Chemical weathering and atmospheric carbon dioxide (CO2) consumption in Shanmuganadhi, South India: evidences from groundwater geochemistry

2020 ◽  
Author(s):  
F. Vinnarasi ◽  
K. Srinivasamoorthy ◽  
K. Saravanan ◽  
S. Gopinath ◽  
R. Prakash ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Chemical Weathering ◽  
South India ◽  
Groundwater Geochemistry ◽  
Co2 Consumption ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2

scholarly journals Consumption of Atmospheric Carbon Dioxide through Weathering of Ultramafic Rocks in the Voltri Massif (Italy): Quantification of the Process and Global Implications

Geosciences ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 258
Author(s):  
Francesco Frondini ◽  
Orlando Vaselli ◽  
Marino Vetuschi Zuccolini
Keyword(s):  
Carbon Dioxide ◽  
Time Scales ◽  
Atmospheric Carbon Dioxide ◽  
Chemical Weathering ◽  
Weighted Average ◽  
Global Scale ◽  
Ultramafic Rocks ◽  
Co2 Consumption ◽  
Atmospheric Carbon ◽  
Good Proxy

Chemical weathering is the main natural mechanism limiting the atmospheric carbon dioxide levels on geologic time scales (>1 Ma) but its role on shorter time scales is still debated, highlighting the need for an increase of knowledge about the relationships between chemical weathering and atmospheric CO2 consumption. A reliable approach to study the weathering reactions is the quantification of the mass fluxes in and out of mono lithology watershed systems. In this work the chemical weathering and atmospheric carbon dioxide consumption of ultramafic rocks have been studied through a detailed geochemical mass balance of three watershed systems located in the metaophiolitic complex of the Voltri Massif (Italy). Results show that the rates of carbon dioxide consumption of the study area (weighted average = 3.02 ± 1.67 × 105 mol km−2 y−1) are higher than the world average CO2 consumption rate and are well correlated with runoff, probably the stronger weathering controlling factor. Computed values are very close to the global average of basic and ultrabasic magmatic rocks, suggesting that Voltri Massif is a good proxy for the study of the feedbacks between chemical weathering, CO2 consumption, and climate change at a global scale.

scholarly journals Using airborne HIAPER Pole-to-Pole Observations (HIPPO) to evaluate model and remote sensing estimates of atmospheric carbon dioxide

2016 ◽  
Author(s):  
C. Frankenberg ◽  
S. S. Kulawik ◽  
S. Wofsy ◽  
F. Chevallier ◽  
B. Daube ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Correlation Coefficients ◽  
Added Value ◽  
Total Carbon ◽  
Accuracy And Precision ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2 ◽  
Global Carbon ◽  
Comparable Quality

Abstract. In recent years, space-borne observations of atmospheric carbon-dioxide (CO2) have become increasingly used in global carbon-cycle studies. In order to obtain added value from space-borne measurements, they have to suffice stringent accuracy and precision requirements, with the latter being less crucial as it can be reduced by just enhanced sample size. Validation of CO2 column averaged dry air mole fractions (XCO2) heavily relies on measurements of the Total Carbon Column Observing Network TCCON. Owing to the sparseness of the network and the requirements imposed on space-based measurements, independent additional validation is highly valuable. Here, we use observations from the HIAPER Pole-to-Pole Observations (HIPPO) flights from January 2009 through September 2011 to validate CO2 measurements from satellites (GOSAT, TES, AIRS) and atmospheric inversion models (CarbonTracker CT2013B, MACC v13r1). We find that the atmospheric models capture the XCO2 variability observed in HIPPO flights very well, with correlation coefficients (r2) of 0.93 and 0.95 for CT2013B and MACC, respectively. Some larger discrepancies can be observed in profile comparisons at higher latitudes, esp. at 300 hPa during the peaks of either carbon uptake or release. These deviations can be up to 4 ppm and hint at misrepresentation of vertical transport. Comparisons with the GOSAT satellite are of comparable quality, with an r2 of 0.85, a mean bias μ of −0.06 ppm and a standard deviation σ of 0.45 ppm. TES exhibits an r2 of 0.75, μ of 0.34 ppm and σ of 1.13 ppm. For AIRS, we find an r2 of 0.37, μ of 1.11 ppm and σ of 1.46 ppm, with latitude-dependent biases. For these comparisons at least 6, 20 and 50 atmospheric soundings have been averaged for GOSAT, TES and AIRS, respectively. Overall, we find that GOSAT soundings over the remote pacific ocean mostly meet the stringent accuracy requirements of about 0.5 ppm for space-based CO2 observations.

scholarly journals Development and field testing of a rapid and ultra-stable atmospheric carbon dioxide spectrometer

2014 ◽  
Vol 7 (8) ◽  
pp. 8101-8123
Author(s):  
B. Xiang ◽  
D. D. Nelson ◽  
J. B. McManus ◽  
M. S. Zahniser ◽  
R. Wehr ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Field Test ◽  
Atmospheric Carbon Dioxide ◽  
Field Measurements ◽  
Field Testing ◽  
Thermal Control ◽  
Long Term Ecological Research ◽  
Calibration Protocol ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2

Abstract. We present field test results for a new spectroscopic instrument to measure atmospheric carbon dioxide (CO2) with high precision (0.02 ppm at 1 Hz) and demonstrate high stability (within 0.1 ppm over more than 8 months), without the need for hourly, daily, or even monthly calibration against high-pressure gas cylinders. The technical novelty of this instrument (ABsolute Carbon dioxide, ABC) is the spectral null method using an internal quartz reference cell with known CO2 column density. Compared to a previously described prototype, the field instrument has better stability and benefits from more precise thermal control of the optics and more accurate pressure measurements in the sample cell (at the mTorr level). The instrument has been deployed at a long-term ecological research site (the Harvard Forest, USA), where it has measured for eight months without on-site calibration and with minimal maintenance, showing drift bounds of less than 0.1 ppm. Field measurements agree well with those of another commercially available cavity ring-down CO2 instrument (Picarro G2301) run with a standard calibration protocol. This field test demonstrates that ABC is capable of performing high-accuracy, unattended, continuous field measurements with minimal use of calibration cylinders.

scholarly journals Assessment of recent advances in measurement techniques for atmospheric carbon dioxide and methane observations

2016 ◽  
Vol 9 (9) ◽  
pp. 4737-4757 ◽  
Author(s):  
Christoph Zellweger ◽  
Lukas Emmenegger ◽  
Mohd Firdaus ◽  
Juha Hatakka ◽  
Martin Heimann ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Measurement Techniques ◽  
Spectroscopic Techniques ◽  
Cavity Output ◽  
The World ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2 ◽  
Improved Accuracy ◽  
Flame Ionisation

Abstract. Until recently, atmospheric carbon dioxide (CO2) and methane (CH4) measurements were made almost exclusively using nondispersive infrared (NDIR) absorption and gas chromatography with flame ionisation detection (GC/FID) techniques, respectively. Recently, commercially available instruments based on spectroscopic techniques such as cavity ring-down spectroscopy (CRDS), off-axis integrated cavity output spectroscopy (OA-ICOS) and Fourier transform infrared (FTIR) spectroscopy have become more widely available and affordable. This resulted in a widespread use of these techniques at many measurement stations. This paper is focused on the comparison between a CRDS "travelling instrument" that has been used during performance audits within the Global Atmosphere Watch (GAW) programme of the World Meteorological Organization (WMO) with instruments incorporating other, more traditional techniques for measuring CO2 and CH4 (NDIR and GC/FID). We demonstrate that CRDS instruments and likely other spectroscopic techniques are suitable for WMO/GAW stations and allow a smooth continuation of historic CO2 and CH4 time series. Moreover, the analysis of the audit results indicates that the spectroscopic techniques have a number of advantages over the traditional methods which will lead to the improved accuracy of atmospheric CO2 and CH4 measurements.

scholarly journals Preservation of terrestrial organic carbon in marine sediments off shore Taiwan: mountain building and atmospheric carbon dioxide sequestration

2013 ◽  
Vol 1 (1) ◽  
pp. 177-206
Author(s):  
S.-J. Kao ◽  
R. G. Hilton ◽  
K. Selvaraj ◽  
M. Dai ◽  
F. Zehetner ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Organic Carbon ◽  
Marine Sediments ◽  
Atmospheric Carbon Dioxide ◽  
Climatic Variability ◽  
Deep Ocean ◽  
Sediment Traps ◽  
Terrestrial Biosphere ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2

Abstract. Geological sequestration of atmospheric carbon dioxide (CO2) can be achieved by the erosion of organic carbon (OC) from the terrestrial biosphere and its burial in long-lived marine sediments. Rivers on mountain islands of Oceania in the western Pacific have very high rates of OC export to the ocean, yet its preservation offshore remains poorly constrained. Here we use the OC content (Corg, %), radiocarbon (Δ14Corg) and stable isotope (δ13Corg) composition of sediments offshore Taiwan to assess the fate of terrestrial OC. We account for rock-derived fossil OC to assess the preservation of OC eroded from the terrestrial biosphere (non-fossil OC) during flood discharges (hyperpycnal river plumes) and when river inputs are dispersed more widely (hypopycnal). The Corg, Δ14Corg and δ13Corg of marine sediment traps and cores indicate that during flood discharges, terrestrial OC is transferred efficiently to the deep ocean and accumulates offshore with little evidence for terrestrial OC loss. In marine sediments fed by dispersive river inputs, the Corg, Δ14Corg and δ13Corg are consistent with mixing of marine OC and terrestrial OC and suggest that efficient preservation of terrestrial OC (> 70%) is also associated with hypopycnal delivery. Re-burial of fossil OC is pervasive. Our findings from Taiwan suggest that erosion and marine burial of terrestrial non-fossil OC may sequester > 8 TgC yr−1 across Oceania, a significant geological CO2 sink which requires better constraint. We postulate that mountain islands of Oceania provide strong link between tectonic uplift and the carbon cycle, one moderated by the climatic variability that controls terrestrial OC delivery to the ocean.

scholarly journals Chemical weathering and consumption of atmospheric carbon dioxide in the Alpine region

2016 ◽  
Vol 136 ◽  
pp. 65-81 ◽  
Author(s):  
Marco Donnini ◽  
Francesco Frondini ◽  
Jean-Luc Probst ◽  
Anne Probst ◽  
Carlo Cardellini ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Chemical Weathering ◽  
Alpine Region ◽  
Atmospheric Carbon

scholarly journals Enhanced chemical weathering as a geoengineering strategy to reduce atmospheric carbon dioxide, supply nutrients, and mitigate ocean acidification

2013 ◽  
Vol 51 (2) ◽  
pp. 113-149 ◽  
Author(s):  
Jens Hartmann ◽  
A. Joshua West ◽  
Phil Renforth ◽  
Peter Köhler ◽  
Christina L. De La Rocha ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
Chemical Weathering ◽  
Atmospheric Carbon

scholarly journals Rapid response of silicate weathering rates to climate change in the Himalaya

2021 ◽  
Author(s):  
Anthony Dosseto ◽  
Nathalie Vigier ◽  
Renaud Joannes-Boyau ◽  
Ian Moffat ◽  
Tejpal Singh ◽  
...  
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Chemical Weathering ◽  
Tight Coupling ◽  
Weathering Rates ◽  
Fluvial Terraces ◽  
Physical Erosion ◽  
Atmospheric Carbon ◽  
Earth’S Climate

Chemical weathering of continental rocks plays a central role in regulating the carbon cycle and the Earth’s climate (Walker et al., 1981; Berner et al., 1983), accounting for nearly half the consumption of atmospheric carbon dioxide globally (Beaulieu et al., 2012). However, the role of climate variability on chemical weathering is still strongly debated. Here we focus on the Himalayan range and use the lithium isotopic composition of clays in fluvial terraces to show a tight coupling between climate change and chemical weathering over the past 40 ka. Between 25 and 10 ka ago, weathering rates decrease despite temperature increase and monsoon intensification. This suggests that at this timescale, temperature plays a secondary role compared to runoff and physical erosion, which inhibit chemical weathering by accel-erating sediment transport and act as fundamental controls in determining the feedback between chemical weathering and atmospheric carbon dioxide.

scholarly journals Towards a stable and absolute atmospheric carbon dioxide instrument using spectroscopic null method

2013 ◽  
Vol 6 (7) ◽  
pp. 1611-1621 ◽  
Author(s):  
B. Xiang ◽  
D. D. Nelson ◽  
J. B. McManus ◽  
M. S. Zahniser ◽  
S. C. Wofsy
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Field Measurements ◽  
Term Operation ◽  
Long Term Stability ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2 ◽  
Stability And Accuracy ◽  
Spectral Null

Abstract. We present a novel spectral method to measure atmospheric carbon dioxide (CO2) with high precision and stability without resorting to calibration tanks during long-term operation. This spectral null method improves precision by reducing spectral proportional noise associated with laser emission instabilities. We employ sealed quartz cells with known CO2 column densities to serve as the permanent internal references in the null method, which improve the instrument's stability and accuracy. A prototype instrument – ABsolute Carbon dioxide (ABC) is developed using this new approach. The instrument has a one-second precision of 0.02 ppm, which averages down to 0.007 ppm within one minute. Long-term stability of within 0.1 ppm is achieved without any calibrations for over a one-month period. These results have the potential for eliminating the need for calibration cylinders for high accuracy field measurements of carbon dioxide.

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