Meridional asymmetries in large-scale atmospheric dynamical phenomena

One simple theoretical description of atmospheric eddies is edge waves in a homogeneous potential vorticity atmosphere, propagating along temperature gradients at either the surface or the tropopause (Eady edge waves). In this dissertation we have shown that the meridional asymmetry arising from the inclusion of meridional variation in the Coriolis parameter is a fundamental property of the higher-order dynamics of Eady edge waves. Our study suggests that this asymmetry may be relevant to structural characteristics of observed atmospheric transients, particularly short waves propagating along the extra-tropical dynamic tropopause.; We also studied how the presence of meridional vorticity gradient will affect the balanced dynamics of the non-linear turbulent motion for the large-scale inviscid flow. A new numerical model including meridional vorticity gradient and higher order dynamics beyond quasi-geostrophic approximation is developed and applied for the freely evolving and forced turbulent motions.; Based on the direct numerical simulations we have shown that the role of geo-physical beta-effect is crucial to the process of transferring from the pure turbulence to waves. After passing through a state of propagating waves, the flow forms jet currents, that are almost stationary steady. The growing with time field anisotropy is exhibited.; In addition statistical and spectral properties of the fully evolved surface potential temperature are studied. Mean surface cooling is prominent in both free and forced turbulence. The minus third power law for the downscale enstrophy local rate cascade is calculated.