0000000000007768

AUTHOR

Jakob Mann

0000-0002-6096-611x

showing 6 related works from this author

Validation of buoyancy driven spectral tensor model using HATS data

2016

We present a homogeneous spectral tensor model for wind velocity and temperature fluctuations, driven by mean vertical shear and mean temperature gradient. Results from the model, including one-dimensional velocity and temperature spectra and the associated co-spectra, are shown in this paper. The model also reproduces two-point statistics, such as coherence and phases, via cross-spectra between two points separated in space. Model results are compared with observations from the Horizontal Array Turbulence Study (HATS) field program (Horst et al. 2004). The spectral velocity tensor in the model is described via five parameters: the dissipation rate (), length scale of energy-containing eddi…

Length scalePhysicsHistoryRichardson numberBuoyancyTurbulenceMathematical analysisDissipationengineering.materialWind speedComputer Science ApplicationsEducationClassical mechanicsengineeringAtmospheric instabilityAnisotropyJournal of Physics: Conference Series
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Europe's offshore winds assessed with synthetic aperture radar, ASCAT and WRF

2020

Europe's offshore wind resource mapping is part of the New European Wind Atlas (NEWA) international consortium effort. This study presents the results of analysis of synthetic aperture radar (SAR) ocean wind maps based on Envisat and Sentinel-1 with a brief description of the wind retrieval process and Advanced Scatterometer (ASCAT) ocean wind maps. The wind statistics at 10 and 100 m above mean sea level (a.m.s.l.) height using an extrapolation procedure involving simulated long-term stability over oceans are presented for both SAR and ASCAT. Furthermore, the Weather Research and Forecasting (WRF) offshore wind atlas of NEWA is presented. This has 3 km grid spacing with data …

Synthetic aperture radar010504 meteorology & atmospheric sciencesMeteorologyRenewable Energy Sustainability and the Environmentlcsh:TJ807-8300211 other engineering and technologieslcsh:Renewable energy sourcesEnergy Engineering and Power Technology02 engineering and technologyScatterometer01 natural sciencesWind speedOffshore wind powerWeather Research and Forecasting ModelWind atlasSubmarine pipelineGeologySea level021101 geological & geomatics engineering0105 earth and related environmental sciencesWind Energy Science
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Europe’s offshore winds assessed from SAR, ASCAT and WRF

2019

Abstract. Europe’s offshore wind resource mapping is part of the New European Wind Atlas (NEWA) international consortium effort. This study presents the results of analysis of Synthetic Aperture Radar (SAR) ocean wind maps based on Envisat and Sentinel-1 with a brief description of the wind retrieval process and Advanced SCATterometer (ASCAT) ocean wind maps. The wind statistics at 10m and 100m height using an extrapolation procedure involving simulated long-term stability over oceans is presented for both SAR and ASCAT. Furthermore, the Weather Research and Forecasting (WRF) offshore wind atlas of NEWA is presented. This has 3 km grid resolution with data every 30 minutes during 30 years f…

Synthetic aperture radarOffshore wind powerMeteorologyWeather Research and Forecasting ModelWind atlasEnvironmental scienceSubmarine pipelineScatterometerScale (map)Wind speed
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Modeling Atmospheric Turbulence via Rapid Distortion Theory: Spectral Tensor of Velocity and Buoyancy

2017

Abstract A spectral tensor model is presented for turbulent fluctuations of wind velocity components and temperature, assuming uniform vertical gradients in mean temperature and mean wind speed. The model is built upon rapid distortion theory (RDT) following studies by Mann and by Hanazaki and Hunt, using the eddy lifetime parameterization of Mann to make the model stationary. The buoyant spectral tensor model is driven via five parameters: the viscous dissipation rate ε, length scale of energy-containing eddies L, a turbulence anisotropy parameter , gradient Richardson number (Ri) representing the local atmospheric stability, and the rate of destruction of temperature variance . Model outp…

Length scaleAtmospheric Science010504 meteorology & atmospheric sciencesK-epsilon turbulence modelFLOWVelocityTensorsWind01 natural sciencesWind speedAtmospheric temperature010305 fluids & plasmasPhysics::Fluid DynamicsEnergy-containing eddiesConvergence of numerical methodsMonin-Obukhov similarity theorySCALEPhysicsTurbulenceAtmospheric turbulenceMechanicsBuoyancySURFACE-LAYER TURBULENCEClassical mechanicsFluxesStratified turbulenceSIMILARITYSIMULATIONBoundary layersStabilityBuoyancyMETEOROLOGYengineering.materialPROFILEAtmospheric thermodynamics0103 physical sciencesAtmospheric instabilityWind shearsSTABLY STRATIFIED TURBULENCETensorRapid distortion theory0105 earth and related environmental sciencesWind shearBoundary layer flowRichardson numberAtmospheric observationsViscous dissipation rateHorizontal array turbulence study field programsTurbulenceBoundary layerengineeringJournal of the Atmospheric Sciences
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New European Wind Atlas: Mesoscale Atlas

2021

The mesoscale part of the New European Wind Atlas (NEWA) was created from WRF model simulations for all of Europe at a grid spacing of 3 km x 3 km, initially covering the 30 years from 1989 to 2018. The WRF model simulations (using WRF V3.8.1) were done in 10 partly overlapping domains using ERA5 reanalysis and OSTIA sea surface temperatures. We used many ensemble members to determine the most suitable configuration for the final production run. The model configuration, production and evaluation of the results against observations are described in Hahmann et al. (2020) and Dörenkämper et al. (2020).Data are accessible through doWIND, an instance of daTap (RESTfull API for data aggregation a…

Electrical energy generation (incl. renewables excl. photovoltaics)Atmospheric sciences not elsewhere classified
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New European Wind Atlas: Microscale Atlas

2021

Wind Atlas layers from the New European Wind Atlas (NEWA) microscale atlas. The atlas was made by downscaling the NEWA mesoscale wind atlas using the Wind Atlas Analysis and Application Program (WAsP) microscale model.Data are accessible through doWIND, an instance of daTap (RESTfull API for data aggregation and subsetting)

Atmospheric dynamicsElectrical energy generation (incl. renewables excl. photovoltaics)Atmospheric sciences not elsewhere classified
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