Abstract

The physiology and behavior of most life at or near the Earth’s surface has evolved over billions of years to be attuned with our planet’s natural light–dark cycle of day and night. However, over a relatively short time span, humans have disrupted this natural cycle of illumination with the introduction and now widespread proliferation of artificial light at night (ALAN). Growing research in a broad range of fields, such as ecology, the environment, human health, public safety, economy, and society, increasingly shows that ALAN is taking a profound toll on our world. Much of our current understanding of light pollution comes from datasets generated by remote sensing, primarily from two missions, the Operational Linescan System (OLS) instrument of the now-declassified Defense Meteorological Satellite Program (DMSP) of the U.S. Department of Defense and its follow-on platform, the Day-Night Band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument on board the Suomi National Polar-Orbiting Partnership satellite. Although they have both proved invaluable for ALAN research, sensing of nighttime lights was not the primary design objective for either the DMSP-OLS or VIIRS-DNB instruments; thus, they have some critical limitations. Being broadband sensors, both the DMSP-OLS and VIIRS-DNB instruments suffer from a lack of spectral information. Additionally, their spatial resolutions are too low for many ALAN research applications, though the VIIRS-DNB instrument is much improved over the DMSP-OLS in this regard, as well as in terms of dynamic range and quantization. Further, the very late local time of VIIRS-DNB observations potentially misses the true picture of ALAN. We reviewed both current literature and guiding advice from ALAN experts, aggregated from a diverse range of disciplines and Science Goals, to derive recommendations for a mission to expand knowledge of ALAN in areas that are not adequately addressed with currently existing orbital missions. We propose a stand-alone mission focused on understanding light pollution and its effects on our planet. Here we review the science cases and the subsequent mission recommendations for NITESat (Nighttime Imaging of Terrestrial Environments Satellite), a dedicated ALAN observing mission.

Excerpt:

Due to the increasing encroachment and intensity of ALAN, burgeoning transition into (bluer) LED lighting, and the general lack of strong lighting policies, it is urgent and crucial to have a spectrally resolved dataset of ALAN to fill current research gaps, support and inspire further study, and aid and inform advocacy efforts to establish and enforce responsible lighting practices. The Nighttime Imaging of Terrestrial Environments Satellite (NITESat), achievable as a small-satellite (<500 kg) mission, is a concept designed to answer questions that cannot be addressed by current methods [19]. This paper outlines the Science Goals driving a proposed NITESat concept and describes the subsequent mission characteristics required to meet those goals.

Light pollution is a novel, significant, and global environmental threat that ranks among the defining characteristics of a proposed geologic era known as the “Anthropocene” [124]. It is one of the ways humans are remaking the environment, altering natural rhythms of day and night that preceded the introduction of electric light by billions of years. The use of ALAN has grown exponentially in recent years, resulting in part from the rapid proliferation of cheap and highly energy-efficient solid-state lighting products that further fuel elastic consumer demand for light at night. Satellite remote sensing of night lights remains our only effective means of understanding the problem of light pollution on a truly planetary scale, yet to date, no satellite mission truly optimized for measuring ALAN from space has ever flown. 

Read the full study at https://www.mdpi.com/2072-4292/13/12/2294/htm

The post A Case for a New Satellite Mission for Remote Sensing of Night Lights appeared first on EMFSA.

Key Points

Question  Are levels of outdoor artificial light at night associated with adolescent sleep patterns and past-year mental disorder?

Findings  In a cross-sectional, nationally representative survey of US adolescents, higher levels of outdoor artificial light at night, measured via satellite, were associated with later weeknight bedtimes; those in the lowest quartile of nighttime light reported the longest weeknight sleep durations. Adolescents in areas with greater levels of nighttime light also had higher prevalence of past-year mood and anxiety disorders.

Meaning  Future studies of adolescent mental and sleep health should consider contextual-level measures of light at night, in addition to individual-level exposure.

Abstract

Importance  Indoor nighttime light exposure influences sleep and circadian rhythms and is known to affect mood-associated brain circuits in animals. However, little is known about the association between levels of nighttime outdoor light and sleep and mental health in the population, especially among adolescents.

Conclusions and Relevance  In this study, area-level outdoor ALAN was associated with less favorable sleep patterns and mood and anxiety disorder in adolescents. Future studies should elucidate whether interventions to reduce exposure to ALAN may positively affect mental and sleep health.

https://jamanetwork.com/journals/jamapsychiatry/article-abstract/2767698

The post Association of Outdoor Artificial Light at Night With Mental Disorders and Sleep Patterns Among US Adolescents appeared first on EMFSA.