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Continental margins are hot spots for iron (Fe) and manganese (Mn) cycling. In the Arctic Ocean, these depositional systems are experiencing rapid changes that could significantly impact biogeochemical cycling. In this study, we investigate whether continental margin sediments north of Svalbard represent a source or sink of Fe and Mn to the water column and how climate change might alter these biogeochemical cycles. Our results highlight that sediments on the Yermak Plateau and Sofia Basin exhibit accumulations of Fe and Mn phases compared to average shale. Conversely, sediments from the Barents Sea slope exhibit lower enrichments of Fe and Mn compared to average shale, with the exception of enriched, near‐surface sediment layers. Pore waters from these slope sites provide evidence for Fe and Mn reduction and diffusion of Fe and Mn into near surface sediments, which are susceptible to physical or biogeochemical remobilization. These regional patterns are best explained by the spatial distribution of sea ice coverage and labile organic carbon fluxes to the seafloor. As sea ice continues to retreat and the Yermak Plateau becomes seasonally ice‐free, productivity is expected to increase, which would increase the flux of carbon to the sediments, thereby increasing oxidant demand, and the reduction of Fe and Mn mineral phases. Our results suggest that as sea ice continues to retreat, the Yermak Plateau and other Arctic continental margins could become sources of Fe and Mn to Arctic bottom waters.

This report describes the results of the first and second collection of data in the joint Nordic Monitoring System of diet, physical activity and overweight. It is well recognized that health in the European Region needs to be improved and Nordic public health researchers have since 2008 developed and validated a Nordic method to assess diet and physical activity among adults and children. Data has collected on health behaviour and overweight in 2011 and 2014 among 18,000 adults and 5,000 children. During the three year survey period, significant changes have occurred in the Nordic countries, especially among adults. The Nordic Monitoring System shows that lifestyle and weight status differ between the Nordic countries despite highly comparable societal structures. Favorable and unfavorable health behaviour is present in all countries and there are areas to be improved in all countries.

Recent studies have correlated dinoflagellate resting cyst morphology to salinity and density variations in the water column, suggesting that morphology can be used for paleoceanographic reconstructions. However, the univariate statistics used by these studies are appropriate only where morphology is related to a single variable. Density is a function of salinity and temperature, so more advanced statistical methods are needed to understand which parameters affect morphology. In this study based on surface (coretop) sediments, a set of environmental variables (sea-surface salinity, temperature, nitrate, and phosphate) was simultaneously correlated to morphological variations seen in resting cysts produced by the dinoflagellate Protoceratium reticulatum (= Operculodinium centrocarpum sensu Wall and Dale). Approximately 3200 measurements were obtained from the North Atlantic Ocean and used to generate a working model based on the Akaike information criterion. Hierarchical partitioning was then applied to establish the independent and joint effects for each predictor variable. Results from these analyses showed that while salinity constitutes the dominant variable affecting process length in the cysts of P. reticulatum in the North Atlantic, it is not the sole explanatory variable and that multicollinearity exists. Temperature and nutrients also showed a significant relationship to the morphology, requiring multiple regression to construct a representative model. The applicability of the North Atlantic working model was finally evaluated by comparing the results to data from the Mediterranean, Marmara, and Black seas, and Baltic–Kattegat–Skagerrak estuarine system. This comparison showed regional differences in morphological–environmental correlation. While salinity constitutes the most important explanatory factor in both the North Atlantic and Baltic–Skagerrak system, this is not so for the Mediterranean–Black Sea region where temperature is the dominant variable. It is concluded that a predictive salinity model based on P. reticulatum cyst morphology has at best a regional application.

Recent studies have correlated dinoflagellate resting cyst morphology to salinity and density variations in the water column, suggesting that morphology can be used for paleoceanographic reconstructions. However, the univariate statistics used by these studies are appropriate only where morphology is related to a single variable. Density is a function of salinity and temperature, so more advanced statistical methods are needed to understand which parameters affect morphology. In this study based on surface (coretop) sediments, a set of environmental variables (sea-surface salinity, temperature, nitrate, and phosphate) was simultaneously correlated to morphological variations seen in resting cysts produced by the dinoflagellate Protoceratium reticulatum (=Operculodinium centrocarpum sensu Wall and Dale). Approximately 3200 measurements were obtained from the North Atlantic Ocean and used to generate a working model based on the Akaike information criterion. Hierarchical partitioning was then applied to establish the independent and joint effects for each predictor variable. Results from these analyses showed that while salinity constitutes the dominant variable affecting process length in the cysts of P. reticulatum in the North Atlantic, it is not the sole explanatory variable and that multicollinearity exists. Temperature and nutrients also showed a significant relationship to the morphology, requiring multiple regression to construct a representative model. The applicability of the North Atlantic working model was finally evaluated by comparing the results to data from the Mediterranean, Marmara, and Black seas, and Baltic-Kattegat-Skagerrak estuarine system. This comparison showed regional differences in morphological-environmental correlation. While salinity constitutes the most important explanatory factor in both the North Atlantic and Baltic-Skagerrak system, this is not so for the Mediterranean-Black Sea region where temperature is the dominant variable. It is concluded that a predictive salinity model based on P. reticulatum cyst morphology has at best a regional application.

Dinoflagellate cysts are useful for reconstructing upper water conditions. For adequate reconstructions detailed information is required about the relationship between modern day environmental conditions and the geographic distribution of cysts in sediments. This Atlas summarises the modern global distribution of 71 organic-walled dinoflagellate cyst species. The synthesis is based on the integration of literature sources together with data of 2405 globally distributed surface sediment samples that have been prepared with a comparable methodology and taxonomy. The distribution patterns of individual cyst species are being compared with environmental factors that are known to influence dinoflagellate growth, gamete production, encystment, excystment and preservation of their organic-walled cysts: surface water temperature, salinity, nitrate, phosphate, chlorophyll-a concentrations and bottom water oxygen concentrations. Graphs are provided for every species depicting the relationship between seasonal and annual variations of these parameters and the relative abundance of the species. Results have been compared with previously published records; an overview of the ecological significance as well as information about the seasonal production of each individual species is presented.The relationship between the cyst distribution and variation in the aforementioned environmental parameters was analysed by performing a canonical correspondence analysis. All tested variables showed a positive relationship on the 99% confidence level. Sea-surface temperature represents the parameter corresponding to the largest amount of variance within the dataset (40%) followed by nitrate, salinity, phosphate and bottom-water oxygen concentration, which correspond to 34%, 33%, 25% and 24% of the variance, respectively. Characterisations of selected environments as well as a discussion about how these factors could have influenced the final cyst yield in sediments are included.

In 2007, a Nordic working group was established with the aim to describe a future Nordic monitoring system on diet, physical activity and overweight. The monitoring system should be simple and at relatively low cost. Therefore it has been decided to conduct the moni-toring as a telephone interview. In 2009, the indicator questions were validated against an objective method (physical activity) or existing survey methods (diet) and the present report mainly describes the validation studies. On basis of the validation studies the working group suggests that the indicators are used in a future monitoring system. In 2011 and 2013 the first collection of data in all Nordic countries will take place.

Absolute abundances (concentrations) of dinoflagellate cysts are often determined through the addition of Lycopodium clavatum marker-grains as a spike to a sample before palynological processing. An inter-laboratory calibration exercise was set up in order to test the comparability of results obtained in different laboratories, each using its own preparation method. Each of the 23 laboratories received the same amount of homogenized splits of four Quaternary sediment samples. The samples originate from different localities and consisted of a variety of lithologies. Dinoflagellate cysts were extracted and counted, and relative and absolute abundances were calculated. The relative abundances proved to be fairly reproducible, notwithstanding a need for taxonomic calibration. By contrast, excessive loss of Lycopodium spores during sample preparation resulted in non-reproducibility of absolute abundances. Use of oxidation, KOH, warm acids, acetolysis, mesh sizes larger than 15 µm and long ultrasonication (> 1 min) must be avoided to determine reproducible absolute abundances. The results of this work therefore indicate that the dinoflagellate cyst worker should make a choice between using the proposed standard method which circumvents critical steps, adding Lycopodium tablets at the end of the preparation and using an alternative method.

Traditionally, dinoflagellate cyst concentrations are calculated by adding an exotic marker or “spike” (such as Lycopodium clavatum) to each sample following the method of Stockmarr (1971). According to Maher (1981), the total error is controlled mainly by the error on the count of Lycopodium clavatum spores. In general, the more L. clavatum spores counted, the lower the error. A dinocyst / L. clavatum spore ratio of ~2 will give optimal results in terms of precision and time spent on a sample. It has also been proven that the use of the aliquot method yields comparable results to the marker-grain method (de Vernal et al., 1987). Critical evaluation of the effect of different laboratory procedures on the marker grain concentration in each sample has never been executed. Although, it has been reported that different processing methods (e.g. ultrasonication, oxidizing, etc.) are to a certain extent damaging to microfossils (e.g. Hodgkinson, 1991), it is not clear how this is translated into concentration calculations. It is wellknown from the literature that concentration calculations of dinoflagellate cysts from different laboratories are hard to resolve into a consistent picture. The aim of this study is to remove these inconsistencies and to make recommendations for the use of a standardized methodology. Sediment surface samples from four different localities (North Sea, Celtic Sea, NW Africa and Benguela) were macerated in different laboratories each using its own palynological maceration technique. A fixed amount of Lycopodium clavatum tablets was added to each sample. The uses of different preparation methodologies (sieving, ultrasonicating, oxidizing …) are compared using both concentrations – calculated from Lycopodium tablets - and relative abundances (more destructive methods will increase the amount of resistant taxa). Additionally, this study focuses on some important taxonomic issues, since obvious interlaboratorial differences in nomenclature are recorded.

Information assembled in this chapter will help the reader understand the basis for the preliminary conclusions of the Expedition 302 Scientists and will also enable the interested investigator to select samples for further analyses. This information concerns offshore and onshore operations and analyses described in the "Sites M0001–M0004" chapter. Methods used by various investigators for shore-based analyses of Expedition 302 samples will be described in the individual contributions published in the Expedition Research Results and in various professional journals.

It has been suggested, on the basis of modern hydrology and fully coupled palaeoclimate simulations, that the warm greenhouse conditions that characterized the early Palaeogene period (55-45 Myr ago) probably induced an intensified hydrological cycle with precipitation exceeding evaporation at high latitudes. Little field evidence, however, has been available to constrain oceanic conditions in the Arctic during this period. Here we analyse Palaeogene sediments obtained during the Arctic Coring Expedition, showing that large quantities of the free-floating fern Azolla grew and reproduced in the Arctic Ocean by the onset of the middle Eocene epoch (approximately 50 Myr ago). The Azolla and accompanying abundant freshwater organic and siliceous microfossils indicate an episodic freshening of Arctic surface waters during an approximately 800,000-year interval. The abundant remains of Azolla that characterize basal middle Eocene marine deposits of all Nordic seas probably represent transported assemblages resulting from freshwater spills from the Arctic Ocean that reached as far south as the North Sea. The termination of the Azolla phase in the Arctic coincides with a local sea surface temperature rise from approximately 10 degrees C to 13 degrees C, pointing to simultaneous increases in salt and heat supply owing to the influx of waters from adjacent oceans. We suggest that onset and termination of the Azolla phase depended on the degree of oceanic exchange between Arctic Ocean and adjacent seas.

International audience; The distribution of dinoflagellate cyst (dinocyst) assemblages in surface sediment samples from 677 sites of the northern North Atlantic, Arctic and sub-Arctic seas is discussed with emphasis on the relationships with sea-surface parameters, including sea-ice cover, salinity and temperature of the coldest and warmest months. Difficulties in developing a circum-Arctic data base include the morphological variation within taxa (e.g. Operculodinium centrocarpum, Islandinium? cezare and Polykrikos sp.), which probably relate to phenotypic adaptations to cold and/or low salinity environments. Sparse hydrographical data, together with large interannual variations of temperature and salinity in surface waters of Arctic seas constitute additional limitations. Nevertheless, the use of the best-analogue technique with this new dinocyst data base including 677 samples permits quantitative reconstruction of sea-surface conditions at the scale of the northern North Atlantic and the Arctic domain. The error of prediction calculated from modern assemblages is +/-1.3 degreesC and +/-1.8 degreesC for the temperature of February and August, respectively, +/-1.8 for the salinity, and +/-1.5 months yr(-1) for the sea-ice cover. Application to late Quaternary sequences from the western and eastern subpolar North Atlantic (Labrador Sea and Barents Sea) provide reconstructions compatible with those obtained using the previous dinocyst data base (n = 371), which mainly included modern data from the northern North Atlantic. Copyright (C) 2001 John Wiley & Sons, Ltd.

Recent studies have correlated dinoflagellate resting cyst morphology to salinity and density variations in the water column, suggesting that morphology can be used for paleoceanographic reconstructions. However, the univariate statistics used by these studies are appropriate only where morphology is related to a single variable. Density is a function of salinity and temperature, so more advanced statistical methods are needed to understand which parameters affect morphology. In this study based on surface (coretop) sediments, a set of environmental variables (sea-surface salinity, temperature, nitrate, and phosphate) was simultaneously correlated to morphological variations seen in resting cysts produced by the dinoflagellate Protoceratium reticulatum (= Operculodinium centrocarpum sensu Wall and Dale). Approximately 3200 measurements were obtained from the North Atlantic Ocean and used to generate a working model based on the Akaike information criterion. Hierarchical partitioning was then applied to establish the independent and joint effects for each predictor variable. Results from these analyses showed that while salinity constitutes the dominant variable affecting process length in the cysts of P . reticulatum in the North Atlantic, it is not the sole explanatory variable and that multicollinearity exists. Temperature and nutrients also showed a significant relationship to the morphology, requiring multiple regression to construct a representative model. The applicability of the North Atlantic working model was finally evaluated by comparing the results to data from the Mediterranean, Marmara, and Black seas, and Baltic–Kattegat–Skagerrak estuarine system. This comparison showed regional differences in morphological–environmental correlation. While salinity constitutes the most important explanatory factor in both the North Atlantic and Baltic–Skagerrak system, this is not so for the Mediterranean–Black Sea region where temperature is the dominant variable. It is concluded that a predictive salinity model based on P . reticulatum cyst morphology has at best a regional application.

During summer 1987, the R/V Polarstern of the Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Federal Republic of Germany (FRG), succeeded in penetrating the eastern Arctic ice pack as far north as the Nansen-Gakkel Ridge in the central eastern Arctic Basin. Our northernmost location, at 86°H′N (Figure 1), was further north than any surface vessel dedicated to marine research has attained previously, although Soviet nuclear-powered ice breakers have managed to penetrate to the North Pole. Prior to this cruise, most knowledge about the eastern Arctic Basin came from remote sensing techniques, Nansen's Fram expedition during 1893–1896 [Boggild, 1906; Gran, 1904; Nansen, 1902, 1904, 1906], Russian ice camps [Gordienko and Laktionov, 1969], the U.S. ice island camps Fram I-Fram IV, 1979–1982 [Hunkins et al, 1979; Baggeroer and Dyer, 1982; Manley et al, 1982; Kristoffersen, 1982; Kristoffersen et al, 1982; Kristoffersen and Husebye, 1985], and explorations by submarines.

Polarforschung

Polarforschung

Polarforschung

Polarforschung

New sediment cores were recovered along two transects from the Canada Basin across the central Mendeleev Ridge towards the Makarov Basin and the Lomonosov Ridge in the Eurasian Arctic (northern transect along 80°30 N, southern transect along 77°30 N). Here, we present first results from Polarstern ARK-XXIII/3 expedition (Aug-Oct 2008). Based on the visual core description, Clarks standard lithological units A to M (CLARK et al. 1980) could also be clearly identified in sediment cores from the northern transect across Mendeleev Ridge. The content of sand-sized material, the prominent pink-white layers, and especially in the upper part of the records the distinct brown/beige colour cycles were considered to be the key sedimentary characteristics used for core correlation and for establishing a tentative age model. Based on this age model, the sediments recovered in cores from the southern transect are younger than Marine Isotope Stage (MIS) 8, whereas the cores from the northern transect also contain sediments probably significantly older than MIS 16. Average sedimentation rates for the time interval MIS 1 to 5 in cores from the northern transect reach values of 0.5-0.9 cm ky-1 (top Mendeleev Ridge and Canadian side), increasing to 1.9-2.4 cm ky-1 at the Makarov Basin side. Along the southern transect, sedimentation rates are significantly higher, reaching 4.2 to >6 cm ky-1. The most distinct pinkish intervals characterized by high numbers of dolomitic ice-rafted debris (IRD) are related to increased IRD supply due to disintegration of an extended Laurentide Ice Sheet during MIS 8 (/7), MIS 5d, and MIS 4/MIS 3. The sand-rich intervals and detrital-carbonate maxima found in the deeper part of the sediment sections from the northern transect may reflect events of IRD input due to disintegration events of the Laurentide Ice Sheet at the end of glacial MIS 8, 10, 12, and 16, a still speculative hypothesis that has to be approved by further studies. A diamicton with erosional structures at its base was identified on southern Mendeleev Ridge in water depths of 800-900 m, suggesting the impact of grounding ice masses during a glaciation older than MIS 5a. Future research of this unique new core material recovered during the Polarstern Expedition may help to answer key questions in Arctic Ocean stratigraphy/chronology to unravel the history of circum-Arctic glaciations.