Nacelle-based Doppler wind lidars have shown promising capabilities to assess power performance, detect yaw misalignment or perform feed-forward control. The power curve application requires uncertainty assessment. Traceable measurements and uncertainties of nacelle-based wind lidars can be obtained through a methodology applicable to any type of existing and upcoming nacelle lidar technology. ...

b = vortex spacing l = lateral displacement N = Brunt–Väisälä frequency q = root-mean-square turbulence velocity t = time u = axial velocity v = lateral velocity, vertical displacement V = aircraft ground speed w = descent speed, vertical wind velocity x = axial coordinate y = spanwise coordinate z = vertical coordinate = circulation = eddy dissipation rate = potential temperature = standard de...

We report a large set of 295 interfacial carbon dioxide (CO2) flux measurements obtained in the Scheldt estuary in November 2002 and April 2003, using the floating chamber method. From concomitant measurements of the air-water CO2 gradient, we computed the gas transfer velocity of CO2. The gas transfer velocity is well correlated to wind speed and a simple linear regression function gives the m...

[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...

Recent work by S. Lentz et al. documents offshore transport in the inner shelf due to a wave-driven return flow associated with the Hasselmann wave stress (the Stokes–Coriolis force). This analysis is extended using observations from the central Oregon coast to identify the wave-driven return flow present and quantify the potential bias of wind-driven across-shelf exchange by unresolved wave-dr...

The forecasting of time series of the wind and solar energy is necessary for the prevention from global warming. This paper explains the technique of time series forecast of the wind power energy and solar energy by using ten minutes intervals meteorological data obtained by AMeDAS(Automated Meteorological Data Acquisition System). We discuss an application of a neural network for forecasting t...

The Global Drifter Program (GDP) has been measuring near-surface ocean currents with surface drifters since 1979. At least half of the World Ocean now has drifter velocity time series longer than 15 years. The availability of this data opens new opportunities to explore observationally how ocean circulation responds to changing surface forcing. In this paper we report evidence of an apparently ...

A so-called six-beam method is proposed to measure atmospheric turbulence using a ground-based wind lidar. This method requires measurement of the radial velocity variances at five equally spaced azimuth angles on the base of a scanning cone and one measurement at the centre of the scanning circle, i.e.using a vertical beam at the same height. The scanning configuration is optimized to minimize...

Designing and manufacturing the multiple jets simulator and experimental investigation of the multiple jets in crossflow at low velocity ratios have been studied Together with design and build a low-speed wind tunnel. A specific rake is used to determine the flow field pressure and changes in static pressure measured by pressure taps in the near field of the jets. There are generally three regi...

We present X-ray spectral fits to a recently obtained Chandra grating spectrum of η Carinae, one of the most massive and powerful stars in the Galaxy and which is strongly suspected to be a colliding wind binary system. Hydrodynamic models of colliding winds are used to generate synthetic X-ray spectra for a range of mass-loss rates and wind velocities. They are then fitted against newly acquir...