Solar ultraviolet radiation dependent decrease of particle light absorption and pigments in lake phytoplankton

The ultraviolet (UV) spectral component of daylight on a clear day at mid-latitudes can significantly reduce phytoplankton pigments within a daylight period. Phytoplankton samples from Redberry Lake, Saskatchewan, dominated by cyanobacteria were incubated in quartz bottles under optical long band-pass filters (cutoff wavelength 420-305 nm) in daylight in June. After incubation, samples were filtered, and in vivo particle light absorption (380-700 nm) and pigment concentrations were measured. Solar ultraviolet-B irradiance (UV-B; 280-320 nm) was measured radiometrically. On sunny days the samples that were exposed to daylight UV light showed a relative decrease in particle absorption and pigment concentration after the incubation compared with samples exposed only to visible daylight. No such decrease was observed during an overcast day. The UV-B data did not show a clear relation with the degree of pigment reduction, suggesting that other environmental factors or the state of adaptation partially controlled the pigment decrease of phytoplankton under UV-B exposure. Neither specific spectral components of the absorption spectrum nor specific pigments were more easily degraded than others by solar UV light, although the ratio of zeaxanthin to chlorophyll a probably increased in cyanobacteria as a result of UV exposure.

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Hatching success and larval survival of the frogs Hyla regilla and Rana aurora under ambient and artificially enhanced solar ultraviolet radiation

Canadian Journal of Zoology ◽

10.1139/z97-130 ◽

1997 ◽

Vol 75 (7) ◽

pp. 1081-1088 ◽

Cited By ~ 70

Author(s):

Kristiina Ovaska ◽

Theodore M. Davis ◽

Iñigo Novales Flamarique

Keyword(s):

Hatching Success ◽

Larval Survival ◽

Ultraviolet B ◽

Experimental Conditions ◽

Solar Ultraviolet Radiation ◽

Hyla Regilla ◽

Rana Aurora ◽

Solar Uv ◽

And Control ◽

Solar Ultraviolet

The aquatic stages of amphibians may be sensitive to increased levels of solar ultraviolet B radiation (UV-B, 280–320 nm) that have been observed at higher latitudes over the past several decades, but the effects on most species are unknown. We exposed eggs and larvae of Hyla regilla and Rana aurora to three experimental treatments: (1) solar UV < 450 nm blocked (control), (2) ambient solar UV, and (3) solar UV-B enhanced 15 and 30% above ambient levels at midday to simulate conditions predicted for the next decades at midlatitudes. The rearing containers were covered with acrylic filters to provide the desired radiation regimes. Hatching success of H. regilla did not differ among the treatments and was 87.7, 71.8, and 87.1% in April 1995 and 94.0, 85.1, and 97.4% in May 1995 for the control, ambient, and enhanced UV-B treatments, respectively. In contrast, hatching success of R. aurora in the enhanced UV-B treatment (56.0%) was lower than in the ambient UV (89.8%) and control (81.0%) treatments. Larval survival over the first 2 months of development was reduced to 18.4% for H. regilla and 2.6% for R. aurora in the enhanced UV-B treatment compared with the ambient UV and control treatments. We conclude that ambient UV levels at the study site did not affect the embryonic or early larval survival of either of the species tested under the experimental conditions, but both species are potentially vulnerable to increases in solar UV-B.

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Effect of solar ultraviolet radiation (280–400 nm) on the eggs and larvae of Atlantic cod (Gadus morhua)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f99-039 ◽

1999 ◽

Vol 56 (6) ◽

pp. 1058-1067 ◽

Cited By ~ 2

Author(s):

France Béland ◽

Howard I Browman ◽

Carolina Alonso Rodriguez ◽

Jean-François St-Pierre

Keyword(s):

Water Column ◽

Gadus Morhua ◽

Atlantic Cod ◽

Outdoor Exposure ◽

Ultraviolet B ◽

Solar Ultraviolet Radiation ◽

Mortality Effect ◽

Eggs And Larvae ◽

Very High ◽

Solar Ultraviolet

In the Gulf of St. Lawrence, Canada, solar ultraviolet B radiation (UV-B, 280-320 nm) penetrates a significant percentage of the summer mixed-layer water column: organisms residing in this layer, such as the eggs of Atlantic cod (Gadus morhua), are exposed to UV-B. In outdoor exposure experiments, Atlantic cod eggs were incubated in the presence versus the absence of UV-B and (or) UV-A (320-400 nm). We tested two hypotheses: H1, UV-B induces mortality in Atlantic cod eggs, and H2, UV-A either exacerbates or mitigates any such UV-B-induced mortality. Hypothesis H1 was supported: there was a significant mortality effect on Atlantic cod eggs exposed to UV-B at the surface and at a depth of 50 cm. Hypothesis H2 was not supported: there was no effect of UV-A. These experiments indicate that Atlantic cod eggs present in the first metre of the water column (likely only a small percentage of the total egg population) are susceptible to UV-B. However, UV-B must be viewed as only one among many environmental factors that produce the very high levels of mortality typically observed in the planktonic early life stages of marine fishes.

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Solar ultraviolet B exposure and global variation in tuberculosis incidence: an ecological analysis

European Respiratory Journal ◽

10.1183/13993003.01979-2016 ◽

2017 ◽

Vol 49 (6) ◽

pp. 1601979 ◽

Cited By ~ 7

Author(s):

Tjarda M. Boere ◽

Douwe H. Visser ◽

A. Marceline van Furth ◽

Paul Lips ◽

Frank G.J. Cobelens

Keyword(s):

Vitamin D ◽

National Level ◽

Risk Groups ◽

Vitamin D Supplementation ◽

Ultraviolet B ◽

Tuberculosis Incidence ◽

Global Variation ◽

Relevant Variables ◽

Solar Uv ◽

Solar Ultraviolet

Epidemiological evidence supports vitamin D deficiency as a risk factor for tuberculosis. Differences in solar ultraviolet B (UV-B) exposure, the major source of vitamin D, might therefore partially explain global variation in tuberculosis incidence.In a global country-based ecological study, we explored the correlation between vitamin D-proxies, such as solar UV-B exposure, and other relevant variables with tuberculosis incidence, averaged over the period 2004–2013.Across 154 countries, annual solar UV-B exposure was associated with tuberculosis incidence. Tuberculosis incidence in countries in the highest quartile of UV-B exposure was 78% (95% CI 57–88%, p<0.001) lower than that in countries in the lowest quartile, taking into account other vitamin D-proxies and covariates. Of the explained global variation in tuberculosis incidence, 6.3% could be attributed to variations in annual UV-B exposure. Exposure to UV-B had a similar, but weaker association with tuberculosis notification rates in the multilevel analysis with sub-national level data for large countries (highestversuslowest quartile 29% lower incidence; p=0.057).The potential preventive applications of vitamin D supplementation in high-risk groups for tuberculosis merits further investigation.

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Episode of unusual high solar ultraviolet radiation in central Europe due to dynamical reduced stratospheric ozone in May 2005

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-5-10409-2005 ◽

2005 ◽

Vol 5 (5) ◽

pp. 10409-10420 ◽

Cited By ~ 1

Author(s):

C. Stick ◽

K. Krüger ◽

N. H. Schade ◽

H. Sandmann ◽

A. Macke

Keyword(s):

Ultraviolet Radiation ◽

Uv Radiation ◽

Stratospheric Ozone ◽

Solar Ultraviolet Radiation ◽

Solar Uv ◽

Resultant Increase ◽

The Tropics ◽

Effective Radiation ◽

Ozone Episodes ◽

Solar Ultraviolet

Abstract. In late May this year unusual high levels of solar ultraviolet radiation were observed in Europe. In Northern Germany the measured irradiance of erythemally effective radiation exceeded the climatological mean by more than about 20%. An extreme low ozone event for the season coincided with the high solar elevation angles during late spring leading to the highest value of erythemal UV-radiation ever observed at this location in May. This ''ozone mini-hole'' was caused by an elevation of tropopause height accompanied with a poleward advection of natural low total ozone from the tropics. The resultant increase in UV-radiation is of particular significance for human health. Dynamically induced low ozone episodes that happen around the summer solstice can considerably enhance the solar UV-radiation in the mid latitudes and therefore contribute to the UV-burden of people living in the mid latitudes.

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Proxy reconstruction of ultraviolet-B irradiance at the Earth’s surface, and its relationship with solar activity and ozone thickness

The Holocene ◽

10.1177/0959683619875798 ◽

2019 ◽

Vol 30 (1) ◽

pp. 155-161 ◽

Cited By ~ 3

Author(s):

Phillip E Jardine ◽

Wesley T Fraser ◽

William D Gosling ◽

C Neil Roberts ◽

Warren J Eastwood ◽

...

Keyword(s):

Solar Activity ◽

Positive Relationship ◽

Pollen Grains ◽

Ultraviolet B ◽

Uv Irradiance ◽

Solar Uv ◽

Long Timescales ◽

Biotic Stressor ◽

Solar Ultraviolet

Solar ultraviolet-B (UV-B) irradiance that reaches the Earth’s surface acts as a biotic stressor and has the potential to modify ecological and environmental functioning. The challenges of reconstructing ultraviolent (UV) irradiance prior to the satellite era mean that there is uncertainty over long-term surface UV-B patterns, especially in relation to variations in solar activity over centennial and millennial timescales. Here, we reconstruct surface UV-B irradiance over the last 650 years using a novel UV-B proxy based on the chemical signature of pollen grains. We demonstrate a statistically significant positive relationship between the abundance of UV-B absorbing compounds in Pinus pollen and modelled solar UV-B irradiance. These results show that trends in surface UV-B follow the overall solar activity pattern over centennial timescales, and that variations in solar output are the dominant control on surface level UV-B flux, rather than solar modulated changes in ozone thickness. The Pinus biochemical response demonstrated here confirms the potential for solar activity driven surface UV-B variations to impact upon terrestrial biotas and environments over long timescales.

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Stratospheric ozone depletion

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2005.1783 ◽

2006 ◽

Vol 361 (1469) ◽

pp. 769-790 ◽

Cited By ~ 98

Author(s):

F. Sherwood Rowland

Keyword(s):

Ultraviolet Radiation ◽

Ozone Depletion ◽

Biological Activities ◽

Stratospheric Ozone ◽

Ozone Layer ◽

Ultraviolet B ◽

Montreal Protocol ◽

Atmospheric Measurements ◽

Solar Ultraviolet Radiation ◽

Solar Ultraviolet

Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO 2 , NO, NO 2 , Cl and ClO. The NO X and ClO X chains involve the emission at Earth's surface of stable molecules in very low concentration (N 2 O, CCl 2 F 2 , CCl 3 F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290–320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime—the ‘Antarctic ozone hole’. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules.

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Spring and summer time ozone and solar ultraviolet radiation variations over Cape Point, South Africa

Annales Geophysicae ◽

10.5194/angeo-37-129-2019 ◽

2019 ◽

Vol 37 (2) ◽

pp. 129-141 ◽

Cited By ~ 1

Author(s):

David J. du Preez ◽

Jelena V. Ajtić ◽

Hassan Bencherif ◽

Nelson Bègue ◽

Jean-Maurice Cadet ◽

...

Keyword(s):

South Africa ◽

Ultraviolet Radiation ◽

Uv Radiation ◽

Stratospheric Ozone ◽

Solar Ultraviolet Radiation ◽

Clear Sky ◽

Solar Uv Radiation ◽

Solar Uv ◽

Solar Ultraviolet ◽

Ozone Levels

Abstract. The correlation between solar ultraviolet radiation (UV) and atmospheric ozone is well understood. Decreased stratospheric ozone levels which led to increased solar UV radiation levels at the surface have been recorded. These increased levels of solar UV radiation have potential negative impacts on public health. This study was done to determine whether the break-up of the Antarctic ozone hole has an impact on stratospheric columnar ozone (SCO) and resulting ambient solar UV-B radiation levels at Cape Point, South Africa, over 2007–2016. We investigated the correlations between UV index, calculated from ground-based solar UV-B radiation measurements and satellite-retrieved column ozone data. The strongest anti-correlation on clear-sky days was found at solar zenith angle 25∘ with exponential fit R2 values of 0.45 and 0.53 for total ozone column and SCO, respectively. An average radiation amplification factor of 0.59 across all SZAs was calculated for clear-sky days. The MIMOSA-CHIM model showed that the polar vortex had a limited effect on ozone levels. Tropical air masses more frequently affect the study site, and this requires further investigation.

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Light Absorptive Properties of Articular Cartilage, ECM Molecules, Synovial Fluid, and Photoinitiators as Potential Barriers to Light-Initiated Polymer Scaffolding Procedures

Cartilage ◽

10.1177/1947603517713815 ◽

2017 ◽

Vol 10 (1) ◽

pp. 82-93 ◽

Cited By ~ 1

Author(s):

Anthony J. Finch ◽

Jamie M. Benson ◽

Patrick E. Donnelly ◽

Peter A. Torzilli

Keyword(s):

Articular Cartilage ◽

Synovial Fluid ◽

Light Absorption ◽

Native Species ◽

In Situ Polymerization ◽

Uv Light ◽

Intact Cartilage ◽

Biochemical Components ◽

The Individual

Objective Many in vivo procedures to repair chondral defects use ultraviolet (UV)-photoinitiated in situ polymerization within the cartilage matrix. Chemical species that absorb UV light might reduce the effectiveness of these procedures by acting as light absorption barriers. This study evaluated whether any of the individual native biochemical components in cartilage and synovial fluid interfered with the absorption of light by common scaffolding photosensitizers. Materials UV-visible spectroscopy was performed on each major component of cartilage in solution, on bovine synovial fluid, and on four photosensitizers, riboflavin, Irgacure 2959, quinine, and riboflavin-5′-phosphate. Molar extinction and absorption coefficients were calculated at wavelengths of maximum absorbance and 365 nm. Intact articular cartilage was also examined. Results The individual major biochemical components of cartilage, Irgacure 2959, and quinine did not exhibit a significant absorption at 365 nm. Riboflavin and riboflavin-5′-phosphate were more effectual light absorbers at 365 nm, compared with the individual native species. Intact cartilage absorbed a significantly greater amount of UV light in comparison with the native species. Conclusion Our results indicate that none of the individual native species in cartilage will interfere with the absorption of UV light at 365 nm by these commonly used photoinitiators. Intact cartilage slices exhibited significant light absorption at 365 nm, while also having distinct absorbance peaks at wavelengths less than 300 nm. Determining the UV absorptive properties of the biomolecules native to articular cartilage and synovial fluid will aid in optimizing scaffolding procedures to ensure sufficient scaffold polymerization at a minimum UV intensity.

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Spring and summer time ozone and solar ultraviolet radiation variations over Cape Point, South Africa

10.5194/angeo-2018-56 ◽

2018 ◽

Cited By ~ 1

Author(s):

D. Jean du Preez ◽

Jelena V. Ajtić ◽

Hassan Bencherif ◽

Nelson Bègue ◽

Caradee Y. Wright

Keyword(s):

South Africa ◽

Ultraviolet Radiation ◽

Uv Radiation ◽

Stratospheric Ozone ◽

Polar Vortex ◽

Solar Ultraviolet Radiation ◽

Solar Uv Radiation ◽

Solar Uv ◽

Solar Ultraviolet ◽

Ozone Levels

Abstract. The correlation between solar ultraviolet radiation (UV) and atmospheric ozone is well understood. Decreased stratospheric ozone levels which led to increased solar UV radiation levels at the surface have been recorded. These increased levels of solar UV radiation have potential negative impacts on public health. This study was done to determine whether or not the break-up of the Antarctic ozone hole has an impact on stratospheric columnar ozone (SCO) concentrations and resulting ambient solar UV-B radiation levels at Cape Point, South Africa. At Cape Point, the strongest anti-correlation on clear-sky days was found at solar zenith angle 20° with exponential fit R2 values of 0.71 and 0.66 for total ozone column and SCO, respectively. An average radiation amplification factor of 0.92 was found and the largest decrease in ozone levels occurred during September months. The MIMIOSA-CHIM model showed that the polar vortex had a limited effect on ozone levels at 435–440 K for September and 600 K over Cape Point during November. Tropical air-masses more frequently affect the study site, and this requires further investigation.

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