Abstract
Our understanding of the Earth's atmospheric dynamics and associated variability across all altitudes, is not well constrained. Observations of the atmosphere are needed to ensure that the dynamics are accurately represented in atmospheric models. In this thesis I use observations to study the dynamics of atmospheric winds and waves in the polar regions across the altitude scales.Gravity waves are one of the few dynamic phenomena present across the full altitude extent of the atmosphere. These waves, usually generated at the surface or near the tropopause, propagate away from where they are formed, growing in amplitude as they travel upwards. Where they break, they deposit their momentum and drive atmospheric circulation.
The purpose of this thesis is to study the dynamics of the polar middle atmosphere: to characterise how well the observed winds and waves are captured by existing atmospheric models and to identify potential sources of gravity waves. Firstly, using meteor radar observations from Antarctica and a general circulation model, the representation of background winds in the mesosphere and lower thermosphere region (80-100 km altitude) is evaluated. Secondly, 3D satellite observations of atmospheric gravity waves in the stratosphere (around 33 km altitude) are combined with a ray-tracing model and used to determine the sources of these gravity waves in the Southern Polar region. Finally, the representation of resolved stratospheric gravity waves in new high resolution models is evaluated by comparing to satellite observations. This thesis provides new insights into dynamical processes of winds and waves in the polar atmosphere to guide and challenge the development of next generation models.
| Date of Award | 13 Nov 2024 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Corwin Wright (Supervisor), Neil Hindley (Supervisor), Tracy Moffat-Griffin (Supervisor), Nicholas Mitchell (Supervisor) & Ivan Astin (Supervisor) |
Keywords
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