scholarly journals Groundwater data improve modelling of headwater stream CO<sub>2</sub> outgassing with a stable DIC isotope approach

2018 ◽  
Vol 15 (10) ◽  
pp. 3093-3106 ◽  
Author(s):  
Anne Marx ◽  
Marcus Conrad ◽  
Vadym Aizinger ◽  
Alexander Prechtel ◽  
Robert van Geldern ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Stream Water ◽  
Temporal Variations ◽  
Headwater Stream ◽  
Integral Approach ◽  
Gas Transfer ◽  
Transfer Velocity ◽  
Outgassing Rate ◽  
Carbon Dioxide Co2

Abstract. A large portion of terrestrially derived carbon outgasses as carbon dioxide (CO2) from streams and rivers to the atmosphere. Particularly, the amount of CO2 outgassing from small headwater streams is highly uncertain. Conservative estimates suggest that they contribute 36 % (i.e. 0.93 petagrams (Pg) C yr−1) of total CO2 outgassing from all fluvial ecosystems on the globe. In this study, stream pCO2, dissolved inorganic carbon (DIC), and δ13CDIC data were used to determine CO2 outgassing from an acidic headwater stream in the Uhlířská catchment (Czech Republic). This stream drains a catchment with silicate bedrock. The applied stable isotope model is based on the principle that the 13C ∕ 12C ratio of its sources and the intensity of CO2 outgassing control the isotope ratio of DIC in stream water. It avoids the use of the gas transfer velocity parameter (k), which is highly variable and mostly difficult to constrain. Model results indicate that CO2 outgassing contributed more than 80 % to the annual stream inorganic carbon loss in the Uhlířská catchment. This translated to a CO2 outgassing rate from the stream of 34.9 kg C m−2 yr−1 when normalised to the stream surface area. Large temporal variations with maximum values shortly before spring snowmelt and in summer emphasise the need for investigations at higher temporal resolution. We improved the model uncertainty by incorporating groundwater data to better constrain the isotope compositions of initial DIC. Due to the large global abundance of acidic, humic-rich headwaters, we underline the importance of this integral approach for global applications.

scholarly journals Groundwater data improve modelling of headwater stream CO<sub>2</sub> outgassing with a stable DIC isotope approach

2017 ◽  
Author(s):  
Anne Marx ◽  
Marcus Conrad ◽  
Vadym Aizinger ◽  
Alexander Prechtel ◽  
Robert van Geldern ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Stream Water ◽  
Temporal Variations ◽  
Headwater Stream ◽  
Integral Approach ◽  
Gas Transfer ◽  
Transfer Velocity ◽  
Outgassing Rate ◽  
Carbon Dioxide Co2

Abstract. A large portion of terrestrially-derived carbon outgasses as carbon dioxide (CO2) from streams and rivers to the atmosphere. Particularly, the amount of CO2 outgassing from small headwater streams was indicated as highly uncertain. Conservative estimates suggest that they contribute 36 % (i.e., 0.93 petagrams C yr−1) of total CO2 outgassing from all rivers and streams worldwide. In this study, stream pCO2, dissolved inorganic carbon (DIC) and δ13CDIC data were used to determine CO2 outgassing from an acidic headwater stream in the Uhlirska catchment (Czech Republic). This stream drains a catchment with silicate bedrock. The applied stable isotope model is based on the principle, that the 13C / 12C ratio of its sources and the intensity of CO2 outgassing control the isotope ratio of DIC in stream water. It avoids the use of the gas transfer velocity parameter (k) that is highly variable and mostly difficult to constrain. Model results indicate that CO2 outgassing contributed 80 % to the annual stream inorganic carbon loss in the Uhlirska catchment. This translated to a CO2 outgassing rate from the stream of 5.2 t C yr−1 and to 2.9 g C m−2 yr−1, when normalised to the catchment area. Large temporal variations with maximum values during spring snowmelt and summer emphasise the need for investigations at higher temporal resolution. We improved the model uncertainty by incorporating groundwater data to better constrain the isotope compositions of initial DIC. Due to the large global abundance of acidic, humic-rich headwaters, we underline the importance of this integral approach for global applications.

scholarly journals Distribution of dissolved inorganic carbon and related parameters in the Thermaikos Gulf (Eastern Mediterranean)

2006 ◽  
Vol 7 (1) ◽  
pp. 63 ◽  
Author(s):  
E. KRASAKOPOULOU ◽  
CH. ANAGNOSTOU ◽  
E. SOUVERMEZOGLOU ◽  
E. PAPATHANASSIOU ◽  
S. RAPSOMANIKIS
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Eastern Mediterranean ◽  
Co2 Exchange ◽  
Extensive Study ◽  
Atmospheric Co2 ◽  
Small Scale ◽  
Gas Transfer ◽  
Transfer Velocity

Data on the distribution of dissolved inorganic carbon (measured as TCO2) and related parameters in the Thermaikos Gulf were obtained during May 1997. High TCO2 concentrations were recorded close to the bottom, especially in the northern part of the gulf, as a result of organic matter remineralisation. The positive relatively good correlation between TCO2 and both apparent oxygen utilisation (AOU) and phosphate at the last sampling depth confi rmed the regenerative origin of a large proportion of TCO2. The comparatively conservative behaviour of alkalinity, together with the relatively low value of the homogenous buffer factor β (β = ∂lnfCO2/∂lnTCO2) revealed that calcifi cation or carbonate dissolution takes place on a very small scale, simultaneously with the organic carbon production. The correlations between fCO2 and chlorophyll α, as well as AOU and the surface temperature, revealed that the carbon dioxide fi xation through the biological activity is the principal factor that modulates the variability of fCO2. A rough first estimate of the magnitude of the air-sea CO2 exchange and the potential role of the Thermaikos Gulf in the transfer of atmospheric CO2 was also obtained. The results showed that during May 1997, the Thermaikos Gulf acted as a weak sink for atmospheric CO2 at a rate of -0.60 - -1.43 mmol m-2 d-1, depending on which formula for the gas transfer velocity was used, and in accordance to recent reports regarding other temperate continental shelves. Extensive study of the dissolved inorganic carbon and related parameters, and continuous shipboard measurements of fCO2 a and fCO2 w during all seasons are necessary to safely quantify the role of the Thermaikos Gulf in the context of the coastal margins CO2 dynamics.

scholarly journals Increase of 14C Activity of Dissolved Inorganic Carbon Along a River Course

Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 515-521 ◽  
Author(s):  
Dušan Srdoč ◽  
Ines Krajcar-Bronić ◽  
Nada Horvatinčić ◽  
Bogomil Obelić
Keyword(s):  
Aquatic Plants ◽  
Water Samples ◽  
Organic Material ◽  
Root Respiration ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Stream Water ◽  
Exchange Process ◽  
Karst Spring ◽  
Stream Waters

Results of measurements for 3 years (1981–1983) of 14C activity of dissolved inorganic carbon (DIG) in water samples from the Korana River, as well as that of recent tufa and aquatic plants, showed that 14C concentration increases from karst spring to the estuary. A model describing the increase of 14C activity was developed assuming that the increase is due to the exchange of the dissolved CO2 in stream water with atmospheric CO2 and to dissolution of CO2 from the decay of organic material and root respiration. It is possible to distinguish these two contributions by measuring the δ13C values of DIC in water. As expected, our data show that the exchange process between atmospheric CO2 and DIC dominates at rapids and waterfalls, while biologic contribution is much higher in lakes and along the lowland flow of the Korana River. Agreement between the calculated and the measured activities supports the proposed mechanisms of chemical and isotopic exchanges in stream waters.

Dissolved Inorganic Carbon Export Across the Soil/Stream Interface and Its Fate in a Boreal Headwater Stream

2009 ◽  
Vol 43 (19) ◽  
pp. 7364-7369 ◽  
Author(s):  
Mats G. Öquist ◽  
Marcus Wallin ◽  
Jan Seibert ◽  
Kevin Bishop ◽  
Hjalmar Laudon
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Headwater Stream ◽  
Carbon Export ◽  
Stream Interface

scholarly journals Installing kelp forests/seaweed beds for mitigation and adaptation against global warming: Korean Project Overview

2013 ◽  
Vol 70 (5) ◽  
pp. 1038-1044 ◽  
Author(s):  
Ik Kyo Chung ◽  
Jung Hyun Oak ◽  
Jin Ae Lee ◽  
Jong Ahm Shin ◽  
Jong Gyu Kim ◽  
...  
Keyword(s):  
Global Warming ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Coastal Region ◽  
Pharmaceutical Products ◽  
Kelp Forests ◽  
Co2 Removal ◽  
Mitigation And Adaptation ◽  
Southern Korea ◽  
Carbon Dioxide Co2

Abstract Chung, I. K., Oak, J. H., Lee, J. A., Shin, J. A., Kim, J. G., and Park, K.-S. 2013. Installing kelp forests/seaweed beds for mitigation and adaptation against global warming: Korean Project Overview. – ICES Journal of Marine Science, 70: 1038–1044. Seaweed beds can serve as a significant carbon dioxide (CO2) sink while also satisfying global needs for food, fodder, fuel, and pharmaceutical products. The goal of our Korean Project has been to develop new baseline and monitoring methodologies for mitigation and adaptation within the context of climate change. Using innovative research approaches, we have established the Coastal CO2 Removal Belt (CCRB), which comprises both natural and man-made plant communities in the coastal region of southern Korea. Implemented on various spatial–temporal scales, this scheme promotes the removal of CO2 via marine forests. For example, when populated with the perennial brown alga Ecklonia, a pilot CCRB farm can draw down ∼10 t of CO2 per ha per year. This success is manifested by an increment in biomass accumulations and a decrease in the amount of dissolved inorganic carbon in the water column.

Variability in the benefits of ocean acidification to photosynthetic rates of macroalgae without CO2-concentrating mechanisms

2020 ◽  
Vol 71 (3) ◽  
pp. 275 ◽  
Author(s):  
C. E. Cornwall ◽  
C. L. Hurd
Keyword(s):  
Ocean Acidification ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Surface Seawater ◽  
Seaweed Species ◽  
Photosynthetic Rates ◽  
Uptake Rates ◽  
Carbon Dioxide Co2 ◽  
Co2 Concentrating Mechanisms ◽  
Emissions Scenario

Increasing concentrations of surface-seawater carbon dioxide (CO2) (ocean acidification) could favour seaweed species that currently are limited for dissolved inorganic carbon (DIC). Among them, those that are unable to use CO2-concentrating mechanisms (CCMs) to actively uptake bicarbonate (HCO3–) across the plasmalemma are most likely to benefit. Here, we assess how the DIC uptake and photosynthetic rates of three rhodophytes without CCMs respond to four seawater CO2 concentrations representing pre-industrial (280μatm), present-day (400μatm), representative concentration pathway (RCP) emissions scenario 8.52050 (650μatm) and RCP 8.52100 (1000μatm). We demonstrated that the photosynthetic rates of only one species increase between the preindustrial and end-of-century scenarios, but because of differing photosynthetic quotients (DIC taken up relative to O2 evolved), all three increase their DIC uptake rates from pre-industrial or present-day scenarios to the end-of-century scenario. These variable, but generally beneficial, responses highlight that not all species without CCMs will respond to ocean acidification uniformly. This supports past assessments that, on average, this group will likely benefit from the impacts of ocean acidification. However, more concerted efforts are now required to assess whether similar benefits to photosynthetic rates and DIC uptake are also observed in chlorophytes and ochrophytes without CCMs.

scholarly journals CO<sub>2</sub> perturbation experiments: similarities and differences between dissolved inorganic carbon and total alkalinity manipulations

2009 ◽  
Vol 6 (2) ◽  
pp. 4441-4462 ◽  
Author(s):  
K. G. Schulz ◽  
J. Barcelos e Ramos ◽  
R. E. Zeebe ◽  
U. Riebesell
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Total Alkalinity ◽  
Carbonate Chemistry ◽  
Surface Ocean ◽  
Seawater Carbonate Chemistry ◽  
Similarities And Differences ◽  
Carbon Dioxide Co2

Abstract. Increasing atmospheric carbon dioxide (CO2) through human activities and invasion of anthropogenic CO2 into the surface ocean alters the seawater carbonate chemistry, increasing CO2 and bicarbonate (HCO3

Carbon isotope fractionation of dissolved inorganic carbon (DIC) due to outgassing of carbon dioxide from a headwater stream

2008 ◽  
Vol 22 (14) ◽  
pp. 2410-2423 ◽  
Author(s):  
Daniel H. Doctor ◽  
Carol Kendall ◽  
Stephen D. Sebestyen ◽  
James B. Shanley ◽  
Nobuhito Ohte ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Isotope ◽  
Isotope Fractionation ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Headwater Stream ◽  
Carbon Isotope Fractionation
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