The large scale and smaller production scale motions contain over the half of turbulent kinetic energy in the flow. These motions are responsible for sediment transport and deposition processes, contaminant mixing and stream bio-diversity. These motions are corresponded to the left and right bounds of -1 power region of the spectral energy. The most well recognized and highly studied power law has been upon Kolmogorov’s -5/3 power law region of the streamwise spectral energy density and this research focused on investigating the -1 power region bounds and energy. Energy budget and time-average turbulence calculations along with spectral analysis are performed to investigate the characteristics of large scale and smaller production scale motions in the flow. Spectral analyses of turbulent flows offers the utility of investigating the distribution of turbulent energy across wavenumber scales as well as identifying prominent wavenumbers at which the periodicity of coherent processes are centered. In turn, the results of spectral analyses can be coupled with visualization of coherent vortices and time-average turbulence results to advance our understanding of turbulent energy distribution and dominant processes that drive environmental phenomena such as sediment transport and solute transfer. A new method for identifying the wavenumbers associated to the macroturbulence and bursting is introduced. Also this study offers a new scaling method of energy spectral that derived from the turbulence energy model for an equilibrium boundary layer. Results of this study show an equilibrium boundary layer for the outer region of the flow in which the flow is uniform and fully-developed. Also for a given roughness, the results of this study provide an approach to calculate the streamwise turbulence kinetic energy of bursting and macroturbulence which show a linkage of this work to applications such as bedload and suspended load sediment transport.

In this thesis, we study the effect of diurnally- and seasonally-varying forcing on the global circulation of planetary atmospheres explored within a large parameter space. This work focusses on studying the spacial and spectral energy budgets across a large range of planetary parameters as well as the momentum transfer as a response to diurnal and seasonal effects. We simulate planetary atmospheres using PUMA-GT, a simple GCM co-developed for this work, that is forced by a semi-grey two-band radiative-convective scheme, dissipated by Rayleigh friction and allows for temporally varying insolation. Our parameter regime includes the variation of the planetary rotation rate, frictional timescale in the boundary layer, the thermal inertia of the surface and the atmosphere, as well as the short-wave optical thickness. We calculate the energy transfer in Martian atmosphere to have a reference case of an atmosphere that is subject to very strong seasonal and diurnal variation. For this we present the first Lorenz energy budget calculated from reanalysis data of a non-Earth planet. A comparison between Martian and Earth atmosphere reveals a fundamentally different behaviour of the barotropic conversion term in the global mean. A significant impact of the thermal tide can be discerned in the generation of eddy kinetic energy, especially during global dust storms. Our study of seasonal variation reaffirms previous work that the equatorial super-rotating jet in the slow-rotating regime is arrested for strong seasonal variation. We find a novel explanation as to why the Titan atmosphere is able to maintain super-rotation despite strong surface seasonality; for non-zero short-wave absorption in the atmosphere the mechanism that hinders equatorial super-rotation is weakened. Diurnally-varying forcing can significantly enhance the equatorial super-rotation in cases with non-zero short-wave absorption. In our simulations this enhancement is maintained by a convergence of vertical momentum flux at the equator. Efforts to identify the atmospheric waves involved in this enhancement point towards thermally-excited gravity waves.