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 20 of 23 for “"contrail"”.
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Assessment of a global contrail modeling method and operational strategies for contrail mitigation
… have raised concerns about the impacts of contrails and aviation-induced cirrus on climate. Increasing demand for aviation will further increase contrail formation. This thesis provides a model to assess operational options for reducing contrail coverage. This model couples realistic flight …
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Development and Evaluation of Contrail Models
Condensation trails (contrails) are aircraft-induced ice clouds that are estimated to account for up to 50% of aviation’s climate impacts. Uncertainties in the impact of individual contrails have motivated the development of contrail models, such as CoCiP, a 0-D rapid assessment model, and APCEMM, …
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Design of Experiments for Contrail Avoidance
Condensation trails (contrails) are line-shaped clouds that form behind aircraft and contribute more to climate change each year than any other form of aircraft emissions. While most contrails have little effect on the climate because they dissipate quickly, contrails persist when they form in …
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Evaluating Fuel-Climate Tradeoffs in Contrail Avoidance
Contrails, the line-shaped clouds that can form behind airplanes, have been estimated to be a major contributor to aviation-induced climate change. Operational contrail avoidance via flight re-routing may be an effective and efficient mitigation approach due to the geometry of contrail-forming …
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Aircraft cruise phase altitude optimization considering contrail avoidance
Contrails have been suggested as one of the main contributors to aviation-induced climate impact in recent years. To reduce the climate impact of contrails, mitigation policies such as taxation will be necessary in the future to incentivize jet aircraft operators to reduce contrail production. …
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An Investigation into Contrail Observability from Different Satellite Platforms
Contrails are line-shaped ice clouds that can form behind aircraft engines and, under certain cold and moist conditions, spread into contrail cirrus that persists for several hours. By adding to the existing cloud cover, contrails can act to either cool or warm, with the latter, on average, being …
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Quantifying and reducing the uncertainties in global contrail radiative forcing
Condensation trails, or contrails, are line-shaped ice clouds that form in the exhaust plume of aircraft engines under sufficiently cold and humid conditions. They can persist for several hours, growing to be indistinguishable from natural cirrus clouds. Numerical simulations of contrails …
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Improving the temporal consistency of satellite-based contrail detections using ensemble Kalman filtering
Condensation trails or contrails are line-shaped ice clouds which can form behind aircraft, and current estimates indicate that they account for the majority of aviation’s climate impacts. While contrail models exist to estimate these effects, a lack of experimental or observational data makes them …
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Satellite-based Analysis and Forecast Evaluation of Aviation Contrails
… over half of this aviation-induced forcing, with contrails and contrail cirrus being the largest contributor. Contrails (short for condensation trails) are the lineshaped clouds that form as a result of the warmer, moister engine exhaust mixing with the colder ambient air. When the air is ice …
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Satellite-based detection of contrails using deep learning
Aircraft condensation trails, known as contrails, are estimated to account for approximately half of all climate warming resulting from aviation emissions, but uncertainty in coverage is high [12, 2]. These artificial clouds form behind aircraft and trap outgoing infrared radiation, leading to a …
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Relationship between synoptic scale meteorology, aircraft parameters, and observable contrails
Long-lasting or "persistent" contrails are line-shaped clouds that form when airplanes fly through cold and humid parts of the atmosphere that are ice-supersaturated. Various studies have shown that persistent contrails may be responsible for more than half of aviation’s radiative forcing [1]. …
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Klimawirkung von Kondensstreifen: Untersuchungen mit einem globalen atmosphärischen Zirkulationsmodell
A parameterization of line-shaped contrails for use within the framework of a general circulation model (ECHAM) was developed for the first time. Contrail coverage, optical properties and radiative forcing are calculated at any model time step depending in a physically based manner on the …
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Non-CO₂ environmental impacts of transportation fuel use and production
… changes in radiative forcing (RF) generated by contrails and contrail cirrus in the scenario of a widespread use of alternative jet fuels in the U.S. The Contrail Evolution and Radiation Model (CERM) is developed to simulate contrail and contrail cirrus cover, properties and radiative forcing …
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Multi-scale path planning for reduced environmental impact of aviation
… aircraft trajectories which mitigate persistent contrail formation, avoid areas of convective weather, and seek a minimum fuel solution. Areas conducive to persistent contrail formation and areas of convective weather occur at disparate temporal and spatial scales, and thereby require the …
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Constraining climate impact uncertainties from future aviation
… the difficulty of validating modeling tools e.g. contrail formation and persistence or stratospheric chemical response to emissions; and (iii) the growing interest in new air transportation technologies such as unmanned aerial vehicles, supersonic aviation, or hydrogen and alternative fuels. These …
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Past, present, and future climate impacts of aviation
… emissions inventory described above. Since contrails are responsible for an estimated 57% of aviation’s effective radiative forcing, we place a particular focus on modeling contrails. Using a mediumfidelity aircraft plume model and ERA5 reanalysis weather data, our results indicate that …
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Micro-physical modeling of aircraft exhaust plumes and condensation Trails
… neglect micro-physical processes, such as contrail formation, occurring in aircraft wakes. This assumption leads to inaccurate estimates of NOy partitioning, and thus, an over-prediction of ozone production. To account for non-linear plume processes, a Lagrangian aircraft plume model has …
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Studies towards assessing the effects of aviation on climate
… under certain atmospheric conditions can lead to contrail formation; and soot and other particles that along with contrails can affect the amount and characteristics of cirrus clouds. Soot and sulfate particles can also change the cloudiness by acting as cloud condensation nuclei. Due to the high …
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Comparative Assessment of the Societal Cost of PtL and LH₂ as Aviation Fuels
… LH₂ aircraft design, and warming from persistent contrail formation.
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The Effect of Reducing Cruise Altitude on the Topology and Emissions of a Commercial Transport Aircraft
… oxides are released into the atmosphere and contrail formation is less likely. The following study was performed using multidisciplinary design optimization (MDO) in ModelCenterTM for cantilever wing, strut-braced wing, and truss-braced wing designs and optimized for minimum takeoff gross …
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