Distribution of Dissolved Inorganic and Organic Carbon in the Eurasian Basin Of The Arctic Ocean

Planktic foraminifera and shelled pteropods are some of the major producers of calcium carbonate (CaCO3) in the ocean. Their calcitic (foraminifera) and aragonitic (pteropods) shells are particularly sensitive to changes in the carbonate chemistry and play an important role for the inorganic and organic carbon pump of the ocean. Here, we have studied the abundance distribution of planktic foraminifera and pteropods (individuals m–3) and their contribution to the inorganic and organic carbon standing stocks (μg m–3) and export production (mg m–2 day–1) along a longitudinal transect north of Svalbard at 81° N, 22–32° E, in the Arctic Ocean. This transect, sampled in September 2018 consists of seven stations covering different oceanographic regimes, from the shelf to the slope and into the deep Nansen Basin. The sea surface temperature ranged between 1 and 5°C in the upper 300 m. Conditions were supersaturated with respect to CaCO3 (Ω > 1 for both calcite and aragonite). The abundance of planktic foraminifera ranged from 2.3 to 52.6 ind m–3 and pteropods from 0.1 to 21.3 ind m–3. The planktic foraminiferal population was composed mainly of the polar species Neogloboquadrina pachyderma (55.9%) and the subpolar species Turborotalita quinqueloba (21.7%), Neogloboquadrina incompta (13.5%) and Globigerina bulloides (5.2%). The pteropod population was dominated by the polar species Limacina helicina (99.6%). The rather high abundance of subpolar foraminiferal species is likely connected to the West Spitsbergen Current bringing warm Atlantic water to the study area. Pteropods dominated at the surface and subsurface. Below 100 m water depth, foraminifera predominated. Pteropods contribute 66–96% to the inorganic carbon standing stocks compared to 4–34% by the planktic foraminifera. The inorganic export production of planktic foraminifera and pteropods together exceeds their organic contribution by a factor of 3. The overall predominance of pteropods over foraminifera in this high Arctic region during the sampling period suggest that inorganic standing stocks and export production of biogenic carbonate would be reduced under the effects of ocean acidification.

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Nutrients, organic carbon and organic nitrogen in the upper water column of the Arctic Ocean: implications for the sources of dissolved organic carbon

Deep Sea Research Part II Topical Studies in Oceanography ◽

10.1016/s0967-0645(97)00051-9 ◽

1997 ◽

Vol 44 (8) ◽

pp. 1571-1592 ◽

Cited By ~ 118

Author(s):

P.A. Wheeler ◽

J.M. Watkins ◽

R.L. Hansing

Keyword(s):

Organic Carbon ◽

Dissolved Organic Carbon ◽

Arctic Ocean ◽

Water Column ◽

Organic Nitrogen ◽

The Arctic ◽

The Arctic Ocean

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Organic carbon burial rates across the Arctic Ocean from the 1994 Arctic Ocean Section expedition

Deep Sea Research Part II Topical Studies in Oceanography ◽

10.1016/s0967-0645(97)00065-9 ◽

1997 ◽

Vol 44 (8) ◽

pp. 1705-1723 ◽

Cited By ~ 11

Author(s):

Ray E. Cranston

Keyword(s):

Organic Carbon ◽

Arctic Ocean ◽

The Arctic ◽

Carbon Burial ◽

Organic Carbon Burial ◽

The Arctic Ocean ◽

Burial Rates

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Recent Sea Ice Decline Did Not Significantly Increase the Total Liquid Freshwater Content of the Arctic Ocean

Journal of Climate ◽

10.1175/jcli-d-18-0237.1 ◽

2018 ◽

Vol 32 (1) ◽

pp. 15-32 ◽

Cited By ~ 11

Author(s):

Qiang Wang ◽

Claudia Wekerle ◽

Sergey Danilov ◽

Dmitry Sidorenko ◽

Nikolay Koldunov ◽

...

Keyword(s):

Spatial Distribution ◽

Sea Ice ◽

Arctic Ocean ◽

Ocean Circulation ◽

General Circulation ◽

The Arctic ◽

Sea Ice Decline ◽

The Arctic Ocean ◽

Eurasian Basin ◽

The Impact

Abstract The freshwater stored in the Arctic Ocean is an important component of the global climate system. Currently the Arctic liquid freshwater content (FWC) has reached a record high since the beginning of the last century. In this study we use numerical simulations to investigate the impact of sea ice decline on the Arctic liquid FWC and its spatial distribution. The global unstructured-mesh ocean general circulation model Finite Element Sea Ice–Ocean Model (FESOM) with 4.5-km horizontal resolution in the Arctic region is applied. The simulations show that sea ice decline increases the FWC by freshening the ocean through sea ice meltwater and modifies upper ocean circulation at the same time. The two effects together significantly increase the freshwater stored in the Amerasian basin and reduce its amount in the Eurasian basin. The salinification of the upper Eurasian basin is mainly caused by the reduction in the proportion of Pacific Water and the increase in that of Atlantic Water (AW). Consequently, the sea ice decline did not significantly contribute to the observed rapid increase in the Arctic total liquid FWC. However, the changes in the Arctic freshwater spatial distribution indicate that the influence of sea ice decline on the ocean environment is remarkable. Sea ice decline increases the amount of Barents Sea branch AW in the upper Arctic Ocean, thus reducing its supply to the deeper Arctic layers. This study suggests that all the dynamical processes sensitive to sea ice decline should be taken into account when understanding and predicting Arctic changes.

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

Океанология ◽

10.31857/s0030-1574594544-552 ◽

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.

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

Biogeosciences Discussions ◽

10.5194/bgd-8-2093-2011 ◽

2011 ◽

Vol 8 (2) ◽

pp. 2093-2143 ◽

Cited By ~ 6

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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A 50 % increase in the mass of terrestrial particles delivered by the Mackenzie River into the Beaufort Sea (Canadian Arctic Ocean) over the last 10 years

Biogeosciences ◽

10.5194/bg-12-3551-2015 ◽

2015 ◽

Vol 12 (11) ◽

pp. 3551-3565 ◽

Cited By ~ 28

Author(s):

D. Doxaran ◽

E. Devred ◽

M. Babin

Keyword(s):

Organic Carbon ◽

Arctic Ocean ◽

Suspended Solids ◽

Beaufort Sea ◽

Freshwater Discharge ◽

The Arctic ◽

Field Observations ◽

The Arctic Ocean ◽

Arctic Rivers ◽

Mackenzie River

Abstract. Global warming has a significant impact on the regional scale on the Arctic Ocean and surrounding coastal zones (i.e., Alaska, Canada, Greenland, Norway and Russia). The recent increase in air temperature has resulted in increased precipitation along the drainage basins of Arctic rivers. It has also directly impacted land and seawater temperatures with the consequence of melting permafrost and sea ice. An increase in freshwater discharge by main Arctic rivers has been clearly identified in time series of field observations. The freshwater discharge of the Mackenzie River has increased by 25% since 2003. This may have increased the mobilization and transport of various dissolved and particulate substances, including organic carbon, as well as their export to the ocean. The release from land to the ocean of such organic material, which has been sequestered in a frozen state since the Last Glacial Maximum, may significantly impact the Arctic Ocean carbon cycle as well as marine ecosystems. In this study we use 11 years of ocean color satellite data and field observations collected in 2009 to estimate the mass of terrestrial suspended solids and particulate organic carbon delivered by the Mackenzie River into the Beaufort Sea (Arctic Ocean). Our results show that during the summer period, the concentration of suspended solids at the river mouth, in the delta zone and in the river plume has increased by 46, 71 and 33%, respectively, since 2003. Combined with the variations observed in the freshwater discharge, this corresponds to a more than 50% increase in the particulate (terrestrial suspended particles and organic carbon) export from the Mackenzie River into the Beaufort Sea.

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