The spectral dynamics analysis of the transitions periods in the convective boundary Layer

In this work we examine the transitions periods in the atmospheric boundary layer (morning-afternoon) from the dynamical energy spectrum equation and Large Eddy Simulation runs. Eddies near the lower edge of the inertial subrange receive most of their energy from slightly larger eddies, but they also absorb some energy directly from the strain rate of the mean flow. The energy is transferred of low to high wavenumber in the cascade process. The turbulent kinetic energy production and the inertial energy transfer are parameterized by scale considerations and energy conservation, where the convective and mechanical sources are connected by the Richardson number. The resultant nonlinear equation is solved by the decomposition Adomian method. The theoretical results are confronted with the Large Eddy Simulation data. The LES simulations were done with the DALES (Dutch Atmospheric Large Eddy Simulation) model.