Coherent Doppler lidar measurements are of increasing interest for the wind energy industry. Wind measurements are fundamental inputs for the evaluation of potential energy yield and performance of wind farms. Three-dimensional scanning Doppler lidar may provide a new basis for wind farm site selection, design and optimization. In this paper, the authors discuss Doppler lidar measurements obtai...

[1] The anomalously strong hurricane activity in the Atlantic sector during the recent years led to a controversy about the impact of global warming on hurricane activity in the Atlantic sector. Here we show that the temperature difference between the tropical North Atlantic and the tropical Indian and Pacific Oceans (IndoPacific) is a key parameter in controlling the vertical wind shear over t...

An experimental campaign of measurements for a Darrieus vertical-axis wind turbine (VAWT) is presented for open field conditions. The turbine is characterized by a twisted bladed design, each blade being placed at a fixed distance from the rotational shaft. The experimental setup to perform the acquisitions is described. The results are lower than expected, due to the high influence of the wind...

Offshore wind turbine (OWT) foundations are subjected to a combination of cyclic and dynamic loading arising from wind, wave, rotor and blade shadowing. Under cyclic loading, most soils change their characteristics including stiffness, which may cause the system natural frequency to approach the loading frequency and lead to unplanned resonance and system damage or even collapse. To investigate...

Ten years of data from the Tropical Rainfall Measurement Mission satellite’s Precipitation Radar (TRMM PR) show the vertical structure of tropical cyclone rainbands. Radar-echo statistics show that rainbands have a two-layered structure, with distinct modes separated by the melting layer. The ice layer is a combination of particles imported from the eyewall and ice left aloft as convective cell...

Global Positioning System radio occultation measurements by the FORMOsa SATellite mission3/Constellation Observing System for Meteorology, Ionosphere and Climate satellites were used to analyse the behaviour of the signature of the terdiurnal tide in sporadic E (ES) layers at midlatitudes (43–63 N). According to theory, the occurrence of ES is expected when the vertical zonal wind shear, which ...

The authors investigate the effects of cloud–radiation interaction and vertical wind shear on convective ensembles interacting with large-scale dynamics in cloud-resolving model simulations, with the large-scale circulation parameterized using the weak temperature gradient approximation. Numerical experiments with interactive radiation are conducted with imposed surface heat fluxes constant in ...

The previous study of helicity, CAPE, and shear in Hurricane Bonnie (1998) was extended to all eight tropical cyclones sampled by NASA during the Convection and Moisture Experiments (CAMEX). Storms were categorized as having large or small ambient vertical wind shear, with 10 m s as the dividing line. In strongly sheared storms, the downshear mean helicity exceeded the upshear mean by a factor ...

In December 2005, operational wind shear alerting at the Hong Kong International Airport (HKIA) reached an important milestone with the launch of the automatic Lidar (light detection and ranging) Windshear Alerting System (LIWAS). This signifies that the anemometer-based and radar-based wind shear detection technologies deployed worldwide in the twentieth century have been further advanced by t...