Stability and Nonlinear Waves in Geophysical Shear Flows

摘要

Results obtained during the most recent phase of the investigation into nonlinear aspects of instability and wave propagation in shear flows are presented. The primary objective of this study was to investigate nonlinear aspects of the turbulence generating processes relevant to the atmosphere and oceans. Stability theory plays a prominent role in the study, but the propagation of periodic or isolated coherent features was also considered in some depth. Four different phenomena were investigated. They are: long nonlinear waves in stratified shear flows; finite-amplitude stability of a zonal shear flow; resonant interaction of internal waves; and weakly nonlinear stability of stratified flows.