Spatial and temporal variations ofpCO2, dissolved inorganic carbon and stable isotopes along a temperate karstic watercourse

2015 ◽  
Vol 29 (15) ◽  
pp. 3423-3440 ◽  
Author(s):  
Robert van Geldern ◽  
Peter Schulte ◽  
Michael Mader ◽  
Alfons Baier ◽  
Johannes A. C. Barth
Keyword(s):  
Stable Isotopes ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Temporal Variations ◽  
Spatial And Temporal Variations

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.

Diel behavior of stable isotopes of dissolved oxygen and dissolved inorganic carbon in rivers over a range of trophic conditions, and in a mesocosm experiment

2010 ◽  
Vol 269 (1-2) ◽  
pp. 22-32 ◽  
Author(s):  
Stephen R. Parker ◽  
Christopher H. Gammons ◽  
Simon R. Poulson ◽  
Michael D. DeGrandpre ◽  
Charmaine L. Weyer ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Dissolved Oxygen ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Mesocosm Experiment ◽  
Trophic Conditions

scholarly journals PHYSICOCHEMICAL AND ISOTOPIC CHARACTERIZATION OF FORMATION WATERS FROM OIL FIELDS IN THE SERGIPE BASIN, BRAZIL

2014 ◽  
Vol 32 (3) ◽  
pp. 531
Author(s):  
Danilo R. Sá Teles ◽  
Antônio Expedito G. de Azevedo ◽  
Alexandre B. Costa ◽  
Maria R. Zucchi ◽  
Alexandre A. Ferreira
Keyword(s):  
Stable Isotopes ◽  
Isotopic Exchange ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Oil Fields ◽  
Northeastern Brazil ◽  
Formation Water ◽  
Water Formation ◽  
Isotopic Characterization

ABSTRACT. This paper presents a study of the physicochemical and isotopic characteristics of formation waters from the Castanhal, Siririzinho and Aguilhadafields in the Sergipe Basin, northeastern Brazil. In each of the samples, pH, conductivity, concentration of dissolved inorganic carbon (DIC), δ18O, δ2H, and δ13C weremeasured. These measurements are used to identify isotopic similarities among waters from local aquifers, which can be used as a proxy for groundwater connectivitywith formation water. Formation waters from the Castanhal and Siririzinho fields are enriched in deuterium, as evidenced by their δ2H values above the Global MeteoricWater Line (GMWL), which may be a result of significant isotopic exchange between water and H2S. These measurements are in accordance with the large enrichment in13C of DIC resulting from biodegradation, with the formation of methane depleted in 13C and CO2 enriched in 13C. These results indicate interaction between formationwater with rocks and other fluids.Keywords: stable isotopes, dissolved inorganic carbon, biodegradation. RESUMO. Este trabalho apresenta um estudo das características físico-químicas e isotópicas de águas de formação dos campos Castanhal, Siririzinho e Aguilhada, localizados na Bacia de Sergipe, nordeste do Brasil. Em cada uma das amostras foram medidos os parâmetros pH, condutividade elétrica, concentração de carbonoinorgânico dissolvido (CID), δ18O, δ2H e δ13C. A partir dos resultados obtidos, foi possível identificar a similaridade isotópica com as águas de aquíferos locais,indicando conexão de água subterrânea com água de formação. As águas de formação dos campos Castanhal e Siririzinho apresentaram um enriquecimento em deutério,resultado da troca isotópica entre a água e o H2S. Também foi verificado, um grande enriquecimento no δ13C do CID, resultado dos processos de biodegradação coma formação de metano empobrecido em 13C e CO2 enriquecido neste isótopo. Os resultados encontrados indicam interação entre a água de formação com as rochas ecom outros fluidos.Palavras-chave: isótopos estáveis, carbono inorgânico dissolvido, biodegradação.

The interplay of glacial/interglacial climate-CO2 and productivity effects on coccolith calcification and vital effects across the MIS 12 to MIS 9 in the western tropical Atlantic

2020 ◽  
Author(s):  
Alba González-Lanchas ◽  
Heather M. Stoll ◽  
José-Abel Flores ◽  
Francisco J. Sierro ◽  
Ivan Hernandez-Almeida ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Isotopic Fractionation ◽  
Tropical Atlantic ◽  
Physiological Mechanisms ◽  
Carbon Isotopic ◽  
Acquisition Strategies ◽  
Climatic Period ◽  
Vital Effects

&lt;p&gt;Coccolithophores play an important dual role in ocean biogeochemistry: they use dissolved inorganic carbon (DIC) in the surface for both photosynthesis and coccolith calcification. Stable isotopes in coccoliths are the result of various effects, including different vital effects, allowing hypotheses about the varying active carbon acquisition strategies in response to changing environmental conditions. Understanding the physiological mechanisms that cause these changes remains challenging.&lt;/p&gt;&lt;p&gt;The MIS 12 to MIS 9 interval is a crucial climatic period encompassing changing glacial-interglacial cyclicity and pronounced variations in atmospheric CO&lt;sub&gt;2&lt;/sub&gt; concentration. Different paleorecords indicate that coccoliths were an important component of the carbonate fraction during this interval, with the outstanding worldwide dominance of the highly calcified coccolithophore species &lt;em&gt;Gephyrocapsa caribbeanica&lt;/em&gt;.&lt;/p&gt;&lt;p&gt;The carbon isotopic fractionation during photosynthesis (&amp;#949;p) in alkenones, biomarkers produced by coccolithophores, is a proxy to reconstruct past aqueous CO&lt;sub&gt;2&lt;/sub&gt; concentration. Here we present a new &amp;#949;p reconstruction spanning this glacial/interglacial interval (460 to 330 kyr) at ODP Site 925 in the western tropical Atlantic. We aim to evaluate the interplay of CO&lt;sub&gt;2 &lt;/sub&gt;and productivity effects on coccolith calcification and stable isotopes (&amp;#948;&lt;sup&gt;18&lt;/sup&gt;O and &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C) in coccolith calcite integrating these data with the size and thickness of coccolith platelets and the geochemical Sr/Ca record.&lt;/p&gt;&lt;p&gt;The comparison of mean coccolith size with coeval samples from the deeper ODP Site 929 allows the evaluation of the degree of nannofossil dissolution across the interval.&lt;/p&gt;

A high-elevation MIS 5 hydrologic record using mollusks and ostracodes from Snowmass Village, Colorado, USA

2014 ◽  
Vol 82 (3) ◽  
pp. 604-617 ◽  
Author(s):  
Saxon E. Sharpe ◽  
Jordon Bright
Keyword(s):  
Stable Isotopes ◽  
Water Temperature ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
High Elevation ◽  
Total Dissolved Solids ◽  
Water Based ◽  
Fossil Site ◽  
Mis 5E ◽  
Mis 5

AbstractSediments containing terrestrial and aquatic mollusks and ostracodes from the Ziegler Reservoir fossil site (2705 m elevation) near Snowmass Village, Colorado, span ~130–87 ka (MIS 5e through 5b). The southeastern area of the site where taxa were recovered was a relatively fresh, shallow, well-vegetated wetland during MIS 5e through 5c time, approximately 2 m deep, with a total dissolved solids value of ~200–1000 mg L− 1. The wetland was seasonally or annually variable and groundwater discharged along the margins of the bounding moraine. Groundwater likely contributed solutes to the system and may have contributed 18O-enriched water. Based on stable isotopes from ostracode calcite (δ18OOST and δ13COST), seasonal evaporation occurred and the dissolved inorganic carbon pool was unexpectedly enriched in 13C. The mollusk and ostracode faunas changed little across the MIS 5e/5d/5c boundaries, whereas a distinct change in the ostracode fauna occurred between the deposition of Unit 11 and Unit 13, which corresponds in time to the MIS 5c/5b boundary, indicating some combination of increased surface and/or groundwater flow, a decrease in water temperature, and a freshening and a possible deepening of the wetland.

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