General information
Title: The dynamical impact of aircraft on clouds and climate - 'distrails' (BI0005)
Supervisors: Dr Edward Gryspeerdt, Professor Oliver Buxton
Reference code: BI0005
Project overview
The trailing vortex generated by aircraft is recognised as a safety risk to aircraft, but recent work suggests that is could also have a significant climate impact. Aircraft often fly just above cloud, such that the trailing vortex mixes non-cloudy air down into the cloud, thinning it and lowering the cloud top. This effect is known as a ‘distrail’. By reducing high clouds, distrails can cool the climate, with initial estimates suggesting it might offset as much as 25% of the aviation warming from CO2 and contrails. However, the size of this cooling effect is uncertain. Variations in the vortex mixing between different aircraft and operational choices modifying the relative positions of aircraft mean that not all aircraft have the same effect. The factors controlling clouds are also highly variable and clouds will likely respond differently to an addition of dry air at the cloud top based on their meteorological environment and their formation mechanism. This leaves the overall size of this effect highly uncertain at a global scale.
In this project, you will produce the first global assessment of the climate impact of distrails, using a range of satellite observations, meteorological data and aircraft observations to identify where the impact of distrails is strongest and how this varies around the globe. Combining this with computational modelling and wind tunnel experiment to assess the controls on aircraft induced mixing, you will assess how possible changes to aircraft routing might enhance (or reduce) this effect – determining how it might change in response to future changes in air traffic.
Research objectives
The project will:
- Produce the first global assessment of the climate impact of aircraft-induced distrails using satellite observations, meteorological data and aircraft observations.
- Determine where and under which atmospheric conditions distrails have the greatest influence on cloud properties and climate, and how this varies geographically around the world.
- Quantify how variations in aircraft wake vortices, aircraft type and operational parameters influence cloud-top mixing and distrail formation.
- Develop and apply computational models and wind-tunnel experiments to improve understanding of the mechanisms controlling aircraft-induced mixing and cloud response.
- Assess how changes in aircraft routing, operations and future air-traffic patterns could enhance or reduce the climate impact of distrails, and evaluate the resulting implications for aviation's overall climate effects.
Contact
We welcome enquiries from prospective applicants interested in the project or the doctoral programme. Please use the contacts below, depending on the nature of your enquiry.
Doctoral programme related enquires
brahmal-aviation@imperial.ac.uk
Project related enquires
- Dr Edward Gryspeerdt (primary)
- Professor Oliver Buxton
