This study surveys and evaluates similarity theory for estimating the sea-surface drag coefficient with the bulk aerodynamic method. The most commonly used formulations of the aerodynamic roughness length, required by similarity theory, are examined using data sets from four different field programs. These relationships include the Charnock formulation and the...
Vertical profiles of the time-averaged wind stress, wind speed and buoyancy flux from the off-shore tower site in the Risø Air Sea Experiment are used to evaluate similarity theory in the coastal zone. The observed dependence of the non-dimensional wind shear on stability is compared to the traditional parametrization. Relationships...
In simple models, the nocturnal boundary layer is generally formulated in terms of eddy diffusivities, which
are functions of height above ground and boundary layer depth. This approach is modified in this study to
include ‘‘z-less’’ turbulence, which is formulated in terms of a stability-dependent mixing length and a Prandtl...
An alternative method to Fourier analysis is discussed for studying the scale dependence of variances and covariances in atmospheric boundary layer time series. Unlike Fourier decomposition, the scale dependence based on multiresolution decomposition depends on the scale of the fluctuations and not the periodicity. An example calculation is presented in...
Feeding conjugated linoleic acids (CLA) improves reproductive performance in dairy cows; however, the molecular mechanisms by which CLA improves reproduction are not well understood. Therefore, we evaluated whether the CLA isomers, trans-10, cis-12 CLA and cis-9, trans-11 CLA altered synthesis of steroidogenic hormones in bovine luteal cells by measuring concentrations...
Observations of the scale-dependent turbulent fluxes, variances, and the bulk transfer parameterization for sensible heat above, within, and beneath a tall closed Douglas-fir canopy in very weak winds are examined. The daytime sub-canopy vertical velocity spectra exhibit a double-peak structure with peaks at timescales of 0.8 s and 51.2 s....
Spatial variations of surface stress over the coastal shoaling zone are studied offshore of Duck, North Carolina, by the LongEZ research aircraft, equipped to measure both atmospheric turbulence and oceanic waves. We find that the spatial variation of the friction velocity with offshore distance is much larger with offshore flow...
A method of calculating surface evapotranspiration by separately
including the effects of vegetation and atmospheric evaporative demand
under the condition of nonlimiting soil moisture is presented. A
literature survey is conducted to determine the effects of plants on
evapotranspiration.
To represent the atmospheric evaporative demand, the original
potential evaporation equation...