Theoretical study of the decaying convective turbulence in a shearbuoyancy PBL
Abstract
The derivation of a theoretical model for the decaying convective turbulence in a shearbuoyancy planetary boundary layer is considered. The model is based on the dynamical equation for the energy density spectrum in which the buoyancy, mechanical and inertial transfer terms are retained. The parameterization for the buoyancy and mechanical terms is provided by the flux Richardson number. Regarding the inertial term an approach employing Heisenberg's spectral transfer theory is used to describe the turbulence friction, caused by small eddies, responsible for the energy dissipation of the large eddies. Therefore, a novelty in this study is to utilize the Adomian decomposition method to solve directly without linearization the energy density spectrum equation, with this the nonlinear nature of the problem is preserved. Therefore, the errors found are only due to the parameterization used. Comparison of the theoretical model is performed against largeeddy simulation data for a decaying convective turbulence in a shearbuoyancy planetary boundary layer. The results show that the existence of a mechanical turbulent driving mechanism reduces in an accentuated way the energy density spectrum and turbulent kinetic energy decay generated by the decaying convective production in a shearbuoyancy planetary boundary layer.
 Publication:

Physica A Statistical Mechanics and its Applications
 Pub Date:
 October 2011
 DOI:
 10.1016/j.physa.2011.04.019
 Bibcode:
 2011PhyA..390.3320K