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  • 101.
    Persson, Susanne
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Ion Physics. Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. jonfysik.
    Alfimov, Vasily
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Ion Physics. Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. Jonfysik.
    Aldahan, Ala
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Ion Physics. Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. ELD.
    Possnert, Göran
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Ion Physics. Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. jonfysik.
    129I variability in precipitation over Europe2005In: 10th International conference on accelerator mass spectrometry, Berkeley, 2005, p. 65-Conference paper (Refereed)
  • 102.
    Possnert, Göran
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Ion Physics. Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Kulan, A
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Berggren, Ann-Marie
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Beryllium isotopes in aerosols over Sweden2006Conference paper (Refereed)
  • 103. Qiao, Jixin
    et al.
    Hansen, Violeta
    Hou, Xiaolin
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Speciation analysis of 129I, 137Cs, 232Th, 238U, 239Pu and 240Pu in environmental soil and sediment2012In: Applied Radiation and Isotopes, ISSN 0969-8043, E-ISSN 1872-9800, Vol. 70, no 8, p. 1698-1708Article in journal (Refereed)
    Abstract [en]

    The environmental mobility and bioavailability of radionuclides are related to their physicochemical forms, namely species. We here present a speciation analysis of important radionuclides including I-129 (also I-127), Cs-137, Th-232, U-238 and plutonium isotopes (Pu-239 and Pu-240) in soil (IAEA-375) and sediment (NIST-4354) standard reference materials and two fresh sediment samples from Ovre Heimdalsvatnet Lake, Norway. A modified sequential extraction protocol was used for the speciation analysis of these samples to obtain fractionation information of target radionuclides. Analytical results reveal that the partitioning behaviour, and thus the potential mobility and bioavailability, are exclusively featured for the individual radionuclide. Iodine is relatively mobile and readily binds to organic matter, while plutonium is mainly bound to both organic matter and nitric acid leachable fractions. Thorium is predominated in nitric acid leachable fraction and caesium is primarily observed in nitric acid and aqua regia leachable fractions and residue. Our analytical results reveal that around 50% of uranium might still remain in the residue which could not be extracted with aggressive acid, namely, aqua regia.

  • 104. Röhringer, I.
    et al.
    Zech, R.
    Abramowski, U.
    Sosin, P.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Kubik, P. W.
    Zöller, L.
    Zech, W.
    The late Pleistocene glaciation in the Bogchigir Valleys (Pamir, Tajikistan) based on 10Be surface exposure dating2012In: Quaternary Research, ISSN 0033-5894, E-ISSN 1096-0287, Vol. 78, no 3, p. 590-597Article in journal (Refereed)
    Abstract [en]

    Glacial chronologies from the Pamir may not only provide insights into past changes in temperature, but also into past changes in precipitation related to the northern-hemispheric westerlies and the monsoonal circulation. We present 18 new exposure ages from the Bogchigir Valleys that complement and refine our previous studies in these valleys. The most extensive dated glaciation in the area occurred ~. 100. ka, during Marine Oxygen Isotope Stage (MIS) 5, and indicates increased precipitation likely from both the westerlies and the monsoonal circulation. A subsequent glacier advance, which deposited characteristic 'chukur' moraine lobes, occurred at ~. 80-75. ka. Circumstantial evidence points to glacial advances at ~. 65 and 40. ka, the latter likely also documenting increased monsoonal moisture supply during MIS 3. Less extensive glacial advances occurred during MIS 2 at ~. 28 and 24. ka and reflect the aridization trend during the course of the last glacial cycle. Deglaciation started ~. 21. ka, interrupted by minor stillstands or readvances at ~. 16 and 12. ka. Local calibration sites and glacier-climate modeling would be very helpful to reduce the systematic methodological uncertainties (still at least 10%) and to draw more detailed paleoclimatic conclusions.

  • 105.
    Sapota, T
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. ION PHYSICS.
    Aldahan, Ala
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. ELD.
    Possnert, Göran
    Timing of Lithofacies Development in Rift2002In: AGU Fall Meeting 19 November, EOS, 2002, p. F1489-Conference paper (Refereed)
  • 106.
    Sapota, Tomasz
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics.
    Al-Aasm, Ihsan S.
    Sedimentary facies and climate control on formation of siderite and vivianite microconcretions in sediments of Lake Baikal, Siberia2006In: Journal of Paleolimnology, ISSN 0921-2728, E-ISSN 1573-0417, Vol. 36, no 3, p. 245-257Article in journal (Refereed)
    Abstract [en]

    Authigenic vivianite and siderite microconcretions were found, respectively, in hemipelagic and deltaic facies of 600-m-long BDP-98 sediment section from Lake Baikal. Textural investigations of these microconcretions show that they are typically < 1 mm in size, irregular in shape and composed of aggregated crystallites. Dissimilar orientation of vivianite and siderite crystallites suggests formation at different depths in the sediment; up to tens of centimeters for vivianite and tens of meters for siderite. Chemical analyses of both the vivianite and the siderite indicate cation composition characterized by minor amounts of Mn, Ca and Mn apart from the dominating Fe. Rather limited and distinctive carbon isotopic composition of the siderite, with delta C-13(VPDB) values between about +13 and +16 degrees, implies formation of the mineral in the methanogenic zone of diagenesis. Isotopic composition of oxygen in the siderite (delta O-18(VPDB) values between about -10 and -11 degrees) is consistent with crystallization temperature at about 10-30 degrees C and water delta O-18(SMOW) values between about -10 and -16 degrees. The distribution of the authigenic minerals in the section suggests changes in both sedimentary facies and climate, where vivianite formation was controlled by hemipelagic depositional conditions during the Pliocene and Quaternary, whereas siderite reflects impact of deltaic conditions during the Miocene.

  • 107.
    Sapota, Tomasz
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. ELD.
    Aldahan, Ala
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. ELD.
    Possnert, Göran
    Technology, Department of Materials Science. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. jonfysik.
    Be isotopes with textural and mineralogical data of sediment from Lake Baikal (Siberia)2005In: NEUES JAHRBUCH FUR GEOLOGIE UND PALAONTOLOGIE, Vol. 238, no 3, p. 355-411Article in journal (Refereed)
  • 108.
    Sapota, Tomasz
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Peck, John
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    King, John
    Prokopenko, Alexander
    Kuzmin, Mikhail
    A late Cenozoic Earth’s crust and climate dynamics record from Lake Baikal2004In: Journal of Paleolimnology, ISSN 0921-2728, E-ISSN 1573-0417, Vol. 32, no 4, p. 341-349Article in journal (Refereed)
    Abstract [en]

    The sedimentary record from Lake Baikal (Siberia, Russia) has been an important source of information about paleoclimatic variability in the northern hemisphere and dynamics of continental rift development. A lack of reliable chronology has, however, been a major obstacle to fully utilizing the Baikal archive for time scales beyond about 4-5 Myr. In this paper we use the distribution of 10Be to establish a new chronology for the longest core drilled in Lake Baikal so far. The 10Be-based chronology spans the last 8 Myr and provides better constraints on sedimentation rates and consequently on an east-west tectonic extension in the lake, which has been apparently coeval with other rifts in Asia that are related to the Tibetan plateau uplift. Our data also show higher 10Be flux in the sediment section older then 5 Myr compared with the younger period. This can be explained partly by warm and humid climatic conditions of the Miocene and partly by a high cosmic ray flux to the Earth resulting from possible low geomagnetic field intensity during that time.

  • 109.
    Sapota, Tomasz
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Air and Water Science. Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Ion Physics.
    Håkanson, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Air and Water Science. Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Ion Physics. LUVA.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Ion Physics. ELD.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Ion Physics. Jonfysik.
    Sediment flux to Lake Baikal (Siberia, Russia): Modeling approach2006In: Geomorphology, Vol. 80, p. 105-113Article in journal (Refereed)
  • 110.
    Scherer, R
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences.
    Aldahan, Ala
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. ELD.
    Possnert, Göran
    Technology, Department of Materials Science. Jonfysik.
    10Be in sediments beneath the West Antarctic ice sheet: hypotheses and assumptions1997In: Antarctic Journal of the United States, Vol. 32, p. 31-32Article in journal (Refereed)
  • 111. Shi, N
    et al.
    Aldahan, A
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. ELD.
    Ye, HP
    Possnert, G
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. jonfysik.
    Königsson, L.-K
    10Be in continental sediments from north China: probing into the last 5.4 Ma 10Be in continental sediments from north China: probing into the last 5.4 Ma continental sediments from north China: probing into the last 5.4 Ma 10Be in continental sediments from north China: probing into the last 5.4 Ma1994In: Quaternary Science Review, Vol. 13, p. 127-136Article in journal (Refereed)
  • 112. Sijinkumar, A. V.
    et al.
    Nath, B. Nagender
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Pulleniatina Minimum Events in the Andaman Sea (NE Indian Ocean): Implications for winter monsoon and thermocline changes2011In: Marine Micropaleontology, ISSN 0377-8398, E-ISSN 1872-6186, Vol. 81, no 3-4, p. 88-94Article in journal (Refereed)
    Abstract [en]

    The late Quaternary record of Pulleniatina obliquiloculata was investigated from two well dated sediment cores from the Andaman Sea (NE Indian Ocean) to examine its paleoceanographic significance and the presence of the Pulleniatina Minimum Events (PME) in the western North Pacific. As in the Pacific, our study shows that PMEs exist in the Indian Ocean albeit with a lower intensity. The Holocene PME occurs between 4.5 and 3.0 cal ka BP with a considerable reduction in P. obliquiloculata abundance, and which matches well with the Pacific records influenced by the Kuroshio Current. Additionally, two significant minimum events of P. obliquiloculata are also seen during the Younger Dryas (YD) and late Last Glacial Maximum (LGM, 20-18 cal ka BP). Overall, the PMEs of the Andaman Sea are not current driven events like in the western Pacific margin either by the weakening of the Kuroshio Current or reduced winter SSTs. The PMEs of the Andaman Sea are characterised by lower abundances of thermocline species indicating the increased depth of the thermocline (DOT) and reduced winter SSTs mainly during the minimum events of the YD and late LGM. The high SSTs during the Holocene PME make this event a mystery. However, the presence of PMEs in the Andaman Sea suggests that these events are not confined to areas influenced by the Kuroshio Current but may be responding to a broad scale oceanographic-climatic process or mechanism which needs to be explored with a detailed study.

  • 113. Sirat, M
    et al.
    Aldahan, Ala
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. ELD.
    Nordlund, U
    neural networks approach to predict sedimentation and climate changes in Arctic Sediment covering last 350 ka1998In: 15th International Sedimentological Congress, Alicante, 1998, p. 725-726Conference paper (Refereed)
  • 114. Sjunneskog, Charlotte
    et al.
    Scherer, R.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Be-10 in glacial marine sediment of the Ross Sea, Antarctica, a potential tracer of depositional environment and sediment chronology2007In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 259, no 1, p. 576-583Article in journal (Refereed)
    Abstract [en]

    Beryllium isotopes (9Be and 10Be) distribution in Holocene and late Pleistocene glacial ice and sediment facies from sub-ice stream and sub-ice shelf settings of the Ross sector of the West Antarctic Ice Sheet (WAIS) and from the open Ross Sea are presented, to assess the temporal and spatial variability of these tracers. Significant variation is detected (>one order of magnitude) among Holocene post-glacial deposits. Late Pleistocene diamictons from bathymetric lows in the Ross Sea show depleted concentrations that are less variable among sites and distinctly lower than bank deposits of similar age. In general, sub-ice shelf and ice stream sediments are the most depleted in 10Be. 10Be with its longer half-life and different pathways compared apparant to 14C is found to be a sensitive marker for evaluating the complex spatial and temporal relationships between texturally similar sediments formed by different depositional processes.

  • 115. Sjunneskog, Charlotte
    et al.
    Scherer, Reed
    Aldahan, Ala
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Technology, Department of Engineering Sciences, Ion Physics. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. ELD.
    Possnert, Göran
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Technology, Department of Engineering Sciences, Ion Physics. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. jonfysik.
    10Be in Antarctica marine and glacial sediment2005In: 10th International conference on accelerator mass spectrometry, Berkeley, 2005, p. 33-Conference paper (Refereed)
  • 116.
    Sturevik-Storm, Anna
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Berggren, Ann-Marie
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Muscheler, Raimund
    Dahl-Jensen, Dorthe
    Vinther, Bo M.
    Usoskin, Ilya
    Be-10 climate fingerprints during the Eemian in the NEEM ice core, Greenland2014In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 4, p. 6408-Article in journal (Refereed)
    Abstract [en]

    Several deep Greenland ice cores have been retrieved, however, capturing the Eemian period has been problematic due to stratigraphic disturbances in the ice. The new Greenland deep ice core from the NEEM site (77.456 degrees N, 51.066 degrees W, 2450 m.a.s.l) recovered a relatively complete Eemian record. Here we discuss the cosmogenic Be-10 isotope record from this core. The results show Eemian average 10Be concentrations about 0.7 times lower than in the Holocene which suggests a warmer climate and approximately 65-90% higher precipitation in Northern Greenland compared to today. Effects of shorter solar variations on 10Be concentration are smoothed out due to coarse time resolution, but occurrence of a solar maximum at 115.26-115.36 kyr BP is proposed. Relatively high 10Be concentrations are found in the basal ice sections of the core which may originate from the glacial-interglacial transition and relate to a geomagnetic excursion about 200 kyr BP.

  • 117.
    Xing, Shan
    et al.
    Chinese Acad Sci, State Key Lab Loess & Quaternary Geol, Shaanxi Key Lab Accelerator Mass Spectrometry Tec, Xian AMS Ctr,Inst Earth Environm, Xian 710061, Peoples R China..
    Hou, Xiaolin
    Chinese Acad Sci, State Key Lab Loess & Quaternary Geol, Shaanxi Key Lab Accelerator Mass Spectrometry Tec, Xian AMS Ctr,Inst Earth Environm, Xian 710061, Peoples R China.;Tech Univ Denmark, Ctr Nucl Technol, Riso Campus, DK-4000 Roskilde, Denmark..
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. United Arab Emirates Univ, Dept Geol, Al Ain, U Arab Emirates..
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Speciation analysis of I-129 in seawater using coprecipitation and accelerator mass spectrometry and its applications2017In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 311, no 1, p. 833-841Article in journal (Refereed)
    Abstract [en]

    Speciation analysis of long-lived I-129 in seawater can provide useful information on the source of water masses. This paper presents an improved method for speciation analysis of I-129 based on coprecipitation of iodide as AgI with Ag2SO3 and AgCl. By adding a small amount of I-127 carrier, the separation efficiency of iodine species and the accuracy and precision of I-129 measurement are remarkably improved. I-129 species in depth profiles of seawater from the Antarctic were analyzed for investigation of water circulation in the Antarctic.

  • 118.
    Xing, Shan
    et al.
    Chinese Acad Sci, State Key Lab Loess & Quaternary Geol, Shaanxi Key Lab Accelerator Mass Spectrometry Tec, Xian AMS Ctr,Inst Earth Environm, Xian 710061, Shaanxi, Peoples R China..
    Hou, Xiaolin
    Chinese Acad Sci, State Key Lab Loess & Quaternary Geol, Shaanxi Key Lab Accelerator Mass Spectrometry Tec, Xian AMS Ctr,Inst Earth Environm, Xian 710061, Shaanxi, Peoples R China.;Techn Univ Denmark, Ctr Nucl Technol, DK-4000 Roskilde, Denmark..
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. United Arab Emirates Univ, Dept Geol, Al Ain 17511, U Arab Emirates..
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Shi, Keliang
    Techn Univ Denmark, Ctr Nucl Technol, DK-4000 Roskilde, Denmark.;Lanzhou Univ, Sch Nucl Sci & Technol, Lanzhou 73000, Gansu, Peoples R China..
    Yi, Peng
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Hohai Univ, Coll Hydrol & Water Resources, Nanjing 210098, Jiangsu, Peoples R China..
    Zhou, Weijian
    Chinese Acad Sci, State Key Lab Loess & Quaternary Geol, Shaanxi Key Lab Accelerator Mass Spectrometry Tec, Xian AMS Ctr,Inst Earth Environm, Xian 710061, Shaanxi, Peoples R China..
    Water Circulation and Marine Environment in the Antarctic Traced by Speciation of I-129 and I-1272017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 7726Article in journal (Refereed)
    Abstract [en]

    Emissions of anthropogenic I-129 from human nuclear activities are now detected in the surface water of the Antarctic seas. Surface seawater samples from the Drake Passage, Bellingshausen, Amundsen, and Ross Seas were analyzed for total I-129 and I-127, as well as for iodide and iodate of these two isotopes. The variability of I-127 and I-129 concentrations and their species (I-127(-)/(IO3-)-I-127, I-129(-)/(IO3-)-I-129) suggest limited environmental impact where ((1.15-3.15) x 10(6) atoms/L for I-129 concentration and (0.61-1.98) x 10(-11) for I-129/I-127 atomic ratios are the lowest ones compared to the other oceans. The iodine distribution patterns provide useful information on surface water transport and mixing that are vital for better understanding of the Southern Oceans effects on the global climate change. The results indicate multiple spatial interactions between the Antarctic Circumpolar Current (ACC) and Antarctic Peninsula Coastal Current (APCC). These interactions happen in restricted circulation pathways that may partly relate to glacial melting and icebergs transport. Biological activity during the warm season should be one of the key factors controlling the reduction of iodate in the coastal water in the Antarctic.

  • 119.
    Yi, Peng
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Goran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Hou, Xiaolin
    Technical University of Denmark, Risø Campus, Roskilde, Denmark.
    He, Peng
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Biao, Wang
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Depth profiles of I-129 species in the Bothnian Sea2013In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 295, no 2, p. 1459-1463Article in journal (Refereed)
    Abstract [en]

    The Bothnian Sea which is located between Finland and Sweden represents an important source of fresh water to the Baltic Sea. We here present new data on the radioactive isotope I-129 species from water samples collected in December 2009 at different depths in the Bothnian Sea. Concentrations of I-129(-) (iodide) in the Bothnian Sea range from 14 x 10(8) to 32 x 10(8) atoms/L, while (IO3)-I-129 (-) (iodate) concentrations are relatively low and fluctuating at 1 x 10(8) atoms/L. For nutrients data determined in the same samples as I-129, significant correlations could be found between I-129(-) and total P, NO3-N, SiO3-Si, but rather poor with NH4-N. The correlations suggest comparable source pathway of I-129(-) and nutrient parameters, while the source of NH4-N may be different. The small amounts and negligible change of (IO3)-I-129 (-) indicate prevailing extensive reduction of iodate in the Baltic Sea.

  • 120.
    Yi, Peng
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Hou, X. L.
    Hansen, V.
    Wang, B.
    I-127 and I-129 Species and Transformation in the Baltic Proper, Kattegat, and Skagerrak Basins2012In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 20, p. 10948-10956Article in journal (Refereed)
    Abstract [en]

    Occurrence of anthropogenic I-129 in seawater has provided invaluable information about water circulation and exchange rates, but results on I-129 species (iodide and iodate) are limited and only available for surface water. We here present the first extensive results on I-129 and I-127 species in samples of seawater depth profiles, which were collected in August 2006 and April 2007 in the Skagerrak, Kattegat, and Baltic Proper. The results expose <= 10% annual reduction of iodate as I-129 is transported from the English Channel along the Dutch coast and German Bight into the Skagerrak and Kattegat. The results also suggest strong variability between surface and bottom seawater with respect to the predominant iodine species. Distribution of iodide and iodate of both I-127 and I-129 in the Kattegat mainly reflects water mixing process rather than speciation transformation. In water of the Baltic Proper, high I-127(-)/(IO3-)-I-127 and I-129-/(IO3-)-I-129 values suggest effective reduction of iodate with a maximum rate of 8 x 10(-7) ((IO3-)-I-127) and 6 x 10(-14) ((IO3-)-I-129) (g/m(3).day). The reduction process of iodate seems to be related to decomposition of organic matter and photochemically induced reactions.

  • 121.
    Yi, Peng
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Hou, X. L.
    He, Peng
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Wang, Biao
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Seasonal variation of I-129 species in the Baltic Proper2013In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 295, no 3, p. 1797-1801Article in journal (Refereed)
    Abstract [en]

    Iodine speciation plays a significant role in iodine volatilizing into atmosphere from the seas, as well as serving as a biological indicator. Despite this importance, the data on iodine species revealed inconclusive evidence of what factors controlling speciation transformation. We here present new data on profiles of I-129 speciation in the Baltic Proper during November 2009. Along with the two earlier investigations (August 2006 and April 2007), an assessment of seasonal variation of I-129 species is presented. The results show that, due to the anoxic nature of Baltic Proper, presence of (IO3)-I-129 (-) in the Baltic Proper does not follow an obvious seasonal cycle, as the case with I-129(-). Concentrations of I-129(-) in the Baltic Proper exhibit higher values in summer than the other two seasons (spring and winter), which might be associated with degrading of organic matter and release from sediment to water column that is more pronounced during summer. I-129(-) in surface water from the three seasons does not reflect the release function from the reprocessing facilities during the period April 2007 to November 2009. Consequently variability of I-129(-) in surface seawater of the Baltic Proper depends, to some extent, on local physical as well as biochemical conditions.

  • 122.
    Yi, Peng
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Chen, X. G.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Hou, X. L.
    Yu, Z. B.
    Xiong, D. H.
    Wang, Biao
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Circulation of water masses in the Baltic Proper revealed through iodine isotopes2013In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 36, p. 118-124Article in journal (Refereed)
    Abstract [en]

    Tracer technology has been used to understand water circulation in marine systems where the tracer dose is commonly injected into the marine waters through controlled experiments, accidental releases or waste discharges. Anthropogenic discharges of I-129 have been used to trace water circulation in the Arctic and North Atlantic Ocean. Here, I-129, together with I-127, is utilized as a tracer of water pathways and circulation in the Baltic Sea through collection of seawater depth profiles. The results indicate the presence of I-129 signatures which are distinct for each water mass and provide evidence for: (1) inflow water masses through the Drogden Sill that may reach as far as the SW of the Arkona Sea, (2) a portion of North Atlantic water in the bottom of Arkona basin, (3) cyclonic upwelling which breaks through the halocline in a pattern similar to the Baltic haline conveyor belt and (4) more influx of fresher water from the Gulf of Finland and Bothnian Sea in August relative to April. These findings provide advances in labeling and understanding water pathways in the Baltic Sea.

  • 123.
    Yi, Peng
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Chen, X. G.
    Bao, D. X.
    Qian, R. Z.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Tian, F. Y.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Bryhn, A. C.
    Gu, T. F.
    Hou, X. L.
    He, Peng
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Yu, Z. B.
    Wang, Biao
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Model simulation of inflow water to the Baltic Sea based on I-1292013In: Applied Radiation and Isotopes, ISSN 0969-8043, E-ISSN 1872-9800, Vol. 82, p. 223-231Article in journal (Refereed)
    Abstract [en]

    The semi-enclosed Baltic Sea represents a vital economic and recreational resource for more than 90 million people inhabiting its coasts. Extensive contamination of this sea by a variety of anthropogenic pollutants has raised the concern of the people in the region. Quantifying seawater inflow is crucial for estimating potential environmental risks as well as to find the best remedial strategy. We present here a model to estimate water inflow from the North Sea to the Baltic Sea by utilizing 1291 as a tracer. The results predicted inflow range of 230-450 km(3)/y with best fit value around 330 km(3)/y from the North Sea to the Baltic Sea during 1980-1999. Despite limited time series data on I-129, the model presented here demonstrates a new management tool for the Baltic Sea to calculate inflow water compared to conventional methods (such as salinity, temperature and hydrographic models). 

  • 124.
    Yi, Peng
    et al.
    Hohai Univ, Coll Hydrol & Water Resources, Nanjing 210098, Jiangsu, Peoples R China;State Key Lab Hydrol Water Resources & Hydraul En, Nanjing 210098, Jiangsu, Peoples R China.
    Wan, Chengwei
    Hohai Univ, Coll Hydrol & Water Resources, Nanjing 210098, Jiangsu, Peoples R China;State Key Lab Hydrol Water Resources & Hydraul En, Nanjing 210098, Jiangsu, Peoples R China.
    Jin, Huijun
    Harbin Inst Technol, Sch Civil Engn, Harbin 150090, Heilongjiang, Peoples R China;Chinese Acad Sci, State Key Lab Frozen Soil Engn, Northwest Inst Ecoenvironm & Resources, Lanzhou 730000, Gansu, Peoples R China.
    Luo, Dongliang
    Chinese Acad Sci, State Key Lab Frozen Soil Engn, Northwest Inst Ecoenvironm & Resources, Lanzhou 730000, Gansu, Peoples R China.
    Yang, Yuzhong
    Chinese Acad Sci, State Key Lab Frozen Soil Engn, Northwest Inst Ecoenvironm & Resources, Lanzhou 730000, Gansu, Peoples R China.
    Wang, Qingfeng
    Chinese Acad Sci, State Key Lab Frozen Soil Engn, Northwest Inst Ecoenvironm & Resources, Lanzhou 730000, Gansu, Peoples R China.
    Yu, Zhongbo
    Hohai Univ, Coll Hydrol & Water Resources, Nanjing 210098, Jiangsu, Peoples R China;State Key Lab Hydrol Water Resources & Hydraul En, Nanjing 210098, Jiangsu, Peoples R China.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. United Arab Emirates Univ, Dept Geol, Al Ain, U Arab Emirates.
    Hydrological insights from hydrogen and oxygen isotopes in Source Area of the Yellow River, east-northern part of Qinghai-Tibet Plateau2018In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 317, no 1, p. 131-144Article in journal (Refereed)
    Abstract [en]

    Analyses of stable (D and O-18) and radioactive (T) isotopes of different waters were applied to obtain the hydrological information in watersheds with different frozen ground types in the Source Area of the Yellow River, northeastern of Qinghai-Tibet Plateau in 2014 and 2016. Variations of oxygen and hydrogen isotope ratios, statistically higher tritium concentrations and lower water yields in thaw lakes confirm disparate sources of recharges to thaw lakes and other lakes. Thaw lakes at various stages of evolution influence the surface and subsurface water systems differently.

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