Skip header and navigation

17 records – page 1 of 2.

Bounding cross-shelf transport time and degradation in Siberian-Arctic land-ocean carbon transfer.

https://arctichealth.org/en/permalink/ahliterature290040
Source
Nat Commun. 2018 02 23; 9(1):806
Publication Type
Journal Article
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't
Date
02-23-2018
Author
Lisa Bröder
Tommaso Tesi
August Andersson
Igor Semiletov
Örjan Gustafsson
Author Affiliation
Department of Environmental Science and Analytical Chemistry, Stockholm University, 10691 Stockholm, Sweden. l.m.broeder@vu.nl.
Source
Nat Commun. 2018 02 23; 9(1):806
Date
02-23-2018
Language
English
Publication Type
Journal Article
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't
Abstract
The burial of terrestrial organic carbon (terrOC) in marine sediments contributes to the regulation of atmospheric CO2 on geological timescales and may mitigate positive feedback to present-day climate warming. However, the fate of terrOC in marine settings is debated, with uncertainties regarding its degradation during transport. Here, we employ compound-specific radiocarbon analyses of terrestrial biomarkers to determine cross-shelf transport times. For the World's largest marginal sea, the East Siberian Arctic shelf, transport requires 3600?±?300 years for the 600?km from the Lena River to the Laptev Sea shelf edge. TerrOC was reduced by ~85% during transit resulting in a degradation rate constant of 2.4?±?0.6?kyr-1. Hence, terrOC degradation during cross-shelf transport constitutes a carbon source to the atmosphere over millennial time. For the contemporary carbon cycle on the other hand, slow terrOC degradation brings considerable attenuation of the decadal-centennial permafrost carbon-climate feedback caused by global warming.
Notes
Cites: Nature. 2015 May 14;521(7551):204-7 PMID 25971513
Cites: Anal Chem. 1996 Mar 1;68(5):904-12 PMID 21619188
Cites: Nature. 2012 Sep 6;489(7414):137-40 PMID 22932271
Cites: Ann Rev Mar Sci. 2012;4:401-23 PMID 22457981
Cites: Nat Commun. 2017 Jun 22;8:15872 PMID 28639616
Cites: Environ Sci Technol. 2015 Feb 17;49(4):2038-43 PMID 25569822
Cites: Ann Rev Mar Sci. 2011;3:123-45 PMID 21329201
Cites: Nature. 2015 Apr 9;520(7546):171-9 PMID 25855454
Cites: Anal Chem. 2007 Mar 1;79(5):2042-9 PMID 17256874
Cites: Nature. 2015 Aug 6;524(7563):84-7 PMID 26245581
Cites: Nature. 2013 Dec 5;504(7478):61-70 PMID 24305149
Cites: Environ Sci Technol. 2015 Jul 7;49(13):7657-65 PMID 26053501
Cites: Nat Commun. 2016 Nov 29;7:13653 PMID 27897191
PubMed ID
29476050 View in PubMed
Less detail

Current rates and mechanisms of subsea permafrost degradation in the East Siberian Arctic Shelf.

https://arctichealth.org/en/permalink/ahliterature283367
Source
Nat Commun. 2017 Jun 22;8:15872
Publication Type
Article
Date
Jun-22-2017
Author
Natalia Shakhova
Igor Semiletov
Orjan Gustafsson
Valentin Sergienko
Leopold Lobkovsky
Oleg Dudarev
Vladimir Tumskoy
Michael Grigoriev
Alexey Mazurov
Anatoly Salyuk
Roman Ananiev
Andrey Koshurnikov
Denis Kosmach
Alexander Charkin
Nicolay Dmitrevsky
Victor Karnaukh
Alexey Gunar
Alexander Meluzov
Denis Chernykh
Source
Nat Commun. 2017 Jun 22;8:15872
Date
Jun-22-2017
Language
English
Publication Type
Article
Abstract
The rates of subsea permafrost degradation and occurrence of gas-migration pathways are key factors controlling the East Siberian Arctic Shelf (ESAS) methane (CH4) emissions, yet these factors still require assessment. It is thought that after inundation, permafrost-degradation rates would decrease over time and submerged thaw-lake taliks would freeze; therefore, no CH4 release would occur for millennia. Here we present results of the first comprehensive scientific re-drilling to show that subsea permafrost in the near-shore zone of the ESAS has a downward movement of the ice-bonded permafrost table of ~14?cm year(-1) over the past 31-32 years. Our data reveal polygonal thermokarst patterns on the seafloor and gas-migration associated with submerged taliks, ice scouring and pockmarks. Knowing the rate and mechanisms of subsea permafrost degradation is a prerequisite to meaningful predictions of near-future CH4 release in the Arctic.
PubMed ID
28639616 View in PubMed
Less detail

Deep water masses and sediments are main compartments for polychlorinated biphenyls in the Arctic Ocean.

https://arctichealth.org/en/permalink/ahliterature257772
Source
Environ Sci Technol. 2014 Jun 17;48(12):6719-25
Publication Type
Article
Date
Jun-17-2014
Author
Anna Sobek
Örjan Gustafsson
Author Affiliation
Department of Applied Environmental Science (ITM) and ‡Bolin Centre for Climate Research, Stockholm University , 10691, Stockholm Sweden.
Source
Environ Sci Technol. 2014 Jun 17;48(12):6719-25
Date
Jun-17-2014
Language
English
Publication Type
Article
Keywords
Arctic Regions
Geologic Sediments - chemistry
Ice Cover - chemistry
Oceans and Seas
Polychlorinated biphenyls - analysis
Uncertainty
Water - chemistry
Water Pollutants, Chemical - analysis
Abstract
There is a wealth of studies of polychlorinated biphenyls (PCB) in surface water and biota of the Arctic Ocean. Still, there are no observation-based assessments of PCB distribution and inventories in and between the major Arctic Ocean compartments. Here, the first water column distribution of PCBs in the central Arctic Ocean basins (Nansen, Amundsen, and Makarov) is presented, demonstrating nutrient-like vertical profiles with 5-10 times higher concentrations in the intermediate and deep water masses than in surface waters. The consistent vertical profiles in all three Arctic Ocean basins likely reflect buildup of PCBs transported from the shelf seas and from dissolution and/or mineralization of settling particles. Combined with measurement data on PCBs in other Arctic Ocean compartments collected over the past decade, the total Arctic Ocean inventory of ?7PCB was estimated to 182 ± 40 t (±1 standard error of the mean), with sediments (144 ± 40 t), intermediate (5 ± 1 t) and deep water masses (30 ± 2 t) storing 98% of the PCBs in the Arctic Ocean. Further, we used hydrographic and carbon cycle parametrizations to assess the main pathways of PCBs into and out of the Arctic Ocean during the 20th century. River discharge appeared to be the major pathway for PCBs into the Arctic Ocean with 115 ± 11 t, followed by ocean currents (52 ± 17 t) and net atmospheric deposition (30 ± 28 t). Ocean currents provided the only important pathway out of the Arctic Ocean, with an estimated cumulative flux of 22 ± 10 t. The observation-based inventory of ?7PCB of 182 ± 40 t is consistent with the contemporary inventory based on cumulative fluxes for ?7PCB of 173 ± 36 t. Information on the concentration and distribution of PCBs in the deeper compartments of the Arctic Ocean improves our understanding of the large-scale fate of POPs in the Arctic and may also provide a means to test and improve models used to assess the fate of organic pollutants in the Arctic.
PubMed ID
24844123 View in PubMed
Less detail

The East Siberian Arctic Shelf: towards further assessment of permafrost-related methane fluxes and role of sea ice.

https://arctichealth.org/en/permalink/ahliterature266006
Source
Philos Trans A Math Phys Eng Sci. 2015 Oct 13;373(2052)
Publication Type
Article
Date
Oct-13-2015
Author
Natalia Shakhova
Igor Semiletov
Valentin Sergienko
Leopold Lobkovsky
Vladimir Yusupov
Anatoly Salyuk
Alexander Salomatin
Denis Chernykh
Denis Kosmach
Gleb Panteleev
Dmitry Nicolsky
Vladimir Samarkin
Samantha Joye
Alexander Charkin
Oleg Dudarev
Alexander Meluzov
Orjan Gustafsson
Source
Philos Trans A Math Phys Eng Sci. 2015 Oct 13;373(2052)
Date
Oct-13-2015
Language
English
Publication Type
Article
Abstract
Sustained release of methane (CH4) to the atmosphere from thawing Arctic permafrost may be a positive and significant feedback to climate warming. Atmospheric venting of CH4 from the East Siberian Arctic Shelf (ESAS) was recently reported to be on par with flux from the Arctic tundra; however, the future scale of these releases remains unclear. Here, based on results of our latest observations, we show that CH4 emissions from this shelf are likely to be determined by the state of subsea permafrost degradation. We observed CH4 emissions from two previously understudied areas of the ESAS: the outer shelf, where subsea permafrost is predicted to be discontinuous or mostly degraded due to long submergence by seawater, and the near shore area, where deep/open taliks presumably form due to combined heating effects of seawater, river run-off, geothermal flux and pre-existing thermokarst. CH4 emissions from these areas emerge from largely thawed sediments via strong flare-like ebullition, producing fluxes that are orders of magnitude greater than fluxes observed in background areas underlain by largely frozen sediments. We suggest that progression of subsea permafrost thawing and decrease in ice extent could result in a significant increase in CH4 emissions from the ESAS.
PubMed ID
26347539 View in PubMed
Less detail

Evidence for an ice shelf covering the central Arctic Ocean during the penultimate glaciation.

https://arctichealth.org/en/permalink/ahliterature269367
Source
Nat Commun. 2016;7:10365
Publication Type
Article
Date
2016
Author
Martin Jakobsson
Johan Nilsson
Leif Anderson
Jan Backman
Göran Björk
Thomas M Cronin
Nina Kirchner
Andrey Koshurnikov
Larry Mayer
Riko Noormets
Matthew O'Regan
Christian Stranne
Roman Ananiev
Natalia Barrientos Macho
Denis Cherniykh
Helen Coxall
Björn Eriksson
Tom Flodén
Laura Gemery
Örjan Gustafsson
Kevin Jerram
Carina Johansson
Alexey Khortov
Rezwan Mohammad
Igor Semiletov
Source
Nat Commun. 2016;7:10365
Date
2016
Language
English
Publication Type
Article
Abstract
The hypothesis of a km-thick ice shelf covering the entire Arctic Ocean during peak glacial conditions was proposed nearly half a century ago. Floating ice shelves preserve few direct traces after their disappearance, making reconstructions difficult. Seafloor imprints of ice shelves should, however, exist where ice grounded along their flow paths. Here we present new evidence of ice-shelf groundings on bathymetric highs in the central Arctic Ocean, resurrecting the concept of an ice shelf extending over the entire central Arctic Ocean during at least one previous ice age. New and previously mapped glacial landforms together reveal flow of a spatially coherent, in some regions >1-km thick, central Arctic Ocean ice shelf dated to marine isotope stage 6 (~140?ka). Bathymetric highs were likely critical in the ice-shelf development by acting as pinning points where stabilizing ice rises formed, thereby providing sufficient back stress to allow ice shelf thickening.
PubMed ID
26778247 View in PubMed
Less detail

Isotope-Based Source Apportionment of EC Aerosol Particles during Winter High-Pollution Events at the Zeppelin Observatory, Svalbard.

https://arctichealth.org/en/permalink/ahliterature265863
Source
Environ Sci Technol. 2015 Sep 11;
Publication Type
Article
Date
Sep-11-2015
Author
Patrik Winiger
August Andersson
Karl E Yttri
Peter Tunved
Örjan Gustafsson
Source
Environ Sci Technol. 2015 Sep 11;
Date
Sep-11-2015
Language
English
Publication Type
Article
Abstract
Black carbon (BC) aerosol particles contribute to climate warming of the Arctic, yet both the sources and the source-related effects are currently poorly constrained. Bottom-up emission inventory (EI) approaches are challenged for BC in general and the Arctic in particular. For example, estimates from three different EI models on the fractional contribution to BC from biomass burning (north of 60° N) vary between 11% and 68%, each acknowledging large uncertainties. Here we present the first dual-carbon isotope-based (?(14)C and d(13)C) source apportionment of elemental carbon (EC), the mass-based correspondent to optically defined BC, in the Arctic atmosphere. It targeted 14 high-loading and high-pollution events during January through March of 2009 at the Zeppelin Observatory (79° N; Svalbard, Norway), with these representing one-third of the total sampling period that was yet responsible for three-quarters of the total EC loading. The top-down source-diagnostic (14)C fingerprint constrained that 52 ± 15% (n = 12) of the EC stemmed from biomass burning. Including also two samples with 95% and 98% biomass contribution yield 57 ± 21% of EC from biomass burning. Significant variability in the stable carbon isotope signature indicated temporally shifting emissions between different fossil sources, likely including liquid fossil and gas flaring. Improved source constraints of Arctic BC both aids better understanding of effects and guides policy actions to mitigate emissions.
PubMed ID
26332725 View in PubMed
Less detail

Observation-based assessment of PBDE loads in Arctic Ocean waters.

https://arctichealth.org/en/permalink/ahliterature269695
Source
Environ Sci Technol. 2016 Feb 3;
Publication Type
Article
Date
Feb-3-2016
Author
Joan A Salvadó
Anna Sobek
Daniel Carrizo
Örjan Gustafsson
Source
Environ Sci Technol. 2016 Feb 3;
Date
Feb-3-2016
Language
English
Publication Type
Article
Abstract
Little is known about the distribution of polybrominated diphenyl ethers (PBDE) -also known as flame retardants- in major ocean compartments, with no reports yet for the large deep-water masses of the Arctic Ocean. Here, PBDE concentrations, congener patterns and inventories are presented for the different water masses of the pan-Arctic shelf seas and the interior basin. Seawater samples were collected onboard three cross-basin oceanographic campaigns in 2001, 2005 and 2008 following strict trace-clean protocols. ?14PBDE concentrations in the Polar Mixed Layer (PML; a surface water mass) range from 0.3 to 11.2 pg·L(-1), with higher concentrations in the pan-Arctic shelf seas and lower levels in the interior basin. BDE-209 is the dominant congener in most of the pan-Arctic areas except for the ones close to North America, where penta-BDE and tetra-BDE congeners predominate. In deep-water masses, ?14PBDE concentrations are up to one order of magnitude higher than in the PML. Whereas BDE-209 decreases with depth, the less-brominated congeners, particularly BDE-47 and BDE-99, increase down through the water column. Likewise, concentrations of BDE-71 -a congener not present in any PBDE commercial mixture- increase with depth, which potentially is the result of debromination of BDE-209. The inventories in the three water masses of the Central Arctic Basin (PML, intermediate Atlantic Water Layer, and the Arctic Deep Water Layer) are 158±77 kg, 6320±235 kg and 30800±3100 kg, respectively. The total load of PBDEs in the entire Arctic Ocean shows that only a minor fraction of PBDEs emissions are transported to the Arctic Ocean. These findings represent the first PBDE data in the deep-water compartments of an ocean.
PubMed ID
26840066 View in PubMed
Less detail

Observed and Modeled Black Carbon Deposition and Sources in the Western Russian Arctic 1800-2014.

https://arctichealth.org/en/permalink/ahliterature311909
Source
Environ Sci Technol. 2021 04 20; 55(8):4368-4377
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
04-20-2021
Author
Meri M Ruppel
Sabine Eckhardt
Antto Pesonen
Kenichiro Mizohata
Markku J Oinonen
Andreas Stohl
August Andersson
Vivienne Jones
Sirkku Manninen
Örjan Gustafsson
Author Affiliation
Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, FI-00014 Helsinki, Finland.
Source
Environ Sci Technol. 2021 04 20; 55(8):4368-4377
Date
04-20-2021
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Air Pollutants - analysis
Arctic Regions
Carbon - analysis
Environmental monitoring
Russia
Soot - analysis
Abstract
Black carbon (BC) particles contribute to climate warming by heating the atmosphere and reducing the albedo of snow/ice surfaces. The available Arctic BC deposition records are restricted to the Atlantic and North American sectors, for which previous studies suggest considerable spatial differences in trends. Here, we present first long-term BC deposition and radiocarbon-based source apportionment data from Russia using four lake sediment records from western Arctic Russia, a region influenced by BC emissions from oil and gas production. The records consistently indicate increasing BC fluxes between 1800 and 2014. The radiocarbon analyses suggest mainly (~70%) biomass sources for BC with fossil fuel contributions peaking around 1960-1990. Backward calculations with the atmospheric transport model FLEXPART show emission source areas and indicate that modeled BC deposition between 1900 and 1999 is largely driven by emission trends. Comparison of observed and modeled data suggests the need to update anthropogenic BC emission inventories for Russia, as these seem to underestimate Russian BC emissions and since 1980s potentially inaccurately portray their trend. Additionally, the observations may indicate underestimation of wildfire emissions in inventories. Reliable information on BC deposition trends and sources is essential for design of efficient and effective policies to limit climate warming.
PubMed ID
33769801 View in PubMed
Less detail

Observed and Modeled Black Carbon Deposition and Sources in the Western Russian Arctic 1800-2014.

https://arctichealth.org/en/permalink/ahliterature311082
Source
Environ Sci Technol. 2021 Apr 20; 55(8):4368-4377
Publication Type
Journal Article
Date
Apr-20-2021
Author
Meri M Ruppel
Sabine Eckhardt
Antto Pesonen
Kenichiro Mizohata
Markku J Oinonen
Andreas Stohl
August Andersson
Vivienne Jones
Sirkku Manninen
Örjan Gustafsson
Author Affiliation
Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, FI-00014 Helsinki, Finland.
Source
Environ Sci Technol. 2021 Apr 20; 55(8):4368-4377
Date
Apr-20-2021
Language
English
Publication Type
Journal Article
Abstract
Black carbon (BC) particles contribute to climate warming by heating the atmosphere and reducing the albedo of snow/ice surfaces. The available Arctic BC deposition records are restricted to the Atlantic and North American sectors, for which previous studies suggest considerable spatial differences in trends. Here, we present first long-term BC deposition and radiocarbon-based source apportionment data from Russia using four lake sediment records from western Arctic Russia, a region influenced by BC emissions from oil and gas production. The records consistently indicate increasing BC fluxes between 1800 and 2014. The radiocarbon analyses suggest mainly (~70%) biomass sources for BC with fossil fuel contributions peaking around 1960-1990. Backward calculations with the atmospheric transport model FLEXPART show emission source areas and indicate that modeled BC deposition between 1900 and 1999 is largely driven by emission trends. Comparison of observed and modeled data suggests the need to update anthropogenic BC emission inventories for Russia, as these seem to underestimate Russian BC emissions and since 1980s potentially inaccurately portray their trend. Additionally, the observations may indicate underestimation of wildfire emissions in inventories. Reliable information on BC deposition trends and sources is essential for design of efficient and effective policies to limit climate warming.
PubMed ID
33769801 View in PubMed
Less detail

Quantifying Degradative Loss of Terrigenous Organic Carbon in Surface Sediments Across the Laptev and East Siberian Sea.

https://arctichealth.org/en/permalink/ahliterature299552
Source
Global Biogeochem Cycles. 2019 Jan; 33(1):85-99
Publication Type
Journal Article
Date
Jan-2019
Author
Lisa Bröder
August Andersson
Tommaso Tesi
Igor Semiletov
Örjan Gustafsson
Author Affiliation
Department of Environmental Science and Analytical Chemistry Stockholm University Stockholm Sweden.
Source
Global Biogeochem Cycles. 2019 Jan; 33(1):85-99
Date
Jan-2019
Language
English
Publication Type
Journal Article
Abstract
Ongoing permafrost thaw in the Arctic may remobilize large amounts of old organic matter. Upon transport to the Siberian shelf seas, this material may be degraded and released to the atmosphere, exported off-shelf, or buried in the sediments. While our understanding of the fate of permafrost-derived organic matter in shelf waters is improving, poor constraints remain regarding degradation in sediments. Here we use an extensive data set of organic carbon concentrations and isotopes (n = 109) to inventory terrigenous organic carbon (terrOC) in surficial sediments of the Laptev and East Siberian Seas (LS + ESS). Of these ~2.7 Tg terrOC about 55% appear resistant to degradation on a millennial timescale. A first-order degradation rate constant of 1.5 kyr-1 is derived by combining a previously established relationship between water depth and cross-shelf sediment-terrOC transport time with mineral-associated terrOC loadings. This yields a terrOC degradation flux of ~1.7 Gg/year from surficial sediments during cross-shelf transport, which is orders of magnitude lower than earlier estimates for degradation fluxes of dissolved and particulate terrOC in the water column of the LS + ESS. The difference is mainly due to the low degradation rate constant of sedimentary terrOC, likely caused by a combination of factors: (i) the lower availability of oxygen in the sediments compared to fully oxygenated waters, (ii) the stabilizing role of terrOC-mineral associations, and (iii) the higher proportion of material that is intrinsically recalcitrant due to its chemical/molecular structure in sediments. Sequestration of permafrost-released terrOC in shelf sediments may thereby attenuate the otherwise expected permafrost carbon-climate feedback.
PubMed ID
31007382 View in PubMed
Less detail

17 records – page 1 of 2.