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  • 251. Ampomah, Osei Yaw
    et al.
    Huss-Danell, Kerstin
    Nodulation of Thermopsis lupinoides by a Mesorhizobium huakuii strain with a unique nodA gene in Kamtchatka, Russia2011In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, p. 5513-5516Article in journal (Refereed)
  • 252. 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 Eurasia2017In: Systematic and Applied Microbiology, ISSN 0723-2020, E-ISSN 1618-0984, Vol. 40, no 1, p. 51-58Article in journal (Refereed)
    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.

  • 253. 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 Acidification2013Book (Other academic)
  • 254. Ander, K.
    Bidrag till kännedomen om de svenska Odonaterna. 5. Norrländska trollsländor.1931In: Entomologisk Tidskrift, Vol. 52, p. 228-244Article in journal (Other academic)
  • 255. Ander, K.
    De svenska odonaternas djurgeografi. Bidrag till kännedomen om de svenska odonaterna. 6.1946In: Opuscula Entomologica, Vol. 11, p. 109-118Article in journal (Other academic)
  • 256. Ander, K.
    Die boreoalpinen Orthopteren Europas.1949In: Opuscula Entomologica, Vol. 14, p. 89-104Article in journal (Other academic)
  • 257. Ander, K.
    Odonata.1951In: Kungliga Fysiografiska Sällskapets Handlingar, NF, Vol. 61, no 2, p. 123-126Article in journal (Other academic)
  • 258. Ander, K.
    Orthoptera.1951In: Kungliga Fysiografiska Sällskapets Handlingar, NF, Vol. 61, no 2, p. 135-137Article in journal (Other academic)
  • 259. Ander, K.
    Revision der Orthopterensammlungen Zetterstedts.1943In: Kungliga Fysiografiska Sällskapets Handlingar, NF, Vol. 53, no 7, p. 1-23Article in journal (Other academic)
  • 260. Ander, K.
    Rätvingar - Orthoptera. (Insektfaunan inom Abisko nationalpark III:14).1931In: Kungliga Svenska Vetenskapsakademiens Skrifter i naturskyddsärenden, Vol. 18, p. 64-69Article in journal (Other academic)
  • 261. Ander, K.
    Trollsländor - Odonata. (Insektfaunan inom Abisko nationalpark III:13).1931In: Kungliga Svenska Vetenskapsakademiens Skrifter i naturskyddsärenden, Vol. 18, p. 60-63Article in journal (Other academic)
  • 262. Ander, K.
    Zur Verbreitung und Phänologie der boreoalpinen Odonaten der Westpaläarktis.1950In: Opuscula Entomologica, Vol. 15, p. 53-71Article in journal (Other academic)
  • 263. Andersen, K. K
    et al.
    and NGRIP members,
    High-resolution record of Northern hemisphere climate extending into the last interglacial period2004In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 431, p. 147-151Article in journal (Refereed)
  • 264. 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 measurements2007In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 259, no 1-2, p. 171-185Article in journal (Refereed)
    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.

  • 265. 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 234U / 238U measurements2007In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 259, p. 171-185Article in journal (Refereed)
  • 266. Anderson, D.
    et al.
    Rich, V. I.
    Hodgkins, S. B.
    Tfaily, M.
    Chanton, J.
    Mapping Microbial Carbon Substrate Utilization Across Permafrost Thaw2014In: AGU Fall Meeting Abstracts, 2014, Vol. 12, article id B31G-0122Conference paper (Other academic)
  • 267.
    ANDERSON, DARYA NICOLE
    The University of Arizona.
    MAPPING MICROBIAL SUBSTRATE UTILIZATION ACROSS A PERMAFROST THAW GRADIENT2016Independent thesis Basic level (degree of Bachelor)Student thesis
    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.

  • 268. Anderson, J. B.
    et al.
    Conway, H.
    Bart, P. J.
    Witus, A. E.
    Greenwood, S. L.
    McKay, R. M.
    Hall, B. L.
    Ackert, R. P.
    Licht, K.
    Jakobsson, M.
    Stone, J. O.
    Ross Sea paleo-ice sheet drainage and deglacial history during and since the LGM2014In: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457X, Vol. 100Article in journal (Refereed)
    Abstract [en]

    Onshore and offshore studies show that an expanded, grounded ice sheet occupied the Ross Sea Embayment during the Last Glacial Maximum (LGM). Results from studies of till provenance and the orientation of geomorphic features on the continental shelf show that more than half of the grounded ice sheet consisted of East Antarctic ice flowing through Transantarctic Mountain (TAM) outlet glaciers; the remainder came from West Antarctica. Terrestrial data indicate little or no thickening in the upper catchment regions in both West and East Antarctica during the LGM. In contrast, evidence from the mouths of the southern and central TAM outlet glaciers indicate surface elevations between 1000 m and 1100 m (above present-day sea level). Farther north along the western margin of the Ross Ice Sheet, surface elevations reached 720 m on Ross Island, and 400 m at Terra Nova Bay. Evidence from Marie Byrd Land at the eastern margin of the ice sheet indicates that the elevation near the present-day grounding line was more than 800 m asl, while at Siple Dome in the central Ross Embayment, the surface elevation was about 950 m asl. Farther north, evidence that the ice sheet was grounded on the middle and the outer continental shelf during the LGM implies that surface elevations had to be at least 100 m above the LGM sea level. The apparent low surface profile and implied low basal shear stress in the central and eastern embayment suggests that although the ice streams may have slowed during the LGM, they remained active. Ice-sheet retreat from the western Ross Embayment during the Holocene is constrained by marine and terrestrial data. Ages from marine sediments suggest that the grounding line had retreated from its LGM outer shelf location only a few tens of kilometer to a location south of Coulman Island by similar to 13 ka BP. The ice sheet margin was located in the vicinity of the Drygalski Ice Tongue by similar to 11 ka BP, just north of Ross Island by similar to 7.8 ka BP, and near Hatherton Glacier by similar to 6.8 ka BP. Farther south, Be-10 exposure ages from glacial erratics on nunataks near the mouths of Reedy, Scott and Beardmore Glaciers indicate thinning during the mid to late Holocene, but the grounding line did not reach its present position until 2 to 3 ka BP. Marine dates, which are almost exclusively Acid Insoluble Organic (AIO) dates, are consistently older than those derived from terrestrial data. However, even these ages indicate that the ice sheet experienced significant retreat after similar to 13 ka BP. Geomorphic features indicate that during the final stages of ice sheet retreat ice flowing through the TAM remained grounded on the shallow western margin of Ross Sea. The timing of retreat from the central Ross Sea remains unresolved; the simplest reconstruction is to assume that the grounding line here started to retreat from the continental shelf more or less in step with the retreat from the western and eastern sectors. An alternative hypothesis, which relies on the validity of radiocarbon ages from marine sediments, is that grounded ice had retreated from the outer continental shelf prior to the LGM. More reliable ages from marine sediments in the central Ross Embayment are needed to test and validate this hypothesis. (C) 2014 The Authors. Published by Elsevier Ltd. All rights reserved.

  • 269. Anderson, L. G.
    Chemical oceanography in polar oceans1994In: Physics of ice covered seas. An advanced study / [ed] M. Lepperanta, Savonlinna: Institute-Summer School , 1994Conference paper (Other academic)
  • 270. Anderson, L. G.
    Chemical oceanography of the Arctic Ocean and its shelf seas1995In: Arctic oceanography: marginal ice zones and continental shelves / [ed] W. O. Smith; J. M. Grebmeier, Washingtom: American Geophysical Union , 1995, , p. 183-202Chapter in book (Other academic)
  • 271. Anderson, L. G.
    et al.
    Björk, G.
    Holby, O.
    Jones, E. P.
    Kattner, G.
    Kolterman, K. P.
    Liljeblad, B.
    Lindegren, R.
    Rudels, B.
    Swift, J.
    Water masses and circulation in the Eurasian basin. Results from the Oden-91 expedition1994In: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 99, no C2, p. 3273-3283Article in journal (Refereed)
  • 272.
    Anderson, L. G.
    et al.
    Univ Gothenburg, Dept Chem, Gothenburg, Sweden..
    Björk, G.
    Univ Gothenburg, Dept Geosci, Gothenburg, Sweden..
    Jutterström, S.
    Univ Gothenburg, Dept Chem, Gothenburg, Sweden.;UNIFOB AS, Bjerknes Ctr Climate Res, Bergen, Norway..
    Pipko, I.
    Pacific Oceanol Inst FEB RAS, Vladivostok, Russia..
    Shakhova, N.
    Pacific Oceanol Inst FEB RAS, Vladivostok, Russia.;Univ Alaska, Int Arctic Res Ctr, Fairbanks, AK 99701 USA..
    Semiletov, I.
    Pacific Oceanol Inst FEB RAS, Vladivostok, Russia.;Univ Alaska, Int Arctic Res Ctr, Fairbanks, AK 99701 USA..
    Wåhlström, I.
    Univ Gothenburg, Dept Chem, Gothenburg, Sweden..
    East Siberian Sea, an Arctic region of very high biogeochemical activity2011In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 8, no 6, p. 1745-1754Article in journal (Refereed)
    Abstract [en]

    Shelf seas are among the most active biogeochemical marine environments and the East Siberian Sea is a prime example. This sea is supplied by seawater from both the Atlantic and Pacific Oceans and has a substantial input of river runoff. All of these waters contribute chemical constituents, dissolved and particulate, but of different signatures. Sea ice formation during the winter season and melting in the summer has a major impact on physical as well as biogeochemical conditions. The internal circulation and water mass distribution is significantly influenced by the atmospheric pressure field. The western region is dominated by input of river runoff from the Laptev Sea and an extensive input of terrestrial organic matter. The microbial decay of this organic matter produces carbon dioxide (CO2) that oversaturates all waters from the surface to bottom relative to atmospheric level, even when primary production, inferred from low surface water nutrients, has occurred. The eastern surface waters were under-saturated with respect to CO2 illustrating the dominance of marine primary production. The drawdown of dissolved inorganic carbon equals a primary production of similar to 0.8 +/- 2 mol C m(-2), which when multiplied by half the area of the East Siberian Sea, similar to 500 000 km(2), results in an annual primary production of 0.4 (+/- 1) x 10(12) mol C or similar to 4 (+/- 10) x 10(12) gC. Microbial decay occurs through much of the water column, but dominates at the sediment interface where the majority of organic matter ends up, thus more of the decay products are recycled to the bottom water. High nutrient concentrations and fugacity of CO2 and low oxygen and pH were observed in the bottom waters. Another signature of organic matter decomposition, methane (CH4), was observed in very high but variable concentrations. This is due to its seabed sources of glacial origin or modern production from ancient organic matter, becoming available due to sub-sea permafrost thaw and formation of so-called taliks. The decay of organic matter to CO2 as well as oxidation of CH4 to CO2 contribute to a natural ocean acidification making the saturation state of calcium carbonate low, resulting in under-saturation of all the bottom waters with respect to aragonite and large areas of under-saturation down to 50% with respect to calcite. Hence, conditions for calcifying organisms are very unfavorable.

  • 273. 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, Svalbard2004In: Journal of Geophysical Research - Oceans, ISSN 2169-9275, E-ISSN 2169-9291, Vol. 109, no C6Article in journal (Refereed)
    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.

  • 274. Anderson, L G
    et al.
    Jones, E P
    Swift, J H
    Export production in the central Arctic Ocean evaluated from phosphate deficits2003In: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 108, no C6Article in journal (Refereed)
    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.

  • 275. 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 decomposition2009In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 36Article in journal (Refereed)
    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.

  • 276. 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 Ocean2004In: Journal of Geophysical Research - Oceans, ISSN 2169-9275, E-ISSN 2169-9291, Vol. 109, no C1Article in journal (Refereed)
    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.

  • 277. Anderson, L G
    et al.
    Kaltin, S
    Carbon fluxes in the Arctic Ocean - potential impact by climate change2001In: Polar Research, ISSN 0800-0395, E-ISSN 1751-8369, Vol. 20, no 2, p. 225-232Article in journal (Refereed)
    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).

  • 278. 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 solubility2010In: Deep Sea Research Part I: Oceanographic Research Papers, ISSN 0967-0637, E-ISSN 1879-0119, Vol. 57, no 7, p. 869-879Article in journal (Refereed)
    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.

  • 279. Anderson, Leif
    Land-ocean interactions1995In: European research in the Arctic - looking ahead: report and recommendations of the first European Networking Conference, Svalbard / [ed] Orheim, O.; et al.,, Oslo: The Research Council of Norway , 1995, , p. 29-30Conference paper (Other academic)
  • 280. Anderson, Leif
    et al.
    Becker, Susan M.
    Breger, Dee
    Falck, Eva
    Gershey, Robert
    Jeansson, Emil
    Jones, Peter
    Jutterström, Sara
    Kivimäe, Caroline
    Olsson, Anders
    Schlosser, Peter
    Swift, Jim
    Zemlyak, Frank
    Chemical oceanography in the East Greenland Current2006In: Polarforskningssekretariatets årsbok 2005, Stockholm: Swedish Polar Research Secretariat , 2006, , p. 109 - 111Chapter in book (Other academic)
  • 281. Anderson, Leif G.
    Chapter 14 - DOC in the Arctic Ocean2002In: Biogeochemistry of Marine Dissolved Organic Matter / [ed] Hansell, Dennis A.; Carlson, Craig A., Academic Press , 2002, p. 665-683Chapter in book (Other academic)
  • 282. Anderson, Leif G.
    Circulation of water masses in the Arctic Ocean deduced from the chemical tracers and its importance for the transport of chemical constituents1999In: Polarforskningssekretariatets årsbok 1998 / [ed] Grönlund, Eva red, Stockholm: Swedish Polar Research , 1999, , p. 93 - 94Chapter in book (Other academic)
  • 283. Anderson, Leif G.
    Oceanographic investigations during leg 3 of the Beringia 2005 expedition2006In: Polarforskningssekretariatets årsbok 2005, Stockholm: Swedish Polar Research Secretariat , 2006, , p. 87 - 91Chapter in book (Other academic)
  • 284. 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 Ocean2013In: Journal of Geophysical Research - Oceans, ISSN 2169-9275, E-ISSN 2169-9291, Vol. 118, no 1, p. 410-421Article in journal (Refereed)
    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.

  • 285. 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 Sea2017In: Ocean Science, ISSN 1812-0784, E-ISSN 1812-0792, Vol. 13, no 2, p. 349-363Article in journal (Refereed)
    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.

  • 286. Anderson, Leif G.
    et al.
    Chierici, Melissa
    Fogelqvist, Elisabet
    Johannessen, Truls
    Flux of anthropogenic carbon and steady state carbon into the deep Greenland sea2000In: J. Geophys, Res., Vol. 105, p. 14 339-14 345Article in journal (Refereed)
  • 287. Anderson, Leif G.
    et al.
    Drange, H.
    Chierici, Melissa
    Fransson, Agneta
    Johannessen, Truls
    Skjelvan, I.
    Rey, F.
    Annual carbon flux in the upper Greenland Sea based on measurements and a box model approach2000In: Tellus, Vol. 53, no 3, p. 1013-1024Article in journal (Refereed)
  • 288. Anderson, Leif G.
    et al.
    Fogelqvist, Elisabet
    Hulth, Stefan
    Olsson, Kristina
    Tanhua, Toste
    Tengberg, Anders
    Zemlyak, Frank
    Water masses and their chemical characteristics in the Southern Weddell Sea1995In: Swedish Antarctic Research Programme 1992/93. Dronning Maud Land, Weddell Sea, James Ross Island, South Georgia . A Cruise Report, Stockholm: Swedish Polar Research Secretariat , 1995, , p. 48-66Chapter in book (Other academic)
  • 289. Anderson, Leif G.
    et al.
    Holby, Ola
    Lindegren, Roger
    Ohlson, Mats
    The transport of anthropogenic carbon dioxide into the Weddell sea1991In: Journal of Geophysical Research, Vol. 96, no C9, p. 16.679-16.687Article in journal (Refereed)
  • 290. Anderson, Leif G.
    et al.
    Jones, Peter
    The transport of CO2 into Arctic and Antarctic seas: similarities and differences in the driving processes1991In: Journal of Marine Systems, Vol. 2, p. 81-95Article in journal (Refereed)
  • 291. 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 Sea2017In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 14, no 7, p. 1811-1823Article in journal (Refereed)
    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.

  • 292. Anderson, Leif G.
    et al.
    Jutterström, Sara
    Hjalmarsson, Sofia
    Wåhlström, Iréne
    Semiletov, Igor
    Out-gassing of CO2 from Siberian Shelf seas by terrestrial organic matter composition2009In: Geophysical Research Letters, Vol. 36Article in journal (Refereed)
  • 293.
    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 environment2015In: Polar Research, ISSN 0800-0395, E-ISSN 1751-8369, Vol. 34, article id 26891Article in journal (Refereed)
    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.

  • 294. Anderson, Leif G.
    et al.
    Olsson, Christina
    Chierici, Melissa
    A carbon budget for the Arctic Ocean1998In: Global Biogeochemical Cycles, Vol. 12, no 3, p. 455-465Article in journal (Refereed)
  • 295. Anderson, Leif G.
    et al.
    Olsson, Kristina
    Input of dissolved carbon from Siberian rivers and biogeochemical transformation over the continental shelves1995In: Swedish-Russian Tundra Ecology-expedition-94. Tundra Ecology-94. A Cruise Report, Stockholm: Swedish Polar Research Secretariat , 1995, , p. 326-333Chapter in book (Other academic)
  • 296. Anderson, Leif G.
    et al.
    Olsson, Kristina
    Jones, E. Peter
    Chierici, Melissa
    Fransson, Agneta
    Anthropogenic carbon dioxide in the Arctic Ocean - inventory and sinks1998In: J. Geophys. Res., Vol. 103, no C12, p. 27707-27716Article in journal (Refereed)
  • 297. Anderson, Leif G.
    et al.
    Olsson, Kristina
    Skoog, Annelie
    Distribution of dissolved inorganic and organic carbon in the Eurasian Basin of the Arctic Ocean1995In: Organic carbon and humic substances the marine environment, Göteborg, Univ. of Göteborg and Chalmers Univ. of Technology , 1995Chapter in book (Other academic)
  • 298. Anderson, L.G.
    et al.
    Carlsson, K. - Å.
    Hall, P. O. J.
    Holm, E.
    Josefsson, D.
    Olsson, K.
    Persson, B. R. R.
    Persson, T.
    Roos, P.
    Tengberg, A.
    Wedborg, M.
    The effect of the Siberian tundra on the environment of the shelf seas and the Arctic Ocean1999In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 28, no 3, p. 270-280Article in journal (Refereed)
  • 299. 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.1992In: Journal of the Geological Society, Vol. 149, p. 727-741Article in journal (Other academic)
  • 300. Andersson, C.
    Kanans land vid Torneträsk.1981In: Lainio - Vår hembygd. Lainio Hembygdsgille Kemi / [ed] Niemi, S, 1981Chapter in book (Other academic)
3456789 251 - 300 of 6168
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