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 15 of 15 for “"Chemical Transport Models"”.
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Development and Acceleration of Parallel Chemical Transport Models
Improving chemical transport models for atmospheric simulations relies on future developments of mathematical methods and parallelization methods. Better mathematical methods allow simulations to more accurately model realistic processes and/or to run in a shorter amount of time. Parellization …
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Deducing trace gas emissions using an inverse method in three-dimensional chemical transport models
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1993.
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Large-Scale Simulations Using First and Second Order Adjoints with Applications in Data Assimilation
… can be achieved by incorporating adjoint models, which are efficient in computing the derivatives of a functional with respect to a large number of model parameters. In this research we employ first order adjoints in air quality simulations. Moreover, we explore theoretically the …
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A Better Tropospheric Aerosol Analysis and Forecast Using Data Assimilation and Coupled Modeling
Chemical transport models are useful to predict air pollutant concentrations and provide advice to people to minimize adverse impacts of high levels of tropospheric aerosols and ozone. This dissertation incorporated a coupled model between meteorology and air quality, as well as data assimilation …
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Optimal determination of global tropospheric OH concentrations using multiple trace gases
… the predicted mixing ratios from atmospheric chemical-transport models and, for the first time, all the measurements of the various titrating gases simultaneously. A two dimensional land-ocean-resolving (LO) statisticaldynamical model and a 12-box model are used to predict the concentrations …
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On the Understanding of the Coastal-Urban Nexus of Weather, Air Quality and Energy
… limitations of urban canopy representation in chemical transport models for forecasting air quality events. The results highlight the importance of accurately representing urban physical processes in weather and air quality models for understanding and addressing air pollution and energy …
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Laboratory studies of atmospheric photochemistry in indoor and outdoor environments
… particulate matter formed through indirect photochemical reactions, influences the climate and contributes to air pollution harmful to human health. While these two effects act at different scales, they are governed by similar chemical processes. This work investigates the atmospheric …
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Air quality impacts and benefits under U.S. policy for air pollution, climate change, and clean energy
… by estimating pollution changes with regional chemical transport models, then applying economic valuations directly to estimates of reduced health risks. In this dissertation, I incorporate and build on this approach by representing the effect of pollution reductions across regions and income …
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Particle-resolved aerosol modeling on the regional scale – insights into importance of capturing aerosol mixing state
… the atmosphere are complex mixtures of different chemical species, and their compositions are constantly evolving as coagulation and multiphase processes act on the particle population. The particles interact with the climate system directly by scattering and absorbing solar radiation, and …
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The Changing Role of Reactive Nitrogen in the Troposphere
… oxidized nitrogen (NOy) species, even modern chemical transport models have struggled to accurately represent their chemistry. This thesis spans three projects that seek to characterize and explain possible sources of this uncertainty. The first project presents a comprehensive budget of …
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Computational Tools for Chemical Data Assimilation with CMAQ
… as receptor-oriented sensitivity analysis and chemical data assimilation. This thesis presents the construction, validation, and properties of new adjoint modules in CMAQ, and illustrates their use in sensitivity analyses and data assimilation experiments. The new module of discrete adjoint of …
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Efficient Computational Tools for Variational Data Assimilation and Information Content Estimation
… of this dissertation are to advance the field of chemical data assimilation, and to develop efficient computational tools that allow the atmospheric science community benefit from state of the art assimilation methodologies. Data assimilation is the procedure to combine data from observations with …
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A case study of weather research and forecasting model over the Midwest USA
Chemical Transport Models (CTMs) are important tools for air quality research, and it is of the same importance to provide accurate weather information as input data to CTMs. In this thesis, the Weather Research and Forecast (WRF) model was used as an input to a CTM and a sensitivity analysis of 17 …
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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
… formation and reactive nitrogen deposition using chemical transport models (CTMs), require representative NH3 emission inventories that capture source specific spatial and temporal variability. Of particular interest are NH3 emissions from chemical fertilizer usage for agriculture that are highly …
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Urban-scale impacts on the global-scale composition and climate effects of anthropogenic aerosols
… produced to simulate the effects of physical, chemical, and meteorological processing of highly reactive trace species in hypothetical urban areas, which is capable of efficiently simulating the urban concentration, surface deposition, and net mass flux of these species. A polynomial chaos …