Download or read book Analysing Recent Spatial and Temporal Atmospheric Methane Variations Using Forward and Inverse Modelling written by Christopher James Wilson and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improving Characterization of Anthropogenic Methane Emissions in the United States written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2018-08-25 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding, quantifying, and tracking atmospheric methane and emissions is essential for addressing concerns and informing decisions that affect the climate, economy, and human health and safety. Atmospheric methane is a potent greenhouse gas (GHG) that contributes to global warming. While carbon dioxide is by far the dominant cause of the rise in global average temperatures, methane also plays a significant role because it absorbs more energy per unit mass than carbon dioxide does, giving it a disproportionately large effect on global radiative forcing. In addition to contributing to climate change, methane also affects human health as a precursor to ozone pollution in the lower atmosphere. Improving Characterization of Anthropogenic Methane Emissions in the United States summarizes the current state of understanding of methane emissions sources and the measurement approaches and evaluates opportunities for methodological and inventory development improvements. This report will inform future research agendas of various U.S. agencies, including NOAA, the EPA, the DOE, NASA, the U.S. Department of Agriculture (USDA), and the National Science Foundation (NSF).
Download or read book Lagrangian Modeling of the Atmosphere written by John Lin and published by John Wiley & Sons. This book was released on 2013-05-09 with total page 591 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 200. Trajectory-based (“Lagrangian”) atmospheric transport and dispersion modeling has gained in popularity and sophistication over the previous several decades. It is common practice now for researchers around the world to apply Lagrangian models to a wide spectrum of issues. Lagrangian Modeling of the Atmosphere is a comprehensive volume that includes sections on Lagrangian modeling theory, model applications, and tests against observations. Published by the American Geophysical Union as part of the Geophysical Monograph Series. Comprehensive coverage of trajectory-based atmospheric dispersion modeling Important overview of a widely used modeling tool Sections look at modeling theory, application of models, and tests against observations
Download or read book Analysis of Recent Atmospheric Methane Trends Using Models and Observations written by Joe Ramu McNorton and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of Atmospheric Chemistry written by Guy P. Brasseur and published by Cambridge University Press. This book was released on 2017-06-19 with total page 631 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mathematical modeling of atmospheric composition is a formidable scientific and computational challenge. This comprehensive presentation of the modeling methods used in atmospheric chemistry focuses on both theory and practice, from the fundamental principles behind models, through to their applications in interpreting observations. An encyclopaedic coverage of methods used in atmospheric modeling, including their advantages and disadvantages, makes this a one-stop resource with a large scope. Particular emphasis is given to the mathematical formulation of chemical, radiative, and aerosol processes; advection and turbulent transport; emission and deposition processes; as well as major chapters on model evaluation and inverse modeling. The modeling of atmospheric chemistry is an intrinsically interdisciplinary endeavour, bringing together meteorology, radiative transfer, physical chemistry and biogeochemistry, making the book of value to a broad readership. Introductory chapters and a review of the relevant mathematics make this book instantly accessible to graduate students and researchers in the atmospheric sciences.
Download or read book Fluxes of Atmospheric Methane Using Novel Instruments Field Measurements and Inverse Modeling written by Gregory Winn Santoni and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The atmospheric concentration of methane (CH4) - the most significant non-CO2 anthropogenic long-lived greenhouse gas - stabilized between 1999 and 2006 and then began to rise again. Explanations for this behavior differ but studies agree that more measurements and better modeling are needed to reliably explain the model-data discrepancies and predict future change. This dissertation focuses on measurements of CH4 and inverse modeling of atmospheric CH4 fluxes using field measurements at a variety of spatial scales.
Download or read book Methane Emission from Swedish Mires in Relation to Different Spatial and Temporal Scales written by Catharina Mikkelä and published by . This book was released on 1999 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inverse Modeling of Atmospheric CH4 and Delta C Thirteen CH4 Measurements From Surface Observation Sites to Understand Trends in Global Methane Emissions Over More Than Three Decades written by and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methane (CH4) is the second most important greenhouse gas. Unlike CO2 whose rate of growth in the atmosphere has remained positive and increased in recent decades, the behavior of atmospheric methane is considerably more complex and is much less understood on account of the spatiotemporal variability of its emissions which include biogenic (e.g., wetlands, ruminants, rice agriculture), thermogenic (fossil fuels), and pyrogenic (i.e., biomass burning) sources. After sustained growth during most of the 20th century, the CH4 growth rate declined during the 1980s to the early 2000s. With some surprise, however, the growth rate rebounded in 2007 to 2020. During this same period, the 13CH4/12CH4 ratio of atmospheric CH4 also declined to suggest the post-2006 CH4 growth was caused by an increase in 13CH4-depleted biogenic emissions. This work provides additional insight into the recent behavior of atmospheric methane by performing a global three-dimensional Bayesian inversion of atmospheric CH4 and 13CH4/12CH4 ratios over the period 1983-2015 using NOAA Global Monitoring Laboratory (GML) CH4 measurements obtained from surface observation sites located worldwide and the GEOS-Chem chemical transport model (CTM).
Download or read book Top down Estimate of Methane Emissions in California Using a Mesoscale Inverse Modeling Technique written by and published by . This book was released on 2015 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methane (CH4) is the primary component of natural gas and has a larger global warming potential than CO2. Some recent top-down studies based on observations showed CH4 emissions in California's South Coast Air Basin (SoCAB) were greater than those expected from population-apportioned bottom-up state inventories. In this study, we quantify CH4 emissions with an advanced mesoscale inverse modeling system at a resolution of 8 km × 8 km, using aircraft measurements in the SoCAB during the 2010 Nexus of Air Quality and Climate Change campaign to constrain the inversion. To simulate atmospheric transport, we use the FLEXible PARTicle-Weather Research and Forecasting (FLEXPART-WRF) Lagrangian particle dispersion model driven by three configurations of the Weather Research and Forecasting (WRF) mesoscale model. We determine surface fluxes of CH4 using a Bayesian least squares method in a four-dimensional inversion. Simulated CH4 concentrations with the posterior emission inventory achieve much better correlations with the measurements (R2 = 0.7) than using the prior inventory (U.S. Environmental Protection Agency's National Emission Inventory 2005, R2 = 0.5). The emission estimates for CH4 in the posterior, 46.3 ± 9.2 Mg CH4/h, are consistent with published observation-based estimates. Changes in the spatial distribution of CH4 emissions in the SoCAB between the prior and posterior inventories are discussed. Missing or underestimated emissions from dairies, the oil/gas system, and landfills in the SoCAB seem to explain the differences between the prior and posterior inventories. Furthermore, we estimate that dairies contributed 5.9 ± 1.7 Mg CH4/h and the two sectors of oil and gas industries (production and downstream) and landfills together contributed 39.6 ± 8.1 Mg CH4/h in the SoCAB.
Download or read book Atmospheric Methane written by Mohammad Aslam Khan Khalil and published by . This book was released on 2014-01-15 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Inverse Modeling Approach to Investigate the Global Atmospheric Methane Cycle written by Ralf Hein and published by . This book was released on 1996 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lamto written by Luc Abbadie and published by Springer Science & Business Media. This book was released on 2006-11-22 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesizing 40 years of ongoing ecological research, this book examines the structure, function, and dynamics of the Lamto humid savanna. From the history of the Lamto ecology station, to an overview of enivronmental conditions of the site, and examining the integrative view of energy and nutrient fluxes relative to the dynamics of the region's vegetation, this exacting work is as unique and treasured as Lamto itself.
Download or read book The Late Holocene Atmospheric Methane Budget Reconstructed from Ice Cores written by Logan E. Mitchell and published by . This book was released on 2013 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ice cores are considered the gold standard for recording past climate and biogeochemical changes. However, gas records derived from ice core analysis have until now been largely limited to centennial and longer timescales because sufficient temporal resolution and analytical precision have been lacking, except during rare times when atmospheric concentrations changed rapidly. In this thesis I used a newly developed methane measurement line to make high-resolution, high-precision measurements of methane during the late Holocene (2800 years BP to present). This new measurement line is capable of an analytical precision of 3 ppb using ~120 g samples whereas the previous highest resolution measurements attained a precision of ± 4.1 ppb using 500-1500g samples [MacFarling Meure et al., 2006]. The reduced sample size requirements as well as automation of a significant portion of the analysis process have enabled me to make1500 discrete ice core methane measurements and construct the highest resolution records of methane available over the late Holocene. Ice core samples came from the recently completed West Antarctic Ice Sheet (WAIS) Divide ice core which has as one of its primary scientific objectives to produce the highest resolution records of greenhouse gases, and from the Greenland Ice Sheet Project (GISP2) ice core which is a proven paleoclimate archive. My thesis has the following three components. I first used a shallow ice core from WAIS Divide (WDC05A) to produce a 1000 year long methane record with a ~9 year temporal resolution. This record confirmed the existence of multidecadal scale variations that were first observed in the Law Dome, Antarctica ice core. I then explored a range of paleoclimate archives for possible mechanistic connections with methane concentrations on multidecadal timescales. In addition, I present a detailed description of the analytical methods used to obtain high-precision measurements of methane including the effects of solubility and a new chronology for the WDC05A ice core. I found that, in general, the correlations with paleoclimate proxies for temperature and precipitation were low over a range of geographic regions. Of these, the highest correlations were found from 1400-1600 C.E. during the onset of the Little Ice Age and with a drought index in the headwater region of the major East Asian rivers. Large population losses in Asia and the Americas are also coincident with methane concentration decreases indicating that anthropogenic activities may have been impacting multidecadal scale methane variability. In the second component I extended the WAIS Divide record back to 2800 years B.P. and also measured methane from GISP2D over this time interval. These records allowed me to examine the methane Inter-Polar Difference (IPD) which is created by greater northern hemispheric sources. The IPD provides an important constraint on changes in the latitudinal distribution of sources. We used this constraint and an 8-box global methane chemical transport model to examine the Early Anthropogenic Hypothesis which posits that humans began influencing climate thousands of years ago by increasing greenhouse gas emissions and preventing the onset of the next ice age. I found that most of the increase in methane sources over this time came from tropical regions with a smaller contribution coming from the extratropical northern hemisphere. Based on previous modeling estimates of natural methane source changes, I found that the increase in the southern hemisphere tropical methane emissions was likely natural and that the northern hemispheric increase in methane emissions was likely due to anthropogenic activities. These results also provide new constraints on the total magnitude of pre-industrial anthropogenic methane emissions, which I found to be between the high and low estimates that have been previously published in the literature. For the final component of my thesis I assembled a coalition of scientists to investigate the effects of layering on the process of air enclosure in ice at WAIS Divide. Air bubbles are trapped in ice 60-100m below the surface of an ice sheet as snow compacts into solid ice in a region that is known as the Lock-In Zone (LIZ). The details of this process are not known and in the absence of direct measurements previous researchers have assumed it to be a smooth process. This project utilized high-resolution methane and air content measurements as well as density of ice, [delta] 15N of N2, and bubble number density measurements to show that air entrapment is affected by high frequency (mm scale) layering in the density of ice within the LIZ. I show that previous parameterizations of the bubble closure process in firn models have not accounted for this variability and present a new parameterization which does. This has implications for interpreting rapid changes in trace gases measured in ice cores since variable bubble closure will impact the smoothing of those records. In particular it is essential to understand the details of this process as new high resolution ice core records from Antarctica and Greenland examine the relative timing between greenhouse gases and rapid climate changes.
Download or read book Atmospheric Inverse Estimates of Methane Emissions from Central California written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Methane mixing ratios measured at a tall-tower are compared to model predictions to estimate surface emissions of CH4 in Central California for October-December 2007 using an inverse technique. Predicted CH4 mixing ratios are calculated based on spatially resolved a priori CH4 emissions and simulated atmospheric trajectories. The atmospheric trajectories, along with surface footprints, are computed using the Weather Research and Forecast (WRF) coupled to the Stochastic Time-Inverted Lagrangian Transport (STILT) model. An uncertainty analysis is performed to provide quantitative uncertainties in estimated CH4 emissions. Three inverse model estimates of CH4 emissions are reported. First, linear regressions of modeled and measured CH4 mixing ratios obtain slopes of 0.73 ± 0.11 and 1.09 ± 0.14 using California specific and Edgar 3.2 emission maps respectively, suggesting that actual CH4 emissions were about 37 ± 21% higher than California specific inventory estimates. Second, a Bayesian 'source' analysis suggests that livestock emissions are 63 ± 22% higher than the a priori estimates. Third, a Bayesian 'region' analysis is carried out for CH4 emissions from 13 sub-regions, which shows that inventory CH4 emissions from the Central Valley are underestimated and uncertainties in CH4 emissions are reduced for sub-regions near the tower site, yielding best estimates of flux from those regions consistent with 'source' analysis results. The uncertainty reductions for regions near the tower indicate that a regional network of measurements will be necessary to provide accurate estimates of surface CH4 emissions for multiple regions.
Download or read book IGBP Report written by and published by . This book was released on 2005 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessment of Climate Change over the Indian Region written by R. Krishnan and published by Springer Nature. This book was released on 2020-06-12 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book discusses the impact of human-induced global climate change on the regional climate and monsoons of the Indian subcontinent, adjoining Indian Ocean and the Himalayas. It documents the regional climate change projections based on the climate models used in the IPCC Fifth Assessment Report (AR5) and climate change modeling studies using the IITM Earth System Model (ESM) and CORDEX South Asia datasets. The IPCC assessment reports, published every 6–7 years, constitute important reference materials for major policy decisions on climate change, adaptation, and mitigation. While the IPCC assessment reports largely provide a global perspective on climate change, the focus on regional climate change aspects is considerably limited. The effects of climate change over the Indian subcontinent involve complex physical processes on different space and time scales, especially given that the mean climate of this region is generally shaped by the Indian monsoon and the unique high-elevation geographical features such as the Himalayas, the Western Ghats, the Tibetan Plateau and the adjoining Indian Ocean, Arabian Sea, and Bay of Bengal. This book also presents policy relevant information based on robust scientific analysis and assessments of the observed and projected future climate change over the Indian region.
Download or read book Thriving on Our Changing Planet A Decadal Strategy for Earth Observation from Space written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-06-18 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: We live on a dynamic Earth shaped by both natural processes and the impacts of humans on their environment. It is in our collective interest to observe and understand our planet, and to predict future behavior to the extent possible, in order to effectively manage resources, successfully respond to threats from natural and human-induced environmental change, and capitalize on the opportunities â€" social, economic, security, and more â€" that such knowledge can bring. By continuously monitoring and exploring Earth, developing a deep understanding of its evolving behavior, and characterizing the processes that shape and reshape the environment in which we live, we not only advance knowledge and basic discovery about our planet, but we further develop the foundation upon which benefits to society are built. Thriving on Our Changing Planet: A Decadal Strategy for Earth Observation from Space (National Academies Press, 2018) provides detailed guidance on how relevant federal agencies can ensure that the United States receives the maximum benefit from its investments in Earth observations from space, while operating within realistic cost constraints. This short booklet, designed to be accessible to the general public, provides a summary of the key ideas and recommendations from the full decadal survey report.
