Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 9 of 9 for “"relaxed-eddy accumulation"”.
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Decomposition of Urban CO2 Fluxes into Fossil and Biogenic Components using a novel Relaxed Eddy Accumulation System
… this thesis is the characterization of a novel relaxed eddy accumulation (REA) system for collection of 14CO2 air samples and its first application in the city of Zurich, Switzerland. The REA system, developed within the ICOS (Integrated Carbon Observation System) Cities project, selects air …
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Carbon fluxes of an extensive meadow and attempts for flux partitioning
… Therefore, micrometeorological methods (Eddy-Covariance – EC, Relaxed Eddy Accumulation – REA), chamber measurements and isotopic methods are applied. First, the investigated area, an extensively managed grassland, was defined as a net carbon sink (–91 g C m–2 a–1) in 2010. Spring …
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Detection and Analysis of Coherent Structures within and above Tall-vegetated Canopies
… flux determination methods such as the eddy covariance and relaxed eddy accumulation techniques. Data were mainly obtained using tower-based single-point turbulence measurements and acoustic remote sensing technique (Sodar-Rass) during extensive field campaigns conducted in summer 2003. …
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Biosphere-atmosphere exchange of ammonia from a fertilized corn canopy in Central Illinois
… Illinois during the 2014 corn-growing season: a relaxed eddy accumulation (REA) system to quantify NH3 flux in 4 h intervals and a flux-gradient (FG) system to quantify 0.5 h averaged NH3 flux. A new method to better the quantify the effect of flux footprint on REA flux measurements was …
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CO2 and Isotope Flux Measurements above a Spruce Forest
… turbulent carbon dioxide (CO2) exchange by the eddy covariance (EC) method has become a fundamental tool for the quantitative determination of the atmospheric CO2 net ecosystem exchange (NEE) and the investigation of the carbon mass balances of ecosystems. Such measurements require a high degree …
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Impact of spatial and temporal distribution of ammonia emissions from chemical fertilizer usage on predictions of air quality in the Midwest United States
… crop, by comparison to measurements using the relaxed eddy accumulation (REA) method. For conditions in Central Illinois (located in the Midwest), DNDC replicated REA measured NH3 fluxes, with greater accuracy for a time period of 33 days after fertilizer usage (correlation coefficient (r) = …
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Biosphere-Atmosphere Exchange of Peroxyacetyl Nitrate: Development of a Flux Measurement System and its Application on a Grassland Ecosystem
… of two flux measurement techniques, hyperbolic relaxed eddy accumulation (HREA) and the modified Bowen ratio (MBR) method, employing a gaschromatograph with electron capture detection (GC-ECD) for PAN analysis. A keystone in its design was the pre-concentration of PAN by capillary columns, which …
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Application of a Mobile Flux Lab for the Atmospheric Measurement of Emissions (FLAME)
… applies a proven, science-based method known as eddy covariance for the direct quantification of anthropogenic emissions to the atmosphere. The mobile flux lab is a tool with novel, multifaceted abilities to assess air quality and improve the fidelity of emission inventories. Measurements of air …