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  • 1
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    Isotopic fractionation of carbon during uptake by phytoplankton across the South Atlantic subtropical convergence (2019)
    Copernicus Publications (EGU)
    In:  Biogeosciences (BG), 16 (18). pp. 3621-3635.
    Details
    Publication Date: 2022-01-31
    Description: The stable isotopic composition of particulate organic carbon (δ13CPOC) in the surface waters of the global ocean can vary with the aqueous CO2 concentration ([CO2(aq)]) and affects the trophic transfer of carbon isotopes in the marine food web. Other factors such as cell size, growth rate and carbon concentrating mechanisms decouple this observed correlation. Here, the variability in δ13CPOC is investigated in surface waters across the south subtropical convergence (SSTC) in the Atlantic Ocean, to determine carbon isotope fractionation (ϵp) by phytoplankton and the contrasting mechanisms of carbon uptake in the subantarctic and subtropical water masses. Our results indicate that cell size is the primary determinant of δ13CPOC across the Atlantic SSTC in summer. Combining cell size estimates with CO2 concentrations, we can accurately estimate "p within the varying surface water masses in this region. We further utilize these results to investigate future changes in "p with increased anthropogenic carbon availability. Our results suggest that smaller cells, which are prevalent in the subtropical ocean, will respond less to increased [CO2(aq)] than the larger cells found south of the SSTC and in the wider Southern Ocean. In the subantarctic water masses, isotopic fractionation during carbon uptake will likely increase, both with increasing CO2 availability to the cell, but also if increased stratification leads to decreases in average community cell size. Coupled with decreasing δ13C of [CO2(aq)] due to anthropogenic CO2 emissions, this change in isotopic fractionation and lowering of δ13CPOC may propagate through the marine food web, with implications for the use of δ13CPOC as a tracer of dietary sources in the marine environment.
    Type: Article , PeerReviewed
    Format: text
    Format: text
    DOI: 10.5194/bg-16-3621-2019
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    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 2
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    Description of a global marine particulate organic carbon-13 isotope data set (2021)
    Copernicus Publications (EGU)
    Details
    Publication Date: 2024-02-07
    Description: Marine particulate organic carbon-13 stable isotope ratios (δ13CPOC) provide insights in understanding carbon cycling through the atmosphere, ocean, and biosphere. They have been used to trace the input of anthropogenic carbon in the marine ecosystem due to the distinct isotopically light signature of anthropogenic emissions. However, δ13CPOC is also significantly altered during photosynthesis by phytoplankton, which complicates its interpretation. For such purposes, robust spatio-temporal coverage of δ13CP OC observations is essential. We collected all such available data sets, merged and homogenized them to provide the largest available marine δ13CPOC data set (Verwega et al., 2021). The data set consists of 4732 data points covering all major ocean basins beginning in the 1960s. We describe the compiled raw data, compare different observational methods, and provide key insights in the temporal and spatial distribution that is consistent with previously observed patterns. The main different sample collection methods (bottle, intake, net, trap) are generally consistent with each other when comparing within regions. An analysis of 1990s mean δ13CP OC values in an meridional section accross the Atlantic Ocean shows relatively high values (≥ −22 ‰) in the low latitudes (〈 30°) trending towards lower values in the Arctic Ocean (∼ −24 ‰) and Southern Ocean (≤ −28 ‰). The temporal trend since the 1960s shows a decrease of mean δ13CPOC by more than 3 ‰ in all basins except for the Southern Ocean which shows a weaker trend but contains relatively poor multi-decadal coverage.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
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    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 3
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    A global marine particulate organic carbon-13 isotope data product (2021)
    PANGAEA
    Details
    Publication Date: 2024-04-20
    Description: A new version (2022) is available: https://doi.org/10.1594/PANGAEA.946915 Marine particulate organic carbon-13 stable isotope ratios (δ13CPOC) provide additional constraints and insights on the cycling of carbon from dissolved pools to the marine ecosystem including anthropogenic contributions. For such purposes, robust spatio-temporal coverage of δ13CPOC observations is essential. We collected all such available known data sets, merged and uniformed them to provide – to the best of our knowledge – the largest available marine δ13CPOC data set. The data set consists of 4732 data points covering all major ocean basins from the 1960s to 2010s. We provide the data in twenty-one different files for best direct application on specific research purposes: a csv file including the 4732 δ13CPOC measurements, their anomalies relative to their mean −23.96 ‰ as well as all available meta-information a NetCDF file including an interpolation onto the 1°x1°-resolution grid based on the World Ocean Atlas (WOA18) data product of all δ13CPOC measurements with full spatio-temporal metadata, averaging all observations from each year together, each year accounting for a time increment on the time axis twelve NetCDF files - one for each month of the year - including an interpolation onto the 1°x1°-resolution grid based on the World Ocean Atlas (WOA18) data product of all δ13CPOC measurements with full spatio-temporal metadata, averaging only observations from the respective month, each year accounting for a time increment on the time axis a NetCDF file including an interpolation onto a 1.8°x3.6°-resolution grid of a δ13CPOC simulating model of all δ13CPOC measurements with full spatial metadata six NetCDF files – one for each decade between the 1960s and 2010s – including an interpolation onto the 1.8°x3.6°-resolution grid of a δ13CPOC simulating model of all δ13CPOC measurements with full spatial metadata and available sample year information
    Keywords: Binary Object; Binary Object (File Size); Binary Object (Media Type); carbon isotope; Description; global; organic carbon; seawater
    Type: Dataset
    Format: text/tab-separated-values, 42 data points
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    DATA PANGAEA
  • 4
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    A global marine particulate organic carbon-13 isotope data product (Version2) (2022)
    PANGAEA
    Details
    Publication Date: 2024-04-20
    Description: Marine particulate organic carbon-13 stable isotope ratios (δ13C-POC) provide additional constraints and insights into the cycling of carbon from dissolved pools to marine ecosystems including anthropogenic contributions. For such purposes, a robust spatio-temporal coverage of δ13C-POC observations is essential. In this data product, we collected and merged two large data compilations (Close and Henderson, 2020; St John Glew et al., 2021) into our previous version (Verwega et al., 2021) to provide the largest available marine δ13C-POC data set. Additionally, we have incorporated more meta information including if the samples were acidified before measuring the isotope ratio. The data set consists of 6952 data points covering the global ocean from year 1966 to 2019. We provide the data in the following two formats for best application on specific research purposes: (1) A spreadsheet file including all collected individual data and meta-information; (2) Network Common Data Form (NetCDF) files that only include acidified samples (6633 total data points) interpolated onto a global ocean grid (1°x1° horizontal resolution, 33 vertical levels based on World Ocean Atlas 2009) for each month individually and all months combined, with each file covering the temporal range from year 1966 to 2019.
    Keywords: Binary Object; Binary Object (File Size); Binary Object (Media Type); carbon isotope ratio (δ13C); Description; global; marine; ocean; Particulate organic carbon
    Type: Dataset
    Format: text/tab-separated-values, 28 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 5
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    n-Alkane composition of organic matter in a rapidly eroding permafrost cliff (2021)
    PANGAEA
    Details
    Publication Date: 2024-05-07
    Description: Organic carbon (OC) stored in Arctic permafrost represents one of Earth’s largest and most vulnerable terrestrial carbon pools. Amplified climate warming across the Arctic results in widespread permafrost thaw. Permafrost deposits exposed at river cliffs and coasts are particularly susceptible to thawing processes. Accelerating erosion of terrestrial permafrost along shorelines leads to increased transfer of organic matter (OM) to nearshore waters. However, the amount of terrestrial permafrost carbon and nitrogen as well as the OM quality in these deposits are still poorly quantified. Here, we characterise the sources and the quality of OM supplied to the Lena River at a rapidly eroding permafrost river shoreline cliff in the eastern part of the delta (Sobo-Sise Island). Our multi-proxy approach captures bulk elemental, molecular geochemical and carbon isotopic analyses of late Pleistocene Yedoma permafrost and Holocene cover deposits, discontinuously spanning the last ~52 ka. We show that the ancient permafrost exposed in the Sobo-Sise cliff has a high organic carbon content (mean of about 5 wt%).We found that the OM quality, which we define as the intrinsic potential to further transformation, decomposition, and mineralization, is also high as inferred by the lipid biomarker inventory. The oldest sediments stem from Marine Isotope Stage (MIS) 3 interstadial deposits (dated to 52 to 28 cal kyr BP) and is overlaid by Last Glacial MIS 2 (dated to 28 to 15 cal ka BP) and Holocene MIS 1 (dated to 7–0 cal ka BP) deposits. The relatively high average chain length (ACL) index of n-alkanes along the cliff profile indicates a predominant contribution of vascular plants to the OM composition. The elevated ratio of iso and anteiso-branched FAs relative to long chain (C ≥ 20) n-FAs in the interstadial MIS 3 and the interglacial MIS 1 deposits, suggests stronger microbial activity and consequently higher input of bacterial biomass during these climatically warmer periods. The overall high carbon preference index (CPI) and higher plant fatty acid (HPFA) values as well as high C / N ratios point to a good quality of the preserved OM and thus to a high potential of the OM for decomposition upon thaw. A decrease of HPFA values downwards along the profile probably indicates a relatively stronger OM decomposition in the oldest (MIS 3) deposits of the cliff.
    Keywords: AWI Arctic Land Expedition; Biomarker; CACOON; Carbon; Changing Arctic Carbon cycle in the cOastal Ocean Near-shore; erosion; Event label; Height above river level; n-alkane; n-Alkane C14, per unit mass total organic carbon; n-Alkane C14, per unit sediment mass; n-Alkane C15, per unit mass total organic carbon; n-Alkane C15, per unit sediment mass; n-Alkane C16, per unit mass total organic carbon; n-Alkane C16, per unit sediment mass; n-Alkane C17, per unit mass total organic carbon; n-Alkane C17, per unit sediment mass; n-Alkane C18, per unit mass total organic carbon; n-Alkane C18, per unit sediment mass; n-Alkane C19, per unit mass total organic carbon; n-Alkane C19, per unit sediment mass; n-Alkane C20, per unit mass total organic carbon; n-Alkane C20, per unit sediment mass; n-Alkane C21, per unit mass total organic carbon; n-Alkane C21, per unit sediment mass; n-Alkane C22, per unit mass total organic carbon; n-Alkane C22, per unit sediment mass; n-Alkane C23, per unit mass total organic carbon; n-Alkane C23, per unit sediment mass; n-Alkane C24, per unit mass total organic carbon; n-Alkane C24, per unit sediment mass; n-Alkane C25, per unit mass total organic carbon; n-Alkane C25, per unit sediment mass; n-Alkane C26, per unit mass total organic carbon; n-Alkane C26, per unit sediment mass; n-Alkane C27, per unit mass total organic carbon; n-Alkane C27, per unit sediment mass; n-Alkane C28, per unit mass total organic carbon; n-Alkane C28, per unit sediment mass; n-Alkane C29, per unit mass total organic carbon; n-Alkane C29, per unit sediment mass; n-Alkane C30, per unit mass total organic carbon; n-Alkane C30, per unit sediment mass; n-Alkane C31, per unit mass total organic carbon; n-Alkane C31, per unit sediment mass; n-Alkane C32, per unit mass total organic carbon; n-Alkane C32, per unit sediment mass; n-Alkane C33, per unit mass total organic carbon; n-Alkane C33, per unit sediment mass; n-Alkane C34, per unit mass total organic carbon; n-Alkane C34, per unit sediment mass; n-Alkane C35, per unit mass total organic carbon; n-Alkane C35, per unit sediment mass; n-fatty acids; PERM; RU-Land_2018_Lena_Sobo-Sise; Sample ID; Sampling permafrost; Siberia; SOB18-01; SOB18-03; SOB18-06; Sobo-Sise 2018; Sobo-Sise Island; Yedoma
    Type: Dataset
    Format: text/tab-separated-values, 1294 data points
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    DATA PANGAEA
  • 6
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    Organic matter characteristics using lipid biomarker analysis of a rapidly eroding permafrost cliff (2021)
    PANGAEA
    Details
    Publication Date: 2024-05-07
    Description: Organic carbon (OC) stored in Arctic permafrost represents one of Earth's largest and most vulnerable terrestrial carbon pools. Amplified climate warming across the Arctic results in widespread permafrost thaw. Permafrost deposits exposed at river cliffs and coasts are particularly susceptible to thawing processes. Accelerating erosion of terrestrial permafrost along shorelines leads to increased transfer of organic matter (OM) to nearshore waters. However, the amount of terrestrial permafrost carbon and nitrogen as well as the OM quality in these deposits are still poorly quantified. Here, we characterise the sources and the quality of OM supplied to the Lena River at a rapidly eroding permafrost river shoreline cliff in the eastern part of the delta (Sobo-Sise Island). Our multi-proxy approach captures bulk elemental, molecular geochemical and carbon isotopic analyses of late Pleistocene Yedoma permafrost and Holocene cover deposits, discontinuously spanning the last ~52 ka. We show that the ancient permafrost exposed in the Sobo-Sise cliff has a high organic carbon content (mean of about 5 wt%).We found that the OM quality, which we define as the intrinsic potential to further transformation, decomposition, and mineralization, is also high as inferred by the lipid biomarker inventory. The oldest sediments stem from Marine Isotope Stage (MIS) 3 interstadial deposits (dated to 52 to 28 cal kyr BP) and is overlaid by Last Glacial MIS 2 (dated to 28 to 15 cal ka BP) and Holocene MIS 1 (dated to 7–0 cal ka BP) deposits. The relatively high average chain length (ACL) index of n-alkanes along the cliff profile indicates a predominant contribution of vascular plants to the OM composition. The elevated ratio of iso and anteiso-branched FAs relative to long chain (C ≥ 20) n-FAs in the interstadial MIS 3 and the interglacial MIS 1 deposits, suggests stronger microbial activity and consequently higher input of bacterial biomass during these climatically warmer periods. The overall high carbon preference index (CPI) and higher plant fatty acid (HPFA) values as well as high C / N ratios point to a good quality of the preserved OM and thus to a high potential of the OM for decomposition upon thaw. A decrease of HPFA values downwards along the profile probably indicates a relatively stronger OM decomposition in the oldest (MIS 3) deposits of the cliff.
    Keywords: Biomarker; CACOON; Carbon; Changing Arctic Carbon cycle in the cOastal Ocean Near-shore; erosion; n-alkane; n-fatty acids; Siberia; Yedoma
    Type: Dataset
    Format: application/zip, 4 datasets
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 7
    facet.materialart.
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    n-Fatty acid composition per sediment mass in a rapidly eroding permafrost cliff (2022)
    PANGAEA
    Details
    Publication Date: 2024-05-07
    Description: Organic carbon (OC) stored in Arctic permafrost represents one of Earth’s largest and most vulnerable terrestrial carbon pools. Amplified climate warming across the Arctic results in widespread permafrost thaw. Permafrost deposits exposed at river cliffs and coasts are particularly susceptible to thawing processes. Accelerating erosion of terrestrial permafrost along shorelines leads to increased transfer of organic matter (OM) to nearshore waters. However, the amount of terrestrial permafrost carbon and nitrogen as well as the OM quality in these deposits are still poorly quantified. Here, we characterise the sources and the quality of OM supplied to the Lena River at a rapidly eroding permafrost river shoreline cliff in the eastern part of the delta (Sobo-Sise Island). Our multi-proxy approach captures bulk elemental, molecular geochemical and carbon isotopic analyses of late Pleistocene Yedoma permafrost and Holocene cover deposits, discontinuously spanning the last ~52 ka. We show that the ancient permafrost exposed in the Sobo-Sise cliff has a high organic carbon content (mean of about 5 wt%).We found that the OM quality, which we define as the intrinsic potential to further transformation, decomposition, and mineralization, is also high as inferred by the lipid biomarker inventory. The oldest sediments stem from Marine Isotope Stage (MIS) 3 interstadial deposits (dated to 52 to 28 cal kyr BP) and is overlaid by Last Glacial MIS 2 (dated to 28 to 15 cal ka BP) and Holocene MIS 1 (dated to 7–0 cal ka BP) deposits. The relatively high average chain length (ACL) index of n-alkanes along the cliff profile indicates a predominant contribution of vascular plants to the OM composition. The elevated ratio of iso and anteiso-branched FAs relative to long chain (C ≥ 20) n-FAs in the interstadial MIS 3 and the interglacial MIS 1 deposits, suggests stronger microbial activity and consequently higher input of bacterial biomass during these climatically warmer periods. The overall high carbon preference index (CPI) and higher plant fatty acid (HPFA) values as well as high C / N ratios point to a good quality of the preserved OM and thus to a high potential of the OM for decomposition upon thaw. A decrease of HPFA values downwards along the profile probably indicates a relatively stronger OM decomposition in the oldest (MIS 3) deposits of the cliff.
    Keywords: 10-methyl-fatty acid C14:0; 10-methyl-fatty acid C16:0; 10-methyl-fatty acid C17:0; 10-methyl-fatty acid C18:0; 12-methyl-fatty acid C16:0; 12-methyl-fatty acid C18:0; 3-hydroxyl-fatty acid C6:0; 3-hydroxyl-fatty acid C7:0; 3-hydroxyl-fatty acid C8:0; anteiso-fatty acid C11:0; anteiso-fatty acid C12:0; anteiso-fatty acid C13:0; anteiso-fatty acid C15:0; anteiso-fatty acid C17:0; anteiso-fatty acid C17:1; AWI Arctic Land Expedition; Biomarker; CACOON; Carbon; Changing Arctic Carbon cycle in the cOastal Ocean Near-shore; cyclo-fatty acid C17; cyclo-fatty acid C19; erosion; Event label; fatty acid C16:1w5; fatty acid C16:1w7cis; fatty acid C16:1w7trans; fatty acid C18:1w7cis; fatty acid C18:1w7trans; fatty acid C18:1w9; fatty acid C18:2w6,9; Height above river level; iso-fatty acid C10:0; iso-fatty acid C11:0; iso-fatty acid C13:0; iso-fatty acid C14:0; iso-fatty acid C15:0; iso-fatty acid C16:0; iso-fatty acid C17:0; iso-fatty acid C17:1; iso-fatty acid C18:0; iso-fatty acid C19:0; methyl-fatty acid C16:0; methyl-fatty acid C17:0; n-alkane; n-fatty acid C10:0; n-fatty acid C11:0; n-fatty acid C12:0; n-fatty acid C13:0; n-fatty acid C14:0; n-fatty acid C15:0; n-fatty acid C16:0; n-fatty acid C17:0; n-fatty acid C17:1; n-fatty acid C18:0; n-fatty acid C18:3; n-fatty acid C19:0; n-fatty acid C19:1; n-fatty acid C20:0; n-fatty acid C20:1; n-fatty acid C21:0; n-fatty acid C22:0; n-fatty acid C23:0; n-fatty acid C24:0; n-fatty acid C24:1; n-fatty acid C25:0; n-fatty acid C26:0; n-fatty acid C27:0; n-fatty acid C28:0; n-fatty acid C29:0; n-fatty acid C30:0; n-fatty acid C32:0; n-fatty acid C8:0; n-fatty acid C9:0; n-fatty acids; PERM; Phytanoic acid; RU-Land_2018_Lena_Sobo-Sise; Sample ID; Sampling permafrost; Siberia; SOB18-01; SOB18-03; SOB18-06; Sobo-Sise 2018; Sobo-Sise Island; Standard deviation; Stigmastenone; Yedoma
    Type: Dataset
    Format: text/tab-separated-values, 923 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 8
    facet.materialart.
    Unknown
    Organic matter biogeochemistry using lipid biomarker analysis of a rapidly eroding permafrost cliff (2021)
    PANGAEA
    Details
    Publication Date: 2024-05-07
    Description: Organic carbon (OC) stored in Arctic permafrost represents one of Earth’s largest and most vulnerable terrestrial carbon pools. Amplified climate warming across the Arctic results in widespread permafrost thaw. Permafrost deposits exposed at river cliffs and coasts are particularly susceptible to thawing processes. Accelerating erosion of terrestrial permafrost along shorelines leads to increased transfer of organic matter (OM) to nearshore waters. However, the amount of terrestrial permafrost carbon and nitrogen as well as the OM quality in these deposits are still poorly quantified. Here, we characterise the sources and the quality of OM supplied to the Lena River at a rapidly eroding permafrost river shoreline cliff in the eastern part of the delta (Sobo-Sise Island). Our multi-proxy approach captures bulk elemental, molecular geochemical and carbon isotopic analyses of late Pleistocene Yedoma permafrost and Holocene cover deposits, discontinuously spanning the last ~52 ka. We show that the ancient permafrost exposed in the Sobo-Sise cliff has a high organic carbon content (mean of about 5 wt%).We found that the OM quality, which we define as the intrinsic potential to further transformation, decomposition, and mineralization, is also high as inferred by the lipid biomarker inventory. The oldest sediments stem from Marine Isotope Stage (MIS) 3 interstadial deposits (dated to 52 to 28 cal kyr BP) and is overlaid by Last Glacial MIS 2 (dated to 28 to 15 cal ka BP) and Holocene MIS 1 (dated to 7–0 cal ka BP) deposits. The relatively high average chain length (ACL) index of n-alkanes along the cliff profile indicates a predominant contribution of vascular plants to the OM composition. The elevated ratio of iso and anteiso-branched FAs relative to long chain (C ≥ 20) n-FAs in the interstadial MIS 3 and the interglacial MIS 1 deposits, suggests stronger microbial activity and consequently higher input of bacterial biomass during these climatically warmer periods. The overall high carbon preference index (CPI) and higher plant fatty acid (HPFA) values as well as high C / N ratios point to a good quality of the preserved OM and thus to a high potential of the OM for decomposition upon thaw. A decrease of HPFA values downwards along the profile probably indicates a relatively stronger OM decomposition in the oldest (MIS 3) deposits of the cliff.
    Keywords: AGE; AWI Arctic Land Expedition; Biomarker; CACOON; Carbon; Carbon, organic, total; Carbon/Nitrogen ratio; Carbon Preference Index, n-Alkanes; Changing Arctic Carbon cycle in the cOastal Ocean Near-shore; erosion; Event label; Height above river level; Higher plant n-fatty acids, per unit sediment mass; Lithologic unit/sequence; n-alkane; n-Alkane, average chain length; n-Alkanes, long-chain, per unit mass total organic carbon; n-Alkanes, long-chain per unit sediment mass; n-Alkanes, short-chain, per unit mass total organic carbon; n-Alkanes, short-chain per unit sediment mass; n-fatty acids; n-fatty acids, C21-C23, per unit mass total organic carbon; n-fatty acids, C21-C23, per unit sediment mass; n-fatty acids, long-chain, per unit mass total organic carbon; n-fatty acids, long-chain per unit sediment mass; n-fatty acids, per unit mass total organic carbon; n-fatty acids, per unit sediment mass; n-fatty acids, short-chain, per unit mass total organic carbon; n-fatty acids, short-chain per unit sediment mass; Nitrogen, total; PERM; Ratio; RU-Land_2018_Lena_Sobo-Sise; Sample ID; Sampling permafrost; Siberia; SOB18-01; SOB18-03; SOB18-06; Sobo-Sise 2018; Sobo-Sise Island; Sum n-alkanes C14-C35, per unit mass total organic carbon; Sum n-alkanes C14-C35, per unit sediment mass; Yedoma; δ13C, organic matter
    Type: Dataset
    Format: text/tab-separated-values, 545 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 9
    facet.materialart.
    Unknown
    n-Fatty acid composition per total organic carbon in a rapidly eroding permafrost cliff (2022)
    PANGAEA
    Details
    Publication Date: 2024-05-07
    Description: Organic carbon (OC) stored in Arctic permafrost represents one of Earth’s largest and most vulnerable terrestrial carbon pools. Amplified climate warming across the Arctic results in widespread permafrost thaw. Permafrost deposits exposed at river cliffs and coasts are particularly susceptible to thawing processes. Accelerating erosion of terrestrial permafrost along shorelines leads to increased transfer of organic matter (OM) to nearshore waters. However, the amount of terrestrial permafrost carbon and nitrogen as well as the OM quality in these deposits are still poorly quantified. Here, we characterise the sources and the quality of OM supplied to the Lena River at a rapidly eroding permafrost river shoreline cliff in the eastern part of the delta (Sobo-Sise Island). Our multi-proxy approach captures bulk elemental, molecular geochemical and carbon isotopic analyses of late Pleistocene Yedoma permafrost and Holocene cover deposits, discontinuously spanning the last ~52 ka. We show that the ancient permafrost exposed in the Sobo-Sise cliff has a high organic carbon content (mean of about 5 wt%).We found that the OM quality, which we define as the intrinsic potential to further transformation, decomposition, and mineralization, is also high as inferred by the lipid biomarker inventory. The oldest sediments stem from Marine Isotope Stage (MIS) 3 interstadial deposits (dated to 52 to 28 cal kyr BP) and is overlaid by Last Glacial MIS 2 (dated to 28 to 15 cal ka BP) and Holocene MIS 1 (dated to 7–0 cal ka BP) deposits. The relatively high average chain length (ACL) index of n-alkanes along the cliff profile indicates a predominant contribution of vascular plants to the OM composition. The elevated ratio of iso and anteiso-branched FAs relative to long chain (C ≥ 20) n-FAs in the interstadial MIS 3 and the interglacial MIS 1 deposits, suggests stronger microbial activity and consequently higher input of bacterial biomass during these climatically warmer periods. The overall high carbon preference index (CPI) and higher plant fatty acid (HPFA) values as well as high C / N ratios point to a good quality of the preserved OM and thus to a high potential of the OM for decomposition upon thaw. A decrease of HPFA values downwards along the profile probably indicates a relatively stronger OM decomposition in the oldest (MIS 3) deposits of the cliff.
    Keywords: 10-methyl-fatty acid C14:0, per unit mass total organic carbon; 10-methyl-fatty acid C16:0, per unit mass total organic carbon; 10-methyl-fatty acid C17:0, per unit mass total organic carbon; 10-methyl-fatty acid C18:0, per unit mass total organic carbon; 12-methyl-fatty acid C16:0, per unit mass total organic carbon; 12-methyl-fatty acid C18:0, per unit mass total organic carbon; 3-hydroxyl-fatty acid C6:0, per unit mass total organic carbon; 3-hydroxyl-fatty acid C7:0, per unit mass total organic carbon; 3-hydroxyl-fatty acid C8:0, per unit mass total organic carbon; anteiso-fatty acid C11:0, per unit mass total organic carbon; anteiso-fatty acid C12:0, per unit mass total organic carbon; anteiso-fatty acid C13:0, per unit mass total organic carbon; anteiso-fatty acid C15:0, per unit mass total organic carbon; anteiso-fatty acid C17:0, per unit mass total organic carbon; anteiso-fatty acid C17:1, per unit mass total organic carbon; AWI Arctic Land Expedition; Biomarker; CACOON; Carbon; Changing Arctic Carbon cycle in the cOastal Ocean Near-shore; cyclo-fatty acid C17, per unit mass total organic carbon; cyclo-fatty acid C19, per unit mass total organic carbon; erosion; Event label; fatty acid C16:1w5, per unit mass total organic carbon; fatty acid C16:1w7cis, per unit mass total organic carbon; fatty acid C16:1w7trans, per unit mass total organic carbon; fatty acid C18:1w7cis, per unit mass total organic carbon; fatty acid C18:1w7trans, per unit mass total organic carbon; fatty acid C18:1w9, per unit mass total organic carbon; fatty acid C18:2w6,9, per unit mass total organic carbon; Height above river level; iso-fatty acid C10:0, per unit mass total organic carbon; iso-fatty acid C11:0, per unit mass total organic carbon; iso-fatty acid C13:0, per unit mass total organic carbon; iso-fatty acid C14:0, per unit mass total organic carbon; iso-fatty acid C15:0, per unit mass total organic carbon; iso-fatty acid C16:0, per unit mass total organic carbon; iso-fatty acid C17:0, per unit mass total organic carbon; iso-fatty acid C17:1, per unit mass total organic carbon; iso-fatty acid C18:0, per unit mass total organic carbon; iso-fatty acid C19:0, per unit mass total organic carbon; methyl-fatty acid C16:0, per unit mass total organic carbon; methyl-fatty acid C17:0, per unit mass total organic carbon; n-alkane; n-fatty acid C10:0, per unit mass total organic carbon; n-fatty acid C11:0, per unit mass total organic carbon; n-fatty acid C12:0, per unit mass total organic carbon; n-fatty acid C13:0, per unit mass total organic carbon; n-fatty acid C14:0, per unit mass total organic carbon; n-fatty acid C15:0, per unit mass total organic carbon; n-fatty acid C16:0, per unit mass total organic carbon; n-fatty acid C17:0, per unit mass total organic carbon; n-fatty acid C17:1, per unit mass total organic carbon; n-fatty acid C18:0, per unit mass total organic carbon; n-fatty acid C18:3, per unit mass total organic carbon; n-fatty acid C19:0, per unit mass total organic carbon; n-fatty acid C19:1, per unit mass total organic carbon; n-fatty acid C20:0, per unit mass total organic carbon; n-fatty acid C20:1, per unit mass total organic carbon; n-fatty acid C21:0, per unit mass total organic carbon; n-fatty acid C22:0, per unit mass total organic carbon; n-fatty acid C23:0, per unit mass total organic carbon; n-fatty acid C24:0, per unit mass total organic carbon; n-fatty acid C24:1, per unit mass total organic carbon; n-fatty acid C25:0, per unit mass total organic carbon; n-fatty acid C26:0, per unit mass total organic carbon; n-fatty acid C27:0, per unit mass total organic carbon; n-fatty acid C28:0, per unit mass total organic carbon; n-fatty acid C29:0, per unit mass total organic carbon; n-fatty acid C30:0, per unit mass total organic carbon; n-fatty acid C32:0, per unit mass total organic carbon; n-fatty acid C8:0, per unit mass total organic carbon; n-fatty acid C9:0, per unit mass total organic carbon; n-fatty acids; PERM; Phytanoic acid, per unit mass total organic carbon; RU-Land_2018_Lena_Sobo-Sise; Sample ID; Sampling permafrost; Siberia; SOB18-01; SOB18-03; SOB18-06; Sobo-Sise 2018; Sobo-Sise Island; Standard deviation; Stigmastenone, per unit mass total organic carbon; Yedoma
    Type: Dataset
    Format: text/tab-separated-values, 923 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 10
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    Nutrient cycling in the Atlantic basin: The evolution of nitrate isotope signatures in water masses (2015)
    In:  EPIC3Global Biogeochemical Cycles, 29(10), pp. 1830-1844
    Details
    Publication Date: 2016-09-14
    Description: A basin-wide transect of nitrate isotopes (δ15NNO3, δ18ONO3), across the UK GEOTRACES 40°S transect in the South Atlantic is presented. This data set is used to investigate Atlantic nutrient cycling and the communication pathways of nitrogen cycling processes in the global ocean. Intermediate waters formed in the subantarctic are enriched in δ15NNO3 and δ18ONO3 from partial utilization of nitrate by phytoplankton and distant denitrification processes, transporting heavy isotope signatures to the subtropical Atlantic. Water mass modification through the Atlantic is investigated by comparing data from 40°S (South Atlantic) and 30°N (North Atlantic). This reveals that nitrate in the upper intermediate waters is regenerated as it transits through the subtropical Atlantic, as evidenced by decreases in δ18ONO3. We document diazotrophy-producing high N:P particle ratios (18–21:1) for remineralization, which is further confirmed by a decrease in δ15NNO3 through the subtropical Atlantic. Thesemodifications influence the isotopic signatures of the North Atlantic Deep Water (NADW) which is subsequently exported from the Atlantic to the Southern Ocean. This study reveals the dominance of recycling processes and diazotrophy on nitrate cycling in the Atlantic. These processes provide a source of low δ15NNO3 to the Southern Ocean via the NADW, to counteract enrichment in δ15NNO3 from water column denitrification in the Indo/Pacific basins. We hence identify the Southern Ocean as a key hub through which denitrification and N2 fixation communicate in the ocean through deepwater masses. Therefore, the balancing of the oceanic N budget and isotopic signatures require time scales of oceanic mixing.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
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