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Gas transfer velocities in Norwegian fjords and the adjacent North Atlantic waters

Banko-Kubis Hanne M., Wurl Oliver, Mustaffa Nur Ili Hamizah, Ribas-Ribas Mariana

Oceanologia

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2019

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No. 61 (4)

460--470

EN

We investigated air-sea carbon dioxide (CO2) transfer in situ to determine the role of wind and turbulence in forcing gas transfer. In situ gas transfer velocities of CO2 were measured with a floating chamber technique along the Norwegian coast and inside the Sogne- and Trondheimsfjord. Gas transfer velocities were related to wind speed and turbulence, but neither wind speed nor turbulence can satisfactorily predict gas transfer velocity. However, comparison to existing wind-based parameterizations showed that the data from this study have a similar trend. Generally, we measured higher transfer velocities than the parameterizations predict. In the North Atlantic, we measured transfer velocities of up to 54.9 cm h-1 versus predicted transfer velocities of 6.3 cm h-1 at a wind speed of 3.7 m s-1. In addition, we observed that measurements of transfer velocities at wind speeds below 4 m s-1 are higher than predictions. Wind-based parameterizations are lacking data in the low wind regime for validation, and we provide 25 data points for this critical wind speed range. Overall, results indicate that Norwegian fjords and the adjacent North Atlantic are sinks for atmospheric CO2 during summer, with uptake rates of -9.6 ± 7.6 μmol m-2 min-1 and -4.1 ± 1.7 μmol m-2 min-1, respectively. Due to the low partial pressure of CO2 in the upper water layer of the stratified fjords (down to 150.7 μatm), the Sogne- and Trondheimsfjord absorb 196 tons of carbon per day during the summer.

2

Spatiotemporal changes in the concentration and composition of suspended particulate matter in front of Hansbreen, a tidewater glacier in Svalbard

Moskalik M., Ćwiąkała J., Szczuciński W., Dominiczak A., Głowacki O., Wojtysiak K., Zagórski P.

Oceanologia

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2018

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No. 60 (4)

446--463

EN

Tidewater glaciers supply large amounts of suspended particulate matter (SPM) and freshwater to fjords and affect oceanographic, sedimentological and biological processes. Our understanding of these processes, is usually limited to the short summer season. Here, we present the results of a one-year-long monitoring of the spatial variability in SPM characteristics in a context of oceanographic and meteorological conditions of a glacial bay next to Hansbreen, a tidewater glacier in Hornsund (southern Spitsbergen). The observed range of SPM concentrations was similar to ranges measured in other sub-polar glaciated fjords, especially in Svalbard. The major source of SPM is the meltwater discharge from the glacier. The maximum water column-averaged SPM concentrations did not correlate with peaks in freshwater discharge and were observed at the beginning of the autumn season, when the fjord water transitioned from stratified to fully mixed. The observed spatiotemporal variations in the total SPM, particulate organic matter (POM) and particulate inorganic matter (PIM) are likely controlled by a combination of factors including freshwater supply, water stratification and circulation, bathymetry, the presence of sea ice, biological productivity and sediment resuspension. During the ablation season, the SPM maximum concentrations were located within the upper water layer, whereas during the winter and spring, the greatest amounts of SPM were concentrated in deeper part. Thus, typical remote sensing-based studies that focus on SPM distributions may not reflect the real SPM levels. POM and PIM concentrations were correlated with each other, during most of the time suggesting that they may have a common source.

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Elektryczne promy morskie na przykładzie Norwegii

Forkiewicz M., Wolski L.

Autobusy : technika, eksploatacja, systemy transportowe

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2018

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R. 19, nr 12

890--895

PL

Norwegia jest światowym liderem wdrażania rozwiązań z zakresu e-mobilności (elektromobilności). W 2018 roku odbyła się ekspedycja naukowa projektu ELMAR w norweskich fiordach, podczas której zwizytowano wybrane promy pasażerskie oraz pasażersko-samochodowe. Zebrane przez autorów doświadczenia zostały przedstawione w artykule.

EN

When it comes to the implementation of e-mobility (electro-mobility) solutions, Norway is a world leader. The scientific expedition to the Norwegian fjords, organised as part of the ELMAR project in 2018, created an opportunity to visit selected passenger ferries and car and passenger ferries. The experience gained by the authors during that visit is presented in this article.

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Benthic Crustacea and Mollusca distribution in Arctic fjord – case study of patterns in Hornsund, Svalbard

Drewnik A., Węsławski J. M., Włodarska-Kowalczuk M.

Oceanologia

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2017

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No. 59 (4)

565--575

EN

We present the results of species distribution modeling conducted on macrobenthic occurrence data collected between 2002 and 2014 in Arctic fjord – Hornsund. We focus on species from Mollusca and Crustacea taxa. This study investigates the importance of individual environmental factors for benthic species distribution, with a special emphasis on bottom water temperature. It aims to verify the hypothesis that the distribution of species is controlled by low water temperatures in the fjord and that the inner basins of the fjord serve as potential refugia for Arctic species threatened by the climate change-related intensification of warmer water inflows. Our results confirm the importance of bottom water temperature in regulating the presence of benthic fauna in the Hornsund fjord. The distribution of studied species is clearly related to specific water mass – colder (<1°C) or warmer (>1°C); and the preferred temperature regimes seem to be species specific and unrelated to analyzed groups. This study supports the notion that inner basins of the Hornsund fjord are potential refugia for cold water Arctic fauna, while the outer and central basins provide suitable habitats for fauna that prefer warmer waters.

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Does the recent pool of benthic foraminiferal tests in fjordic surface sediments reflect interannual environmental changes? The resolution limit of the foraminiferal record

Łącka M., Zajączkowski M.

Annales Societatis Geologorum Poloniae

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2016

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Vol. 86, No. 1

59--71

EN

Benthic foraminifera tests (living + dead) and conductivity, temperature and depth (CTD) records in Hornsund Fjord (SW Spitsbergen) were studied over five non-consecutive summer seasons during 2002–2011. The data indicated significant changes in the abundance of benthic foraminifera, species composition and the variability of hydrological and micro-environmental conditions in this fjord. The increased inflow of Atlantic Water (AW) resulted in higher foraminiferal biodiversity and a greater number of rare species; however, many of these were fragile and were thus poorly preserved in the sediment. Cold years significantly reduced species richness in the fjord centre, while more stable hydrological conditions with a predominance of opportunistic foraminifera were noted at the fjord head. Elphidium excavatum f. clavata and Cassidulina reniforme exhibited sensitivity to salinity changes and food supply. The dynamic foraminiferal response to hydrological changes led to the conclusion that the annual foraminiferal flux, compounded by the poor preservation of fragile individuals, significantly changed the spatial and interannual composition of the foraminiferal tests remaining in the sediment. Furthermore, only mature individuals are representative of yearlong or multi-year fjord conditions, since the juveniles that bloom during their maximum growth periods in spring can die out under poor summer and winter conditions. The findings of this study indicated that the upper 8 cm of the sediment in the intense depositional systems of the Svalbard fjords provide good representation of recently departed benthic foraminifera, because of their mobility in surface sediments and further sediment compaction. Hence, the corresponding 10- to 15-year resolution in palaeoceanographic investigations seems to be the most reliable.