scholarly journals Spatiotemporal variations in water dissolved organic carbon and dissolved inorganic carbon concentrations in Wenwusha Reservoir in subtropical estuary, Southeast China

2021 ◽  
Vol 33 (4) ◽  
pp. 1123-1137
Author(s):  
Yang Ping ◽  
◽  
Tang Chen ◽  
Lu Miaohui ◽  
Zhang Linhai ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Spatiotemporal Variations ◽  
Southeast China ◽  
Subtropical Estuary ◽  
Carbon Concentrations

14C Measurements of Dissolved Inorganic and Organic Carbon in Qinghai Lake and Inflowing Rivers (NE Tibet, Qinghai Plateau), China

Radiocarbon ◽  
2014 ◽  
Vol 56 (3) ◽  
pp. 1115-1127 ◽  
Author(s):  
A J T Jull ◽  
G S Burr ◽  
W Zhou ◽  
P Cheng ◽  
S H Song ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Qinghai Lake ◽  
Main Process ◽  
The Past ◽  
Atmospheric Exchange ◽  
Sediment Carbon ◽  
Inorganic And Organic

There have been a number of studies that have attempted to estimate the past radiocarbon reservoir effects in Qinghai Lake, China. This article reports on measurements on modern samples collected at the lake in October 2003 and October 2009, which allow us to better understand the systematics of the lake and shed new insights on the processes occurring in the lake. The results indicate that atmospheric exchange of 14C is the main process affecting surface dissolved inorganic carbon (DIC) in the lake, but dissolved organic carbon (DOC) can be explained as a combination of sources. We also conclude that sediment carbon can be explained by a model where input from the surrounding rivers and groundwater are important, in agreement with the model of Yu et al. (2007).

scholarly journals Helium, inorganic and organic carbon isotopes of fluids and gases across the Costa Rica convergent margin

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Peter H. Barry ◽  
Mayuko Nakagawa ◽  
Donato Giovannelli ◽  
J. Maarten de Moor ◽  
Matthew Schrenk ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Gas Phase ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Costa Rican ◽  
C Isotopes ◽  
He Isotopes ◽  
Autotrophic Biomass ◽  
Calcite Deposition ◽  
Carbon Concentrations

AbstractIn 2017, fluid and gas samples were collected across the Costa Rican Arc. He and Ne isotopes, C isotopes as well as total organic and inorganic carbon concentrations were measured. The samples (n = 24) from 2017 are accompanied by (n = 17) samples collected in 2008, 2010 and 2012. He-isotopes ranged from arc-like (6.8 RA) to crustal (0.5 RA). Measured dissolved inorganic carbon (DIC) δ13CVPDB values varied from 3.55 to −21.57‰, with dissolved organic carbon (DOC) following the trends of DIC. Gas phase CO2 only occurs within ~20 km of the arc; δ13CVPDB values varied from −0.84 to −5.23‰. Onsite, pH, conductivity, temperature and dissolved oxygen (DO) were measured; pH ranged from 0.9–10.0, conductivity from 200–91,900 μS/cm, temperatures from 23–89 °C and DO from 2–84%. Data were used to develop a model which suggests that ~91 ± 4.0% of carbon released from the slab/mantle beneath the Costa Rican forearc is sequestered within the crust by calcite deposition with an additional 3.3 ± 1.3% incorporated into autotrophic biomass.

scholarly journals Degradation of permafrost carbon in the Kolyma River

2020 ◽  
Author(s):  
Kirsi Keskitalo ◽  
Lisa Bröder ◽  
Dirk Jong ◽  
Nikita Zimov ◽  
Anya Davydova ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Climate Impacts ◽  
Frozen Ground ◽  
River Bank ◽  
Permafrost Thaw ◽  
Degradation Rates ◽  
Kolyma River

<p>Soil temperatures in permafrost (i.e. perennially frozen ground) are rising globally. The increasing temperatures accelerate permafrost thaw and release of organic carbon, that has been locked in permafrost soils since the last glacial period, to the contemporary carbon cycle. The potential remineralisation of organic carbon to greenhouse gases can contribute to further climate warming. Particulate organic carbon (POC) in the Kolyma River is older than dissolved organic carbon (DOC) thus serves as a good tracer for abrupt permafrost thaw (i.e. river bank erosion and thermokarst) that dominantly releases old POC. While dissolved organic carbon (DOC) mobilised from the old Yedoma outcrops on the banks of the Kolyma River is shown to be highly labile, vulnerability of POC to biodegradation is not yet known. In this study we aim to constrain degradation rates for POC in the Kolyma River. To capture seasonal variability of the POC pool and its degradation rate the incubation was conducted both during the spring freshet and in late summer (2019 and 2018, respectively). We incubated whole-water samples over 9 to 15 days and quantified POC (and DOC) loss over time, as well as dissolved inorganic carbon (DIC). The incubation was carried out in the dark. We also tracked changes in POC composition and age with carbon isotopes (d<sup>13</sup>C-OC, d<sup>13</sup>C-DIC, ∆<sup>14</sup>C). Preliminary results from 2018 suggest a decrease in POC concentrations of up to 30 % while those of DOC decrease by up to 11 %. The rate of POC degradation is nearly three times faster than DOC though the absolute amounts of DOC are in turn higher than those of POC (< 1 mg L<sup>-1</sup> for POC and ~3 mg L<sup>-1</sup> for DOC). Furthermore, the changes in d<sup>13</sup>C of POC, DOC and DIC suggest ongoing microbial degradation and conversion of organic carbon into inorganic carbon. These first estimates show that POC degrades fairly rapidly while transported in the Kolyma River. A better understanding of POC degradation along lateral flow paths is critical for improving our knowledge of permafrost thaw and its possible climate impacts in the future.</p>

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