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Dinoflagellate cysts and benthic foraminifera from surface sediments of Svalbard fjords and shelves as paleoenvironmental indicators

Telesiński Maciej M., Pospelova Vera, Mertens Kenneth Neil, Kucharska Małgorzata, Zajączkowski Marek

Oceanologia

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2023

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Vol. 65 (4)

571--594

EN

Due to the Arctic amplification effect, the Svalbard archipelago is an important area for studying ongoing environmental changes. However, its marine ecosystem is extremely complex. In this study, we analyze modern assemblages of dinoflagellate cysts (dinocysts) and benthic foraminifera from surface sediment samples around Svalbard. We use multivariate statistical analyses to examine relationships between environmental conditions (summer and winter sea surface temperature and salinity, sea-ice cover, etc.) and both microfossil groups to evaluate their use as proxies for reconstructions of the marine environment in the region. Our results show that the most important factor controlling the environment around Svalbard is the Atlantic Water which mostly impacts the western coast, but its influence reaches as far as the eastern coast of Nordaustlandet. However, on a local scale, such factors as the sea-ice cover, the presence of tidewater glaciers, or even the morphology and hydrology of fjords become increasingly important. We found that two dinocyst species, cysts of Polarella glacialis and Echinidinium karaense, can be considered regional winter drift ice indicators. The relationships between environmental parameters and benthic foraminiferal assemblages are much more difficult to interpret. Although statistical analysis shows a correlation of benthic foraminiferal species with various environmental parameters, this correlation might be somewhat coincidental and caused by other factors not analyzed in this study. Nevertheless, the use of two complementary microfossil groups as (paleo)environmental indicators can provide a more comprehensive picture of the environmental conditions.

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Increases in the temperature and salinity of deep and intermediate waters in the West Spitsbergen Current region in 1997-2016

Merchel Małgorzata, Walczowski Waldemar

Oceanologia

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2020

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No. 62 (4PA)

501--510

EN

This study investigated the temporal variability in the basic physical properties of deep and intermediate waters in the West Spitsbergen Current region at 76°30’N latitude from 1997 to 2016. Emphasis was placed on quantifying the changes in temperature and salinity and determining the potential drivers of these changes. Hydrographic data were obtained during annual summer cruises aboard the r/v Oceania in the Nordic Seas. The increase in the water temperature, which was especially strong in the western part of the investigated section, was associated with considerable changes in the water layers salinity. The temperature and salinity of the intermediate water increased much faster (0.021°C yr−1 and 0.0022 yr−1, respectively) than those of the deep water (0.009°C yr−1 and 0.0004 yr−1, respectively). The warming rate in the upper 2000 m was also higher than the mean warming rate of the global ocean. The source of the deep water temperature and salinity increases was the deep water inflow from the Arctic Ocean into the Greenland Sea. In contrast, the increase in these properties in the intermediate water was associated with the advection of warmer and more saline Atlantic Water from the North Atlantic to the Nordic Seas.

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Oceanographic observations in the Nordic Sea and Fram Strait in 2016 under the IO PAN long-term monitoring program AREX

Walczowski W., Beszczyńska-Möller A., Wieczorek P., Merchel M., Grynczel A.

Oceanologia

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2017

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No. 59 (2)

187--194

EN

Since 1987 annual summer cruises to the Nordic Seas and Fram Strait have been conducted by the IO PAN research vessel Oceania under the long-term monitoring program AREX. Here we present a short description of measurements and preliminary results obtained during the open ocean part of the AREX 2016 cruise. Spatial distributions of Atlantic water temperature and salinity in 2016 are similar to their long-term mean fields except for warmer recirculation of Atlantic water in the northern Fram Strait. The longest observation record from the section N along 76°30′N reveals a steady increase of Atlantic water salinity, while temperature trend depends strongly on parametrization used to define the Atlantic water layer. However spatially averaged temperature at different depths indicate an increase of Atlantic water temperature in the whole layer from the surface down to 1000 m.

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Optical water types of the Nordic Seas and adjacent areas [commun.]

Aas E., Hojerslev N. K., Hokedal J., Sorensen K.

Oceanologia

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2013

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No. 55 (2)

471-482

EN

A new map of Jerlov's optical water types in the Nordic Seas and adjacent waters at 139 locations, as well as a table with statistical and geographical properties of the vertical attenuation coefficient of downward irradiance at 475 nm, are presented. The data analysis is based on 715 recordings at different stations, at latitudes between 54° and 82°N, and longitudes between 31°W and 49°E, obtained by different authors from May 1954 to August 2003. The results show that the Atlantic and Polar waters are typically of oceanic type II-III, although during algal blooms the optical conditions may change to coastal types 1, 3 and 5, which are also the most frequent types found in coastal areas.

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Temporal and spatial changes in the bio-optical properties of seawater in the Nordic Seas - AREX'2003 and 2006

Drozdowska V., Poryvkina L.

Oceanologia

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2011

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No. 53 (3)

731-743

EN

For many years the Nordic Seas have been the subject of research into ocean circulation carried out by the Institute of Oceanology PAS, especially the inflow of Atlantic water and the intensive turbulent mixing of these waters with Arctic and shelf waters. Ocean currents affect various biological processes, among them the supply of organic matter and oxygen, which constitute the foundation for the unique flora and fauna of the Svalbard islands. Spectrophotometric examinations of surface waters using an M32 B spectrofluorophotometer (LDI Ltd.) were carried out repeatedly during Arctic cruises on board r/v "Oceania". The results presented in this paper come from the AREX campaigns of 2003 and 2006. Analysis of the chlorophyll a fluorescence excitation spectra recorded shows an increase in phytoplankton abundance and the changes in the spatial distribution of the phytoplankton species characteristic of Atlantic, Arctic and shelf waters. The spatial patterns of the phytoplankton pigments and their abundance were compared with the physical characteristics of water masses. The analysis confirmed that phytoplankton species move together with the Atlantic water as this flows into northern latitudes.

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Warming of the West Spitsbergen Current and sea ice north of Svalbard

Piechura J., Walczowski W.

Oceanologia

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2009

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No. 51 (2)

147-164

EN

According to the results of recent research, besides the atmospheric circulation, it is heat transport to the Arctic Ocean (AO) by ocean currents, the West Spitsbergen Current (WSC) in particular, that is playing a significant role in the process of Arctic warming. Data collected by the Institute of Oceanology, Polish Academy of Sciences (IO PAS), in the Norwegian and Greenland Seas, and Fram Strait during the last 20 years reveal considerable changes in the amount of heat transported by the WSC into the Arctic Ocean. An increase in Atlantic Water (AW) temperature and the intensification of heat transport were observed in 2004-06; after this period, both parameters decreased. The aim of this study was to find out whether the fluctuations in heat input by the WSC have influenced the sea-ice distribution around Svalbard. In fact they do, but oceanic heat transport should nonetheless be regarded as just one of many processes influencing sea-ice behaviour.