We study the atmospheric structure in response to the propagation of gravity waves under nonisothermal (nonzero vertical temperature gradient), wind-shear (nonzero vertical zonal/meridional wind speed gradients), and dissipative (nonzero molecular viscosity and thermal conduction) conditions. As an alternative to the “complex wave-frequency” model proposed by Vadas and Fritts, we employ the tra...

It seems that the wind shear theory is accepted for the explanation of sporadic E at mid and low latitudes. Some examples from Arecibo are displayed to show this. The e€ect of lunar tides should then modify the wind-shear theory in a manner that yields the observed features of the lunar tide in the critical frequency foEs and the height h¢Es of the sporadic E. This is shown to imply that the ph...

In the mid-latitude ionospheric region, sporadic-E layers (Es layers) have often been observed, revealing multiple layers. The Es layers observed during the SEEK-2 rocket campaign showed double electron density peaks; namely, there are stable lower peaks and relatively unstable upper peaks. We examined the effects of wind shear and the electric fields on the generation of the multiple layer str...

The transport of sand in saltation is driven by the persistently unsteady stresses exerted by turbulent winds. Based on coupled high-frequency observations of wind velocity and sand flux on a desert dune during intermittent saltation, we show here how observations of saltation by natural winds depend significantly on the timescale and method used for determining shear stress and sand flux. The ...

This paper presents two findings in wind farm layout uncertainty analysis research: sensitivity to parameters and representation of landowner participation. It first tests a farm design optimization model's sensitivity to the parameters of surface roughness, economies-of-scale cost reduction, and wind shear. Then, the paper presents a new and novel landowner participation model of willingness-t...

Tropical Pacific Ocean warming has been separated into two modes based on the spatial distribution of the maximum sea surface temperature (SST) anomaly: an east Pacific warming (EPW) and a central Pacific warming (CPW). When combined with east Pacific cooling (EPC), these three regimes are shown to have different impacts on tropical cyclone (TC) activity over the North Pacific by differential m...

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...

In the North Sea, an array of wind profiling wind lidars were deployed mainly on offshore platforms. The purpose was to observe free stream winds at hub height. Eight lidars were validated prior to offshore deployment with observations from cup anemometers at 60, 80, 100 and 116 m on an onshore met mast situated in flat terrain. The so-called “NORSEWInD standard” for comparing lidar and mast wi...

[1] Gravity waves forced by circular bell-shaped mountains are simulated using the Advanced Regional Prediction System model for four directionally sheared wind profiles W1, W2, W2a, and W2b. W1 is eastward at the surface, while the latter three are southeastward. With the vertical shear directed northward, W1 shows an increasing speed with height, whereas W2, W2a, and W2b are first decelerated...

A numerical study of atmospheric turbulence effects on wind-turbine wakes is presented. Large-eddy simulations of neutrally-stratified atmospheric boundary layer flows through stand-alone wind turbines were performed over homogeneous flat surfaces with four different aerodynamic roughness lengths. Emphasis is placed on the structure and characteristics of turbine wakes in the cases where the in...