Kongsfjorden-Krossfjorden and the adjacent West Spitsbergen Shelf meet at the common mouth of the two fjord arms. This paper presents our most up-to-date information about the physical environment of this fjord system and identifies important gaps in knowledge. Particular attention is given to the steep physical gradients along the main fjord axis, as well as to seasonal environmental changes. Physical processes on different scales control the large-scale circulation and small-scale (irreversible) mixing of water and its constituents. It is shown that, in addition to the tide, run-off (glacier ablation, snowmelt, summer rainfall and ice calving) and local winds are the main driving forces acting on the upper water masses in the fjord system. The tide is dominated by the semi-diurnal component and the freshwater supply shows a marked seasonal variation pattern and also varies interannually. The wind conditions are characterized by prevailing katabatic winds, which at times are strengthened by the geostrophic wind field over Svalbard. Rotational dynamics have a considerable influence on the circulation patterns within the fjord system and give rise to a strong interaction between the fjord arms. Such dynamics are also the main reason why variations in the shelf water density field, caused by remote forces (tide and coastal winds), propagate as a Kelvin wave into the fjord system. This exchange affects mainly the intermediate and deep water, which is also affected by vertical convection processes driven by cooling of the surface and brine release during ice formation in the inner reaches of the fjord arms. Further aspects covered by this paper include the geological and geomorphological characteristics of the Kongsfjorden area, climate and meteorology, the influence of glaciers, freshwater supply, sea ice conditions, sedimentation processes as well as underwater radiation conditions. The fjord system is assumed to be vulnerable to possible climate changes, and thus is very suitable as a site for the demonstration and investigation of phenomena related to climate change.

https://www.tandfonline.com/doi/pdf/10.3402/polar.v21i1.6479

The physical environment of Kongsfjorden–Krossfjorden, an Arctic fjord system in Svalbard

http://users.ntua.gr/mmakro/UVsource-measurem.pdf

Sources and measurement of ultraviolet radiation.

Measurements of photosynthesis, germination capacity and assessment of DNA damage were carried out in the laboratory to determine the effect of different conditions of ultraviolet (UV) and photosynthetically active radiation (PAR) on zoospores of various large brown algae collected on Spitsbergen (Svalbard, High Arctic) and Tarifa (Cadiz, southern Spain). Results were correlated to in situ light conditions and indicated that zoospores suffer photoinhibition of photosynthesis, loss of viability and DNA damage in relation to the growth depth of parental sporophytes. At both sites, germination capacity of zoospores in species collected in deep waters was more strongly impaired after exposure to the same UV doses than in species from shallower waters. In general, zoospores exposed to PAR+UVA+UVB showed higher mortality rates than after exposure to PAR+UVA or PAR alone. For Laminaria digitata from Spitsbergen, it was found that the loss of zoospore viability is the result of DNA damage and photodamage of the photosynthetic apparatus. UVB irradiances occurring in southern Spain at water depths shallower than 7 m prevented the germination of spores of deep water Laminariales from this region.

/pdf/impact-of-uv-radiation-on-viability-photosynthetic-42o22onbjy.pdf

Impact of UV-radiation on viability, photosynthetic characteristics and DNA of brown algal zoospores : implications for depth zonation

https://www.cidjournal.com/article/S0738-081X(07)00206-4/pdf

Outdoor sports and skin cancer.

The effect of artificial ultraviolet (UV) and natural solar radiation on photosynthesis, respiration and growth was investigated in 14 red, green and brown macroalgal species on Spitsbergen (Norway) during summer 1998. In June, maximum mean solar radiation at sea level was 120 W m -2 of visible (370 to 695 nm) and 15 W m -2 of UV radiation (300 to 370 nm), and decreased gradually until the end of the summer. In spite of incident irradiance, levels were low in comparison with other latitudes, and UV radiation stress on growth of Arctic macroalgae was evident. Transplantation experiments of plants from deeper to shallow waters showed, for most algae, an inhibitory effect of both UVA and UVB on growth, except in the intertidal species Fucus distichus. The growth rate of selected macroalgae was directly correlated to the variations in natural solar radiation during the summer. Underwater experiments both in situ and using UV-transparent incubators revealed a linear relationship between the depth distribution and the growth rate of the algae. In almost all species the photosynthetic oxygen production decreased after 2 h incubation in the laboratory under 38 μmol m -2 s -1 photosynthetic active radiation (PAR 400 to 700 nm) supplemented with 8 W m -2 UVA (320 to 400 nm) and 0.36 W m -2 UVB (280 to 320 nm) compared to only PAR without UV. Like in the growth experiments, the only exception was the brown alga F. distichus, in which photosynthesis was not affected by UV. The degree of inhibition of photosynthesis showed a relation to the depth distribution, i.e. algae from deeper waters were more inhibited than species from shallow waters. In general, no inhibitory UV effect on respiratory oxygen consumption in all macroalgae studied was detected under the artificial radiation regimes described above, with the exception of the brown alga Desmarestia aculeata and the green alga Mono-stroma arcticum, both showing a significant stimulation of respiration after 2 h of UV exposure. The ecological relevance of the seasonal variations in the solar radiation and the optical characteristics of the water column with respect to the vertical zonation of the macroalgae is discussed.

/pdf/effects-of-solar-radiation-on-growth-photosynthesis-and-aahkqr28qb.pdf

Effects of solar radiation on growth, photosynthesis and respiration of marine macroalgae from the Arctic

The UV action spectra of two different biologically weighing UV protofilms (spore films), produced with Bacillus subtilis spores (wild-type and DNA repair-deficient strains), were determined at the Okasaki large spectrograph (OLS) within the wavelength range 254–400 nm. The action spectrum of the mutant strain film was modified with a cut-off filter, yielding a sensitivity curve similar to the action spectrum for erythemal induction in human skin. The detector system was tested in a field study and in a study using lamps with different UV spectral compositions. The systems demonstrated its applicability over the spectral region from λ = 290 nm to the visible light. The system could be calibrated to give the minimal erythemal dose.

Characterization and application of UV detector spore films: the sensitivity curve of a new detector system provides good similarity to the action spectrum for UV-induced erythema in human skin

The available physical and biological broadband radiometers designed to determine erythema-effective radiation do not show any response or over/underestimate the biologically effective radiation to a high extent in the ultraviolet (UV)A spectral region. The data presented in this paper demonstrate that the biological system used in this study is the first one to make possible measurements of erythema-effective radiation in the sun in the UVA and UVB spectral region. These measurements were performed with a spore-film filter system as well as with spectroradiometers. It was demonstrated that this biotechnological method could be used to determine exact values expressed as minimal erythemal dose (MED). The spore-film system was tested in various field campaigns performed in Germany and in Japan. The seasonal daily variation of UV radiation in Germany determined in the period November 1995 to December 1996 using the spore-film filter system in sunny conditions tallied well with model calculations. The daily dose in Germany measured with the spore-film system close to the summer solstice, in sunny conditions (20.45 MED), was approximately 20 times higher than the lowest value measured close to the winter solstice (0.82 MED), a result which was in accordance with model calculations. The data determined with the spore-film filter system in Sapporo and Naha, Japan, fitted to the erythema-weighted data calculated from spectroradiometric measurements (Brewer), even at low solar radiation angles in a solar spectrum with less UVB but significant UVA. The spore-film dosimeter values were about 103 ± 8% of the integrated dose of the Brewer instrument. The standard deviation of the spore-film measurements obtained in Japan was 12.8%. The responsivity of the spore-film system towards longer wavelengths within the UVA spectrum was tested with the Okasaki Large Spectrograph with monochromatic radiation. At a wavelength of 365 nm – in a spectral region which is dominant in many tanning lamps and with minor importance for solar radiation in summer conditions – the tested spore-film system gave results that were close (112% compared to the calibration dose) to the calibration dose which was used for irradiation.

Determination of erythema-effective solar radiation in Japan and Germany with a spore monolayer film optimized for the detection of UVB and UVA--results of a field campaign.

L. E. Quintern

Papers

Characterization and application of UV detector spore films: the sensitivity curve of a new detector system provides good similarity to the action spectrum for UV-induced erythema in human skin

Determination of erythema-effective solar radiation in Japan and Germany with a spore monolayer film optimized for the detection of UVB and UVA--results of a field campaign.