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Cambridge NERC Doctoral Training Partnerships

Graduate Research Opportunities
Brief summary: 
Investigating the role of the lower atmosphere (<50 km altitude) in causing North-South asymmetries in the polar upper atmosphere (>100 km altitude) using a state-of-the-art global climate model
Importance of the area of research concerned: 
The polar regions of the upper atmosphere (100-500 km altitude) play a key role in the interaction of the terrestrial system with outputs from the Sun, which causes “space weather”, analogous to weather near the surface. Space storms are a natural part of space weather. They produce beautiful auroral displays, but also pose a hazard to the increasing number of satellites operating in near-Earth space, as well as technological systems on the ground. To first order, one may assume that the Northern and Southern polar regions are mirror images of each other, and solar-terrestrial coupling symmetric. However, there are important differences between the two hemispheres (Laundal et al., 2017). The lower atmosphere is a possible source of these. Differences in land-sea distribution and topography cause systematic differences in the climate of the Northern and Southern polar regions, which can affect the upper atmosphere via (differences in) upwardly propagating waves. This way, the lower atmosphere could cause large-scale modulations of space weather and space climate. It is essential to understand and quantify this effect to help protect our technology from the effects of space storms.
Project summary : 
This project will use the Whole Atmosphere Climate Model eXtension (WACCM-X) to understand and quantify the impact of North-South asymmetries in the climate near the Earth’s surface on the upper atmosphere (100-500 km altitude). WACCM-X is one of very few models that can simulate the entire atmosphere from surface up to space (up to 500-700 km altitude). It is therefore the ideal tool to investigate coupling between the lower and upper atmosphere. Dedicated model experiments will be set up to isolate the role of North-South asymmetries generated near the surface on the upper atmosphere, for instance by modifying the topography and land/sea distribution within the model. The results will be analyzed to understand better how the lower atmosphere affects the upper atmosphere and quantify this effect in the context of North-South asymmetries.
What will the student do?: 
The student will help to design the finer details of the model experiments with WACCM-X to isolate the effect of North-South asymmetries in the lower atmosphere on the climate of the upper atmosphere. They will be responsible for setting up the experiments, running the model, and analyzing and visualizing the results. The student will be expected to largely develop their own code in Matlab or similar software to do this. They will also compare model outputs to satellite and/or ground-based observations of North-South asymmetries to assess to what extent the observed asymmetries are caused by the lower atmosphere. The student will be expected to take a leading role in writing scientific publications based on the results of the project and also present the results at scientific meetings.
References - references should provide further reading about the project: 
Cnossen, I., & Förster, M. 2016. North-South asymmetries in the polar thermosphere-ionosphere system: Solar cycle and seasonal influences. Journal of Geophysical Research Space Physics, vol. 121, pp. 612-627, doi: 10.1002/2015JA021750.
Förster, M., & Cnossen, I. 2013. Upper atmosphere differences between northern and southern high latitudes: The role of magnetic field asymmetry. Journal of Geophysical Research Space Physics, vol. 118, pp. 5951-5966, doi: 10.1002/jgra.50554.
Laundal, K.M., Cnossen, I., Milan, S.E., Haaland, S.E., Coxon, J., Pedatella, N.M., Förster, M., & Reistad, J.P. 2017. North-South asymmetries in Earth’s magnetic field: Effects on high-latitude geospace, Space Science Reviews, vol. 206, pp. 225-257, doi: 10.1007/s11214-016-0273-0.
You can find out about applying for this project on the British Antarctic Survey (BAS) page.
Ingrid Cnossen
Dr Michael Herzog
British Antarctic Survey Graduate Administrator