River flux of dissolved organic carbon (DOC) and particulate organic carbon (POC) to the Arctic Ocean: what are the consequences of the global changes?

Author(s):  
Viacheslav V. Gordeev ◽  
Marina D. Kravchishina
2019 ◽  
Vol 59 (4) ◽  
pp. 544-552
Author(s):  
A. A. Vetrov ◽  
E. A. Romankevich

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.


2016 ◽  
Vol 30 (7) ◽  
pp. 1054-1068 ◽  
Author(s):  
George Tanski ◽  
Nicole Couture ◽  
Hugues Lantuit ◽  
Antje Eulenburg ◽  
Michael Fritz

2021 ◽  
Author(s):  
Daria Polosukhina ◽  
Anatoly Prokushkin ◽  
Axel Steinhof

<p>There is the significant progress in recent decades in the quantification of terrigenous carbon release to the rivers of the Arctic Ocean basin and characterization of its chemical properties, origin and age (e.g. Amon et al., 2012, Holmes et al., 2012). As warming accelerates the thawing permafrost may potentially increase the release the ancient carbon (Wild et al., 2019, Estop-Aragonés et al., 2020). However, more detailed analysis is still needed particularly in regard of the age of carbon exported from the diverse landscapes of large Arctic rivers and its transformation during the transport to the Arctic ocean.</p><p>In this study we analyzed D14C in dissolved organic carbon (DOC) and particulate organic carbon (POC) of the Yenisei River main channel and its major tributaries between 56oN and 68oN at freshet, summer and fall seasons. D14C was measured in Max Planck Institute for Biogeochemistry (Germany) by the accelerator mass spectrometry (AMS) system based on a 3MV Tandetron accelerator as described earlier (Steinhof et al., 2017).</p><p> The oldest DOC in the Yenisei main stem was detected right after the Krasnoyarsk dam (56oN) and varied during a year without clear seasonal pattern in the range of the fraction of modern C (fMC) from 0.868 to 1.028. At freshet the fMC increased down stream up to 1.12 at 60oN and then remained relatively stable between 61o and 67.4oN (1.097±0.014). The major tributaries released DOC with fMC ranging from 1.0869 (Angara, 58oN) to 1.1046 (Kurejka (66.5oN), demonstrating more modern C with latitude. During the summer-fall season the Yenisei main channel and main Eastern tributaries contained older DOC (fMC = 0.968-1.054 and 0.949-1.045, respectively).</p><p>The POC of the Yenisei River was sufficiently older (fMC = 0.83-0.92) than DOC at all seasons and showed similar latitudinal pattern, i.e. the youngest POC was detected near 60-61oN (fMC > 0.90). The D14C-POC values in analyzed tributaries were increasing with latitude at freshet (R2 = 0.53) and summer lowflow (R2 = 0.33), except the largest Eastern tributaries, demonstrating the slight opposite pattern. On the other hand, increasingly more ancient POC was releasing by permafrost-dominated Eastern tributaries with increasing basin size. In opposite, D14C-POC of Western tributaries showed increased input of more recently fixed carbon. Our findings provided new data on the formation of terrigenic carbon fluxes to the Arctic Ocean from one of the largest river basins in the Arctic. This study was supported by RFBR grants #18-05-60203-Arktika. The radiocarbon analyses were kindly supported by Max-Plank Institute for biogeochemistry (ZOTTO project).</p>


2004 ◽  
Vol 31 (5) ◽  
pp. n/a-n/a ◽  
Author(s):  
Ronald Benner ◽  
Bryan Benitez-Nelson ◽  
Karl Kaiser ◽  
Rainer M. W. Amon

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