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Author Kocifaj, M.; Solano Lamphar, H.A.; Kundracik, F.
Title Retrieval of Garstang's emission function from all-sky camera images Type Journal Article
Year 2015 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal Mon. Not. R. Astron. Soc.
Volume (down) 453 Issue 1 Pages 819-827
Keywords Skyglow; scattering; atmospheric effects; light pollution; methods: data analysis; methods: numerical methods: observational
Abstract The emission function from ground-based light sources predetermines the skyglow features to a large extent, while most mathematical models that are used to predict the night sky brightness require the information on this function. The radiant intensity distribution on a clear sky is experimentally determined as a function of zenith angle using the theoretical approach published only recently in MNRAS, 439, 3405–3413. We have made the experiments in two localities in Slovakia and Mexico by means of two digital single lens reflex professional cameras operating with different lenses that limit the system's field-of-view to either 180º or 167º. The purpose of using two cameras was to identify variances between two different apertures. Images are taken at different distances from an artificial light source (a city) with intention to determine the ratio of zenith radiance relative to horizontal irradiance. Subsequently, the information on the fraction of the light radiated directly into the upward hemisphere (F) is extracted. The results show that inexpensive devices can properly identify the upward emissions with adequate reliability as long as the clear sky radiance distribution is dominated by a largest ground-based light source. Highly unstable turbidity conditions can also make the parameter F difficult to find or even impossible to retrieve. The measurements at low elevation angles should be avoided due to a potentially parasitic effect of direct light emissions from luminaires surrounding the measuring site.
Address ICA, Slovak Academy of Sciences, Dúbravská Road 9, 845 03 Bratislava, Slovak Republic; kocifaj(at)savba.sk
Corporate Author Thesis
Publisher Oxford Journals 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 Conference
Notes Approved no
Call Number IDA @ john @ Serial 1249
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Author Xiaolong, G.; Mo, Z.; Xian, L.; Ce, S.; Changbin, S.; Ying, L.
Title Effects of LED light quality on the growth, metabolism, and energy budgets of Haliotis discus discus Type Journal Article
Year 2016 Publication Aquaculture Abbreviated Journal Aquaculture
Volume (down) 453 Issue Pages 31-39
Keywords Animals; Abalone; LED; Metabolism; Energy budgets; Haliotis discus; Haliotis discus discus; Photobiology
Abstract In this study, a bioenergetics approach was used to examine the effects of different LED light qualities (red, orange, blue, green light, natural light and a dark setting) on the growth and survival of the abalone Haliotis discus discus, and its physiological response mechanism under different light qualities. The results suggest that under blue or green light, the survival rate, specific growth rate, food intake, and food conversion efficiency of H. d. discus were significantly lower than in those groups under red or orange light (P < 0.05). Under red or orange light, pepsin, amylase and cellulose activity was significantly higher than those in any other light quality group (P < 0.05), whereas lipase activity exhibited no significant difference among the light quality groups (P > 0.05). Under blue or green light, lactate dehydrogenase activity and lactic acid content were higher (P < 0.05), suggesting enhanced anaerobic metabolism. Under blue or green light, H. d. discus lost more energy via excretion, feces and respiration than was acquired from its food. Under red or orange light, H. d. discus acquired more energy from its food and lost less energy via excretion and feces; as a result, its assimilation efficiency (K1) and net growth efficiency (K2) were significantly higher than those of any other group (P < 0.05). Therefore, we suggest that red or orange light should be used as a light source for the aquaculture of H. d. discus.
Address Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
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 0044-8486 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1311
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Author Kocifaj, M.; Posch, T.; Solano Lamphar, H.A.
Title On the relation between zenith sky brightness and horizontal illuminance Type Journal Article
Year 2015 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS
Volume (down) 446 Issue Pages 2895–2901
Keywords Skyglow; scattering; atmospheric effects; light pollution; numerical methods
Abstract The effects of artificial light at night are an emergent research topic for astronomers, physicists, engineers and biologists around the world. This leads to a need for measurements of the night sky brightness (= diffuse luminance of the night sky) and nocturnal illuminance. Currently, the most sensitive light meters measure the zenith sky brightness in mag_V/arcsec^2 or – less frequently – in cd/m^2. However, the horizontal illuminance resulting only from the night sky is an important source of information that is difficult to obtain with common instruments. Here we present a set of approximations to convert the zenith luminance into horizontal illuminance. Three different approximations are presented for three idealized atmospheric conditions: homogeneous sky brightness, an isotropically scattering atmosphere and a turbid atmosphere. We also apply the resulting conversion formulae to experimental data on night sky luminance, obtained during the past three years.
Address Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska dolina, 842 48 Bratislava, Slovak Republic
Corporate Author Thesis
Publisher Royal Astronomical Society Place of Publication Editor
Language Summary Language 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 1076
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Author Sciezor, T.; Kubala, M.
Title Particulate matter as an amplifier for astronomical light pollution Type Journal Article
Year 2014 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal Monthly Notices of the Royal Astronomical Society
Volume (down) 444 Issue 3 Pages 2487-2493
Keywords atmospheric effects; light pollution; methods; data analysis; site testing
Abstract In this paper, we state that the main factor that influences seasonal changes in the brightness of the cloudless, moonless, light-polluted night sky is primarily particulate matter, emitted mainly from low-emission sources, especially in winter. This effect is particularly noticeable in Cracow and its surroundings, one of the places in Europe that is most polluted by particulate matter. Measurements taken over a period of one year have allowed us to show a linear relationship between the concentration of particulate matter and the brightness of the clear, cloudless night sky. We have also found similar correlations in other, industrialized areas of Poland, as well as at the Mount Suhora Astronomical Observatory. We believe that the factor described here should be taken into account when planning the construction of new astronomical observatories, especially those located near large urban areas.
Address Cracow University of Technology, Faculty of the Environmental Engineering, Warszawska 24, P-31-155 Kraków, Poland
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 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 366
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Author Kocifaj, M.; Solano Lamphar, H.A.
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.
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 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ christopher.kyba @ Serial 538
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