|   | 
Details
   web
Records
Author Clark, G.F.; Stark, J.S.; Johnston, E.L.; Runcie, J.W.; Goldsworthy, P.M.; Raymond, B.; Riddle, M.J.
Title Light-driven tipping points in polar ecosystems Type Journal Article
Year 2013 Publication Global Change Biology Abbreviated Journal Glob Chang Biol
Volume 19 Issue 12 Pages 3749-3761
Keywords Ecology; benthic; biodiversity; irradiance; macroalgae; marine ecology; polar; regime shift
Abstract (down) Some ecosystems can undergo abrupt transformation in response to relatively small environmental change. Identifying imminent 'tipping points' is crucial for biodiversity conservation, particularly in the face of climate change. Here, we describe a tipping point mechanism likely to induce widespread regime shifts in polar ecosystems. Seasonal snow and ice-cover periodically block sunlight reaching polar ecosystems, but the effect of this on annual light depends critically on the timing of cover within the annual solar cycle. At high latitudes, sunlight is strongly seasonal, and ice-free days around the summer solstice receive orders of magnitude more light than those in winter. Early melt that brings the date of ice-loss closer to midsummer will cause an exponential increase in the amount of sunlight reaching some ecosystems per year. This is likely to drive ecological tipping points in which primary producers (plants and algae) flourish and out-compete dark-adapted communities. We demonstrate this principle on Antarctic shallow seabed ecosystems, which our data suggest are sensitive to small changes in the timing of sea-ice loss. Algae respond to light thresholds that are easily exceeded by a slight reduction in sea-ice duration. Earlier sea-ice loss is likely to cause extensive regime shifts in which endemic shallow-water invertebrate communities are replaced by algae, reducing coastal biodiversity and fundamentally changing ecosystem functioning. Modeling shows that recent changes in ice and snow cover have already transformed annual light budgets in large areas of the Arctic and Antarctic, and both aquatic and terrestrial ecosystems are likely to experience further significant change in light. The interaction between ice-loss and solar irradiance renders polar ecosystems acutely vulnerable to abrupt ecosystem change, as light-driven tipping points are readily breached by relatively slight shifts in the timing of snow and ice-loss.
Address School of Biological, Earth and Environmental Science, University of New South Wales, Sydney, NSW, 2052, Australia
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1354-1013 ISBN Medium
Area Expedition Conference
Notes PMID:23893603 Approved no
Call Number LoNNe @ kagoburian @ Serial 850
Permanent link to this record
 

 
Author Baugh, K.; Elvidge, C.D.; Ghosh, T.; Ziskin, D.
Title Development of a 2009 Stable Lights Product using DMSP-OLS data Type Journal Article
Year 2013 Publication Proceedings of the Asia-Pacific Advanced Network Abbreviated Journal APAN Proceedings
Volume 30 Issue Pages 114
Keywords DMSP-OLS; remote sensing
Abstract (down) Since 1994, NGDC has had an active program focused on global mapping of nighttime lights using the data collected by the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) sensors. The basic product is a global annual cloud-free composite, which averages the OLS visible band data for one satellite from the cloud-free segments of individual orbits. Over the years, NGDC has developed automatic algorithms for screening the quality of the nighttime visible band observations to remove areas contaminated by sunlight, moonlight, and the presence of clouds. In the Stable Lights product generation, fires and other ephemeral lights are removed based on their high brightness and short duration. Background noise is removed by setting thresholds based on visible band values found in areas known to be free of detectable lights. In 2010, NGDC released the version 4 time series of Stable Lights, spanning the years 1992-2009. These are available online at <http://www.ngdc.noaa.gov/dmsp/downloadV4composites.html>.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2227-3026 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 207
Permanent link to this record
 

 
Author Haus, E.L.; Smolensky, M.H.
Title Shift work and cancer risk: potential mechanistic roles of circadian disruption, light at night, and sleep deprivation Type Journal Article
Year 2013 Publication Sleep Medicine Reviews Abbreviated Journal Sleep Med Rev
Volume 17 Issue 4 Pages 273-284
Keywords Cell Cycle/physiology; Circadian Rhythm/*physiology; Epigenesis, Genetic/physiology; Humans; Light; Melatonin/physiology; Neoplasms/*etiology; Risk Factors; Sleep Deprivation/*complications; Work Schedule Tolerance/*physiology; oncogenesis
Abstract (down) Shift work that includes a nighttime rotation has become an unavoidable attribute of today's 24-h society. The related disruption of the human circadian time organization leads in the short-term to an array of jet-lag-like symptoms, and in the long-run it may contribute to weight gain/obesity, metabolic syndrome/type II diabetes, and cardiovascular disease. Epidemiologic studies also suggest increased cancer risk, especially for breast cancer, in night and rotating female shift workers. If confirmed in more controlled and detailed studies, the carcinogenic effect of night and shift work will constitute additional serious medical, economic, and social problems for a substantial proportion of the working population. Here, we examine the possible multiple and interconnected cancer-promoting mechanisms as a consequence of shift work, i.e., repeated disruption of the circadian system, pineal hormone melatonin suppression by exposure to light at night, sleep-deprivation-caused impairment of the immune system, plus metabolic changes favoring obesity and generation of proinflammatory reactive oxygen species.
Address Department of Laboratory Medicine & Pathology, University of Minnesota and Health Partners Medical Group, Regions Hospital, 640 Jackson Street, St. Paul, Minnesota 55101, USA. Erhard.X.Haus@HealthPartners.com
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1087-0792 ISBN Medium
Area Expedition Conference
Notes PMID:23137527 Approved no
Call Number IDA @ john @ Serial 157
Permanent link to this record
 

 
Author Kocifaj, M.; Solano Lamphar, H.A.
Title Skyglow effects in UV and visible spectra: radiative fluxes Type Journal Article
Year 2013 Publication Journal of Environmental Management Abbreviated Journal J Environ Manage
Volume 127 Issue Pages 300-307
Keywords Animals; Darkness; Environmental Exposure/*analysis; *Light; Models, Theoretical; *Ultraviolet Rays; Light pollution; Optical thickness; Public lighting system; Two stream approximation
Abstract (down) Several studies have tried to understand the mechanisms and effects of radiative transfer under different night-sky conditions. However, most of these studies are limited to the various effects of visible spectra. Nevertheless, the invisible parts of the electromagnetic spectrum can pose a more profound threat to nature. One visible threat is from what is popularly termed skyglow. Such skyglow is caused by injudiciously situated or designed artificial night lighting systems which degrade desired sky viewing. Therefore, since lamp emissions are not limited to visible electromagnetic spectra, it is necessary to consider the complete spectrum of such lamps in order to understand the physical behaviour of diffuse radiation at terrain level. In this paper, the downward diffuse radiative flux is computed in a two-stream approximation and obtained ultraviolet spectral radiative fluxes are inter-related with luminous fluxes. Such a method then permits an estimate of ultraviolet radiation if the traditionally measured illuminance on a horizontal plane is available. The utility of such a comparison of two spectral bands is shown, using the different lamp types employed in street lighting. The data demonstrate that it is insufficient to specify lamp type and its visible flux production independently of each other. Also the UV emissions have to be treated by modellers and environmental scientists because some light sources can be fairly important pollutants in the near ultraviolet. Such light sources can affect both the living organisms and ambient environment.
Address ICA, Slovak Academy of Sciences, 9, Dubravska Road, 845 03 Bratislava, Slovak Republic. kocifaj@savba.sk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0301-4797 ISBN Medium
Area Expedition Conference
Notes PMID:23792881 Approved no
Call Number IDA @ john @ Serial 265
Permanent link to this record
 

 
Author Figueiro, M.G.; Wood, B.; Plitnick, B.; Rea, M.S.
Title The impact of watching television on evening melatonin levels: Impact of watching television on evening melatonin Type Journal Article
Year 2013 Publication Journal of the Society for Information Display Abbreviated Journal Jnl Soc Info Display
Volume 21 Issue 10 Pages 417-421
Keywords Human Health; television; correlated color temperature; sleep; melatonin levels; blue light; circadian disruption
Abstract (down) Self-luminous electronic devices emit optical radiation at short wavelengths, close to the peak sensitivity of melatonin suppression. The present paper investigated if light from a 178-cm (70&#8201;in.) television suppressed melatonin. Results showed that light from televisions does not impact melatonin levels in the evening.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1071-0922 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ christopher.kyba @ Serial 498
Permanent link to this record