1,721,003 research outputs found
Turbulence fields for atmospheric dispersion models in horizontally non-homogeneous conditions
No full textComparison between different turbulence closures in a flow model applied to a schematic 2-D valley in a wind tunnel experiment
No full textComparison of turbulence closure models over a schematic valley in a neutral boundary layer
No full textLagrangian particle simulation of an EPA wind tunnel tracer experiment in a schematic two-dimensional valley
No full textETA and RAMS numerical mesoscale simulations at high resolution in complex terrain
No full textAn intercomparison between numerical simulations obtained by ETA model and RAMS model during a period of about 48 hours is presented. A nesting procedure was performed, so that the highest horizontal resolution is about 4 km. The domain covers the Rhine Valley and surroundings and the time window is from 00 UTC September 16, to 00 UTC September 18. During this period, the TRACT Field Measurement Campaign was performed, so that further comparisons between simulations and observations are presented, using statistical indices such as root-mean-square error and fractional bias
Intercomparison of two models, ETA and RAMS, with TRACT field campaign data
No full textIn this work a model intercomparison between RAMS and ETA models is carried out, with the aim of evaluating the quality and accuracy of these mesoscale models in reproducing the time evolution of the meteorology in real complex terrain. This is of great importance not only for meteorological forecast but also for air quality assessment. Numerical simulations are performed to reproduce the mean variables' fields and to compare them with measurements collected during the field campaign TRACT. The domain covers the Rhine valley and surrounding mountainous region and we consider a time period of two days. Results from simulations are compared to observations relative to ground stations and radiosoundings. A qualitative analysis is joined to a quantitative estimation of some reference statistical indexes. Both RAMS and ETA models performances are satisfactory when compared to the measured data and also their relative agreement is good. The mean variable fields are reproduced with a satisfactory degree of reliability, even if the simulated profiles are not able to describe the largest fluctuations of the variables. At the surface stations, the best agreement between predictions and observations is obtained for the wind velocity, while the quality of the results is lower for temperature and humidity
The role of horizontal diffusion and mixing height parameterization in the ETEX long-rang dispersion modelling
No full textIn situ diagnostic or nested prognostic meteorological models to drive dispersion simulations in complex area: a comparison in a real application
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The role of wind field, mixing height and horizontal diffusion investigated through two Lagrangian particle models
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