scholarly journals Impact of a decreasing sea ice cover on the vertical export of particulate organic carbon in the northern Laptev Sea, Siberian Arctic Ocean

2009 ◽  
Vol 36 (21) ◽  
Author(s):  
Catherine Lalande ◽  
Simon Bélanger ◽  
Louis Fortier
Keyword(s):  
Organic Carbon ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Particulate Organic Carbon ◽  
Ice Cover ◽  
Laptev Sea ◽  
Siberian Arctic ◽  
Vertical Export

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 ◽  
Vol 13 (22) ◽  
pp. 6121-6138 ◽  
Author(s):  
Joan A. Salvadó ◽  
Tommaso Tesi ◽  
Marcus Sundbom ◽  
Emma Karlsson ◽  
Martin Kruså ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Sea Ice ◽  
River Plume ◽  
Outer Shelf ◽  
Carbon Pools ◽  
Laptev Sea ◽  
Lena River ◽  
Lignin Phenols ◽  
East Siberian Sea ◽  
Siberian Arctic

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 may have a preferential role in the transport of Terr-OC to the outer shelf. DOC concentrations (740–3600 µg L−1) were 1 order of magnitude higher than POC (20–360 µg L−1), with higher concentrations towards the Lena River plume. 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. Further, the Pacific inflow and the sea-ice coverage, which works as a barrier preventing the input of “young” DOC and POC, seem to have a strong influence in these carbon pools, presenting older and more enriched δ13C signatures under the sea-ice extent. Lignin phenols exhibited higher OC-normalized concentrations 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. Syringyl ∕ vanillyl and cinnamyl ∕ vannillyl phenol ratios presented distinct clustering between DOC, POC and SOC, implying that those pools may be carrying different Terr-OC of partially different origin. Moreover, 3,5-dihydroxybenzoic acid to vanillyl phenol ratios and p-coumaric acid to ferulic acid ratios, used as a diagenetic indicators, enhanced in POC and SOC, suggesting more degradation within these pools. Overall, the key contrast between enhanced lignin yields both in the youngest DOC and the oldest POC samples reflects a significant decoupling of terrestrial OC sources and pathways.

scholarly journals Contrasting trends in sea ice and primary production in the Bering Sea and Arctic Ocean

2012 ◽  
Vol 69 (7) ◽  
pp. 1180-1193 ◽  
Author(s):  
Zachary W. Brown ◽  
Kevin R. Arrigo
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Arctic Ocean ◽  
Bering Sea ◽  
Net Primary Productivity ◽  
Remote Sensing Data ◽  
Ice Cover ◽  
The Arctic ◽  
Light Limitation ◽  
The Bering Sea

Abstract Brown, Z. W., and Arrigo, K. R. 2012. Contrasting trends in sea ice and primary production in the Bering Sea and Arctic Ocean. – ICES Journal of Marine Science, 69: . Satellite remote sensing data were used to examine recent trends in sea-ice cover and net primary productivity (NPP) in the Bering Sea and Arctic Ocean. In nearly all regions, diminished sea-ice cover significantly enhanced annual NPP, indicating that light-limitation predominates across the seasonally ice-covered waters of the northern hemisphere. However, long-term trends have not been uniform spatially. The seasonal ice pack of the Bering Sea has remained consistent over time, partially because of winter winds that have continued to carry frigid Arctic air southwards over the past six decades. Hence, apart from the “Arctic-like” Chirikov Basin (where sea-ice loss has driven a 30% increase in NPP), no secular trends are evident in Bering Sea NPP, which averaged 288 ± 26 Tg C year−1 over the satellite ocean colour record (1998–2009). Conversely, sea-ice cover in the Arctic Ocean has plummeted, extending the open-water growing season by 45 d in just 12 years, and promoting a 20% increase in NPP (range 441–585 Tg C year−1). Future sea-ice loss will likely stimulate additional NPP over the productive Bering Sea shelves, potentially reducing nutrient flux to the downstream western Arctic Ocean.

Increasing Multiyear Sea Ice Loss in the Beaufort Sea: A New Export Pathway for the Diminishing Multiyear Ice Cover of the Arctic Ocean

2021 ◽  
Author(s):  
David Gareth Babb ◽  
Ryan J. Galley ◽  
Stephen E. L. Howell ◽  
Jack Christopher Landy ◽  
Julienne Christine Stroeve ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Beaufort Sea ◽  
Ice Cover ◽  
The Arctic ◽  
Export Pathway ◽  
The Arctic Ocean ◽  
Multiyear Ice

scholarly journals Distribution, fluxes and balance of particulate organic carbon in the Arctic ocean

2019 ◽  
Vol 59 (4) ◽  
pp. 544-552
Author(s):  
A. A. Vetrov ◽  
E. A. Romankevich
Keyword(s):  
Organic Carbon ◽  
Arctic Ocean ◽  
Particulate Organic Carbon ◽  
The Arctic ◽  
Climate Data ◽  
Arctic Seas ◽  
The Pacific ◽  
The Arctic Ocean ◽  
Main Component ◽  
Depth Horizon

Particulate organic carbon (POC) is one of main component of carbon cycle in the Ocean. In this study an attempt to construct a picture of the distribution and fluxes of POC in the Arctic Ocean adjusting for interchange with the Pacific and Atlantic Oceans has been made. The specificity of this construction is associated with an irregular distribution of POC measurements and complicated structure and hydrodynamics of the waters masses. To overcome these difficulties, Multiple Linear Regression technic (MLR) was performed to test the significant relation between POC, temperature, salinity, as well depth, horizon, latitude and offshore distance. The mapping of POC distribution and its fluxes was carrying out at 38 horizons from 5 to 4150 m (resolution 1°×1°). Data on temperature, salinity, meridional and zonal components of current velocities were obtained from ORA S4 database (Integrated Climate Data Center, http://icdc.cen.uni-hamburg.de/las). The import-export of POC between the Arctic, Atlantic and Pacific Oceans as well as between Arctic Seas was precomputed by summer fluxes. The import of POC in the Arctic Ocean is estimated to be 38±8Tg Cyr-1, and the export is -9.5±4.4Tg Cyr-1.

scholarly journals On the biogeochemical signature of the Lena River from its headwaters to the Arctic Ocean

2011 ◽  
Vol 8 (2) ◽  
pp. 2093-2143 ◽  
Author(s):  
I. P. Semiletov ◽  
I. I. Pipko ◽  
N. E. Shakhova ◽  
O. V. Dudarev ◽  
S. P. Pugach ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Arctic Ocean ◽  
River Discharge ◽  
Total Carbon ◽  
The Arctic ◽  
Time Shift ◽  
Laptev Sea ◽  
Lena River ◽  
The Arctic Ocean ◽  
The Laptev Sea

Abstract. The Lena River integrates biogeochemical signals from its vast drainage basin and its signal reaches far out over the Arctic Ocean. Transformation of riverine organic carbon into mineral carbon, and mineral carbon into the organic form in the Lena River watershed, can be considered a quasi-equilibrated processes. Increasing the Lena discharge causes opposite effects on total organic (TOC) and inorganic (TCO2) carbon: TOC concentration increases, while TCO2 concentration decreases. Significant inter-annual variability in mean values of TCO2, TOC, and their sum (TC) has been found. This variability is determined by changes in land hydrology which cause differences in the Lena River discharge, because a negative correlation may be found between TC in September and mean discharge in August (a time shift of about one month is required for water to travel from Yakutsk to the Laptev Sea). Total carbon entering the sea with the Lena discharge is estimated to be almost 10 Tg C y−1. The annual Lena River discharge of particulate organic carbon (POC) may be equal to 0.38 Tg (moderate to high estimate). If we instead accept Lisytsin's (1994) statement concerning the precipitation of 85–95% of total particulate matter (PM) (and POC) on the marginal "filter", then only about 0.03–0.04 Tg of POC reaches the Laptev Sea from the Lena River. The Lena's POC export would then be two orders of magnitude less than the annual input of eroded terrestrial carbon onto the shelf of the Laptev and East Siberian seas, which is about 4 Tg. The Lena River is characterized by relatively high concentrations of primary greenhouse gases: CO2 and dissolved CH4. During all seasons the river is supersaturated in CO2 compared to the atmosphere: up to 1.5–2 fold in summer, and 4–5 fold in winter. This results in a narrow zone of significant CO2 supersaturation in the adjacent coastal sea. Spots of dissolved CH4 in the Lena delta channels may reach 100 nM, but the CH4 concentration decreases to 5–20 nM towards the sea, which suggests only a minor role of riverborne export of CH4 for the East Siberian Arctic Shelf (ESAS) CH4 budget in coastal waters. Instead, the seabed appears to be the source that provides most of the CH4 to the Arctic Ocean.

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