The enhanced cumulus convection in tropical disturbances acts in two opposing ways. In one sense the condensation heat from the cumulus acts to warm the inner portions of the disturbance and induce vertical shear of the horizontal wind through the thermal wind relationship. In the opposite sense the cumulus also act to suppress vertical wind shear by transfer of horizontal momentum within their...

Spatially resolved wind fields are derived by cross correlation of aerosol backscatter data from horizontal and vertical scans of the University of Wisconsin volume imaging lidar during the 1997/98 Lake-Induced Convection Experiment. Data from three cases are analyzed. The first two cases occurred on 10 and 13 January 1998 during cold-air outbreaks. Horizontal scans at 5 m above the lake reveal...

Vertical axis wind turbines (VAWT) are an alternative to horizontal axis wind turbines (HAWT) for wind and tidal energy harvesting applications. Studies of vertical axis wind turbines have heavily invested in understanding the behaviour of the complete turbine, but often with only cursory assessment of the contributions of unsteady aerodynamics of individual blades. This paper experimentally ex...

The VHF radar system at Aberystwyth (52:4 N, 4:1 E) has been used to make high-timeresolution, multi-beam observations of mesospheric summer echo layers. These show that the altitude and the sense of vertical movement of the layers can vary over time-scales of minutes and horizontal scales of kilometres. In general, the altitude pro®les of signal-tonoise ratio provide evidence of a bifurcated s...

Wind speed is a most important weather parameter to record and monitor for many applications like meteorology, shipping, aviation etc. Wind observations are very important for general (operational) aviation meteorology, and weather prediction. Wind profilers are vertically directed pulsed Doppler radars which can analyze the back scattered signals and determine the velocity of air along the bea...

We have computed two Geophysical Model Functions (one for the vertical and one for the horizontal polarization) for the NSCAT scatterometer by using neural networks. These Neural Network Geophysical Model Functions (NN-GMF) were estimated with NSCAT scatterometer sigma-0 measurements collocated with ECMWF analyzed wind vectors during the period 15 January 1997 to 15 April 1997. We performed a S...

It is well known that vertical wind shear can organize deep convective systems and greatly extend their lifetimes. Much less is known about the influence of shear on the bulk properties of tropical convection in statistical equilibrium. To address the latter question, the authors present a series of cloud-resolving simulations on a doubly periodic domain with parameterized large-scale dynamics ...

[1] Variations in deep convective activity during the 4month Tropical Ocean Global Atmosphere-Coupled Ocean Atmosphere Response Experiment (TOGA-COARE) field campaign are simulated using a cloud-resolving model (CRM). Convection in the model is coupled to large-scale vertical velocities that are parameterized using one of two different methods: the damped gravity wave (Damped-wave) method and t...

Wind-profiling lidars are now regularly used in boundary-layer meteorology and in applications such as wind energy and air quality. Lidar wind profilers exploit the Doppler shift of laser light backscattered from particulates carried by the wind to measure a line-of-sight (LOS) velocity. The Doppler beam swinging (DBS) technique, used by many commercial systems, considers measurements of this L...

downbursts are small-scale, short-lived and energetic events in the atmosphere. they usually occur from the beginning of spring to summer when the weather is more humid and the convective weather conditions are suitable. because of the small-scale property of the downburst, it has sometimes been observed only in a meteorological station and other stations have not observed considerable changes....