Change search
Refine search result
1 - 2 of 2
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Charkin, A. N.
    et al.
    Dudarev, O. V.
    Semiletov, I. P.
    Kruhmalev, A. V.
    Vonk, J. E.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Sanchez-Garcia, L.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Karlsson, Emma
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Gustafsson, Örjan
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Seasonal and interannual variability of sedimentation and organic matter distribution in the Buor-Khaya Gulf: the primary recipient of input from Lena River and coastal erosion in the southeast Laptev Sea2011In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 8, no 9, p. 2581-2594Article in journal (Refereed)
    Abstract [en]

    Climate warming is amplified in the land-sea system of the East Siberian Arctic, which also holds large pools of vulnerable carbon in permafrost. This coastal area is strongly influenced by sediment and carbon transport from both its large rivers and extensive erosion of Pleistocene permafrost along its coastline. This study is investigating the coastal fate of the sediment and organic carbon delivered to the Buor-Khaya Gulf, which is the first recipient of the overwhelming fluvial discharge from the Lena River and is additionally receiving large input from extensive erosion of the coastal ice-complex (permafrost a. k.a. Yedoma; loess soil with high organic carbon content). Both water column suspended particulate matter (SPM) and surface sediments were sampled at about 250 oceanographic stations in the Gulf in this multi-year effort, including one winter campaign, and analyzed for the distribution and sorting of sediment size, organic carbon content, and stable carbon isotope signals. The composition of the surface sediment suggests an overwhelmingly terrestrial contribution from both river and coastal erosion. The objective of this paper is to improve our understanding of the seasonal (i.e., winter vs summer) and interannual variability of these coastal sedimentation processes and the dynamics of organic carbon (OC) distribution in both the water column SPM and the surface sediments of the Buor-Khaya Gulf. Based on data collected during several years in the period 2000-2008, two different sedimentation regimes were revealed for the Buor-Khaya Gulf, the relative importance of each at a given time depend on hydrometeorological conditions, the Lena River water discharge and sea-ice regime: Type 1 erosion-accumulation and Type 2 accumulation. The Type 1 erosion-accumulation sedimentation regime is typical (2000-2006) for the ice-free period of the year (here considered in detail for August 2005). Under such conditions terrigenous sources of SPM and particulate organic carbon (POC) stem predominantly from river discharge, thermal erosion of coastal ice-complex and remobilized bottom sediments. The Type 2 accumulation sedimentation regime develops under ice-covered conditions, and only occasionally during the ice-free period (August 2008). In Type 2 winter, combined terrigenous and marine-biogenic SPM and POC sources are dominating due to relatively low overall terrigenous input (April 2007). In Type 2 summer, river alluvium becomes the major SPM and POC source (August 2008). The water column SPM and POC loadings vary by more than a factor of two between the two regimes. This study underscores the necessity of multi-year investigations to better understand the functioning of the primary recipient of terrestrially expulsed matter in the East Siberian Arctic.

  • 2.
    Karlsson, Emma
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Charkin, A.
    Dudarev, O.
    Semiletov, I.
    Vonk, J. E.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Sanchez-Garcia, L.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Andersson, August
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Gustafsson, Örjan
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Carbon isotopes and lipid biomarker investigation of sources, transport and degradation of terrestrial organic matter in the Buor-Khaya Bay, SE Laptev Sea2011In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 8, no 7, p. 1865-1879Article in journal (Refereed)
    Abstract [en]

    The world's largest continental shelf, the East Siberian Shelf Sea, receives substantial input of terrestrial organic carbon (terr-OC) from both large rivers and erosion of its coastline. Degradation of organic matter from thawing permafrost in the Arctic is likely to increase, potentially creating a positive feedback mechanism to climate warming. This study focuses on the Buor-Khaya Bay (SE Laptev Sea), an area with strong terr-OC input from both coastal erosion and the Lena river. To better understand the fate of this terr-OC, molecular (acyl lipid biomarkers) and isotopic tools (stable carbon and radiocarbon isotopes) have been applied to both particulate organic carbon (POC) in surface water and sedimentary organic carbon (SOC) collected from the underlying surface sediments. Clear gradients in both extent of degradation and differences in source contributions were observed both between surface water POC and surface sediment SOC as well as over the 100 s km investigation scale (about 20 stations). Depleted delta(13)C-OC and high HMW/LMW n-alkane ratios signaled that terr-OC was dominating over marine/planktonic sources. Despite a shallow water column (10-40 m), the isotopic shift between SOC and POC varied systematically from +2 to +5 per mil for delta(13)C and from +300 to +450 for Delta(14)C from the Lena prodelta to the Buor-Khaya Cape. At the same time, the ratio of HMW n-alkanoic acids to HMW n-alkanes as well as HMW n-alkane CPI, both indicative of degradation, were 5-6 times greater in SOC than in POC. This suggests that terr-OC was substantially older yet less degraded in the surface sediment than in the surface waters. This unusual vertical degradation trend was only recently found also for the central East Siberian Sea. Numerical modeling (Monte Carlo simulations) with delta(13)C and Delta(14)C in both POC and SOC was applied to deduce the relative contribution of - plankton OC, surface soil layer OC and yedoma/mineral soil OC. This three end-member dual-carbon-isotopic mixing model suggests quite different scenarios for the POC vs SOC. Surface soil is dominating (63 +/- 10 %) the suspended organic matter in the surface water of SE Laptev Sea. In contrast, the yedoma/mineral soil OC is accounting for 60 +/- 9% of the SOC. We hypothesize that yedoma-OC, associated with mineral-rich matter from coastal erosion is ballasted and thus quickly settles to the bottom. The mineral association may also explain the greater resistance to degradation of this terr-OC component. In contrast, more amorphous humic-like and low-density terr-OC from surface soil and recent vegetation represents a younger but more bioavailable and thus degraded terr-OC component held buoyant in surface water. Hence, these two terr-OC components may represent different propensities to contribute to a positive feedback to climate warming by converting OC from coastal and inland permafrost into CO(2).

1 - 2 of 2
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf