scholarly journals Study on the Change Characters of the Urban Spatial Light Pollution from Ground to Zenith

2018 ◽  
Author(s):  
Ming Liu ◽  
Baogang Zhang ◽  
Qingli Hao ◽  
Xiaowei Guo ◽  
Weishan Li
Keyword(s):  
Urban Space ◽  
Urban Canopy ◽  
Light Environment ◽  
Ground Layer ◽  
Color Temperature ◽  
Light Pollution ◽  
Canopy Layer ◽  
Artificial Lighting ◽  
Urban Canopy Layer ◽  
Night Sky

As the problem of light pollution becomes more serious, more and more scholars pay attention to this issue and carry out related research. In the perspective of cities, the measurements of light pollution mainly focus on the brightness of the sky or artificial lighting on the ground. However, there is lack of research on the whole urban space. With the two-dimensional brightness analyses, this paper processes the changes of the light environment of the whole urban space into image quantization. It gets the 3D and 2D light environment changes of luminance distribution, color temperature distribution and chromaticity in the three space layers, the ground layer, the urban canopy layer and the sky layer, from dusk with natural light to night with artificial lighting completely. It is found that the brightness difference between the light environments among the three city levels gradually reduces with the measuring time, and the final values maintain at 0.11~0.25 cd/m2. In the ground layer, the light environment is mainly affected by the lighting facilities, and vegetation can prevent the light from scattering up. The light environment of the urban canopy layer is the brightest in the whole city space and has the largest influence on the sky layer. The color concentrates in the range of yellow and red. The color temperature near the ground distributes in 3000K~15000K, and near the sky distributes in 2300K~2700K which is warmer than the natural night sky. The sky brightness of Dalian city is about 951 times than the natural night sky. 

scholarly journals Perceptions, Practices and Principles: Increasing Awareness of ‘Night Sky’ in Urban Landscapes

SURG Journal ◽  
2011 ◽  
Vol 5 (1) ◽  
pp. 54-62
Author(s):  
Robin Mosseri
Keyword(s):  
Literature Review ◽  
Public Perception ◽  
Light Pollution ◽  
Urban Landscapes ◽  
Public Realm ◽  
Artificial Lighting ◽  
Design Considerations ◽  
Planning And Design ◽  
Night Sky ◽  
Natural Cycles

In urban centres the natural cycles of day and night have dramatically been altered by artificial lighting, creating a perpetually lit environment that is rarely considered an issue. Artificial lights are illuminating roadways, structures and public plazas with lighting schemes that are, in most cases, inefficient. Consequently, light pollution has greatly impacted the night by reflecting and refracting light into the atmosphere. Without appropriate consideration of integrating artificial lighting into the urban environment, our “night sky” experience is at risk due to poor approaches to public realm design. This study qualitatively explores light pollution analyzing it based on the environment, society and economy as a whole. A literature review, key informants, and case studies contribute to a greater understanding of light and create a framework to develop a design reference to light efficient urban development. This study examines the need for a shift in public perception, broadening an understanding of the effects of light pollution, and provides design considerations to aid urban night sky awareness, planning and design.

scholarly journals Coloured light pollution in the urban environment

2019 ◽  
Vol 11 (4) ◽  
pp. 93
Author(s):  
Justyna Kowalska
Keyword(s):  
Urban Space ◽  
Marine Biology ◽  
High Efficiency ◽  
Organic Light Emitting Diodes ◽  
Color Temperature ◽  
Light Pollution ◽  
Light At Night ◽  
Light Emitting ◽  
Engineering Society ◽  
Night Illumination

The article deals with issues related to colored lighting occurring in urban space. On the example of the Colosseum Amphitheatre 3D model, applications of colorful illumination were shown and the rationale for using color in individual cases was discussed. The aim of the article is to draw attention to proper planning and modernization of lighting to limit the negative interference of light in the ecosystem. Full Text: PDF ReferencesP. R. Boyce, "The benefits of light at night", Building and Environment, 151, 356-367 (2019) CrossRef Y. Hu,T. Zhang ,J. Chen, D. Ma ,C. Cheng, " Hybrid Organic Light-Emitting Diodes with Low Color-Temperature and High Efficiency for Physiologically- Friendly Night Illumination", Israel Journal of Chemistry, 54, 979-985 (2014) CrossRef W. Jernarczyk, "Dwa oblicza światła", Kosmos, 64, 625-632 (2015) DirectLink J.D.Bullough, M.S Mies, "The blue-light hazard:A review", Journal of the Illuminating Engineering Society,29, 6-14 (2013) CrossRef M. Rivas., P.T. Santidrian, J. U. Dieguez, A. Marco, " Leatherback hatchling sea-finding in response to artificial lighting:Interaction between wavelenght and moonlight", Journal of Experimental Marine Biology and Ecology, 463, 143-149 (2015) CrossRef S. Marcinkowska, E. Tęgowska, "Oddziaływanie światła o różnym spectrum na bezkręgowce zmierzchu I pełnego dnia", Kosmos, 64, 589-597 (2015) DirectLink P. Jakubowski, "Wpływ rozkładu widmowego mocy promienistej ulicznych opraw oświetleniowych typu LED na zanieczyszczenie światłem otoczenia", Kosmos, 64, 643-653 (2015) DirectLink K. Skarżyński, "Iluminacja obiektów architektonicznych a zanieczyszczenie środowiska światłem", Kosmos, 64, 553-562 (2015) DirectLink P. Tabaka, I. Fryc, "Zależność poziomu zanieczyszczenia otoczenia światłem od kształtu krzywej użytkowanej oprawy oświetleniowej", Kosmos, 64, 669-677 (2015) DirectLink W.Żagan, K.Skarżyński, "Analysis of light pollution from floodlighting: Is there a different approach to floodlighting?", Light and Engineering, 25, 75-82 (2017) DirectLink J.Kowalska, "Zanieczyszczenie światłem barwnym obrazu miast", Polish Journal for Sustainable Development, 21, 69-76 (2017) CrossRef C.Gardner, "The use and misuse of coloured lighting in the urban enviroment", Optics&Laser Technology, 38, 366-376 (2006) CrossRef

scholarly journals Evidence That Reduced Air and Road Traffic Decreased Artificial Night-Time Skyglow during COVID-19 Lockdown in Berlin, Germany

2020 ◽  
Vol 12 (20) ◽  
pp. 3412
Author(s):  
Andreas Jechow ◽  
Franz Hölker
Keyword(s):  
Road Traffic ◽  
Satellite Image ◽  
Color Temperature ◽  
Light Pollution ◽  
Artificial Light ◽  
Night Time ◽  
Sky Brightness ◽  
Night Sky ◽  
The Impact ◽  
Night Sky Brightness

Artificial skyglow, the brightening of the night sky by artificial light at night that is scattered back to Earth within the atmosphere, is detrimental to astronomical observations and has an impact on ecosystems as a form of light pollution. In this work, we investigated the impact of the lockdown caused by the COVID-19 pandemic on the urban skyglow of Berlin, Germany. We compared night sky brightness and correlated color temperature (CCT) measurements obtained with all-sky cameras during the COVID-19 lockdown in March 2020 with data from March 2017. Under normal conditions, we expected an increase in night sky brightness (or skyglow, respectively) and CCT because of the transition to LED. This is supported by a measured CCT shift to slightly higher values and a time series analysis of night-time light satellite data showing an increase in artificial light emission in Berlin. However, contrary to this observation, we measured a decrease in artificial skyglow at zenith by 20% at the city center and by more than 50% at 58 km distance from the center during the lockdown. We assume that the main cause for the reduction of artificial skyglow originates from improved air quality due to less air and road traffic, which is supported by statistical data and satellite image analysis. To our knowledge, this is the first reported impact of COVID-19 on artificial skyglow and we conclude that air pollution should shift more into the focus of light pollution research.

scholarly journals Absolute moisture content in mid-latitude urban canopy layer

2018 ◽  
Vol 51-52 (1) ◽  
pp. 37-45 ◽  
Author(s):  
János Unger ◽  
Nóra Skarbit ◽  
Tamás Gál
Keyword(s):  
Spatial Distribution ◽  
Moisture Content ◽  
Case Studies ◽  
Urban Canopy ◽  
Absolute Humidity ◽  
Temperature Dependent ◽  
Canopy Layer ◽  
Urban Canopy Layer ◽  
Absolute Measure ◽  
Urban Rural

This part of the study on absolute moisture content in the mid-latitude urban canopy layer first gives a comparison on intra-urban relative and absolute humidity patterns showing an example based on a long dataset. The comparison clearly demonstrates the usefulness of the utilization of absolute measure opposite to the temperature dependent relative one. This supports the earlier statements found in the literature albeit these statements are based on only case studies or short datasets. Then a short overview follows which presents the main results of studies about urban absolute moisture content. These studies focused mainly on urban-rural and less on intra-urban humidity differences. The scale differences are used for the grouping of studies based on the number of available measurement sites as well as their spatial distribution and density in the investigated urban regions.

scholarly journals Observations of Air Temperature in the Urban Canopy Layer in Nagahama-city

1998 ◽  
Vol 26 ◽  
pp. 487-492
Author(s):  
Hirohito KIRIHARA ◽  
Takeshi FUJINO ◽  
Takehiko MIKAMI
Keyword(s):  
Air Temperature ◽  
Urban Canopy ◽  
Canopy Layer ◽  
Urban Canopy Layer
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