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  • 101. Alm, C.G.
    Om Carex macloviana d'Urv. och dess utbredning i Nordeuropa.1944Ingår i: The Svedberg 1884 - 1944, Festskrift 1944, Uppsala, 1944, s. 578-600Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 102. Alm, C.G.
    Plantanthera parvula Schltr. , en nybeskriven svensk växt.1923Ingår i: Svensk Botanisk Tidskrift, Vol. 17, nr 2, s. 224-227Artikel i tidskrift (Övrigt vetenskapligt)
  • 103. Alm, C.G.
    Skogsfrublomman i Torne Lappmark.1921Ingår i: Sveriges Natur, Vol. 12, s. 163-164Artikel i tidskrift (Övrigt vetenskapligt)
  • 104. Alm, C.G.
    Vår sällsyntaste orkidé och dess öden.1929Ingår i: Sveriges Natur, Vol. 20, s. 134-137Artikel i tidskrift (Övrigt vetenskapligt)
  • 105. Alm, C.G.
    et al.
    Fries, Th.C.E.
    Botanische Exkursionen in Torne Lappmark. Kurzer Führer über das Gebiet von Kiruna und der Umgebung des Torneträsk.1925Rapport (Övrigt vetenskapligt)
  • 106. Alm, G.
    Monographie der Schwedischen Süsswasser-Ostracoden nebst systematischen Besprechungen der tribus Podocopa1916Rapport (Övrigt vetenskapligt)
  • 107. Alm, G.
    Ostracoden aus den nordschwedischen Hochgebirgen1914Rapport (Övrigt vetenskapligt)
  • 108. Alm, T.
    Noen fugletuer i fjellet.1993Ingår i: Polarflokken, Vol. 17, nr 1, s. 131-137Artikel i tidskrift (Övrigt vetenskapligt)
  • 109. Almquist, E.
    Järnvägsfloristiska notiser. Ett apropos till järnvägsjubileet.1957Ingår i: Svensk Botanisk Tidskrift, Vol. 51, nr 1, s. 223-263Artikel i tidskrift (Övrigt vetenskapligt)
  • 110. Almquist, E.
    Växtlokaler från Torne och Lule Lappmarker.1917Ingår i: Svensk Botanisk Tidskrift, Vol. 11, nr 1, s. 125-130Artikel i tidskrift (Övrigt vetenskapligt)
  • 111. Alonso-Saez, Laura
    et al.
    Andersson, Anders
    Heinrich, Friederike
    Bertilsson, Stefan
    High archaeal diversity in Antarctic circumpolar deep waters2011Ingår i: Environmental Microbiology Reports, ISSN 1758-2229, E-ISSN 1758-2229, Vol. 3, nr 6, s. 689-697Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Archaea are abundant in polar oceans but important ecological aspects of this group remain enigmatic, such as patterns of diversity and biogeography. Here, we provide the first high-throughput sequencing population study of Antarctic archaea based on 198 bp fragments of the 16S rRNA gene, targeting different water masses across the Amundsen and Ross Seas. Our results suggest that archaeal community composition is strongly shaped by hydrography and significantly influenced by environmental parameters. Archaeal communities from cold continental shelf waters (SW) of the Ross Sea were similar over depth with a single thaumarchaeal phylotype dominating Antarctic surface waters (AASW) and deeper SW (contributing up to 80% of reads). However, this phylotype contributed less than 8% of reads in circumpolar deep waters (CDW). A related thaumarchaeon (98% identity) was almost absent in AASW, but contributed up to 30% of reads in CDW, suggesting ecological differentiation of closely related phylotypes. Significantly higher archaeal richness and evenness were observed in CDW, with Shannon indices (c. 2.5) twice as high as for AASW, and high contributions of Group II Euryarchaeota. Based on these results, we suggest that CDW is a hotspot of archaeal diversity and may play an important role in the dispersal of archaeal phylotypes to other oceanic water masses.

  • 112. Alonso-Saez, Laura
    et al.
    Waller, Alison S.
    Mende, Daniel R.
    Bakker, Kevin
    Farnelid, Hanna
    Yager, Patricia L.
    Lovejoy, Connie
    Tremblay, Jean-Eric
    Potvin, Marianne
    Heinrich, Friederike
    Estrada, Marta
    Riemann, Lasse
    Bork, Peer
    Pedros-Alio, Carlos
    Bertilsson, Stefan
    Role for urea in nitrification by polar marine Archaea2012Ingår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 109, nr 44, s. 17989-17994Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Despite the high abundance of Archaea in the global ocean, their metabolism and biogeochemical roles remain largely unresolved. We investigated the population dynamics and metabolic activity of Thaumarchaeota in polar environments, where these microorganisms are particularly abundant and exhibit seasonal growth. Thaumarchaeota were more abundant in deep Arctic and Antarctic waters and grew throughout the winter at surface and deeper Arctic halocline waters. However, in situ single-cell activity measurements revealed a low activity of this group in the uptake of both leucine and bicarbonate (<5% Thaumarchaeota cells active), which is inconsistent with known heterotrophic and autotrophic thaumarchaeal lifestyles. These results suggested the existence of alternative sources of carbon and energy. Our analysis of an environmental metagenome from the Arctic winter revealed that Thaumarchaeota had pathways for ammonia oxidation and, unexpectedly, an abundance of genes involved in urea transport and degradation. Quantitative PCR analysis confirmed that most polar Thaumarchaeota had the potential to oxidize ammonia, and a large fraction of them had urease genes, enabling the use of urea to fuel nitrification. Thaumarchaeota from Arctic deep waters had a higher abundance of urease genes than those near the surface suggesting genetic differences between closely related archaeal populations. In situ measurements of urea uptake and concentration in Arctic waters showed that small-sized prokaryotes incorporated the carbon from urea, and the availability of urea was often higher than that of ammonium. Therefore, the degradation of urea may be a relevant pathway for Thaumarchaeota and other microorganisms exposed to the low-energy conditions of dark polar waters.

  • 113. Alsander, J.
    et al.
    Hill, A.
    Nilsson, I.
    Paktajokk. Vattenföring, fluvial transport och denudation.1978Rapport (Övrigt vetenskapligt)
  • 114. Alsos, I G
    et al.
    Engelskjon, T
    Gielly, L
    Taberlet, P
    Brochmann, C
    Impact of ice ages on circumpolar molecular diversity: insights from an ecological key species2005Ingår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 14, nr 9, s. 2739-2753Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We address the impact of the ice age cycles on intraspecific cpDNA diversity, for the first time on the full circumboreal-circumarctic scale. The bird-dispersed bog bilberry (or arctic blueberry, Vaccinium uliginosum) is a key component of northern ecosystems and is here used to assess diversity in previously glaciated vs. unglaciated areas and the importance of Beringia as a refugium and source for interglacial expansion. Eighteen chloroplast DNA haplotypes were observed in and among 122 populations, grouping into three main lineages which probably diverged before, and thus were affected more or less independently by, all major glaciations. The boreal ‘Amphi-Atlantic lineage’ included one haplotype occurring throughout northern Europe and one occurring in eastern North America, suggesting expansion from at least two bottlenecked, glacial refugium populations. The boreal ‘Beringian lineage’ included seven haplotypes restricted to Beringia and the Pacific coast of USA. The ‘Arctic-Alpine lineage’ included nine haplotypes, one of them fully circumpolar. This lineage was unexpectedly diverse, also in previously glaciated areas, suggesting that it thrived on the vast tundras during the ice ages and recolonized deglaciated terrain over long distances. Its largest area of persistence during glaciations was probably situated in the north, stretching from Beringia and far into Eurasia, and it probably also survived the last glaciation in southern mountain ranges. Although Beringia apparently was important for the initial divergence and expansion of V. uliginosum as well as for continuous survival of both the Beringian and Arctic-Alpine lineages during all ice ages, this region played a minor role as a source for later interglacial expansions.

  • 115. Alsos, Inger Greve
    et al.
    Eidesen, Pernille Bronken
    Ehrich, Dorothee
    Skrede, Inger
    Westergaard, Kristine
    Jacobsen, Gro Hilde
    Landvik, Jon Y.
    Taberlet, Pierre
    Brochmann, Christian
    Frequent long-distance plant colonization in the changing Arctic2007Ingår i: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 316, nr 5831, s. 1606-1609Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The ability of species to track their ecological niche after climate change is a major source of uncertainty in predicting their future distribution. By analyzing DNA fingerprinting ( amplified fragment-length polymorphism) of nine plant species, we show that long-distance colonization of a remote arctic archipelago, Svalbard, has occurred repeatedly and from several source regions. Propagules are likely carried by wind and drifting sea ice. The genetic effect of restricted colonization was strongly correlated with the temperature requirements of the species, indicating that establishment limits distribution more than dispersal. Thus, it may be appropriate to assume unlimited dispersal when predicting long-term range shifts in the Arctic.

  • 116. Alstrup, V.
    Lichens and lichenicolous fungi from the Torneträsk area.1991Ingår i: Graphis Scripta, Vol. 3, s. 54-67Artikel i tidskrift (Övrigt vetenskapligt)
  • 117. Alstrup, V.
    Lichens from Björkliden, Northern Sweden.1986Ingår i: Graphis Scripta, Vol. 1, nr 1, s. 3-6Artikel i tidskrift (Övrigt vetenskapligt)
  • 118. Alverson, K.
    et al.
    Bradley, R.
    Briffa, K.
    Cole, J.
    Hughes, M.
    Larocque, I.
    Pedersen, T.
    Thompson, L.
    Tudhope, S.
    Disappearing Evidence: the Need for a Global Paleoclimate Observing System.2001Ingår i: Global Change NewsLetter, Vol. 46, s. 2-6Artikel i tidskrift (Övrigt vetenskapligt)
  • 119. Alwmark, Carl
    et al.
    Ormö, Jens
    Nielsen, Arne T.
    Shocked quartz grains in the early Cambrian Vakkejokk Breccia, Sweden—Evidence of a marine impact2019Ingår i: Meteoritics and Planetary Science, ISSN 1086-9379, E-ISSN 1945-5100, Vol. 54, nr 3, s. 609-620Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Here we present a study of the abundance and orientation of planar deformation features (PDFs) in the Vakkejokk Breccia, a proposed lower Cambrian impact ejecta layer in the North-Swedish Caledonides. The presence of PDFs is widely accepted as evidence for shock metamorphism associated with cosmic impact events and their presence confirms that the Vakkejokk Breccia is indeed the result of an impact. The breccia has previously been divided into four lithological subunits (from bottom to top), viz. lower polymict breccia (LPB), graded polymict breccia (GPB), top sandstone (TS), and top conglomerate (TC). Here we show that the LPB contains no shock metamorphic features, indicating that the material derives from just outside of the crater and represents low-shock semi-autochthonous bombarded strata. In the overlying, more fine-grained GPB and TS, quartz grains with PDFs are relatively abundant (2?5% of the grain population), and with higher shock levels in the upper parts, suggesting that they have formed by reworking of more distal ejecta by resurge of water toward the crater in a marine setting. The absence of shocked quartz grains in the TC indicates that this unit represents later slumps associated with weathering and erosion of the protruding crater rim. Sparse shocked quartz grains (<0.2%) were also found in sandstone beds occurring at the same stratigraphic level as the Vakkejokk Breccia 15?20 km from the inferred crater site. It is currently unresolved whether the sandstone at these distal sites is related to the impact or just contains rare reworked quartz grains with PDFs.

  • 120.
    Amnéus, E.
    Naturgeografiska institutionen, Avdelningen för Naturgeografi.
    Markanvändningsförändringar i Torneträskområdet.1989Studentuppsats (Examensarbete)
  • 121. Amon, D. J.
    et al.
    Wiklund, H.
    Dahlgren, T. G.
    Copley, J. T.
    Smith, C. R.
    Jamieson, A. J.
    Glover, A. G.
    Molecular taxonomy of Osedax (Annelida: Siboglinidae) in the Southern Ocean2014Ingår i: Zoologica Scripta, ISSN 0300-3256, E-ISSN 1463-6409, Vol. 43Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report the discovery of three new species of Osedax in the deep Southern Ocean, expanding the diversity and geographical range of this genus of bone-eating worms. Osedax rogersi sp. n. and Osedax crouchi sp. n. were found on a whale skeleton at 1444m in the Kemp Caldera in the East Scotia Sea during the Chemosynthetic Ecosystems of the Southern Ocean (ChEsSo) project. The recently described species, Osedax antarcticus, found on whale bones implanted at a depth of 550-650m off Smith Island in the Bransfield Strait, was also found inhabiting the whale skeleton in the Kemp Caldera. Osedax crouchi as well as another new species Osedax nordenskjoeldi sp. n. have also been found on the implanted whale bones off Smith Island. These two localities are approximately 1800km apart demonstrating a wide distribution of species within the genus. We describe the three new species, O.rogersi, O.crouchi and O.nordenskjoeldi and report the second record of O.antarcticus. We also present a new phylogenetic analysis for Osedax, including data examining genetic connectivity between the Scotia Arc and the Bransfield Strait.

  • 122. Ampomah, Osei Yaw
    et al.
    Huss-Danell, Kerstin
    Nodulation of Thermopsis lupinoides by a Mesorhizobium huakuii strain with a unique nodA gene in Kamtchatka, Russia2011Ingår i: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, s. 5513-5516Artikel i tidskrift (Refereegranskat)
  • 123. Ampomah, Osei Yaw
    et al.
    Mousavi, Seyed Abdollah
    Lindström, Kristina
    Huss-Danell, Kerstin
    Diverse Mesorhizobium bacteria nodulate native Astragalus and Oxytropis in arctic and subarctic areas in Eurasia2017Ingår i: Systematic and Applied Microbiology, ISSN 0723-2020, E-ISSN 1618-0984, Vol. 40, nr 1, s. 51-58Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Abstract Rhizobia nodulating native Astragalus and Oxytropis spp. in Northern Europe are not well-studied. In this study, we isolated bacteria from nodules of four Astragalus spp. and two Oxytropis spp. from the arctic and subarctic regions of Sweden and Russia. The phylogenetic analyses were performed by using sequences of three housekeeping genes (16S rRNA, rpoB and recA) and two accessory genes (nodC and nifH). The results of our multilocus sequence analysis (MLSA) of the three housekeeping genes tree showed that all the 13 isolates belonged to the genus Mesorhizobium and were positioned in six clades. Our concatenated housekeeping gene tree also suggested that the isolates nodulating Astragalus inopinatus, Astragalus frigidus, Astragalus alpinus ssp. alpinus and Oxytropis revoluta might be designated as four new Mesorhizobium species. The 13 isolates were grouped in three clades in the nodC and nifH trees. 15N analysis suggested that the legumes in association with these isolates were actively fixing nitrogen.

  • 124. Amundsen, Helene
    et al.
    Anderson, Leif
    Andersson, Andreas
    Azetsu-Scott, Kumiko
    Bellerby, Richard
    Beman, Michael
    Browman, Howard I
    Carlson, Craig
    Cheung, William WL
    Chierici, Melissa
    AMAP Assessment 2013: Arctic Ocean Acidification2013Bok (Övrigt vetenskapligt)
  • 125. Ander, K.
    Bidrag till kännedomen om de svenska Odonaterna. 5. Norrländska trollsländor.1931Ingår i: Entomologisk Tidskrift, Vol. 52, s. 228-244Artikel i tidskrift (Övrigt vetenskapligt)
  • 126. Ander, K.
    De svenska odonaternas djurgeografi. Bidrag till kännedomen om de svenska odonaterna. 6.1946Ingår i: Opuscula Entomologica, Vol. 11, s. 109-118Artikel i tidskrift (Övrigt vetenskapligt)
  • 127. Ander, K.
    Die boreoalpinen Orthopteren Europas.1949Ingår i: Opuscula Entomologica, Vol. 14, s. 89-104Artikel i tidskrift (Övrigt vetenskapligt)
  • 128. Ander, K.
    Odonata.1951Ingår i: Kungliga Fysiografiska Sällskapets Handlingar, NF, Vol. 61, nr 2, s. 123-126Artikel i tidskrift (Övrigt vetenskapligt)
  • 129. Ander, K.
    Orthoptera.1951Ingår i: Kungliga Fysiografiska Sällskapets Handlingar, NF, Vol. 61, nr 2, s. 135-137Artikel i tidskrift (Övrigt vetenskapligt)
  • 130. Ander, K.
    Revision der Orthopterensammlungen Zetterstedts.1943Ingår i: Kungliga Fysiografiska Sällskapets Handlingar, NF, Vol. 53, nr 7, s. 1-23Artikel i tidskrift (Övrigt vetenskapligt)
  • 131. Ander, K.
    Rätvingar - Orthoptera. (Insektfaunan inom Abisko nationalpark III:14).1931Ingår i: Kungliga Svenska Vetenskapsakademiens Skrifter i naturskyddsärenden, Vol. 18, s. 64-69Artikel i tidskrift (Övrigt vetenskapligt)
  • 132. Ander, K.
    Trollsländor - Odonata. (Insektfaunan inom Abisko nationalpark III:13).1931Ingår i: Kungliga Svenska Vetenskapsakademiens Skrifter i naturskyddsärenden, Vol. 18, s. 60-63Artikel i tidskrift (Övrigt vetenskapligt)
  • 133. Ander, K.
    Zur Verbreitung und Phänologie der boreoalpinen Odonaten der Westpaläarktis.1950Ingår i: Opuscula Entomologica, Vol. 15, s. 53-71Artikel i tidskrift (Övrigt vetenskapligt)
  • 134. Andersen, M. B.
    et al.
    Stirling, C. H.
    Porcelli, D.
    Halliday, A. N.
    Andersson, P. S.
    Baskaran, M.
    The tracing of riverine U in Arctic seawater with very precise U-234/U-238 measurements2007Ingår i: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 259, nr 1-2, s. 171-185Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The riverine flux of U that enters the deep oceans is not well constrained since the net losses during estuarine mixing are difficult to quantify. Riverine-dissolved U normally has a higher U-234/(238) U activity ratio (U-234/U-238(ar)) than the uniform value that characterizes open ocean seawater and could be used as a tracer of riverine inputs if one could resolve subtle variations in seawater composition. Using new mass spectrometry techniques we achieve a long-term reproducibility +/- 0.3 parts per thousand on U-234/U-238(ar) which permits the tracing of riverine U in seawater samples from the Arctic - a partially restricted basin that is ideal for such a study. We find that surface waters from the Arctic basins carry elevated U-234/(238)Uar when compared with deep ocean seawater. Samples from the Canada Basin have a significant freshwater component and provide evidence that the Mackenzie River loses similar to 65% of its U in the Mackenzie shelf/estuary zone before entering the deeper basin. This is in contrast to samples from the Makarov Basin, which provide evidence that all of the freshwater input is derived from the major Yenisey River alone, despite the proximity of the Lena and Ob Rivers. The differing behaviour of U between the Mackenzie and Yenisey Rivers is most likely a consequence of the strong binding of U to dissolved organic matter (DOC) or secondary phases in these rivers. The Yenisey River appears to transport the majority of the DOC through the shelf and into the Makarov Basin. In contrast, the Mackenzie River appears to lose a significant amount of DOC (> 50%) in the estuary/shelf zone, which may lead to loss of associated U. These findings offer a more detailed picture of the fresh riverine water flow patterns in the Arctic Ocean when compared to other geochemical proxies. The non-conservative behaviour of U in the Mackenzie River through the shelf/estuaries has important implications for U input into oceans and the total marine budget. (c) 2007 Elsevier B.V. All rights reserved.

  • 135. Anderson, D.
    et al.
    Rich, V. I.
    Hodgkins, S. B.
    Tfaily, M.
    Chanton, J.
    Mapping Microbial Carbon Substrate Utilization Across Permafrost Thaw2014Ingår i: AGU Fall Meeting Abstracts, 2014, Vol. 12, artikel-id B31G-0122Konferensbidrag (Övrigt vetenskapligt)
  • 136.
    ANDERSON, DARYA NICOLE
    The University of Arizona.
    MAPPING MICROBIAL SUBSTRATE UTILIZATION ACROSS A PERMAFROST THAW GRADIENT2016Självständigt arbete på grundnivå (kandidatexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    Permafrost thaw is likely to create a substantial positive feedback to climate change, as previously frozen organic carbon (OC) becomes available for biological metabolism and is released to the atmosphere. Microbes mediate transformation and release of formerly stored C, while also consuming recently fixed plant C and age stored C in the seasonally-thawed peat active layer. This biological activity releases carbon dioxide (CO2) and methane (CH4) to the atmosphere. To investigate microbial C cycling changes with permafrost thaw, we examined how microbial community C substrate degradation differed between two thaw features in Stordalen Mire, Sweden, located at the discontinuous southern edge of the permafrost zone. The progression of thaw results in increasing organic matter lability, shifting microbial community composition, and changing C gas emissions. However, the interrelationship of the population metabolism with the gas release remains unclear. We analyzed microbial C substrate utilization in bog and fen sites using Biolog Ecoplates and measurements of CH4 and CO2 production in anaerobic incubations of peat with select C substrate amendments. Overall, the results suggest that, with permafrost thaw, substrates for microbial carbon processing diversify, utilization of these substrates reaches a greater extent, and pathways of carbon degradation shift towards methanogenesis.

  • 137. Anderson, L G
    et al.
    Falck, E
    Jones, E P
    Jutterstrom, S
    Swift, J H
    Enhanced uptake of atmospheric CO2 during freezing of seawater: A field study in Storfjorden, Svalbard2004Ingår i: Journal of Geophysical Research - Oceans, ISSN 2169-9275, E-ISSN 2169-9291, Vol. 109, nr C6Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The waters of Storfjorden, a fjord in southern Svalbard, were investigated in late April 2002. The temperature was at the freezing point throughout the water column; the salinity in the top 30 m was just above 34.8, then increased nearly linearly to about 35.8 at the bottom. Nutrient and oxygen concentrations showed a minimal trend all through the water column, indicating minimal decay of organic matter. Normalized dissolved inorganic carbon, fCO(2), and CFCs increase with depth below the surface mixed layer, while pH decreases. In waters below 50 m, there was an increase in dissolved inorganic carbon, corrected for decay of organic matter using the phosphate profile, corresponding to about 9 g C m(-2) relative to the surface water concentration. We suggest this excess is a result of enhanced air-sea exchange of CO2 caused by sea ice formation. This enhancement is suggested to be a result of an efficient exchange through the surface film during the ice crystal formation and the rapid transport of the high salinity brine out of the surface layer.

  • 138. Anderson, L G
    et al.
    Jones, E P
    Swift, J H
    Export production in the central Arctic Ocean evaluated from phosphate deficits2003Ingår i: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 108, nr C6Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    [1] Primary productivity in the central Arctic Ocean has recently been reported as being much higher than earlier thought. If a significant fraction of this primary production were exported from the immediate surface region, present estimates of the carbon budget for the Arctic Ocean would have to be reassessed. Using the deficit of phosphate in the central Arctic Ocean, we show that the export production is very low, on an average less than 0.5 gC m(-2) yr(-1). This is at least an order of magnitude lower than the total production as measured or estimated from oxygen data, thus indicating extensive recycling of nutrients in the upper waters of the central Arctic Ocean and very little export production.

  • 139. Anderson, L. G.
    et al.
    Jutterstrom, S.
    Hjalmarsson, S.
    Wahlstrom, I.
    Semiletov, I. P.
    Out-gassing of CO2 from Siberian Shelf seas by terrestrial organic matter decomposition2009Ingår i: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 36Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Siberian shelf seas cover large shallow areas that receive substantial amounts of river discharge. The river runoff contributes nutrients that promote marine primary production, but also dissolved and particulate organic matter. The coastal regions are built up of organic matter in permafrost that thaws and result in coastal erosion and addition of organic matter to the sea. Hence there are multiple sources of organic matter that through microbial decomposition result in high partial pressures of CO2 in the shelf seas. By evaluating data collected from the Laptev and East Siberian Seas in the summer of 2008 we compute an excess of DIC equal to 10.10(12) g C that is expected to be outgassed to the atmosphere and suggest that this excess mainly is caused by terrestrial organic matter decomposition. Citation: Anderson, L. G., S. Jutterstrom, S. Hjalmarsson, I. Wahlstrom, and I. P. Semiletov (2009), Out-gassing of CO2 from Siberian Shelf seas by terrestrial organic matter decomposition, Geophys. Res. Lett., 36, L20601, doi:10.1029/2009GL040046.

  • 140. Anderson, L G
    et al.
    Jutterstrom, S
    Kaltin, S
    Jones, E P
    Bjork, G R
    Variability in river runoff distribution in the Eurasian Basin of the Arctic Ocean2004Ingår i: Journal of Geophysical Research - Oceans, ISSN 2169-9275, E-ISSN 2169-9291, Vol. 109, nr C1Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The distribution of freshwater within the Arctic Ocean and its export from it are intimately involved in climate and climate change processes both within and outside the Arctic Ocean. River runoff in the Arctic Ocean constitutes a major part of the Arctic Ocean freshwater budget. Within the Arctic Ocean, variability in the distribution of river runoff will be reflected in the location of the cold halocline that isolates the sea ice from the warm Atlantic Layer. Outside the Arctic Ocean, such variability will impact on the salinity of North Atlantic waters (Great Salinity Anomaly) and on deep convection areas of the North Atlantic Ocean, and thereby potentially on global thermohaline circulation. Rivers entering the Arctic Ocean have high levels of total alkalinity that contribute significantly to the total alkalinity of the surface Polar Mixed Layer. We exploit total alkalinity data to trace river runoff in the surface Polar Mixed Layer and to observe variability in the river runoff distribution in the Eurasian Basin over the period 1987-2001. The river runoff front changed from a position over the Gakkel Ridge in 1987 and 1991 to over the Lomonosov Ridge in 1996, and returned to a midpoint between the two ridges in 2001. Wind field changes as characterized by the Arctic Oscillation index are considered to be a major factor in determining ice and surface water flow. We note a correlation with 4-6 years delay between changes in river runoff distribution and the Arctic Oscillation index. We show that the delay can be inferred from a geostrophic flow calculation.

  • 141. Anderson, L G
    et al.
    Kaltin, S
    Carbon fluxes in the Arctic Ocean - potential impact by climate change2001Ingår i: Polar Research, ISSN 0800-0395, E-ISSN 1751-8369, Vol. 20, nr 2, s. 225-232Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Because of its ice cover the central Arctic Ocean has not been considered as a sink of atmospheric carbon dioxide. With recent observations of decreasing ice cover there is the potential for an increased air-sea carbon dioxide flux. Though the sensitivity of the carbon fluxes to a climate change can at present only be speculated, we know the responses to some of the forcing, including: melting of the sea ice cover make the air-sea flux operate towards equilibrium; increased temperature of the surface water will decrease the solubility and thus the air-sea flux; and an open ocean might increase primary production through better utilization of the nutrients. The potential change in air-sea CO2 fluxes caused by different forcing as a result of climate change is quantified based on measured data. If the sea ice melts, the top 100 m water column of the Eurasian Basin has, with the present conditions, a potential to take up close to 50 g C m(-2). The freshening of the Surface water caused by a sea ice melt will increase the CO2 solubility corresponding to an uptake of similar to3 g C m(-2), while a temperature increase of 1 degreesC in the same waters will out-gas 8 g C m(-2), and a utilization of all phosphate will increase primary production by 75 g C m(-2).

  • 142. Anderson, L. G.
    et al.
    Tanhua, T.
    Bjork, G.
    Hjalmarsson, S.
    Jones, E. P.
    Jutterstrom, S.
    Rudels, B.
    Swift, J. H.
    Wahlstom, I.
    Arctic ocean shelf-basin interaction: An active continental shelf CO2 pump and its impact on the degree of calcium carbonate solubility2010Ingår i: Deep Sea Research Part I: Oceanographic Research Papers, ISSN 0967-0637, E-ISSN 1879-0119, Vol. 57, nr 7, s. 869-879Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Arctic Ocean has wide shelf areas with extensive biological activity including a high primary productivity and an active microbial loop within the surface sediment. This in combination with brine production during sea ice formation result in the decay products exiting from the shelf into the deep basin typically at a depth of about 150 m and over a wide salinity range centered around S similar to 33. We present data from the Beringia cruise in 2005 along a section in the Canada Basin from the continental margin north of Alaska towards the north and from the International Siberian Shelf Study in 2008 (ISSS-08) to illustrate the impact of these processes. The water rich in decay products, nutrients and dissolved inorganic carbon (DIC), exits the shelf not only from the Chukchi Sea, as has been shown earlier, but also from the East Siberian Sea. The excess of DIC found in the Canada Basin in a depth range of about 50-250 m amounts to 90 +/- 40 g C m(-2). If this excess is integrated over the whole Canadian Basin the excess equals 320 +/- 140 x 10(12) g C. The high DIC concentration layer also has low pH and consequently a low degree of calcium carbonate saturation, with minimum aragonite values of 60% saturation and calcite values just below saturation. The mean age of the waters in the top 300 m was calculated using the transit time distribution method. By applying a future exponential increase of atmospheric CO2 the invasion of anthropogenic carbon into these waters will result in an under-saturated surface water with respect to aragonite by the year 2050, even without any freshening caused by melting sea ice or increased river discharge. (C) 2010 Elsevier Ltd. All rights reserved.

  • 143. Anderson, Leif G.
    Chapter 14 - DOC in the Arctic Ocean2002Ingår i: Biogeochemistry of Marine Dissolved Organic Matter / [ed] Hansell, Dennis A.; Carlson, Craig A., Academic Press , 2002, s. 665-683Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 144. Anderson, Leif G.
    et al.
    Andersson, Per S.
    Bjork, Goran
    Jones, E. Peter
    Jutterstrom, Sara
    Wahlstrom, Irene
    Source and formation of the upper halocline of the Arctic Ocean2013Ingår i: Journal of Geophysical Research - Oceans, ISSN 2169-9275, E-ISSN 2169-9291, Vol. 118, nr 1, s. 410-421Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The upper halocline of the Arctic Ocean has a distinct chemical signature with high nutrient concentrations as well as low oxygen and pH values. This signature is formed in the Chukchi and East Siberian seas, by a combination of mineralization of organic matter and release of decay products to the sea ice brine enriched bottom water. Salinity and total alkalinity data show that the fraction of sea ice brine in the nutrient-enriched upper halocline water in the central Arctic Ocean is up to 4%. In the East Siberian Sea the bottom waters with exceptional high nutrient concentration and low pH have typically between 5 and 10% of sea ice brine as computed from salinity and oxygen-18 values. On the continental slope, over bottom depths of 150-200 m, the brine contribution was 6% at the nutrient maximum depth (50-100 m). At the same location as well as over the deeper basin the silicate maximum was found over a wider salinity range than traditionally found in the Canada Basin, in agreement with earlier observations east of the Chukchi Plateau. A detailed evaluation of the chemical and the temperature-salinity properties suggests at least two different areas for the formation of the nutrient-rich halocline within the East Siberian Sea. This has not been observed before 2004 and it could be a sign of a changing marine climate in the East Siberian Sea, caused by more open water in the summer season followed by more sea ice formation and brine production in the fall/winter. Citation: Anderson, L. G., P. S. Andersson, G. Bjork, E. Peter Jones, S. Jutterstrom, and I. Wahlstrom (2013), Source and formation of the upper halocline of the Arctic Ocean, J. Geophys. Res. Oceans, 118, 410-421, doi:10.1029/2012JC008291.

  • 145. Anderson, Leif G.
    et al.
    Bjork, Goran
    Holby, Ola
    Jutterstrom, Sara
    Morth, Carl Magnus
    O’Regan, Matt
    Pearce, Christof
    Semiletov, Igor
    Stranne, Christian
    Stoven, Tim
    Tanhua, Toste
    Ulfsbo, Adam
    Jakobsson, Martin
    Shelf-Basin interaction along the East Siberian Sea2017Ingår i: Ocean Science, ISSN 1812-0784, E-ISSN 1812-0792, Vol. 13, nr 2, s. 349-363Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Extensive biogeochemical transformation of organic matter takes place in the shallow continental shelf seas of Siberia. This, in combination with brine production from sea-ice formation, results in cold bottom waters with relatively high salinity and nutrient concentrations, as well as low oxygen and pH levels. Data from the SWERUS-C3 expedition with icebreaker Oden, from July to September 2014, show the distribution of such nutrient-rich, cold bottom waters along the continental margin from about 140 to 180 degrees E. The water with maximum nutrient concentration, classically named the upper halocline, is absent over the Lomonosov Ridge at 140 degrees E, while it appears in the Makarov Basin at 150 degrees E and intensifies further eastwards. At the intercept between the Mendeleev Ridge and the East Siberian continental shelf slope, the nutrient maximum is still intense, but distributed across a larger depth interval. The nutrient-rich water is found here at salinities of up to similar to 34.5, i.e. in the water classically named lower halocline. East of 170 degrees E transient tracers show significantly less ventilated waters below about 150 m water depth. This likely results from a local isolation of waters over the Chukchi Abyssal Plain as the boundary current from the west is steered away from this area by the bathymetry of the Mendeleev Ridge. The water with salinities of similar to 34.5 has high nutrients and low oxygen concentrations as well as low pH, typically indicating decay of organic matter. A deficit in nitrate relative to phosphate suggests that this process partly occurs under hypoxia. We conclude that the high nutrient water with salinity similar to 34.5 are formed on the shelf slope in the Mendeleev Ridge region from interior basin water that is trapped for enough time to attain its signature through interaction with the sediment.

  • 146. Anderson, Leif G.
    et al.
    Jorgen, E. K.
    Ericson, Ylva
    Humborg, Christoph
    Semiletov, Igor
    Sundbom, Marcus
    Ulfsbo, Adam
    Export of calcium carbonate corrosive waters from the East Siberian Sea2017Ingår i: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 14, nr 7, s. 1811-1823Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Siberian shelf seas are areas of extensive biogeochemical transformation of organic matter, both of marine and terrestrial origin. This in combination with brine production from sea ice formation results in a cold bottom water of relative high salinity and partial pressure of carbon dioxide (pCO(2)). Data from the SWERUS-C3 expedition compiled on the icebreaker Oden in July to September 2014 show the distribution of such waters at the outer shelf, as well as their export into the deep central Arctic basins. Very high pCO(2) water, up to similar to 1000 mu atm, was observed associated with high nutrients and low oxygen concentrations. Consequently, this water had low saturation state with respect to calcium carbonate down to less than 0.8 for calcite and 0.5 for aragonite. Waters undersaturated in aragonite were also observed in the surface in waters at equilibrium with atmospheric CO2; however, at these conditions the cause of undersaturation was low salinity from river runoff and/or sea ice melt. The calcium carbonate corrosive water was observed all along the continental margin and well out into the deep Makarov and Canada basins at a depth from about 50 m depth in the west to about 150 m in the east. These waters of low aragonite saturation state are traced in historic data to the Canada Basin and in the waters flowing out of the Arctic Ocean north of Greenland and in the western Fram Strait, thus potentially impacting the marine life in the North Atlantic Ocean.

  • 147.
    Anderson, Leif G.
    et al.
    Univ Gothenburg, Dept Marine Sci, SE-41296 Gothenburg, Sweden..
    Macdonald, Robie W.
    Inst Ocean Sci, Dept Fisheries & Oceans, Sidney, BC V8L 4B2, Canada..
    Observing the Arctic Ocean carbon cycle in a changing environment2015Ingår i: Polar Research, ISSN 0800-0395, E-ISSN 1751-8369, Vol. 34, artikel-id 26891Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Climate warming is especially pronounced in the Arctic, which has led to decreased sea-ice coverage and substantial permafrost thawing. These changes have a profound impact on the carbon cycle that directly affects the air-sea exchange of carbon dioxide (CO2), possibly leading to substantial feedback on atmospheric CO2 concentration. Several recent studies have indicated such feedback but the future quantitative impact is very uncertain. To minimize these uncertainties, there is a need for extensive field studies in order to achieve both a better process understanding as well as to detect probable trends in these processes. In this contribution, we describe a number of processes that have been reported to be impacted by climate change and suggest a coordinated international observational programme for their study.

  • 148. Anderson, M.W.
    et al.
    Barker, A.J.
    Bennett, D.G.
    Dallmeyer, R.D.
    A tectonic model for Scandian terrane accretion in the northern Scandinavian Caledonides.1992Ingår i: Journal of the Geological Society, Vol. 149, s. 727-741Artikel i tidskrift (Övrigt vetenskapligt)
  • 149. Andersson, C.
    Kanans land vid Torneträsk.1981Ingår i: Lainio - Vår hembygd. Lainio Hembygdsgille Kemi / [ed] Niemi, S, 1981Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 150. Andersson, C.
    et al.
    Löfstedt, H.
    Schoning, K.
    Kärkevagge -95 - en studie över tre landformer. Geovetenskap i fjällen.1995Rapport (Övrigt vetenskapligt)
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