Gravity waves are periodic disturbances in the atmosphere, generated by wind flowing over mountains, convection, and wind-shear (e.g. jet-stream) instabilities. They have large impacts on global atmospheric circulation. However, these waves are poorly constrained in models, and observations of them can only infer their sources. I undertake the largest ray-tracing study of gravity waves ever performed in order to determine their sources over the Southern Ocean. For June 2010, I ray-trace 38 million AIRS data points from 40 km over the Southern Ocean back to their sources. I find clear sources of gravity waves from the Andes, the Antarctic Peninsula and Kerguelen Island. I also demonstrate significant horizontal propagation, and propagation meridionally into a belt around the 60°S latitude band. This provides key insights needed to improve our global climate models, and in particular demonstrates a possible source of ‘missing momentum flux’ over 60°S which may be a key contributor to weather and climate forecasting errors.
MATADOR: Measuring And Tracking Atmospheric Disturbances through Observations and Ray tracing: (Alternative Format Thesis)
Perrett, J. (Author). 11 Sept 2024
Student thesis: Masters Thesis › MPhil