Carbon Dioxide Flux and Carbon and Helium Isotopic Composition of Soil Gases Across the FORGE Site and Opal Mound Fault, Utah

2019 ◽  
Author(s):  
Kristen Rahilly ◽  
Stuart Simmons ◽  
Tobias P. Fischer
Keyword(s):  
Carbon Dioxide ◽  
Isotopic Composition ◽  
Carbon Dioxide Flux ◽  
Helium Isotopic Composition ◽  
Soil Gases

scholarly journals Carbon dioxide fluxes increase from day to night across European streams

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Katrin Attermeyer ◽  
Joan Pere Casas-Ruiz ◽  
Thomas Fuss ◽  
Ada Pastor ◽  
Sophie Cauvy-Fraunié ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Large Scale ◽  
Carbon Dioxide Flux ◽  
Time Of Day ◽  
Night Time ◽  
Carbon Dioxide Fluxes ◽  
Large Scale Assessment ◽  
Air Interface ◽  
Flux Variability

AbstractGlobally, inland waters emit over 2 Pg of carbon per year as carbon dioxide, of which the majority originates from streams and rivers. Despite the global significance of fluvial carbon dioxide emissions, little is known about their diel dynamics. Here we present a large-scale assessment of day- and night-time carbon dioxide fluxes at the water-air interface across 34 European streams. We directly measured fluxes four times between October 2016 and July 2017 using drifting chambers. Median fluxes are 1.4 and 2.1 mmol m−2 h−1 at midday and midnight, respectively, with night fluxes exceeding those during the day by 39%. We attribute diel carbon dioxide flux variability mainly to changes in the water partial pressure of carbon dioxide. However, no consistent drivers could be identified across sites. Our findings highlight widespread day-night changes in fluvial carbon dioxide fluxes and suggest that the time of day greatly influences measured carbon dioxide fluxes across European streams.

scholarly journals Vertical advection and nocturnal deposition of ozone over a boreal pine forest

2009 ◽  
Vol 9 (6) ◽  
pp. 2089-2095 ◽  
Author(s):  
Ü. Rannik ◽  
I. Mammarella ◽  
P. Keronen ◽  
T. Vesala
Keyword(s):  
Carbon Dioxide ◽  
Eddy Covariance ◽  
Turbulence Intensity ◽  
Carbon Dioxide Flux ◽  
Pine Forest ◽  
Night Time ◽  
Vertical Advection ◽  
Ozone Deposition ◽  
Storage Change ◽  
Ozone Sink

Abstract. Night-time ozone deposition for a Scots pine forest in Southern Finland was studied at the SMEAR II measurement station by evaluating the turbulent eddy covariance (EC), storage change and vertical advection fluxes. Similarly to night-time carbon dioxide flux, the eddy-covariance flux of ozone was decreasing with turbulence intensity (friction velocity), and storage change of the compound did not compensate the reduction (well-known night-time measurement problem). Accounting for vertical advection resulted in invariance of ozone deposition rate on turbulence intensity. This was also demonstrated for carbon dioxide, verified by independent measurements of NEE by chamber systems. The result highlights the importance of advection when considering the exchange measurements of any scalar. Analysis of aerodynamic and laminar boundary layer resistances by the model approach indicated that the surface resistance and/or chemical sink strength was limiting ozone deposition. The possible aerial ozone sink by known fast chemical reactions with sesquiterpenes and NO explain only a minor fraction of ozone sink. Thus the deposition is controlled either by stomatal uptake or surface reactions or both of them, the mechanisms not affected by turbulence intensity. Therefore invariance of deposition flux on turbulence intensity is expected also from resistance and chemical sink analysis.

scholarly journals FORMATION CONDITIONS OF GROUNDWATER OF THE UPPER JURASSIC OF THE CENTRAL REGIONS OF THE ZAURAL MEGAMONOCLYSIS

2021 ◽  
Vol 2 (1) ◽  
pp. 181-190
Author(s):  
Dmitry A. Novikov ◽  
Aleksandr N. Pyrayev ◽  
Fedor F. Dultsev ◽  
Anatoliy V. Chernykh ◽  
Svetlana V. Bakustina ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Isotopic Composition ◽  
Upper Jurassic ◽  
Biogenic Origin ◽  
Dissolved Carbon ◽  
Dissolved Carbon Dioxide ◽  
Oxygen And Hydrogen Isotopes ◽  
Central Regions ◽  
First Results ◽  
Formation Conditions

The article presents the first results of complex isotope-hydrogeochemical studies of reservoir waters of the Upper Jurassic deposits of the central regions of the Zaural megamonoclysis. It was shown that most waters have a narrow distribution of oxygen and hydrogen isotopes (δD from -103.2 to -85.6 ‰ and δO from -15.4 to -12.9 ‰). Some of them have pronounced excursions on the isotopic composition, which indicates a difference in their genesis: from condensate to mixed with ancient infiltrogenic. The isotopic composition of carbon of water-dissolved carbon dioxide (δС from -41.6 to -16.3 ‰) indicates its biogenic origin and the possibility of interstratal flows from overlying horizons.

scholarly journals Surface flux estimates derived from UAS-based mole fraction measurements by means of a nocturnal boundary layer budget approach

2019 ◽  
Author(s):  
Martin Kunz ◽  
Jost V. Lavric ◽  
Rainer Gasche ◽  
Christoph Gerbig ◽  
Richard H. Grant ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Boundary Layer ◽  
Mole Fraction ◽  
Surface Flux ◽  
Nocturnal Boundary Layer ◽  
Carbon Dioxide Flux ◽  
Unmanned Aircraft ◽  
Atmospheric Conditions ◽  
Transport Modelling ◽  
Stable Conditions

Abstract. The carbon exchange between ecosystems and the atmosphere has a large influence on the Earth system and specifically on the climate. This exchange is therefore being studied intensively, often using the eddy covariance (EC) technique. EC measurements provide reliable results under turbulent atmospheric conditions, but under stable conditions – as they often occur at night – these measurements are known to misrepresent exchange fluxes. Nocturnal boundary layer (NBL) budgets can provide independent flux estimates under stable conditions, but their application so far has been limited by rather high cost and practical difficulties. Unmanned aircraft systems (UASs) equipped with trace gas analysers have the potential to make this method more accessible. We present the methodology and results of a proof of concept study carried out during the ScaleX 2016 campaign. Successive vertical profiles of carbon dioxide dry air mole fraction in the NBL were taken with a compact analyser carried by a UAS. We estimate an average carbon dioxide flux of 12 μmol m−2 s−1, which is plausible for nocturnal respiration in this region in summer. Transport modelling suggests that the NBL budgets represent an area on the order of 100 km2.

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