Weather influence on aviation NOx climate impacts via ozone and methane

• Main Author: Rosanka, Simon (author)
• Other Authors: Grewe, V. (mentor), Delft University of Technology (degree granting institution)
• Format: Master Thesis
• Language: English
• Published: 2017
• Subjects: North Atlantic
• Online Access: http://resolver.tudelft.nl/uuid:3a8c9694-45ce-426d-bc59-75e4398cdd09

Aviation activities contribute substantially to the anthropogenic climate impact. Due to an increasing demand on aviation transport, multiple mitigation strategies have been established to reduce the contribution to climate change by aviation. One promising strategy is to re-route aircraft, such that climate sensitive atmospheric areas are avoided. This mitigation strategy, depends on the scientific understanding of all processes involved. The European project REACT4C assessed the feasibility of such a mitigation technique by simulating the climate impact of NOx, as well as other emissions and contrail formation for eight distinct weather pattern. For each weather pattern, unit emissions of NOx are emitted in the North Atlantic flight sector. Each air parcel, containing the emitted NOx, is tracked within the atmosphere. This unique model set-up allows to analyse concentration changes of O3 and CH4 along each trajectory. In general, due to the emitted NOx, O3 is produced and CH4 is lost. Most recent results showed that by just increasing the operation cost by 1%, the climate impact can be reduced by about 10%. By comparing climate cost functions (CCF), a metric of the climate impact per unit emission, to weather charts, a link between high pressure ridges and the total climate impact of NOx is observed. Therefore, this research focuses on identifying weather influences on the temporal development of O3 and CH4 due to aviation attributed NOx emission. In this thesis, the NOx chemistry, atmospheric transport processes and the model set-up of the REACT4C project is reviewed. The temporal development analysis of O3 is split-up into two parts, the O3 build-up and the O3 depletion. First, all data from the climate model are re-gridded and chemical production and loss rates are isolated from all other loss terms (i.e. diffusion). Certain characteristics of the temporal concentration changes of O3 are identified. A systematic analysis of the background chemical compounds and all important chemical reactions involved, ...