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Full-Text Articles in Physics
Mechanisms Of Methane Transport Through Trees, Ellynne Marie Kutschera
Mechanisms Of Methane Transport Through Trees, Ellynne Marie Kutschera
Dissertations and Theses
Although the dynamics of methane (CH4) emission from croplands and wetlands have been fairly well investigated, the contribution of trees to global methane emission and the mechanisms of tree transport are relatively unknown. Methane emissions from the common wetland tree species Populus trichocarpa (black cottonwood) native to the Pacific Northwest were measured under hydroponic conditions in order to separate plant transport mechanisms from the influence of soil processes. Roots were exposed to methane enriched water and canopy emissions of methane were measured using a canopy enclosure. Methane accumulation in the canopy was generally linear and the average canopy …
A 30-Year Record Of The Isotopic Composition Of Atmospheric Methane, Doaa Galal Mohammed Teama
A 30-Year Record Of The Isotopic Composition Of Atmospheric Methane, Doaa Galal Mohammed Teama
Dissertations and Theses
Methane (CH4) is one of the most important greenhouse gases after water vapor and carbon dioxide due to its high concentration and global warming potential 25 times than that of CO2 (based on a 100 year time horizon). Its atmospheric concentration has more than doubled from the preindustrial era due to anthropogenic activities such as rice cultivation, biomass burning, and fossil fuel production. However, the rate of increase of atmospheric CH4 (or the growth rate) slowed from 1980 until present. The main reason for this trend is a slowdown in the trend of CH4 sources. …
Investigation Of The Sources And Sinks Of Atmospheric Methane, Christopher Lee Butenhoff
Investigation Of The Sources And Sinks Of Atmospheric Methane, Christopher Lee Butenhoff
Dissertations and Theses
The work presented here represents a number of independent studies that investigated various components of the CH4 budget, namely the sources and sinks. We used a chemical-tracer model and created unique long-term time series of atmospheric CH4, carbon monoxide (CO), molecular hydrogen (H2), and methylchloroform (CH3CCl3) measurements at marine background air to derive histories of atmospheric hydroxyl radical (OH) - the main chemical oxidant of CH4, biomass burning - an important source of CH4 in the tropics, and emissions of CH4 from rice paddies - one of …