scholarly journals Dynamics of methane ebullition from a peat monolith revealed from a dynamic flux chamber system

2014 ◽  
Vol 119 (9) ◽  
pp. 1789-1806 ◽  
Author(s):  
Zhongjie Yu ◽  
Lee D. Slater ◽  
Karina V. R. Schäfer ◽  
Andrew S. Reeve ◽  
Ruth K. Varner
Keyword(s):  
Chamber System ◽  
Flux Chamber ◽  
Dynamic Flux Chamber ◽  
Methane Ebullition

scholarly journals Tidal controls on trace gas dynamics in a seagrass meadow of the Ria Formosa lagoon (southern Portugal)

2015 ◽  
Vol 12 (6) ◽  
pp. 1683-1696 ◽  
Author(s):  
E. Bahlmann ◽  
I. Weinberg ◽  
J. V. Lavrič ◽  
T. Eckhardt ◽  
W. Michaelis ◽  
...  
Keyword(s):  
Trace Gases ◽  
Coastal Areas ◽  
Transport Processes ◽  
Trace Gas ◽  
Series Data ◽  
Chamber System ◽  
Flux Chamber ◽  
Seagrass Meadows ◽  
Phytoplankton Communities ◽  
Dynamic Flux Chamber

Abstract. Coastal zones are important source regions for a variety of trace gases, including halocarbons and sulfur-bearing species. While salt marshes, macroalgae and phytoplankton communities have been intensively studied, little is known about trace gas fluxes in seagrass meadows. Here we report results of a newly developed dynamic flux chamber system that can be deployed in intertidal areas over full tidal cycles allowing for highly time-resolved measurements. The fluxes of CO2, methane (CH4) and a range of volatile organic compounds (VOCs) showed a complex dynamic mediated by tide and light. In contrast to most previous studies, our data indicate significantly enhanced fluxes during tidal immersion relative to periods of air exposure. Short emission peaks occurred with onset of the feeder current at the sampling site. We suggest an overall strong effect of advective transport processes to explain the elevated fluxes during tidal immersion. Many emission estimates from tidally influenced coastal areas still rely on measurements carried out during low tide only. Hence, our results may have significant implications for budgeting trace gases in coastal areas. This dynamic flux chamber system provides intensive time series data of community respiration (at night) and net community production (during the day) of shallow coastal systems.

scholarly journals Tidal controls on trace gas dynamics in a seagrass meadow of the Ria Formosa lagoon (southern Portugal)

2014 ◽  
Vol 11 (7) ◽  
pp. 10571-10603 ◽  
Author(s):  
E. Bahlmann ◽  
I. Weinberg ◽  
J. V. Lavrič ◽  
T. Eckhard ◽  
W. Michaelis ◽  
...  
Keyword(s):  
Trace Gases ◽  
Coastal Areas ◽  
Transport Processes ◽  
High Time ◽  
Trace Gas ◽  
Series Data ◽  
Chamber System ◽  
Flux Chamber ◽  
Time Resolved ◽  
Dynamic Flux Chamber

Abstract. Coastal zones are important source regions for a variety of trace gases including halocarbons and sulphur-bearing species. While salt-marshes, macroalgae and phytoplankton communities have been intensively studied, little is known about trace gas fluxes in seagrass meadows. Here we report results of a newly developed dynamic flux chamber system that can be deployed in intertidal areas over full tidal cycles allowing for high time resolved measurements. The trace gases measured in this study included carbon dioxide (CO2), methane (CH4) and a variety of hydrocarbons, halocarbons and sulphur-bearing compounds. The high time resolved CO2 and CH4 flux measurements revealed a complex dynamic mediated by tide and light. In contrast to most previous studies our data indicate significantly enhanced fluxes during tidal immersion relative to periods of air exposure. Short emission peaks occured with onset of the feeder current at the sampling site. We suggest an overall strong effect of advective transport processes to explain the elevated fluxes during tidal immersion. Many emission estimates from tidally influenced coastal areas still rely on measurements carried out during low tide only. Hence, our results may have significant implications for budgeting trace gases in coastal areas. This dynamic flux chamber system provides intensive time series data of community respiration (at night) and net community production (during the day) of shallow coastal systems.

Improved Chamber Systems for Rapid, Real-Time Nitrous Oxide Emissions from Manure and Soil

2017 ◽  
Vol 60 (4) ◽  
pp. 1235-1258 ◽  
Author(s):  
David B. Parker ◽  
Kenneth D. Casey ◽  
Richard W. Todd ◽  
Heidi M. Waldrip ◽  
Gary M. Marek ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Greenhouse Gas ◽  
Real Time ◽  
Nitrous Oxide Emissions ◽  
Chamber System ◽  
Flux Chamber ◽  
Total N ◽  
Recirculating Flow ◽  
Flux Measurements ◽  
Flow Through

Abstract. Nitrous oxide (N2O) emission rates have traditionally been measured using non-flow-through (NFT), non-steady-state (NSS) chambers, which rely on measuring the increase in N2O concentration in the sealed chamber headspace over time. These flux measurements are very labor- and time-intensive, requiring three to four gas samples collected over a 30 to 60 min period, followed by laboratory N2O measurement with a gas chromatograph (GC) and subsequent flux rate calculation. The objective of this research was to develop and evaluate improved, real-time flux chamber designs that rapidly quantify N2O emissions from manure and soil. The first chamber system consisted of six square 0.95 m2 chamber pans. The chamber pans were mounted on a rail system to facilitate controlled indoor/outdoor laboratory research at a pilot scale. An aluminum lid was moved among the chamber pans. A second portable chamber system with a circular footprint (0.49 m internal dia.) was designed for use in field measurements. With both systems, N2O concentrations were measured each second with 0.1 ppb resolution by recirculating sample air through a real-time continuous N2O analyzer with return flow into the recirculating-flow-through (RFT-NSS) chamber. Performance and observational data are presented for different chamber vent designs, sealing mechanisms between the chamber pan and lid, recirculation pumps, and presence/absence of an internal fan that mixes headspace air within the sealed chamber. As examples of the repeatability and precision of the methodology, ten consecutive flux measurements were obtained using moist manure (32.6% wet basis water content, WCWB) within a 15 min period in which chamber pans were fitted with lids for 60 s and removed for 30 s. The mean calculated N2O flux was 43.08 ±0.89 mg N2O m-2 h-1. Using dry manure (WCWB = 10.8%), five consecutive flux measurements showed a very low, but consistent, flux that averaged 0.025 ±0.0016 mg N2O m-2 h-1. Five case study experiments demonstrate the usefulness of these chamber systems and highlight discoveries and lessons learned to enhance future research efforts. Major discoveries and observations include: (1) installation of a small internal fan within the chamber lids decreased N2O fluctuation over small time periods, allowing precise measurement of manure N2O fluxes as low as 0.0073 mg N2O m-2 h-1 during a 60 s measurement period; (2) two distinct N2O peaks were observed at 1 and 21 d following the addition of water to manure (initial WCWB = 32.6%), with the second peak accounting for 83% of the total N2O emitted over 45 d; and (3) there was notable diurnal variation in N2O fluxes due to temperature variation, even when the manure was dry (WCWB = 10.8%). These flux chamber systems proved to be more rapid, precise, and repeatable than traditional flux chamber methods and offer promise for future greenhouse gas emissions research on manure and soil. Keywords: Cattle, Chamber, Diurnal, Fan, Feedlot, Greenhouse gas, Manure, Precision.

Passive diffusive flux chambers – a new method to quantify vapour intrusion into indoor air

2018 ◽  
Vol 20 (3) ◽  
pp. 523-530 ◽  
Author(s):  
Adrian C. Heggie ◽  
Bill Stavropoulos
Keyword(s):  
Risk Assessment ◽  
Indoor Air ◽  
New Method ◽  
Diffusive Flux ◽  
Flux Chamber ◽  
Contaminated Land ◽  
Mass Fluxes ◽  
Dynamic Flux Chamber ◽  
Flux Chambers

A conceptually new method to quantify mass fluxes of toxic vapours for contaminated land risk assessment applications was developed and compared against the traditional dynamic flux chamber.

scholarly journals Key Factors in Measuring Ammonia Emissions with Dynamic Flux Chamber in Barns

2020 ◽  
Vol 12 (15) ◽  
pp. 6276
Author(s):  
Seongmin Kang ◽  
Yoonjung Hong ◽  
Moon Soon Im ◽  
Seong-Dong Kim ◽  
Eui-Chan Jeon
Keyword(s):  
Large Sample Size ◽  
Key Factors ◽  
Flux Chamber ◽  
Stabilization Time ◽  
Real Time Measurement ◽  
Livestock Sector ◽  
Seasonal Factors ◽  
Emissions Factor ◽  
Dynamic Flux Chamber ◽  
Ammonia Flux

In this study, measurement methods for estimating the NH3 emissions in barns and the development of different emission factors were reviewed, and the factors to be considered when applying a dynamic flux chamber approach were analyzed. First, one of the factors to be considered when applying the dynamic flux chamber was determined as the stabilization time in the chamber. As a result of the experiment, it was confirmed that the concentration in the chamber stabilized after 45 min. This is considered to take longer than the stabilization time of 20 min suggested in the previous study. The second is the choice of the measurement method. This method includes real-time measurement and the indophenol method. As a result of the experiment in both methods, the ammonia flux showed a difference of about 10%, so both methods are considered to be considered. Therefore, it is judged that the methodology should be selected according to the situation, such as weather or electric power secured at the barn site. In the future, if studies on whether the stabilization time in the chamber can be changed according to seasonal factors and ambient temperature, and based on a sufficiently large sample size, the results will contribute to improving the reliability of the estimated ammonia(NH3) emissions and the development of an emissions factor for use in the livestock sector in Korea.

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