Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (11)

Search Parameters:
Keywords = sky glow

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
13 pages, 4106 KiB  
Article
A Paradox of LED Road Lighting: Reducing Light Pollution Is Not Always Linked to Energy Savings
by Irena Fryc, Maciej Listowski, Christophe Martinsons, Jiajie Fan and Dariusz Czyżewski
Energies 2024, 17(22), 5727; https://doi.org/10.3390/en17225727 - 15 Nov 2024
Cited by 1 | Viewed by 1598
Abstract
A variety of LED types can be employed for street and road lighting purposes. White phosphor-converted LEDs represent the most widely used option. However, amber LEDs are increasingly being used to reduce some negative effects associated with light pollution. These LEDs can be [...] Read more.
A variety of LED types can be employed for street and road lighting purposes. White phosphor-converted LEDs represent the most widely used option. However, amber LEDs are increasingly being used to reduce some negative effects associated with light pollution. These LEDs can be manufactured using both phosphor-converted and monochromatic direct chip technologies. This paper addresses the link between the reduction in short-wavelength light emissions which contribute to sky glow and the energy efficiency of LED-based road lighting. This paper focuses on an example illustrating the common misconception that reducing light pollution also means saving energy. Through the consideration of how spectral power distribution influences both mesopic vision and the amount of emitted blue light, it has been concluded that while monochromatic direct amber LEDs consume more energy than their white or amber phosphor-converted counterparts, their use in outdoor lighting is justifiable due to their potential effects of reducing sky brightness. Full article
(This article belongs to the Section B: Energy and Environment)
Show Figures

Figure 1

17 pages, 2477 KiB  
Article
Quantifying Night Sky Brightness as a Stressor for Coastal Ecosystems in Moreton Bay, Queensland
by Noam Levin, Rachel Madeleine Cooper and Salit Kark
Remote Sens. 2024, 16(20), 3828; https://doi.org/10.3390/rs16203828 - 15 Oct 2024
Cited by 1 | Viewed by 1405
Abstract
Growing light pollution is increasingly studied in terrestrial environments. However, research on night lights in coastal ecosystems is limited. We aimed to complement spaceborne remote sensing with ground-based hemispheric photos to quantify the exposure of coastal habitats to light pollution. We used a [...] Read more.
Growing light pollution is increasingly studied in terrestrial environments. However, research on night lights in coastal ecosystems is limited. We aimed to complement spaceborne remote sensing with ground-based hemispheric photos to quantify the exposure of coastal habitats to light pollution. We used a calibrated DSLR Canon camera with a fisheye lens to photograph the night sky in 24 sites in the rapidly developing area of Moreton Bay, Queensland, Australia, extracting multiple brightness metrics. We then examined the use of the LANcubeV2 photometer and night-time satellite data from SDGSAT-1 for coastal areas. We found that the skies were darker in less urbanized areas and on islands compared with the mainland. Sky brightness near the zenith was correlated with satellite observations only at a coarse spatial scale. When examining light pollution horizontally above the horizon (60–80° degrees below the zenith), we found that the seaward direction was brighter than the landward direction in most sites due to urban glow on the seaward side. These findings emphasize the importance of ground measurements of light pollution alongside satellite imagery. In order to reduce the exposure of coastal ecosystems to light pollution, actions need to go beyond sites with conservation importance and extend to adjacent urban areas. Full article
(This article belongs to the Special Issue Nighttime Light Remote Sensing Products for Urban Applications)
Show Figures

Figure 1

28 pages, 8540 KiB  
Review
Earthquake Lights Observed in Japan—Possible Underlying Mechanisms
by Yuji Enomoto
Atmosphere 2024, 15(8), 916; https://doi.org/10.3390/atmos15080916 - 31 Jul 2024
Cited by 2 | Viewed by 7464
Abstract
In Japan, a country prone to earthquakes, numerous damaging earthquakes have been recorded throughout history, often accompanied by descriptions of mysterious earthquake lights (EQL), which may involve various mechanisms. In this article, the possible mechanisms for different types of EQL in 11 cases [...] Read more.
In Japan, a country prone to earthquakes, numerous damaging earthquakes have been recorded throughout history, often accompanied by descriptions of mysterious earthquake lights (EQL), which may involve various mechanisms. In this article, the possible mechanisms for different types of EQL in 11 cases are reviewed among 21 selected earthquakes. These involve preseismic physicochemical variations in the geological structure of the fault in the lithosphere, which contains deep Earth gases such as radon, methane, and others, as a primary factor for EQL generation. Additionally, various seismic, atmospheric, hydrospheric, and ionospheric variations interact with each other, resulting in the visualization of characteristic anomalous phenomena, such as glowing or shining ground, mountains, offshore areas, and skies of various colors. These phenomena appear momentarily but can sometimes last for extended periods. Because EQL often appear just before an earthquake, their study might be significant for earthquake prediction. Additionally, EQL involving methane flames in the ground is an important research topic as it relates to public safety. Was what they witnessed paranormal? Full article
(This article belongs to the Special Issue Recent Advances in Lightning Research)
Show Figures

Figure 1

23 pages, 2211 KiB  
Article
Calibrating Nighttime Satellite Imagery with Red Photometer Networks
by Borja Fernandez-Ruiz, Miquel Serra-Ricart, Miguel R. Alarcon, Samuel Lemes-Perera, Idafen Santana-Perez and Juan Ruiz-Alzola
Remote Sens. 2023, 15(17), 4189; https://doi.org/10.3390/rs15174189 - 25 Aug 2023
Viewed by 2457
Abstract
The data retrieved from satellite imagery and ground-based photometers are the two main sources of information on light pollution and are thus the two main tools for tackling the problem of artificial light pollution at night (ALAN). While satellite data offer high spatial [...] Read more.
The data retrieved from satellite imagery and ground-based photometers are the two main sources of information on light pollution and are thus the two main tools for tackling the problem of artificial light pollution at night (ALAN). While satellite data offer high spatial coverage, on the other hand, photometric data provide information with a higher degree of temporal resolution. Thus, studying the proper correlation between both sources will allow us to calibrate and integrate them to obtain data with both high temporal resolution and spatial coverage. For this purpose, more than 15,000 satellite measurements and 400,000 measurements from 72 photometers for the year 2022 were used. The photometers used were the Sky-Glow Wireless Autonomous Sensor (SG-WAS) and Telescope Encoder and Sky Sensor WIFI (TESS-W) types, located at different ground-based locations, mainly in Spain. These photometers have a spectral sensitivity closer to that of VIIRS than to the Sky Quality Meter (SQM). In this study, a good correlation of data from the Day–Night Band (DNB) from the Visible Infrared Imaging Radiometer Suite (VIIRS) with a red photometric network between 19.41 mag/arcsec2 and 21.12 mag/arcsec2 was obtained. Full article
(This article belongs to the Section Urban Remote Sensing)
Show Figures

Figure 1

14 pages, 5646 KiB  
Communication
NSKY-CD: A System for Cloud Detection Based on Night Sky Brightness and Sky Temperature
by Luciano Massetti, Alessandro Materassi and Francesco Sabatini
Remote Sens. 2023, 15(12), 3063; https://doi.org/10.3390/rs15123063 - 12 Jun 2023
Cited by 4 | Viewed by 2893
Abstract
Cloud cover is important meteorological information that still requires expensive equipment to be monitored from the ground, especially at night. The use of artificial lights at night causes light pollution, and clouds amplify this by reflecting light downward. In addition, cloud thermal radiation [...] Read more.
Cloud cover is important meteorological information that still requires expensive equipment to be monitored from the ground, especially at night. The use of artificial lights at night causes light pollution, and clouds amplify this by reflecting light downward. In addition, cloud thermal radiation emissions affect sky temperature. In this study, we describe a system (NSKY-CD) that can be used to detect clouds at night since it integrates a sky quality meter that measures night sky brightness (NSB) and an air temperature and an infrared temperature sensor that measure sky temperature. We defined a cloud detection method based on fixed threshold values determined with two different procedures that we called ‘optimal’ and ‘antimode’. We then quantitatively assessed the performance of these methods in detecting the presence or absence of clouds in the urban area of Florence during two full moon cycles. Accuracy for the ‘optimal’ method varied between 87% and 91%, while for the ‘antimode’ method, it varied between 86% and 89%. Our results suggest that the two parameters are complementary since NSB has a better performance on moonless nights, and the difference between air temperature and sky temperature has a better performance on moonlit nights. Our method can also be used to analyze historical series of NSB to estimate cloud presence backwards, thus providing important information for meteorological, environmental and astronomical studies. Full article
(This article belongs to the Special Issue Light Pollution Monitoring Using Remote Sensing Data II)
Show Figures

Figure 1

23 pages, 10475 KiB  
Article
Influence of Illumination Parameters on Night Sky Observation in Rural Areas
by Alejandro Martínez-Martín, Adrián Bocho-Roas, Diego Carmona-Fernández, Manuel Calderón-Godoy, Miguel Ángel Jaramillo-Morán and Juan Félix González
Sustainability 2023, 15(12), 9359; https://doi.org/10.3390/su15129359 - 9 Jun 2023
Cited by 4 | Viewed by 2385
Abstract
Currently, there are concerns about the significant increase in the level of night-time light pollution, which has become more dramatic in recent years. This causes several environmental problems and makes it impossible to observe the starry night sky, especially in rural areas where [...] Read more.
Currently, there are concerns about the significant increase in the level of night-time light pollution, which has become more dramatic in recent years. This causes several environmental problems and makes it impossible to observe the starry night sky, especially in rural areas where observatories are often located. Incorrect orientation and arrangement of lighting are often responsible for this pollution. This study quantified the level of interference of lighting parameters in the night sky. The influence of other environmental factors which may interfere with observation was also evaluated. A predictive model was developed to determine the level of darkness in rural areas. It was concluded that the distance from the emission point to the observation site is critical for sky observation. A series of guidelines were proposed for designing the lighting around observatories, which could help reduce light pollution and increase the stars’ perception. The conclusions and guidelines obtained could also be applied to designing the lighting in other areas, such as protected natural areas, historical monuments, urban lighting, and computer tools used for lighting. Globally, the results obtained in this study could help to reduce the level of night-time light pollution in rural areas, leading to improvements in the environment and in the observation of the night sky. This finding is of great relevance for astronomical observatories, which are spread around the world in strategic positions for sky observation, usually in rural areas. Full article
Show Figures

Figure 1

15 pages, 6922 KiB  
Article
SG-WAS: A New Wireless Autonomous Night Sky Brightness Sensor
by Miguel R. Alarcon, Marta Puig-Subirà, Miquel Serra-Ricart, Samuel Lemes-Perera, Manuel Mallorquín and César López
Sensors 2021, 21(16), 5590; https://doi.org/10.3390/s21165590 - 19 Aug 2021
Cited by 9 | Viewed by 4124
Abstract
The main features of SG-WAS (SkyGlow Wireless Autonomous Sensor), a low-cost device for measuring Night Sky Brightness (NSB), are presented. SG-WAS is based on the TSL237 sensor –like the Unihedron Sky Quality Meter (SQM) or the STARS4ALL Telescope Encoder and Sky Sensor (TESS)–, [...] Read more.
The main features of SG-WAS (SkyGlow Wireless Autonomous Sensor), a low-cost device for measuring Night Sky Brightness (NSB), are presented. SG-WAS is based on the TSL237 sensor –like the Unihedron Sky Quality Meter (SQM) or the STARS4ALL Telescope Encoder and Sky Sensor (TESS)–, with wireless communication (LoRa, WiFi, or LTE-M) and solar-powered rechargeable batteries. Field tests have been performed on its autonomy, proving that it can go up to 20 days without direct solar irradiance and remain hibernating after that for at least 4 months, returning to operation once re-illuminated. A new approach to the acquisition of average NSB measurements and their instrumental uncertainty (of the order of thousandths of a magnitude) is presented. In addition, the results of a new Sky Integrating Sphere (SIS) method have shown the possibility of performing mass device calibration with uncertainties below 0.02 mag/arcsec2. SG-WAS is the first fully autonomous and wireless low-cost NSB sensor to be used as an independent or networked device in remote locations without any additional infrastructure. Full article
(This article belongs to the Section Physical Sensors)
Show Figures

Figure 1

41 pages, 8060 KiB  
Article
Effect of Street Lighting on the Urban and Rural Night-Time Radiance and the Brightness of the Night Sky
by Tomasz Ściężor
Remote Sens. 2021, 13(9), 1654; https://doi.org/10.3390/rs13091654 - 23 Apr 2021
Cited by 33 | Viewed by 7721
Abstract
In April 2020, due to the coronavirus pandemic and the tourism decrease in Cracow (Poland), the Road Authority of the City of Cracow, followed by the authorities of several neighbouring municipalities, decided to turn off street lighting at night. It is worth noting [...] Read more.
In April 2020, due to the coronavirus pandemic and the tourism decrease in Cracow (Poland), the Road Authority of the City of Cracow, followed by the authorities of several neighbouring municipalities, decided to turn off street lighting at night. It is worth noting that this is the first time that street lighting has been turned off in such a large area on a longer time frame at this scale, including one of the most populated cities in Poland, which made it possible to make unique observations. During this period, with the help of small night-sky radiance meters (Sky Quality Meters (SQM)), many ground-based measurements were made, both within the city and in its vicinity. For this purpose, the existing light pollution monitoring stations in Cracow and neighbouring cities were used. It was found that after switching off street lighting, the zenith surface brightness of the cloudless sky decreased by 15–39%, and this value was proportional to the city’s population. The night-time light satellite data (VIIRS/DNB) on radiance from Cracow and neighbouring communes were also analysed, both their daily values as well as monthly and annual averages. It was found that in the case of a large city such as Cracow, turning off all street lighting reduces the amount of light energy radiated into the sky by about 50%, which is a relatively small decrease in radiance, while reducing the surface brightness of the night sky by about 40%, regardless of the state of the atmosphere. The effect of a significant decrease in radiance as a result of switching off street lighting was found in each of the analysed communes, especially the urbanised ones. Full article
(This article belongs to the Special Issue Light Pollution Monitoring Using Remote Sensing Data)
Show Figures

Figure 1

16 pages, 16167 KiB  
Article
Using Simulation-Based Modeling to Evaluate Light Trespass in the Design Stage of Sports Facilities
by Kwang-Hoon Kim and Gon Kim
Sustainability 2021, 13(9), 4725; https://doi.org/10.3390/su13094725 - 23 Apr 2021
Cited by 15 | Viewed by 3556
Abstract
Artificial light is a pollutant with broad implications for society. Consequently, laws and regulations aimed at curbing the improper use of artificial lighting (i.e., light pollution) are becoming common. For such laws to become effective, light pollution must first be evaluated and quantified. [...] Read more.
Artificial light is a pollutant with broad implications for society. Consequently, laws and regulations aimed at curbing the improper use of artificial lighting (i.e., light pollution) are becoming common. For such laws to become effective, light pollution must first be evaluated and quantified. Current methods for evaluating lit environments in sports facilities are only applicable after the facilities have been built, making it challenging to prevent light pollution preemptively. Here, a technique to predict light pollution during the planning stage is proposed. To analyze the upward light generated by the large lights found in sports facilities using a computer simulation, a method of defining a virtual horizontal board above the stadium is proposed. To analyze how light trespasses out of the stadium, a method of dividing and analyzing the space outside the stadium by zone is also presented. In addition, a method to predict the formation of high luminance surfaces under outdoor lighting is presented. The proposed methods are validated on two large sports facilities currently being constructed in Korea. As a consequence, horizontal and vertical illuminances are reduced by 74.5% and 72.2%, respectively. The methods are useful to lighting designers with interest in reducing light pollution. Full article
(This article belongs to the Special Issue Design of Architectural Sustainable Lighting)
Show Figures

Figure 1

32 pages, 6389 KiB  
Article
Assessment of Citizens’ Actions against Light Pollution with Guidelines for Future Initiatives
by Karolina M. Zielińska-Dabkowska, Kyra Xavia and Katarzyna Bobkowska
Sustainability 2020, 12(12), 4997; https://doi.org/10.3390/su12124997 - 18 Jun 2020
Cited by 51 | Viewed by 15259
Abstract
Due to the wide reach of media reports about scientific research and technological tools such as the world wide web (WWW), the Internet, and web browsers, citizens today have access to factual information about the negative impact of artificial light at night (ALAN) [...] Read more.
Due to the wide reach of media reports about scientific research and technological tools such as the world wide web (WWW), the Internet, and web browsers, citizens today have access to factual information about the negative impact of artificial light at night (ALAN) on their dark skies, and their health and well-being. This means they can now make educated decisions and take the necessary steps to help protect themselves and their communities from disruptive light pollution. Whilst this action is positive and welcomed, unfortunately, according to collected data, not all such initiatives have been successful. Although our understanding of this groundswell movement is deepening, further studies are required to complete a worldwide picture of the current situation. This paper therefore investigates the various actions taken by citizens, as well as the challenges, methods, and tools involved, regarding good practices initiated by grass roots activism on how to reduce existing and potential light pollution. The results of a comparative analysis of 262 international case studies (lawsuits and online petitions) reveal that, since the 1990s, there has been an increase in the number of legal cases related to light pollution due to the rise in public awareness, the availability of scientific knowledge via the Internet, and the ability to take accurate lighting measurements and perform lighting simulations. Also, in the last decade a new tool for digital participation in the form of online petitions has established a new movement of citizen action to mitigate the effects of light pollution. Based on this information, a seven-step framework involving recommendations for citizen action has been developed. It is expected that this new knowledge will benefit those citizens planning future efforts involving the development, implementation, and monitoring processes of outdoor lighting. Additionally, it might support the evolution of planning and policy approaches that are sustainable and necessary to improve the application and installation of ecologically/biologically responsible illumination for towns, cities, and natural habitats. Full article
Show Figures

Figure 1

19 pages, 8074 KiB  
Article
Influence of a Light Source Installed in a Luminaire of Opal Sphere Type on the Effect of Light Pollution
by Przemyslaw Tabaka and Pawel Rozga
Energies 2020, 13(2), 306; https://doi.org/10.3390/en13020306 - 8 Jan 2020
Cited by 12 | Viewed by 4406
Abstract
The article presents the results of the studies concerning the influence of a light source installed in luminaire of opal sphere type on the light pollution effect of the night sky. It is known from literature reports that the effect of light pollution [...] Read more.
The article presents the results of the studies concerning the influence of a light source installed in luminaire of opal sphere type on the light pollution effect of the night sky. It is known from literature reports that the effect of light pollution is influenced by the spectral distribution of light. Although the influence of the spectral distribution has been widely studied from different perspectives, there is still a need to study this phenomenon—for example, from the point of view of the spectral reflection properties of the ground, on which the lanterns are installed. Hence, the above-mentioned aspect was considered in the authors’ investigations. The luminaire considered has been equipped with 20 different light sources, including the latest generation of lamps (light-emitting diodes, LEDs) as well as the conventional ones. With respect to these light sources, the measurements of light distribution and spectral distribution of emitted radiation of the luminaire were performed. Having these measurement data, the simulations were carried out using the DIALux software, and the calculations were made using the specially prepared calculation tool. On the basis of the results obtained in this way this was stated that the type of light source installed in the luminaire has a significant effect on the sky glow. An important factor affecting light pollution is not only the value of the luminous flux emitted upward but also the spectral characteristics of the emitted radiation, the impact of which is most noticeable. The conclusions from the studies indicate the next steps in the analysis of the light pollution effect. These steps will be focused on extended analysis of LEDs as modern and developed light sources. Full article
(This article belongs to the Section B: Energy and Environment)
Show Figures

Figure 1

Back to TopTop