Kocifaj, M., & Kómar, L. (2016). A role of aerosol particles in forming urban skyglow and skyglow from distant cities. MNRAS, 458(1), 438–448.
Abstract: Aerosol particles may represent the largest uncertainty about skyglow change in many locations under clear sky conditions. This is because aerosols are ubiquitous in the atmosphere and influence the ground-reaching radiation in different ways depending on their concentrations, origins, shapes, sizes, and compositions. Large particles tend to scatter in Fraunhofer diffraction regime, while small particles can be treated in terms of Rayleigh formalism. However, the role of particle microphysics in forming the skyglow still remains poorly quantified. We have shown in this paper that the chemistry is somehow important for backscattering from large particles that otherwise work as efficient attenuators of light pollution if composed of absorbing materials. The contribution of large particles to the urban skyglow diminishes as they become more spherical in shape. The intensity of backscattering from non-absorbing particles is more-or-less linearly decreasing function of particle radius even if number size distribution is inversely proportional to the fourth power of particle radius. This is due to single particle backscattering that generally increases steeply as the particle radius approaches large values. Forward scattering depends on the particle shape but is independent of the material composition, thus allowing for a simplistic analytical model of skyglow from distant cities. The model we have developed is based on mean value theorem for integrals and incorporates the parametrizable Garstang's emission pattern, intensity decay along optical beam path, and near-forward scattering in an atmospheric environment. Such model can be used by modellers and experimentalists for rapid estimation of skyglow from distant light sources.
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Ben-Attia, M., Reinberg, A., Smolensky, M. H., Gadacha, W., Khedaier, A., Sani, M., et al. (2016). Blooming rhythms of cactus Cereus peruvianus with nocturnal peak at full moon during seasons of prolonged daytime photoperiod. Chronobiol Int, 33(4), 419–430.
Abstract: Cereus peruvianus (Peruvian apple cactus) is a large erect and thorny succulent cactus characterized by column-like (cereus [L]: column), that is, candle-shaped, appendages. For three successive years (1100 days), between early April and late November, we studied the flowering patterns of eight cacti growing in public gardens and rural areas of north and central Tunisia, far from nighttime artificial illumination, in relation to natural environmental light, temperature, relative humidity and precipitation parameters. Flower blooming was assessed nightly between 23:00 h and until at least 02:00 h, and additionally around-the-clock at ~1 h intervals for 30 consecutive days during the late summer of each year of study to quantify both nyctohemeral (day-night) and lunar patterns. During the summer months of prolonged daytime photoperiod, flower blooming of C. peruvianus exhibited predictable-in-time variation as “waves” with average period of 29.5 days synchronized by the light of the full moon. The large-sized flower (~16 cm diameter) opens almost exclusively at night, between sunset and sunrise, as a 24 h rhythm during a specific 3-4-day span of the lunar cycle (full moon), with a strong correlation between moon phase and number and proportion of flowers in bloom (ranging from r = +0.59 to +0.91). Black, blue and red cotton sheets were used to filter specific spectral bands of nighttime moonlight from illuminating randomly selected plant appendages as a means to test the hypothesis of a “gating” 24 h rhythm phenomenon of photoreceptors at the bud level. Relative to control conditions (no light filtering), black sheet covering inhibited flower bud induction by 87.5%, red sheet covering by 46.6% and blue sheet covering by 34%, and the respective inhibiting effects on number of flowers in bloom were essentially 100%, ~81% and ~44%. C. peruvianus is a unique example of a terrestrial plant that exhibits a circadian flowering rhythm (peak ~00:00 h) “gated” by 24 h, lunar 29.5-day (bright light of full moon) and annual 365.25-day (prolonged summertime day length) environmental photoperiod cycles.
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Coughlin, M., Stubbs, C., & Claver, C. (2016). A daytime measurement of the lunar contribution to the night sky brightness in LSST’s ugrizy bands–initial results. Exp Astron, 41(3), 393–408.
Abstract: We report measurements from which we determine the spatial structure ofthe lunar contribution to night sky brightness, taken at the LSST site on Cerro Pachonin Chile. We use an array of six photodiodes with filters that approximate the LargeSynoptic Survey Telescope’su, g, r, i, z,andybands. We use the sun as a proxy forthe moon, and measure sky brightness as a function of zenith angle of the point onsky, zenith angle of the sun, and angular distance between the sun and the point onsky. We make a correction for the difference between the illumination spectrum of thesun and the moon. Since scattered sunlight totally dominates the daytime sky bright-ness, this technique allows us to cleanly determine the contribution to the (cloudless)night sky from backscattered moonlight, without contamination from other sourcesof night sky brightness. We estimate our uncertainty in the relative lunar night skybrightness vs. zenith and lunar angle to be between 0.3–0.7 mags depending on thepassband. This information is useful in planning the optimal execution of the LSSTsurvey, and perhaps for other astronomical observations as well. Although our pri-mary objective is to map out the angular structure and spectrum of the scattered lightfrom the atmosphere and particulates, we also make an estimate of the expected num-ber of scattered lunar photons per pixel per second in LSST, and find values that arein overall agreement with previous estimates.
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Phelps, J. (2016). A powerful non-pharmacologic treatment for mania – virtually. Bipolar Disord, 18(4), 379–382.
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Matsuda, R., Yamano, T., Murakami, K., & Fujiwara, K. (2016). Effects of spectral distribution and photosynthetic photon flux density for overnight LED light irradiation on tomato seedling growth and leaf injury. Scientia Horticulturae, 198, 363–369.
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