Mark C. Kelly

Vertical cross-spectral phases in neutral atmospheric flow

The cross-spectral phases between velocity components at two heights are analyzed from observations at the Hovsore test site and from the field experiments under the Cooperative Atmosphere-Surface Exchange Study in 1999. These phases represent the degree to which turbulence sensed at one height leads (or lags) in time the turbulence sensed at the other height. The phase angle of the cross-wind component is observed to be significantly greater than the phase for the along-wind component, which in turn is greater than the phase for the vertical component. The cross-wind and along-wind phases increase with stream-wise wavenumber and vertical separation distance, but there is no significant change in the phase angle of vertical velocity, which remains close to zero. The phases are also calculated using a rapid distortion theory model and large-eddy simulation. The results from the models show similar order in phasing, but the slopes of the phase curves are slightly different from the observations, especially for low wavenumbers.

Consistent Two-Equation Closure Modelling for Atmospheric Research: Buoyancy and Vegetation Implementations

A self-consistent two-equation closure treating buoyancy and plant drag effects has been developed, through consideration of the behaviour of the supplementary equation for the length-scale-determining variable in homogeneous turbulent flow. Being consistent with the canonical flow regimes of grid turbulence and wall-bounded flow, the closure is also valid for homogeneous shear flows commonly observed inside tall vegetative canopies and in non-neutral atmospheric conditions. Here we examine the most often used two-equation models, namely

Addressing Spatial Variability of Surface-Layer Wind with Long-Range WindScanners

{E - \varepsilon}

Idealized Mesoscale Model Simulations of Open Cellular Convection Over the Sea

and E − ω (where

On Displacement Height, from Classical to Practical Formulation: Stress, Turbulent Transport and Vorticity Considerations

{\varepsilon}

Comparison of OpenFOAM and EllipSys3D for neutral atmospheric flow over complex terrain

is the dissipation rate of turbulent kinetic energy, E, and