Natural vs. anthropogenic effects in the composition of dissolved inorganic carbon in a boreal river with a seasonal base flow component

2017 ◽  
Vol 48 (6) ◽  
pp. 1585-1593
Author(s):  
Paula I. A. Niinikoski ◽  
Juha A. Karhu
Keyword(s):  
Carbon Balance ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Surface Flow ◽  
Base Flow ◽  
Annual Cycles ◽  
Carbon Quality ◽  
Flow Component ◽  
Boreal River

Abstract Studying the carbon balance in surface waters gives information on the annual cycles of photosynthesis and respiration. It also provides insight on the water body's capability to serve as a source or sink for atmospheric CO2, which may be essential in evaluating the effects of climate change. The target of this study was the Vantaanjoki River known to have a significant base flow component, located in a densely populated area in southern Finland. The aims of this study were firstly to study if human induced changes are evident in the inorganic carbon quality of the river, and secondly to determine whether the river releases carbon to the atmosphere. These aims were achieved by studying the isotopic composition and contents of dissolved inorganic carbon (DIC) in relation to river discharge. It was evident from the results that the human activities only have mild local and temporal effects on the quality of the DIC in the river. The most important contributors to the changes in the carbon balance are the annual changes in the proportion of the base flow and surface flow components and the escape of CO2 to the atmosphere.

scholarly journals Changes of Hydrological Components in Arctic Rivers Based on Multi-Source Data during 2003–2016

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3494
Author(s):  
Hao Wu ◽  
Min Xu ◽  
Mengyan Zhu
Keyword(s):  
Global Warming ◽  
River Basin ◽  
Hydrological Cycle ◽  
River Basins ◽  
Surface Flow ◽  
Base Flow ◽  
The Arctic ◽  
Current Case ◽  
Annual Cycles ◽  
Earth’S System

The hydrological cycle of the Arctic river basin holds an important position in the Earth’s system, which has been significantly disturbed by global warming. This study analyzed recent changes in the hydrological components of two representative Arctic river basins in Siberia and North America, the Lena River Basin (LRB) and Mackenzie River Basin (MRB), respectively. The trends were diagnosed in hydrological components through a comparative analysis and estimations based on remote sensing and observational datasets during 2003–2016. The results showed that the annual precipitation decreased at rates of 1.9 mm/10a and 18.8 mm/10a in the MRB and LRB, respectively. In contrast, evapotranspiration (ET) showed increasing trends, with rates of 9.5 mm/10a and 6.3 mm/10a in the MRB and LRB, respectively. Terrestrial water storage (TWS) was obviously decreased, with rates of 30.3 mm/a and 18.9 mm/a in the MRB and LRB, respectively, which indicated that more freshwater was released. Contradictive trends of the runoffs were found in the two basins, which were increased in the LRB and decreased in the MRB, due to the contributions of the surface water and base flow. In addition, the mean annual cycles of precipitation, ET, TWS, runoff depth, surface flow and base flow behaved differently in both magnitudes and distributions in the LRB and MRB, the trends of which will likely continue with the pronounced warming climate. The current case studies can help to understand the recent changes in the Arctic hydro-climatology and the consequence of global warming in Arctic river basins.

scholarly journals Inorganic carbon cycling and biogeochemical processes in an Arctic inland sea (Hudson Bay)

2016 ◽  
Vol 13 (16) ◽  
pp. 4659-4671 ◽  
Author(s):  
William J. Burt ◽  
Helmuth Thomas ◽  
Lisa A. Miller ◽  
Mats A. Granskog ◽  
Tim N. Papakyriakou ◽  
...  
Keyword(s):  
Carbon Cycling ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Total Alkalinity ◽  
Hudson Bay ◽  
Near Surface ◽  
Annual Cycles ◽  
Detailed Assessment ◽  
Freshwater Inputs ◽  
End Members

Abstract. The distributions of carbonate system parameters in Hudson Bay, which not only receives nearly one-third of Canada's river discharge but is also subject to annual cycles of sea-ice formation and melt, indicate that the timing and magnitude of freshwater inputs play an important role in carbon biogeochemistry and acidification in this unique Arctic ecosystem. This study uses basin-wide measurements of dissolved inorganic carbon (DIC) and total alkalinity (TA), as well as stable isotope tracers (δ18O and δ13CDIC), to provide a detailed assessment of carbon cycling processes within the bay. Surface distributions of carbonate parameters reveal the particular importance of freshwater inputs in the southern portion of the bay. Based on TA, we surmise that the deep waters in the Hudson Bay are largely of Pacific origin. Riverine TA end-members vary significantly both regionally and with small changes in near-surface depths, highlighting the importance of careful surface water sampling in highly stratified waters. In an along-shore transect, large increases in subsurface DIC are accompanied by equivalent decreases in δ13CDIC with no discernable change in TA, indicating a respiratory DIC production on the order of 100 µmol kg−1 DIC during deep water circulation around the bay.

scholarly journals Watershed geomorphology modifies the sensitivity of aquatic ecosystem metabolism to temperature

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
K. J. Jankowski ◽  
D. E. Schindler
Keyword(s):  
Temperature Sensitivity ◽  
Aquatic Ecosystem ◽  
Aquatic Ecosystems ◽  
Ecosystem Respiration ◽  
Ecosystem Metabolism ◽  
Temperature Sensitive ◽  
Carbon Quality ◽  
Carbon Cycles ◽  
Boreal River

AbstractThe regulation of aquatic carbon cycles by temperature is a significant uncertainty in our understanding of how watersheds will respond to climate change. Aquatic ecosystems transport substantial quantities of carbon to the atmosphere and ocean, yet we have limited understanding of how temperature modifies aquatic ecosystem metabolic processes and contributions to carbon cycles at watershed to global scales. We propose that geomorphology controls the distribution and quality of organic material that forms the metabolic base of aquatic ecosystems, thereby controlling the response of aquatic ecosystem metabolism to temperature across landscapes. Across 23 streams and four years during summer baseflow, we estimated variation in the temperature sensitivity of ecosystem respiration (R) among streams draining watersheds with different geomorphic characteristics across a boreal river basin. We found that geomorphic features imposed strong controls on temperature sensitivity; R in streams draining flat watersheds was up to six times more temperature sensitive than streams draining steeper watersheds. Further, our results show that this association between watershed geomorphology and temperature sensitivity of R was linked to the carbon quality of substrates that changed systematically across the geomorphic gradient. This suggests that geomorphology will control how carbon is transported, stored, and incorporated into river food webs as the climate warms.

scholarly journals Inorganic Carbon Cycling and Biogeochemical Processes in an Arctic Inland Sea (Hudson Bay)

2016 ◽  
Author(s):  
William J. Burt ◽  
Helmuth Thomas ◽  
Lisa A. Miller ◽  
Mats A. Granskog ◽  
Tim N. Papakyriakou ◽  
...  
Keyword(s):  
Carbon Cycling ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Total Alkalinity ◽  
Hudson Bay ◽  
Near Surface ◽  
Annual Cycles ◽  
Detailed Assessment ◽  
Freshwater Inputs ◽  
End Members

Abstract. The distributions of carbonate system parameters in Hudson Bay, which not only receives nearly one third of Canada's river discharge, but which is also subject to annual cycles of sea-ice formation and melt, indicate that the timing and magnitude of freshwater inputs play an important role in carbon biogeochemistry and acidification in this unique Arctic ecosystem. This study uses basin-wide measurements of dissolved inorganic carbon (DIC) and total alkalinity (TA), as well as stable isotope tracers (δ18O and δ13CDIC), to provide a detailed assessment of carbon cycling processes within the bay. Surface distributions of carbonate parameters reveal the particular importance of freshwater inputs in the southern portion of the bay. Based on TA, we surmise that the deep waters in the Hudson Bay are largely of Pacific origin. Riverine TA end-members vary significantly both regionally and with small changes in near-surface depths, highlighting the importance of careful surface water sampling in highly stratified waters. In an along-shore transect, large increases in subsurface DIC are accompanied by equivalent decreases in δ13CDIC with no discernable change in TA, indicating a respiratory DIC production on the order of 100 μmol kg−1 during deep water circulation around the bay.

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