Environmental Science & Technology · 1996 · 61 citations · 9 references
EngineeringEnvironmental EngineeringSoil SciencesAerodynamicsSoil PhysicsSoil ScienceAir Pollution InstrumentationAirflow DistributionExperimental AerodynamicsGreenhouse Gas FluxesSoil-atmosphere ExchangeSoil-plant-atmosphere InteractionsEmission FluxesField MeasurementsFumigationGas Flux MeasurementGreenhouse Gas EmissionsMethyl Bromide FumigationSoil Gas FluxesSoil Greenhouse Gas Emissions
Dynamic or flow‑through flux chambers are convenient tools for field measurements of gas fluxes from soils to the atmosphere. This study designs and fabricates a dynamic flux chamber based on aerodynamic principles to satisfy the assumptions of the flux model. The chamber features an inlet transition zone, a square main body, an outlet transition zone, and six equally‑spaced air channels that create a simple, horizontal, uniform airstream over the soil, and it was employed in a field fumigation experiment to measure methyl bromide emission. Laboratory aerodynamic tests confirm a constant airflow over the soil with no stagnant zones, and field measurements of methyl bromide emission agree with micrometeorological methods.
Dynamic or flow-through flux chambers are convenient tools for field measurements of gas fluxes from soils to the atmosphere. In this study, a dynamic flux chamber is designed and fabricated on the basis of aerodynamic considerations so that the conditions assumed for the flux model are closely satisfied. The chamber consists of an inlet transition zone, a square main body, and an outlet transition zone. Six equally-spaced air channels are installed in both inlet and outlet transition zones to conduct and spread the flowing air uniformly across the soil surface, which help to produce a simple, horizontal, and uniform airstream above the covered soil surface. Aerodynamic tests in the laboratory show that the air sweeps over the entire covered soil surface with a relatively constant velocity at a given air flow rate, and no stagnant air zones are present. The chamber is used in a field fumigation experiment to measure methyl bromide emission at the soil surface. The emission results obtained from the chamber are consistent with those obtained from micrometeor- ological methods used in the same experiment.
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