previous we highlight a crucial role of solar radiometry for determining the atmospheric optical depth before night-time observation is to be made. Aerosol optical depth at visible wavelengths extracted from the data measured provides then the information on size distribution or mean refractive index of aerosol particles that in turn are both necessary to make night sky brightness prediction more accurate. Therefore, combining daytime and night-time radiometry we can achieve accuracy much higher than ever before. This is due to significantly reduced uncertainty in aerosol properties.

The aerosol data are retrieved from a new portable multi-wavelength optical analyzer that operates Ocean Optics spectrometer. The equipment provides the radiance data from 350 nm to 1000 nm with spectral resolution of 1 nm. Due to high sun radiance levels we use a system of mirrors each reducing the signal to about 4%, while keeping the integration time short. The minimum integration time of 3 ms allows for detection of direct sunlight. The system developed is sensitive to small changes in the aerosol system, while showing a good detection limit even under low turbidity conditions. The system performance is demonstrated in field experiment conducted shortly after front passage when most of aerosol particles is effectively removed by rain.
 
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  ISSN 0022-4073 ISBN Medium  
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  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2906  
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Author Hassan, M.; El‑Taieb, M.; Fares, N.; Fayed, H.; Toghan, R.; Ibrahim, H. url  doi
openurl 
  Title Men with idiopathic oligoasthenoteratozoospermia exhibit lower serum and seminal plasma melatonin levels: Comparative effect of night‑light exposure with fertile males Type Journal Article
  Year (down) 2020 Publication Experimental and Therapeutic Medicine Abbreviated Journal Exp Ther Med  
  Volume in press Issue Pages in press  
  Keywords Human Health  
  Abstract Melatonin is a darkness hormone secreted by the pineal gland, which serves a role in idiopathic oligoasthenoteratozoospermia (iOAT). The present study aimed to evaluate the seminal plasma and serum melatonin levels of 50 patients with iOAT and 50 normal fertile controls and the effects of exposure to light at night on semen parameters. Semen analyses were performed according to the World Health Organization 2010 guidelines. Measurements of serum and seminal plasma melatonin, serum TSH, FT3, FT4, free testosterone, prolactin, FSH and LH were performed using ELISA. The overall results revealed that the serum and seminal plasma levels of melatonin were lower in patients with iOAT compared with the control subjects (P=0.0004 and 0.01, respectively). Patients with iOAT who were exposed to light at night exhibited lower serum and seminal plasma melatonin levels compared with those who were not exposed to light at night (P<0.0001 and 0.02, respectively). Additionally, similar significant differences were identified in control subjects exposed to light at night when compared to non‑exposed controls. There was a significantly positive correlation between serum melatonin levels and sperm motility in the entire iOAT patient cohort (r=0.614; P<0.0001) and a significantly positive correlation between the serum and seminal plasma melatonin levels in the non‑exposed iOAT patient subgroup (r=0.753; P<0.001). Thus, darkness and sleep at night may improve the semen parameters of patients with iOAT, as evidenced by the effects of light exposure at night on the serum and seminal plasma levels of melatonin and, consequently, on semen parameters.  
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  ISSN 1792-0981 ISBN Medium  
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  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2907  
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Author Sanchez de Miguel, A.; Kyba, C.C.M.; Zamorano, J.; Gallego, J.; Gaston, K.J. url  doi
openurl 
  Title The nature of the diffuse light near cities detected in nighttime satellite imagery Type Journal Article
  Year (down) 2020 Publication Scientific Reports Abbreviated Journal Sci Rep  
  Volume 10 Issue Pages 7829  
  Keywords Skyglow; Remote Sensing; Instrumentation  
  Abstract Diffuse glow has been observed around brightly lit cities in nighttime satellite imagery since at least the first publication of large scale maps in the late 1990s. In the literature, this has often been assumed to be an error related to the sensor, and referred to as “blooming”, presumably in relation to the effect that can occur when using a CCD to photograph a bright light source. Here we show that the effect seen on the DMSP/OLS, SNPP/VIIRS-DNB and ISS is not only instrumental, but in fact represents a real detection of light scattered by the atmosphere. Data from the Universidad Complutense Madrid sky brightness survey are compared to nighttime imagery from multiple sensors with differing spatial resolutions, and found to be strongly correlated. These results suggest that it should be possible for a future space-based imaging radiometer to monitor changes in the diffuse artificial skyglow of cities.  
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  ISSN 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2909  
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Author Kocifaj, M.; Bará, S. url  doi
openurl 
  Title Aerosol characterization using satellite remote sensing of light pollution sources at night Type Journal Article
  Year (down) 2020 Publication Monthly Notices of the Royal Astronomical Society: Letters Abbreviated Journal MNRAS  
  Volume 495 Issue 1 Pages L76-L80  
  Keywords Skyglow; Radiative transfer; Light scattering; Aerosols  
  Abstract A demanding challenge in atmospheric research is the night-time characterization of aerosols using passive techniques, that is, by extracting information from scattered light that has not been emitted by the observer. Satellite observations of artificial night-time lights have been used to retrieve some basic integral parameters, like the aerosol optical depth. However, a thorough analysis of the scattering processes allows one to obtain substantially more detailed information on aerosol properties. In this letter, we demonstrate a practicable approach for determining the aerosol particle size number distribution function in the air column, based on the measurement of the angular radiance distribution of the scattered light emitted by night- time lights of cities and towns, recorded from low Earth orbit. The method is self-calibrating and does not require the knowledge of the absolute city emissions. The input radiance data are readily available from several spaceborne platforms, like the VIIRS-DNB radiometer onboard the Suomi-NPP satellite.  
  Address Faculty of Mathematics, Physics, and Informatics, Comenius University, Mlynska Dolina, 842 48 Bratislava, Slovakia; Miroslav.Kocifaj(at)savba.sk  
  Corporate Author Thesis  
  Publisher OUP Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1745-3925 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 2910  
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Author Wallner, S.; Kocifaj, M.; Komar, L.; Solano-Lamphar, H.A. url  doi
openurl 
  Title Night-sky imaging as a potential tool for characterization of total lumen output from small and medium-sized cities Type Journal Article
  Year (down) 2020 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal  
  Volume 494 Issue 4 Pages 5008-5017  
  Keywords Skyglow  
  Abstract In this article, the asymptotic formula developed in past work and applied to predict skyglow due to distant sources was evolved, with the objective of characterizing small and medium-sized cities in the observer's surroundings. To enable this, a combination of theoretical computations and in situ measurements is needed, aiming to distinguish between dominant and smaller light-emitting sources, with the latter usually being camouflaged when measuring the night sky. Furthermore, for numerical modelling of skyglow, few of the most important parameters, specifically the amount of total lumens installed and radiated to the upward hemisphere, can be derived. Astronomical observatories, in particular, can profit from this concept, since they are usually situated far away from large cities but can still be surrounded by smaller villages and towns. We present a detailed description of how theoretical computations are combined with all-sky photometry in order to obtain the properties mentioned. Results are compared with satellite data, showing that, regarding approximations undertaken for processing, they are comparable, underlining the functionality of our approach. The idea of including in situ observations enables us to quantify the impact of small and medium-sized cities globally and independent of location, as long as measurements were conducted outside light domes. In addition, the presented work may be of major interest to the light-pollution community if conducting long-term observations of cities, since the quality of commonly used satellite data is going to decrease in the future, due to blindness in short wavelengths and upcoming conversions of public lighting systems to blue-enlightened LEDs.  
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  Series Volume Series Issue Edition  
  ISSN 0035-8711 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2911  
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