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Author (up) Thomas, D.N.; Lara, R.J.; Eicken, H.; Kattner, G.; Skoog, A. url  openurl
  Title Dissolved organic matter in Arctic multi-year sea ice during winter: major components and relationship to ice characteristics Type Journal Article
  Year 1995 Publication Polar Biology Abbreviated Journal Polar Biol  
  Volume 15 Issue 6 Pages 447-483  
  Keywords sea ice; Arctic; Dom  
  Abstract Ice cores were collected between 10.03.93 and 15.03.93 along a 200 m profile on a large ice floe in Fram Strait. The ice was typical of Arctic multi-year ice, having a mean thickness along the profile of 2.56 ±0.53 m. It consisted mostly of columnar ice (83%) grown through congelation of seawater at the ice bottom, and the salinity profiles were characterized by a linear increase from 0 psu at the top to values ranging between 3 and 5 psu at depth. Distributions of dissolved organic carbon (DOC) and nitrogen (DON) and major nutrients were compared with ice texture, salinity and chlorophyll a. DOC, DON, dissolved inorganic nitrogen (DIN), NH?? and NO?? were present in concentrations in excess of that predicted by dilution curves derived from Arctic surface water values. Only NO?? was depleted, although not exhausted. High DOC and DON values in conjunction with high NH?? levels indicated that a significant proportion of the dissolved organic matter (DOM) was a result of decomposition/grazing of ice algae and/or detritus. The combination of high NH?? and NO?? points to regeneration of nitrogen compounds. There was no significant correlation between DOC and Chl a in contrast to DON, which had a positively significant correlation with both salinity and Chl a, and the distribution of DOM in the cores might best be described as a combination of both physical and biological processes. There was no correlation between DOC and DON suggesting an uncoupling of DOC and DON dynamics in multi year ice.  
  Address  
  Corporate Author Thesis  
  Publisher Springer-Verlag Place of Publication Heidelberg Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0722-4060 ISBN Medium  
  Area Expedition Conference  
  Notes D Approved no  
  Call Number refbase @ admin @ Thomas++1995 Serial 763  
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Author (up) Thomas, D.N.; Lara, R.J.; Haas, C.; Schnack-Schiel, S.B.; Dieckmann, G.S.; Kattner, G.; Nöthig, E.-M.; Mizdalski, E. url  isbn
openurl 
  Title Biological soup within decaying summer sea ice in the Amundsen Sea, Antarctica Type Book Chapter
  Year 1998 Publication Antarctic sea ice: Biological processes, interactions and variability Abbreviated Journal  
  Volume Issue Pages 161-171  
  Keywords Marine biology; Algae; Ice composition; Pack ice; Decomposition; Ecology; Nutrient cycle; Antarctica; Amundsen Sea  
  Abstract In late February 1994, during the ANT XI/3 expedition of R/V Polarstern, ice cores from perennial sea ice were sampled in the Amundsen Sea in areas of dense pack ice. The ice was largely rotten, and a conspicuous feature was the occurrence of thick gaps and voids, often filled with a dark brown slush comprised of loose ice chunks and crystals. These interior ice assemblages were at depths between 1.0 and 1.5 m in 3 to 4 m thick ice floes, and had remarkably rich interior ice algal assemblages (<= 377 µg Chl a L?¹) which were in turn a food source for unusually large numbers of foraminifers (<= 1262 individuals L?¹), the calanoid copepod Stephos longipes (<= 163 individuals L?¹) and harpacticoid copepods (<= 168 individuals L?¹). Analysis of inorganic nutrients (nitrate, phosphate, ammonium, nitrite, and silicate) and dissolved organic carbon (DOC) showed that these were sites of high nutrient supply coupled with high rates of nutrient regeneration.  
  Address  
  Corporate Author Thesis  
  Publisher American Geophysical Union Place of Publication Washington, DC Editor Lizotte, M.P.; Arrigo, K.R.  
  Language Summary Language Original Title  
  Series Editor Series Title Antarctic Research Series Abbreviated Series Title  
  Series Volume 73 Series Issue Edition  
  ISSN ISBN 0-87590-901-9 Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ admin @ Thomas++1998 Serial 764  
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Author (up) Thomas, D.N.; Mock, T. url  openurl
  Title Life in frozen veins – coping with the cold Type Journal Article
  Year 2005 Publication The Biochemist Abbreviated Journal Biochemist  
  Volume 27 Issue 1 Pages 12-16  
  Keywords adaptation; Antarctic; Arctic; low temperature; micro-organism; sea ice  
  Abstract Every autumn a fundamental transition occurs in the surface waters of Polar Oceans. The surface waters of millions of square kilometres freeze to form an ice layer that varies from a few centimetres through to several metres thick, and which effectively separates the ocean from the atmosphere above. Ice made from seawater is a porous, semi-solid matrix permeated by a labyrinth of brine channels and pores, and within these a diverse microbial assemblage, including viruses, archaea, bacteria, flagellates and unicellular algae can thrive. These assemblages can reach such high abundances that the ice becomes a rich coffee colour. The microbial assemblages are in turn a rich food source for grazing proto- and zooplankton, especially in winter when food in the water column is scarce.  
  Address  
  Corporate Author Thesis  
  Publisher Biochemical Society Place of Publication London Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ admin @ Thomas+Mock2005 Serial 765  
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Author (up) Thomas, D.N.; Papadimitriou, S. isbn  openurl
  Title Biogeochemistry of sea ice Type Book Chapter
  Year 2003 Publication Sea ice – an introduction to its physics, chemistry, biology and geology Abbreviated Journal  
  Volume Issue Pages 267-302  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Blackwell Science Ltd Place of Publication Oxford Editor Thomas, D.N.; Dieckmann, G.S.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN 0-632-05808-0 Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ admin @ Thomas+Papadimitriou2003 Serial 766  
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Author (up) Underwood, G.J.C.; Aslam, S.N.; Michel, C.; Niemi, A.; Norman, L.; Meiners, K.M.; Laybourn-Parry, J.; Paterson, H.; Thomas, D.N. url  doi
openurl 
  Title Broad-scale predictability of carbohydrates and exopolymers in Antarctic and Arctic sea ice Type Journal Article
  Year 2013 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc Natl Acad Sci U S A  
  Volume 110 Issue 39 Pages 15734-15739  
  Keywords Antarctic Regions; Arctic Regions; Biopolymers/*analysis; Carbohydrates/*analysis; Ice Cover/*chemistry; Models, Chemical; Molecular Weight; Solubility; algae; biogeochemistry; global relationships; microbial  
  Abstract Sea ice can contain high concentrations of dissolved organic carbon (DOC), much of which is carbohydrate-rich extracellular polymeric substances (EPS) produced by microalgae and bacteria inhabiting the ice. Here we report the concentrations of dissolved carbohydrates (dCHO) and dissolved EPS (dEPS) in relation to algal standing stock [estimated by chlorophyll (Chl) a concentrations] in sea ice from six locations in the Southern and Arctic Oceans. Concentrations varied substantially within and between sampling sites, reflecting local ice conditions and biological content. However, combining all data revealed robust statistical relationships between dCHO concentrations and the concentrations of different dEPS fractions, Chl a, and DOC. These relationships were true for whole ice cores, bottom ice (biomass rich) sections, and colder surface ice. The distribution of dEPS was strongly correlated to algal biomass, with the highest concentrations of both dEPS and non-EPS carbohydrates in the bottom horizons of the ice. Complex EPS was more prevalent in colder surface sea ice horizons. Predictive models (validated against independent data) were derived to enable the estimation of dCHO concentrations from data on ice thickness, salinity, and vertical position in core. When Chl a data were included a higher level of prediction was obtained. The consistent patterns reflected in these relationships provide a strong basis for including estimates of regional and seasonal carbohydrate and dEPS carbon budgets in coupled physical-biogeochemical models, across different types of sea ice from both polar regions.  
  Address School of Biological Sciences, University of Essex, Colchester, Essex CO4 3SQ, United Kingdom  
  Corporate Author Thesis  
  Publisher National Academy of Sciences Place of Publication Washington, DC Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0027-8424 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:24019487; PMCID:PMC3785782 Approved no  
  Call Number refbase @ user @ Serial 17491  
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