The “Leipzig Wind Profile” is a unique example of a representative wind distribution in the frictional layer which resulted from MILDNER’S set of 28 pilot-balloon observations with two theodolites on October 20, 1931, near Leipzig for a stable weather situation. It is shown, that the vectors of geostrophic motion and ground drag follow from the wind profile when a scalar austausch is assumed. T...

A series of numerical simulations of tropical cyclones in idealized large-scale environments is performed to examine the effects of vertical wind shear on the structure and intensity of hurricanes. The simulations are performed using the nonhydrostatic Pennsylvania State University–National Center for Atmospheric Research fifth-generation Mesoscale Model using a 5-km fine mesh and fully explici...

Aeolian sediment traps are widely used to estimate the total volume of wind-driven sediment transport, but also to study the vertical mass distribution of a saltating sand cloud. The reliability of sediment flux estimations from such measurements are dependent upon the specific configuration of the measurement compartments and the analysis approach used. In this study, we analyse the uncertaint...

We study the modulation of atmospheric nonisothermality and wind shears on the propagation of seismic tsunami-excited gravity waves by virtue of the vertical wavenumber, m (with its imaginary and real parts, mi and mr, respectively), within a correlated characteristic range of tsunami wave periods in tens of minutes. A generalized dispersion relation of inertio-acoustic-gravity (IAG) waves is o...

[1] The solar wind is filled with strong current sheets and sudden velocity shears; often the two are co-located. Sudden velocity shears at 1 AU are statistically analyzed using ACE measurements from 1998 to 2008. The occurrence rates of passage and the orientations of the shear planes are examined. For shear layers with vector velocity changes |Dv| > 50 km/s, an average of 12 pass the Earth pe...

[1] Based on the best track data of tropical cyclones (TCs) in the North Atlantic and the NCEP/NCAR reanalysis during 1981–2008,the effect of vertical wind shear (VWS) between different vertical levels and with different directions of shear on TC intensity change for TCs of different intensities, translational speeds, and latitudes were statistically analyzed. The results show that TC intensity...

[1] Understanding and quantifying the multiscale interactions between surface shear stress and velocity in the boundary layer is essential to improving boundary condition parameterizations used in numerical models of turbulent boundary layers. In this study, high-frequencymeasurements obtained in a wind tunnel are used to identify dominant scales of interaction (quantified in terms of scale-dep...

Distortions are often seen in the angular distribution of echo-power from VHF wind-profiling radars, suggesting that thin stable layers, within the air flow, are distorted and tilted from horizontal. In vertical shear of the horizontal wind, the distribution of the layer tilt angles becomes skewed. A case study using six days of VHF radar data and synoptic charts above western Europe indicates ...

We present a numerical study of Rayleigh-Bénard convection disturbed by a longitudinal wind. Our results show that under the action of the wind, the vertical heat flux through the cell initially decreases, due to the mechanism of plume sweeping, and then increases again when turbulent forced convection dominates over the buoyancy. As a result, the Nusselt number is a nonmonotonic function of th...

The contribution from the divergent part of the horizontal wind to the energy conversion between the vertical shear flow and the vertical mean flow has been computed using atmospheric data from the isobaric surfaces: 850, 700, 500, 300, and 200 mb. The new calculations supplement earlier computations giving the energy conversion based on an assumption that the horizontal winds are non-divergent...