Energy Estimation of Light Pollution (the Case Study of the Vorobyovy Gory Nature Reserve in Moscow)

It was an August afternoon in 2003 when the lights went out on Broadway, and for that matter, throughout most of the Northeast, Midwest, and Ontario—a power blackout left 50 million customers in the dark overnight. Despite complaints about the inconveniences, the stranded commuters, and the food spoilage in restaurants and markets, many city dwellers were also awed; as evening came on, they gazed upward, and between the dark skyscrapers they could see something amazing—the starry night sky. The New York Times reported spontaneous stargazing gatherings in the usually electrified cities of the Northeast.

Light pollution is generally referred to as an unplanned increase in artificial lighting and the result is a change in light levels. Population growth and the rapid expansion of urbanization and industrialization can be a factor in increasing light pollution in Iran. Therefore, monitoring night light changes and determining areas with high light pollution is essential and can provide a new approach for environmental planners to use it to manage light pollution at the national and provincial levels. There are several tools for evaluating changes in night light, including operational linear satellite scanning data related to the Meteorological Defense Satellite Program (DMSP / OLS). These data not only help assess the severity of light pollution, but can also be used as a tool for pollution risk management and risk zoning. This study tries to analyze the spatial-temporal pattern of artificial light and light pollution in Iran between 1996 and 2013 by processing DMSP / OLS data and detects critical sources of light pollution. Night light data were used in six time periods (1996, 2001, 2004, 2006, 2011 and2013). The changes in night light and the intensity of light pollution on a national scale evaluated. Besides the relationship between the relative population density changes in each province and its effect on the changes in night light were analyzed in this research. The results show an increase in night light as well as conversion of low-brightness areas with high-brightness areas during study periods across the country. In addition, the provinces of Tehran and Alborz were identified as the provinces with the highest levels of light pollution in the country, and followed by Khuzestan, Isfahan, Bushehr and Fars. Increasing relative density and unbalanced distribution of population, migration and its intensification between 1996 and 2011 are the main factors in the increase light pollution in the country and also the concentration of maximum light pollution in some provinces.

Light pollution reduces activity, food consumption and growth rates in a sandy beach invertebrate

Spatio-temporal networks of light pollution

The modern lifestyle of many people takes place in conditions of "light pollution". Prolongation of the photoperiod not only inhibits the synthesis and secretion of melatonin (universal endogenous adaptogen), but also causes induction of anovulation and promotes premature puberty and premature aging, which may occur against the background of impaired secretion of sex hormones. The purpose of the study was to examine the long-term change in the light regime to the level of sex hormones, testosterone and estradiol in the blood plasma of rats. The experiment was performed on 120 Wistar rats. According to the nature of the action and intensity of lighting, we formed 3 groups (20 rats in each): K – control (intact), the animals of which were in natural light; group 12/12 – under the influence of artificial lighting for 12 hours a day: from 6 am to 6 pm and group 24/00 – under the influence of noctidial artificial lighting. Artificial lighting was carried out with an incandescent lamp with a power of 100 watts. The light intensity in the cages, which was measured using a Yu-117 luxmeter, was 40-50 lux. The content of free testosterone and estradiol was determined in the blood plasma of rats by enzyme-linked immunosorbent assay. Statistical processing of the obtained data was performed by methods of mathematical statistics. A statistically significant difference in averages was established using Student's test (t). The changes were considered significant at p≤0.05. While processing the obtained data, the ratio of testosterone/estradiol was calculated, the median estimate was given, and the oscillation ranges were 25-75% of the intervals. The study proved that in males, the change in light regime caused a statistically significant decrease in free testosterone levels and an increase in estradiol in plasma, while in females the opposite changes were observed. Hypertestosteronemia in females and hypotestosteronemia in males with changes in estradiol levels were also shown to be adaptive responses to the changes in the photoperiod. We found out that a statistically significant decrease in the ratio of testosterone/ estradiol in males (in the 12/12 group by 42.6%; in the 24/00 group – by 65%) and its increase in females (in the 12/12 group by 60.6%, in the 24/00 group – by 79%), were probably compensatory reactions to the stress factor, which was a long-term change in lighting. In general, a higher range of testosterone/estradiol index deviations in 24-hour rats (24/00) indicated that they had a more acute stress response to changes in lighting and reduced adaptability. This "adaptation fee" is generally aimed at survival, but leads to sexual dysfunction in rats

In 1879, Thomas Edison’s incandescent light bulbs first illuminated a New York street, and the modern era of electric lighting began. Since then, the world has become awash in electric light. Powerful lamps light up streets, yards, parking lots, and billboards. Sports facilities blaze with light that is visible for tens of miles. Business and office building windows glow throughout the night. According to the Tucson, Arizona–based International Dark-Sky Association (IDA), the sky glow of Los Angeles is visible from an airplane 200 miles away. In most of the world’s large urban centers, stargazing is something that happens at a planetarium. Indeed, when a 1994 earthquake knocked out the power in Los Angeles, many anxious residents called local emergency centers to report seeing a strange “giant, silvery cloud” in the dark sky. What they were really seeing—for the first time—was the Milky Way, long obliterated by the urban sky glow. None of this is to say that electric lights are inherently bad. Artificial light has benefited society by, for instance, extending the length of the productive day, offering more time not just for working but also for recreational activities that require light. But when artificial outdoor lighting becomes inefficient, annoying, and unnecessary, it is known as light pollution. Many environmentalists, naturalists, and medical researchers consider light pollution to be one of the fastest growing and most pervasive forms of environmental pollution. And a growing body of scientific research suggests that light pollution can have lasting adverse effects on both human and wildlife health. When does nuisance light become a health hazard? Richard Stevens, a professor and cancer epidemiologist at the University of Connecticut Health Center in Farmington, Connecticut, says light photons must hit the retina for biologic effects to occur. “However, in an environment where there is much artificial light at night—such as Manhattan or Las Vegas—there is much more opportunity for exposure of the retina to photons that might disrupt circadian rhythm,” he says. “So I think it is not only ‘night owls’ who get those photons. Almost all of us awaken during the night for periods of time, and unless we have blackout shades there is some electric lighting coming in our windows. It is not clear how much is too much; that is an important part of the research now.” According to “The First World Atlas of the Artificial Night Sky Brightness,” a report on global light pollution published in volume 328, issue 3 (2001) of the Monthly Notices of the Royal Astronomical Society, two-thirds of the U.S. population and more than one-half of the European population have already lost the ability to see the Milky Way with the naked eye. Moreover, 63% of the world population and 99% of the population of the European Union and the United States (excluding Alaska and Hawaii) live in areas where the night sky is brighter than the threshold for light-polluted status set by the International Astronomical Union—that is, the artificial sky brightness is greater than 10% of the natural sky brightness above 45° of elevation. Light pollution comes in many forms, including sky glow, light trespass, glare, and over illumination. Sky glow is the bright halo that appears over urban areas at night, a product of light being scattered by water droplets or particles in the air. Light trespass occurs when unwanted artificial light from, for instance, a floodlight or streetlight spills onto an adjacent property, lighting an area that would otherwise be dark. Glare is created by light that shines horizontally. Overillumination refers to the use of artificial light well beyond what is required for a specific activity, such as keeping the lights on all night in an empty office building.

Light pollution may create demographic traps for nocturnal insects

The Central Yangtze ecoregion in China includes a number of lakes, but these have been greatly affected by human activities over the past several decades, resulting in severe loss of biodiversity. In this paper, we document the present distribution of the major lakes and the changes in size that have taken place over the past 50 years, using remote sensing data and historical observations of land cover in the region. We also provide an overview of the changes in species richness, community composition, population size and age structure, and individual body size of aquatic plants, fishes, and waterfowl in these lakes. The overall species richness of aquatic plants found in eight major lakes has decreased substantially during the study period. Community composition has also been greatly altered, as have population size and age and individual body size in some species. These changes are largely attributed to the integrated effects of lake degradation, the construction of large hydroelectric dams, the establishment of nature reserves, and lake restoration practices.

Human-induced environmental changes can have major impacts on how individuals communicate. Species using sexual signals may experience especially rapid shifts in their interactions with both intended receivers (mates) and eavesdroppers (predators). Artificial light at night and anthropogenic noise represent 2 major environmental features of human-dominated habitats which may alter selection pressures imposed on sexual signalers. In this study, we used a full factorial design to investigate individual and combined effects of experimentally added light and noise pollution on the attraction of female frogs and bat predators to speakers broadcasting male túngara frog (Engystomops pustulosus) calls. We conducted 2-choice tests in the field to examine whether predatory and mating preferences for signals differing in conspicuousness change in response to noise and light pollution. Light pollution reduced the number of approaches from predators and mates attracted to our playbacks. The addition of noise pollution enhanced this effect on predators but decreased it for female frogs. Light also lowered female frog preference for conspicuous calls, but this effect was counteracted when noise pollution was added. Reduced numbers of predators and female frogs found under lit conditions suggest light pollution can both reduce natural selection and increase sexual selection pressures on male signals. These findings indicate that light pollution could be responsible for the reduced numbers of predatory bats and female frogs found in urban environments, providing a causal explanation for more conspicuous and attractive sexual signalling in males from urban populations.

In this article, the results of the estimation of total and direct solar radiation in the summer season over the territory of Ukraine depending on changes in planetary and regional atmospheric circulation since the beginning of the 21st century are presented. The estimation was conducted for the period from 1991 to 2020 based on the ERA5 reanalysis data, which is currently considered one of the best and most widely used models. General trends in the increase in the values of total and direct solar radiation over the territory of Ukraine have been established. The detected increase has been occurring since 2001, which corresponds to the time of display of a new regional atmospheric circulation. The amounts of direct and total solar radiation increased on average by 100—150 MJ/m2 in the second decade of the 21st century compared to the last decade of the 20th century. There is a synchronous change in total and direct solar radiation. Analysis of individual summer months revealed that the lowest values of direct solar radiation over the territory of Ukraine were observed in 2001 and the highest in 2019. At the same time, the difference in monthly sums between these years was 150—170 MJ/m2. In July, the lowest values of direct solar radiation were observed in 1997, and the highest values in 2012. The difference in monthly sums is close to the values of June. In August, the lowest values of direct solar radiation were observed in 1997 and the highest in 2015 and 2018. The difference between the sums per month for these years is close to the values of the previous summer months. In August, although the increase in total and direct solar radiation persists, as in June and July, their values for this month are already lower than those of the two previous months. In general, the increase in direct solar radiation over the territory of Ukraine is determined by new features of the course of synoptic processes with a stable anticyclonic character, which cause cloudless or partly cloudy, hot weather without precipitation.

Simple SummaryThe Northern house mosquito transmits West Nile virus and survives the winter by entering a state of dormancy called diapause. Light pollution has been shown to interfere with diapause initiation in this mosquito. The effects of light pollution on daily activity rhythms and metabolic products have not been thoroughly investigated in diapausing and non-diapausing Northern house mosquitoes. We found that light pollution affected mosquito activity levels and several metabolic products differently depending on photoperiod, indicating that light pollution may disrupt nutrient accumulation and possibly interfere with diapause initiation in this species.The Northern House mosquito, Culex pipiens, is an important disease vector, and females are capable of surviving the winter in a state of overwintering diapause. This species’ diapause response has been extensively studied, and recent evidence suggests that the circadian clock is involved in measuring seasonal changes in daylength to initiate the diapause response. However, differences in the circadian activity of diapausing and non-diapausing Cx. pipiens have not been thoroughly investigated. Additionally, recent findings indicate that artificial light at night (ALAN) can disrupt mosquito diapause, potentially prolonging the mosquito biting season. We compared the circadian locomotor activity of mosquitoes reared in diapause-averting, long-day conditions and diapause-inducing, short-day conditions with and without ALAN to elucidate the interplay between circadian activity, diapause, and light pollution. We also uncovered metabolic differences between mosquitoes reared under diapausing and non-diapausing photoperiods with and without ALAN by measuring the concentration of protein, fructose, glycogen, water-soluble carbohydrates, and lipids. We found that ALAN exposure altered several diapause-associated phenotypes including slightly, but not significantly, increasing activity levels in short day-reared mosquitoes; and preventing some short day-reared mosquitoes from accumulating lipids. ALAN also significantly reduced glycogen and water-soluble carbohydrate levels in long day-reared mosquitoes. Based on our findings, light pollution may decrease insect fitness by perturbing metabolism, and may also impact several phenotypes associated with insect diapause, potentially extending the mosquito biting season and preventing insects in urban environments from overwintering successfully.

Light energy directly affects microalgae growth and productivity. Microalgae in natural environments receive light through solar fluxes, and their duration and distribution are highly variable over time. Consequently, microalgae must adjust their photosynthetic processes to avoid photo limitation and photoinhibition and maximize yield. Considering these circumstances, adjusting light capture through artificial lighting in the main culture systems benefits microalgae growth and induces the production of commercially important compounds. In this sense, this review provides a comprehensive study of the role of light in microalgae biotechnology. For this, we present the main fundamentals and reactions of metabolism and metabolic alternatives to regulate photosynthetic conversion in microalgae cells. Light conversions based on natural and artificial systems are compared, mainly demonstrating the impact of solar radiation on natural systems and lighting devices, spectral compositions, periodic modulations, and light fluxes when using artificial lighting systems. The most commonly used photobioreactor design and performance are shown herein, in addition to a more detailed discussion of light-dependent approaches in these photobioreactors. In addition, we present the principal advances in photobioreactor projects, focusing on lighting, through a patent-based analysis to map technological trends. Lastly, sustainability and economic issues in commercializing microalgae products were presented.

In recent decades, the fast advancement of lighting technology has resulted in a significant surge in outdoor lights and night-sky luminance, which is one of the most visible signs of light pollution. Intense glare, persistently increasing illumination, and sudden lighting variations are all examples of ecological light pollution. Skyglow, lighted structures and towers, streetlights, cruise ships, alarm systems, lights on automobiles, rockets on offshore oil rigs, and even led lighting on submarine exploration equipment are all contributors of ecological light pollution, which can be found in practically any habitat. Unnecessary light pollution alludes to light flow transmitted at night by artificial light sources that are unsuitable in ferocity, orientation, and/or spectral range, or when artificial lighting is used in specific locations, such as observatories, nature reserves, or susceptible landforms, and is pointless to bring out the feature they are destined for. Any pollution is a result of urbanization dynamics, and it poses a serious threat to human health and the environment. Excessive lighting harms a person’s health, according to 90% of respondents. At least 70% of people have trouble sleeping as a result of light pollution. This chapter aims to define the underlying idea of light pollution, as well as its varieties, causes, and growth. This chapter also explains and defines how light pollution affects human health, plants, animals, astronomy, and economic sustainability. In addition, the chapter briefly examines the economics of light pollution, as well as the strategies and recommendations that are needed in the context of light pollution, as well as the scope for future research.

ABSTRACTSolar radiation is a major sustainable and clean energy resource, and use of solar radiation is expected to increase. The utilization efficiency of solar energy varies with the relative proportions of the direct and diffuse components that compose total solar radiation and with the slope and aspect of the irradiated surface. The purpose of this paper is to develop a simple method for estimating diffuse and direct solar radiation at sites with observation of only total solar radiation. An existing model for estimating diffuse radiation, i.e., a linear relationship between the diffuse fraction (the ratio of diffuse radiation to total solar radiation) and the clearness index (the ratio of total solar radiation to extraterrestrial radiation), is applied to 7 sites across the continental United States with observations of diffuse and total radiation. The linear model shows good monthly performance. The model parameters (slope and interception) show a strong seasonal pattern that exhibits small variation across the 7 sites; therefore, the average values of the two monthly parameters may be used for estimating diffuse radiation for other locations with observations of total radiation.

When conserving or protecting rare or endangered species, current general guidelines for reducing light pollution might not suffice to ensure long-term threatened species’ survival. Many protected areas are exposed to artificial light at levels with the potential to induce ecological impacts with unknown implications for the ecosystems they are designated to protect. Consequently, it is recommended that precautionary methods for the avoidance and mitigation of light pollution in protected areas be integrated into their management plans. This paper’s aims are to present an overview of best practices in precautionary methods to avoid and mitigate light pollution in protected areas and to identify and discuss what ecosystems should be considered light-sensitive and how to prioritise species and habitats that need protection from artificial light, including examples of legislation covering ecological light pollution in the European Union and in Sweden. The important aspects to include when considering light pollution at a landscape level are listed, and a proposal for prioritisation among species and habitats is suggested. Sensitive and conservation areas and important habitats for particularly vulnerable species could be prioritised for measures to minimise artificial lighting’s negative effects on biodiversity. This may be done by classifying protected natural environments into different zones and applying more constrained principles to limit lighting. The light pollution sensitivity of various environments and ecosystems suggests that different mitigation strategies and adaptations should be used depending on landscape characteristics, species sensitivity and other factors that may determine whether artificial light may be detrimental. Issues of the currently used measurement methods for artificial light at night are reviewed. We also propose and discuss the principles and benefits of using standardized measurement methods and appropriate instrumentation for field measurements of artificial light concerning the environmental impact of light pollution.