scholarly journals Rivers across the Siberian Arctic unearth the patterns of carbon release from thawing permafrost

2019 ◽  
Vol 116 (21) ◽  
pp. 10280-10285 ◽  
Author(s):  
Birgit Wild ◽  
August Andersson ◽  
Lisa Bröder ◽  
Jorien Vonk ◽  
Gustaf Hugelius ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Large Scale ◽  
Temporal Dynamics ◽  
High Temporal Resolution ◽  
Drainage Basins ◽  
Discontinuous Permafrost ◽  
Spatial And Temporal Dynamics ◽  
Siberian Arctic ◽  
Carbon Release ◽  
Thawing Permafrost

Climate warming is expected to mobilize northern permafrost and peat organic carbon (PP-C), yet magnitudes and system specifics of even current releases are poorly constrained. While part of the PP-C will degrade at point of thaw to CO2 and CH4 to directly amplify global warming, another part will enter the fluvial network, potentially providing a window to observe large-scale PP-C remobilization patterns. Here, we employ a decade-long, high-temporal resolution record of 14C in dissolved and particulate organic carbon (DOC and POC, respectively) to deconvolute PP-C release in the large drainage basins of rivers across Siberia: Ob, Yenisey, Lena, and Kolyma. The 14C-constrained estimate of export specifically from PP-C corresponds to only 17 ± 8% of total fluvial organic carbon and serves as a benchmark for monitoring changes to fluvial PP-C remobilization in a warming Arctic. Whereas DOC was dominated by recent organic carbon and poorly traced PP-C (12 ± 8%), POC carried a much stronger signature of PP-C (63 ± 10%) and represents the best window to detect spatial and temporal dynamics of PP-C release. Distinct seasonal patterns suggest that while DOC primarily stems from gradual leaching of surface soils, POC reflects abrupt collapse of deeper deposits. Higher dissolved PP-C export by Ob and Yenisey aligns with discontinuous permafrost that facilitates leaching, whereas higher particulate PP-C export by Lena and Kolyma likely echoes the thermokarst-induced collapse of Pleistocene deposits. Quantitative 14C-based fingerprinting of fluvial organic carbon thus provides an opportunity to elucidate large-scale dynamics of PP-C remobilization in response to Arctic warming.

Large-scale spatial and temporal dynamics of the vulnerable and highly mobile superb parrot

2007 ◽  
Vol 34 (2) ◽  
pp. 289-304 ◽  
Author(s):  
Adrian D. Manning ◽  
David B. Lindenmayer ◽  
Simon C. Barry ◽  
Henry A. Nix
Keyword(s):  
Large Scale ◽  
Temporal Dynamics ◽  
Spatial And Temporal Dynamics

scholarly journals Contrasting composition of terrigenous organic matter in the dissolved, particulate and sedimentary organic carbon pools on the outer East Siberian Arctic Shelf

2016 ◽  
Author(s):  
Joan A. Salvadó ◽  
Tommaso Tesi ◽  
Marcus Sundbom ◽  
Emma Karlsson ◽  
Martin Kruså ◽  
...  
Keyword(s):  
Organic Carbon ◽  
River Plume ◽  
Outer Shelf ◽  
Carbon Pools ◽  
Laptev Sea ◽  
Lena River ◽  
Lignin Phenols ◽  
East Siberian Sea ◽  
Siberian Arctic ◽  
Thawing Permafrost

Abstract. Fluvial discharge and coastal erosion of the permafrost-dominated East Siberian Arctic delivers large quantities of terrigenous organic carbon (Terr-OC) to marine waters. The composition and fate of the remobilized Terr-OC needs to be better constrained as it impacts the potential for a climate-carbon feedback. In the present study, the bulk isotope (δ13C and Δ14C) and macromolecular (lignin-derived phenols) composition of the cross-shelf exported organic carbon (OC) in different marine pools is evaluated. For this purpose, as part of the SWERUS-C3 expedition (July–September 2014), sediment organic carbon (SOC) as well as water column (from surface and near-bottom seawater) dissolved organic carbon (DOC) and particulate organic carbon (POC) samples were collected along the outer shelves of the Kara Sea, Laptev Sea and East Siberian Sea. The results show that the Lena River and the DOC have a preferential role in the transport of Terr-OC to the outer shelf. DOC concentrations (740–3600 μg L−1) were one order of magnitude higher than POC (20–360 μg L−1), with higher concentrations towards to the Lena River plume. Depleted δ13C, modern Δ14C and lignin phenols concentrations were all well correlated with DOC levels indicating a relatively young terrestrial contribution. In contrast, POC may have a preferential marine origin, as its concentrations were not correlated with isotope and terrestrial biomarker proxies. The δ13C signatures in the three carbon pools varied from −23.9 ± 1.9 ‰ in the SOC, −26.1 ± 1.2 ‰ in the DOC and −27.1 ± 1.9 ‰ in the POC. The Δ14C values ranged between −395 ± 83 ‰ (SOC), −226 ± 92 ‰ (DOC) and −113 ± 122 ‰ (POC). These stable and radiocarbon isotopes were also different between the Laptev Sea and the East Siberian Sea. Both DOC and POC showed a depleted and younger trend off the Lena River plume. The older and more enriched δ13C signatures in the outer-shelf of the ESS suggest instead a greater influence of the sea ice coverage and the Pacific inflow from the east. Lignin phenols exhibited higher OC-normalized concentration in the SOC (0.10–2.34 mg g−1 OC) and DOC (0.08–2.40 mg g−1 OC) than in the POC (0.03–1.14 mg g−1 OC). The good relationship between lignin and Δ14C signatures in the DOC suggests that a significant fraction of the outer-shelf DOC comes from ''young'' Terr-OC. By contrast, the slightly negative correlation between lignin phenols and Δ14C signatures in POC, with higher lignin concentrations in older POC from near-bottom waters, may reflect the off-shelf transport of OC from remobilized permafrost in the nepheloid layer. Moreover, syringyl/vanillyl and cinnamyl/vannillyl phenols ratios presented distinct clustering between DOC, POC and SOC, suggesting that those pools are carrying different Terr-OC of partially different origin. Finally, 3,5-dihydroxybenzoic acid to vanillyl phenols ratios and p-coumaric acid to ferulic acid ratios, used as a diagenetic indicators, enhanced in POC and SOC. This suggests that the remobilized old OC from thawing permafrost, which is mainly transported within these pools, could experience less burial and more mineralization than believed earlier. Overall, DOC is strongly affected by the Lena River plume transporting young Terr-OC from topsoil and/or recently produced vascular pant material, while near-bottom POC and SOC preferentially carries off-shelf old OC released from thawing permafrost.

scholarly journals Organic carbon characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, West-Alaska

2018 ◽  
Author(s):  
Loeka L. Jongejans ◽  
Jens Strauss ◽  
Josefine Lenz ◽  
Francien Peterse ◽  
Kai Mangelsdorf ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Lake Sediments ◽  
Lake Basin ◽  
Study Region ◽  
Thermokarst Lake ◽  
Discontinuous Permafrost ◽  
Lipid Biomarker ◽  
Biomarker Analysis ◽  
Thawing Permafrost

Abstract. As Arctic warming continues and permafrost thaws, more soil and sedimentary organic carbon (OC) will be decomposed in northern high latitudes. Still, uncertainties remain in the quantity and quality of OC stored in different deposit types of permafrost landscapes. This study presents OC data from deep permafrost and lake deposits on the Baldwin Peninsula which is located in the southern portion of the continuous permafrost zone in West Alaska. Sediment samples from yedoma and drained thermokarst lake basin (DTLB) deposits as well as thermokarst lake sediments were analyzed for cryostratigraphical and biogeochemical parameters and their lipid biomarker composition to identify the size and quality of belowground OC pools in ice-rich permafrost on Baldwin Peninsula. We provide the first detailed characterization of yedoma deposits on Baldwin Peninsula. We show that three quarters of soil organic carbon in the frozen deposits of the study region (total of 68 Mt) is stored in DTLB deposits (52 Mt) and one quarter in the frozen yedoma deposits (16 Mt). The lake sediments contain a relatively small OC pool (4 Mt), but have the highest volumetric OC content (93 kg/m3) compared to the DTLB (35 kg/m3) and yedoma deposits (8 kg/m3), largely due to differences in the ground ice content. The biomarker analysis indicates that the OC in both yedoma and DTLB deposits is mainly of terrestrial origin. Nevertheless, the relatively high carbon preference index of plant leaf waxes in combination with a lack of degradation trend with depth in the yedoma deposits indicates that OC stored in yedoma is less degraded than that stored in DTLB deposits. This suggests that OC in yedoma has a higher potential for decomposition upon thaw, despite the relatively small size of this pool. These findings highlight the importance of molecular OC analysis for determining the potential future greenhouse gas emissions from thawing permafrost, especially because this area close to the discontinuous permafrost boundary is projected to thaw substantially within the 21st century.

Spatial and temporal dynamics of Siberian silk moth large-scale outbreak in dark-needle coniferous tree stands in Altai

2016 ◽  
Vol 9 (6) ◽  
pp. 711-720 ◽  
Author(s):  
V. I. Kharuk ◽  
D. A. Demidko ◽  
E. V. Fedotova ◽  
M. L. Dvinskaya ◽  
U. A. Budnik
Keyword(s):  
Large Scale ◽  
Temporal Dynamics ◽  
Coniferous Tree ◽  
Silk Moth ◽  
Spatial And Temporal Dynamics ◽  
Siberian Silk Moth

Natural and Anthropogenic Drivers of Acidification in Large Estuaries

2021 ◽  
Vol 13 (1) ◽  
pp. 23-55 ◽  
Author(s):  
Wei-Jun Cai ◽  
Richard A. Feely ◽  
Jeremy M. Testa ◽  
Ming Li ◽  
Wiley Evans ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Large Scale ◽  
Coastal Upwelling ◽  
Temporal Dynamics ◽  
Anaerobic Respiration ◽  
Weak Acid ◽  
Ecosystem Functions ◽  
Acid Base ◽  
Fisheries Resources ◽  
Spatial And Temporal Dynamics

Oceanic uptake of anthropogenic carbon dioxide (CO2) from the atmosphere has changed ocean biogeochemistry and threatened the health of organisms through a process known as ocean acidification (OA). Such large-scale changes affect ecosystem functions and can have impacts on societal uses, fisheries resources, and economies. In many large estuaries, anthropogenic CO2-induced acidification is enhanced by strong stratification, long water residence times, eutrophication, and a weak acid–base buffer capacity. In this article, we review how a variety of processes influence aquatic acid–base properties in estuarine waters, including coastal upwelling, river–ocean mixing, air–water gas exchange, biological production and subsequent aerobic and anaerobic respiration, calcium carbonate (CaCO3) dissolution, and benthic inputs. We emphasize the spatial and temporal dynamics of partial pressure of CO2 ( pCO2), pH, and calcium carbonate mineral saturation states. Examples from three large estuaries—Chesapeake Bay, the Salish Sea, and Prince William Sound—are used to illustrate how natural and anthropogenic processes and climate change may manifest differently across estuaries, as well as the biological implications of OA on coastal calcifiers.

scholarly journals The Reservoir Age Effect Varies With the Mobilization of Pre-Aged Organic Carbon in a High-Altitude Central Asian Catchment

2021 ◽  
Vol 9 ◽  
Author(s):  
Natalie Schroeter ◽  
Jens Mingram ◽  
Julia Kalanke ◽  
Stefan Lauterbach ◽  
Rik Tjallingii ◽  
...  
Keyword(s):  
Organic Carbon ◽  
High Altitude ◽  
Temporal Dynamics ◽  
Temporal Variations ◽  
Age Effect ◽  
Short Chain ◽  
High Temporal Resolution ◽  
Preparative Gas Chromatography ◽  
Reservoir Age ◽  
Long Chain

Lake sediments provide excellent archives to study past environmental and hydrological changes at high temporal resolution. However, their utility is often restricted by chronological uncertainties due to the “reservoir age effect” (RAE), a phenomenon that results in anomalously old radiocarbon ages of total organic carbon (TOC) samples that is mainly attributed to the contribution of pre-aged carbon from aquatic organisms. Although the RAE is a well-known problem especially in high altitude lakes, detailed studies analyzing the temporal variations in the contribution of terrestrial and aquatic organic carbon (OC) on the RAE are scarce. This is partially due to the complexity of isolating individual compounds for subsequent compound-specific radiocarbon analysis (CSRA). We developed a rapid method for isolating individual short-chain (C16 and C18) and long-chain (>C24) saturated fatty acid methyl esters (FAMEs) by using high-pressure liquid chromatography (HPLC). Our method introduces only minor contaminations (0.50 ± 0.22 µg dead carbon on average) and requires only few injections (≤10), therefore offering clear advantages over traditional preparative gas chromatography (prep-GC). Here we show that radiocarbon values (Δ14C) of long-chain FAs, which originate from terrestrial higher plant waxes, reflect carbon from a substantially pre-aged OC reservoir, whereas the Δ14C of short-chain FAs that originate from aquatic sources were generally less pre-aged. 14C ages obtained from the long-chain FAs are in closer agreement with 14C ages of the corresponding bulk TOC fraction, indicating a high control of pre-aged terrestrial OC input from the catchment on TOC-derived 14C ages. Variations in the age offset between terrestrial and aquatic biomarkers are related to changes in bulk sediment log(Ti/K) that reflect variations in detrital input from the catchment. Our results indicate that the chronological offset between terrestrial and aquatic OC in this high-altitude catchment is mainly driven by temporal variations in the mobilization of pre-aged OC from the catchment. In conclusion, to obtain accurate and process-specific lake sediment chronologies, attention must be given to the temporal dynamics of the RAE. Variations in the apparent ages of aquatic and terrestrial contributions to the sediment and their mass balance can substantially alter the reservoir age effect.

Transport of Dissolved Organic Carbon, Nutrients, and Trace Metals from the Wilson and Blossom Rivers to Smeaton Bay, Southeast Alaska

1984 ◽  
Vol 41 (1) ◽  
pp. 180-190 ◽  
Author(s):  
Susan F. Sugai ◽  
David C. Burrell
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Large Scale ◽  
Nutrient Export ◽  
Drainage Basins ◽  
Southeast Alaska ◽  
Scale Removal ◽  
Reducing Conditions ◽  
Fe And Mn ◽  
Topographical Relief

Regional and seasonal differences in chemical input from the Wilson and Blossom rivers, two pristine, major salmon-producing rivers in southeast Alaska, were examined. For a period of 2 yr, concentrations of dissolved organic carbon, nutrients, Cu, Fe, and Mn in the rivers were determined at approximately monthly intervals and used to calculate export rates. Because of extremely high annual precipitation (400–450 cm) and drainage basins restricted by high topographical relief, the concentrations and export rates of nutrients and Cu are low in the rivers for most of the year. The maximum nutrient export from the Wilson–Blossom system appears to be closely tied to the annual salmon cycle. Iron and Mn export rates from the watersheds are much higher than those for Cu, reflecting solubilization of Fe and Mn under reducing conditions that develop in muskeg ponds during drought periods. The association of metals with organics allows transport of Fe and possibly other metals throughout the fjord system, in contrast with the large-scale removal of metals in or near the river's mouth, as has been observed elsewhere.

scholarly journals Remobilization of dormant carbon from Siberian-Arctic permafrost during three past warming events

2020 ◽  
Vol 6 (42) ◽  
pp. eabb6546
Author(s):  
Jannik Martens ◽  
Birgit Wild ◽  
Francesco Muschitiello ◽  
Matt O’Regan ◽  
Martin Jakobsson ◽  
...  
Keyword(s):  
Large Scale ◽  
Ice Cores ◽  
Early Holocene ◽  
The Arctic ◽  
Last Deglaciation ◽  
Siberian Arctic ◽  
Carbon Release ◽  
Order Of Magnitude ◽  
Global Sea Level ◽  
Carbon Remobilization

Carbon cycle models suggest that past warming events in the Arctic may have caused large-scale permafrost thaw and carbon remobilization, thus affecting atmospheric CO2 levels. However, observational records are sparse, preventing spatially extensive and time-continuous reconstructions of permafrost carbon release during the late Pleistocene and early Holocene. Using carbon isotopes and biomarkers, we demonstrate that the three most recent warming events recorded in Greenland ice cores—(i) Dansgaard-Oeschger event 3 (~28 ka B.P.), (ii) Bølling-Allerød (14.7 to 12.9 ka B.P.), and (iii) early Holocene (~11.7 ka B.P.)—caused massive remobilization and carbon degradation from permafrost across northeast Siberia. This amplified permafrost carbon release by one order of magnitude, particularly during the last deglaciation when global sea-level rise caused rapid flooding of the land area thereafter constituting the vast East Siberian Arctic Shelf. Demonstration of past warming-induced release of permafrost carbon provides a benchmark for the sensitivity of these large carbon pools to changing climate.

Effects of a Forested State Park on Suspended Solid and Dissolved Organic Carbon Concentrations in an Agriculturally Impacted Watershed

2021 ◽  
Author(s):  
Eileen Rintsch ◽  
Tessa Farthing ◽  
Bartosz Grudzinski
Keyword(s):  
Water Quality ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Agricultural Land ◽  
Temporal Dynamics ◽  
Suspended Solid ◽  
Spatial And Temporal Dynamics ◽  
Agricultural Areas ◽  
Work Done ◽  
Carbon Concentrations

<p>Previous research has indicated that agricultural land use can reduce water quality in streams. This includes: 1) an increase in suspended solids (SS) due to elevated erosion and 2) shifts in dissolved organic carbon (DOC) particularly due to different C:N between agricultural crops and natural vegetation. We examine spatial and temporal dynamics of SS and DOC in four rivers, located in an agriculturally impacted watershed in SW Ohio, as they flow from agricultural land cover through a naturally forested State Park. Nineteen surface water sites were sampled bimonthly from December 2019 to December 2020. Results will be presented to determine if a forested state park improved the water quality in SW Ohio. We will further discuss how the work done in SW Ohio could be replicated in other intensive agricultural areas of Europe with similar climate patterns.</p>

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