scholarly journals Gas transport in a confined unsaturated zone during atmospheric pressure cycles

1998 ◽  
Vol 34 (11) ◽  
pp. 2855-2862 ◽  
Author(s):  
Bo Elberling ◽  
Flemming Larsen ◽  
Steen Christensen ◽  
Dieke Postma
Keyword(s):  
Atmospheric Pressure ◽  
Unsaturated Zone ◽  
Gas Transport

scholarly journals Advective and diffusive contributions to reactive gas transport during pyrite oxidation in the unsaturated zone

2007 ◽  
Vol 43 (2) ◽  
Author(s):  
P. J. Binning ◽  
D. Postma ◽  
T. F. Russell ◽  
J. A. Wesselingh ◽  
P. F. Boulin
Keyword(s):  
Unsaturated Zone ◽  
Gas Transport ◽  
Pyrite Oxidation ◽  
Reactive Gas

scholarly journals Field-Scale Sulfur Hexafluoride Tracer Experiment to Understand Long Distance Gas Transport in the Deep Unsaturated Zone

2014 ◽  
Vol 13 (8) ◽  
pp. vzj2014.04.0045 ◽  
Author(s):  
Michelle A. Walvoord ◽  
Brian J. Andraski ◽  
Christopher T. Green ◽  
David A. Stonestrom ◽  
Robert G. Striegl
Keyword(s):  
Unsaturated Zone ◽  
Sulfur Hexafluoride ◽  
Gas Transport ◽  
Tracer Experiment ◽  
Field Scale ◽  
Long Distance

How fast the earth surface breathe? Gas transport in high permeability soils and earth surface discontinuities

2021 ◽  
Author(s):  
Noam Weisbrod ◽  
Maria Dragila ◽  
Elad Levintal
Keyword(s):  
Atmospheric Pressure ◽  
Gas Transport ◽  
Surface Wind ◽  
Earth Surface ◽  
Earth Atmosphere ◽  
Atmospheric Conditions ◽  
Ambient Conditions ◽  
The Earth ◽  
The Media ◽  
Surface Discontinuities

<p>Gas movement within the earth’s subsurface and its exchange with the atmosphere are some of the principal processes in soil, ecosystem, and atmospheric environments. For a decade, our group has explored the roles played by atmospheric conditions and matrix properties in gas transport at the earth-atmosphere interface, where surface discontinuities, such as fractures, boreholes and aggregated soils, exist and may affect the process.</p><p>The gas transport mechanisms, resulting from the development of a thermal gradient and surface wind, were analyzed both independently and in combination. Two types of experiments were carried out: (1) under field conditions and (2) under highly controlled laboratory conditions. During all studies, temperature and wind conditions across the media and at the media-atmosphere interface were monitored. Results show that the magnitudes of thermal- and wind-induced convection were directly related to the media permeability, given favorable ambient conditions at the media-atmosphere interface. Such ambient conditions included high diurnal temperature amplitude (~± 10 ᵒC) or high surface wind (~2 m/s measured 10 m above ground). In addition, specific results from the field experiment were used to establish an empirical model that predicts gas transport magnitude as a function of wind speed and media permeability.</p><p>With respect to other discontinuities, such as boreholes and fractures, the effect of atmospheric conditions was investigated, namely atmospheric pressure and temperature, on air, CO<sub>2</sub>, and radon transport. Using high-resolution spatiotemporal measurements, it was concluded that diurnal atmospheric pressure oscillations (barometric pumping) and borehole-atmospheric temperature differences (thermal-induced convection) controlled the air transport within the boreholes. For one of the boreholes monitored, the air velocities and CO<sub>2</sub> emissions to the atmosphere were quantified (up to ~6 m/min and ~5 g-CO<sub>2</sub>/min, respectively). This reveals the role of boreholes as a source of greenhouse gas emissions.</p><p>The results and conclusions derived from our studies are expected to improve our understanding of the governing mechanisms controlling gas movement in porous media, fractures, and boreholes, and their functions in gas exchange across the earth-atmosphere interface.</p>

Assessment of the effect of atmospheric pressure on the level and ground waters flow

2019 ◽  
Vol 12 (11-12) ◽  
pp. 44-51 ◽  
Author(s):  
S. A. Lavrov ◽  
M. L. Markov
Keyword(s):  
Ground Water ◽  
Water Level ◽  
Atmospheric Pressure ◽  
Unsaturated Zone ◽  
Water Discharge ◽  
Ground Water Level ◽  
Ground Waters ◽  
Barometric Efficiency ◽  
Observation Wells ◽  
Interstitial Air

The problem of understanding the interaction of river and ground water waters is intimately bound to questions of formation and unloading of ground waters in river network. The analysis of the previous researches showed that change of atmospheric pressure affects on the water level in observation wells and water discharge of springs. However, the mechanisms of this influence still weren't completely opened. For the solution of this task the complex laboratory, field and theoretical researches including overseeing by a drain, ground water level, atmospheric pressure and air pressure in an unsaturated (vadose) zone were conducted. On the basis of the conducted researches regularities the connecting size of change of ground water level and a drain of ground water waters with atmospheric pressure were received. As a result of generalization field and laboratory researches it was shown that the crucial role in formation of these regularities is played by the area located over a mirror of ground waters with the isolated interstitial air.With an increase in atmospheric pressure, the volume of interstitial air decreases, and at pressure drop volume increases. It, in turn, leads to change in the level and a flow of ground waters. The settlement formula for numerical assessment of variability of level ground depending on atmospheric pressure (barometric efficiency) and degree of air isolation was received from it in an unsaturated zone. As an indicator of isolation, a characteristic is used such as the volume of interstitial air involved in the inflow (outflow) of water into a measuring well or watercourse and not having direct contact with the atmosphere. Research results showed that, in addition to gravitational force in the movement of ground water and the formation of ground water inflow of rivers and lakes, another force plays a certain role - the pressure difference between atmospheric air and air in the unsaturated zone above the aquifer.

scholarly journals Multimodel analysis of anisotropic diffusive tracer‐gas transport in a deep arid unsaturated zone

2015 ◽  
Vol 51 (8) ◽  
pp. 6052-6073 ◽  
Author(s):  
Christopher T. Green ◽  
Michelle A. Walvoord ◽  
Brian J. Andraski ◽  
Robert G. Striegl ◽  
David A. Stonestrom
Keyword(s):  
Unsaturated Zone ◽  
Gas Transport ◽  
Tracer Gas
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