title: Resources of dark skies in German climatic health resorts.
abstract: Illumination of nocturnal environments is increasing steadily worldwide. While there are some benefits for mankind, light at night affects animals, plants, and human health by blurring the natural distinction between day and night. International regulations exist to protect the environment for the maintenance of human health but nocturnal darkness is not considered. In Germany, cities and communities labeled as Climatic Health Resorts provide for high standards in air quality. However, their degree of nocturnal darkness is unexplored so far. In our study, we examined the degree of nocturnal darkness in German Climatic Health Resorts by two datasets based on georeferenced remote sensing data. The majority of Climatic Health Resorts (93.1 %) are able to offer a relative respite (≥ 20 mag/arcsec2) from a degraded nocturnal environment, while only 3.4 % are able to offer a dark, if by no means pristine, night environment (≥ 21 mag/arcsec2). Climatic Health Resorts emit less light as well as are less affected by night sky brightness compared to the average of non-classified communities. In combination with daytime requirements, the resorts provide conditions for a more distinct day-and-night-cycle than non-classified communities.
authors.affiliation: Institute of Public Health and Nursing Research, Department of Social Epidemiology, University of Bremen, Grazer Str. 4, room 3050, 28359, Bremen, Germany. katharina.gabriel@uni-bremen.de.|Health Sciences Bremen, University of Bremen, Bremen, Germany. katharina.gabriel@uni-bremen.de.
authors.forename: Katharina M A
authors.initials: KM
authors.lastname: Gabriel
authors.affiliation: Leibniz-Institute for Freshwater Ecology and Inland Fisheries, Berlin, Germany.|Luftbild Umwelt Planung GmbH, Potsdam, Germany.
authors.forename: Helga U
authors.initials: HU
authors.lastname: Kuechly
authors.affiliation: Light Pollution Science and Technology Institute (ISTIL), Thiene, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Falchi
authors.affiliation: Institute of Statistics, University of Bremen, Bremen, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Wosniok
authors.affiliation: Leibniz-Institute for Freshwater Ecology and Inland Fisheries, Berlin, Germany.
authors.forename: Franz
authors.initials: F
authors.lastname: Hölker
mesh_terms: D003624:Darkness; D005858:Germany; D006294:Health Resorts; D058998:Remote Sensing Technology
keywords: Circadian rhythm; Germany; Health resorts; Light pollution; Regulation; Remote sensing