scholarly journals 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

2015 ◽  
Vol 12 (11) ◽  
pp. 3551-3565 ◽  
Author(s):  
D. Doxaran ◽  
E. Devred ◽  
M. Babin

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.

2015 ◽  
Vol 12 (1) ◽  
pp. 305-344 ◽  
Author(s):  
D. Doxaran ◽  
E. Devred ◽  
M. Babin

Abstract. Global warming has a significant impact at 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 precipitations along the drainage basins of Arctic Rivers. It has also directly impacted land and seawater temperatures with the consequence of melting the 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 was sequestered as frozen 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-colour satellite data and field observations collected in 2009 to estimate the amount 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.


2007 ◽  
Vol 373 (1) ◽  
pp. 178-195 ◽  
Author(s):  
Daniel R. Leitch ◽  
Jesse Carrie ◽  
David Lean ◽  
Robie W. Macdonald ◽  
Gary A. Stern ◽  
...  

2021 ◽  
Author(s):  
Rene Preusker ◽  
Jan El Kassar ◽  
Bennet Juhls

<p>As air temperatures in the Arctic continue to rise, permafrost thaw intensifies, and discharge from the Arctic rivers increases. These drastic changes are likely to accelerate mobilization of organic matter and its export through rivers into the Arctic Ocean. Therefore, thorough monitoring of these processes becomes increasingly important. The Lena River with its large catchment area is one of the major sources of the organic carbon in the Arctic Ocean and, therefore, plays a crucial role in the Arctic carbon cycle. <br>To observe current and future changes of carbon transport via the Lena River, a new monitoring program has been initiated in 2018. In situ water samples are collected from the one of the Lena Delta branches every several days. Since generally the in situ sampling in the Arctic is challenging and costly, in this study, we test the potential of remote sensing to complement the field observations. Remote sensing provides synoptic spatial coverages and high temporal resolution at high latitudes. <br>We test the retrieval of dissolved organic carbon (DOC) from satellite-derived chromophoric dissolved organic matter (CDOM). For this, we use measurements of the Ocean & Land Colour Instrument (OLCI) on board the Sentinel-3 satellites in combination with beforehand tested atmospheric correction algorithms and CDOM retrieval algorithms. The quality of the satellite retrieved DOC of the Lena River water is assessed by DOC, measured in the in situ samples. Remotely sensed DOC contributes to an improvement of DOC fluxes monitoring, which can potentially be extended to all big Arctic rivers.</p>


2007 ◽  
Vol 21 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Peter A. Raymond ◽  
J. W. McClelland ◽  
R. M. Holmes ◽  
A. V. Zhulidov ◽  
K. Mull ◽  
...  

2012 ◽  
Vol 9 (8) ◽  
pp. 3213-3229 ◽  
Author(s):  
D. Doxaran ◽  
J. Ehn ◽  
S. Bélanger ◽  
A. Matsuoka ◽  
S. Hooker ◽  
...  

Abstract. Climate change significantly impacts Arctic shelf regions in terms of air temperature, ultraviolet radiation, melting of sea ice, precipitation, thawing of permafrost and coastal erosion. Direct consequences have been observed on the increasing Arctic river flow and a large amount of organic carbon sequestered in soils at high latitudes since the last glacial maximum can be expected to be delivered to the Arctic Ocean during the coming decade. Monitoring the fluxes and fate of this terrigenous organic carbon is problematic in such sparsely populated regions unless remote sensing techniques can be developed and proved to be operational. The main objective of this study is to develop an ocean colour algorithm to operationally monitor dynamics of suspended particulate matter (SPM) on the Mackenzie River continental shelf (Canadian Arctic Ocean) using satellite imagery. The water optical properties are documented across the study area and related to concentrations of SPM and particulate organic carbon (POC). Robust SPM and POC : SPM proxies are identified, such as the light backscattering and attenuation coefficients, and relationships are established between these optical and biogeochemical parameters. Following a semi-analytical approach, a regional SPM quantification relationship is obtained for the inversion of the water reflectance signal into SPM concentration. This relationship is reproduced based on independent field optical measurements. It is successfully applied to a selection of MODIS satellite data which allow estimating fluxes at the river mouth and monitoring the extension and dynamics of the Mackenzie River surface plume in 2009, 2010 and 2011. Good agreement is obtained with field observations representative of the whole water column in the river delta zone where terrigenous SPM is mainly constrained (out of short periods of maximum river outflow). Most of the seaward export of SPM is observed to occur within the west side of the river mouth. Future work will require the validation of the developed SPM regional algorithm based on match-ups with field measurements, then the routine application to ocean colour satellite data in order to better estimate the fluxes and fate of SPM and POC delivered by the Mackenzie River to the Arctic Ocean.


2009 ◽  
Vol 40 (11) ◽  
pp. 1151-1159 ◽  
Author(s):  
Martin P. Cooke ◽  
Bart E. van Dongen ◽  
Helen M. Talbot ◽  
Igor Semiletov ◽  
Natalia Shakhova ◽  
...  

2021 ◽  
Author(s):  
David Gareth Babb ◽  
Ryan J. Galley ◽  
Stephen E. L. Howell ◽  
Jack Christopher Landy ◽  
Julienne Christine Stroeve ◽  
...  

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.


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