Atmospheric Waves in the Stratosphere in Observations and Models

: (Alternative Format Thesis)

Abstract

Atmospheric waves exist on a range of scales, from very small-scale acoustic waves, to planetary-scale Rossby waves. This thesis focuses on studying atmospheric gravity waves. These waves have longer wavelengths than acoustic waves, but are small-scale in comparison with Rossby waves. Gravity waves transport momentum throughout the atmosphere, which is deposited when they break, causing a deceleration or acceleration of the background winds. Through this process, these waves force the atmospheric circulation and have important effects on atmospheric dynamical processes.

In this thesis, the representation of these waves in a high-resolution model run is compared to satellite observations to validate the model. There are many differences between models and observations, including their resolutions, and noise that is present only in observations. For the model to be comparable to the observations, it is important to ‘resample’ the model as the satellite observations. Resampling methods aim to find what the satellite instrument data would look like if it was observing the model atmosphere.

In the second results chapter of this thesis, the daily variation of gravity wave activity in the tropical stratosphere is investigated using observations from satellites and instruments carried by superpressure balloons. As convection, a source of gravity waves, follows a diurnal cycle, convective gravity waves are also expected to follow this cycle, with differences due to waves propagating away from their sources, and wave breaking that may occur before these waves can reach the stratosphere.

Date of Award	18 Feb 2026
Original language	English
Awarding Institution	University of Bath
Sponsors	The Royal Society
Supervisor	Corwin Wright (Supervisor), Neil Hindley (Supervisor) & Ivan Astin (Supervisor)