jeff vinuesa

Publications

• The impact of MM5 and WRF meteorology over complex terrain on CHIMERE model calculations

  A. de Meij, Gzella A, Thunis P, Cuvelier C, Bessagnet B, J. F. Vinuesa, Menut L

  Atmospheric Chemistry and Physics Discussions. 01/2009;

  The objective of this study is to evaluate the impact of meteorological input data on calculated gas and aerosol concentrations. We use two different meteorological models (MM5 and WRF) together with the chemistry transport model CHIMERE. We focus on the Po valley area (Italy) for January and June 2... [more] The objective of this study is to evaluate the impact of meteorological input data on calculated gas and aerosol concentrations. We use two different meteorological models (MM5 and WRF) together with the chemistry transport model CHIMERE. We focus on the Po valley area (Italy) for January and June 2005. Firstly we evaluate the meteorological parameters with observations. The analysis shows that the performance of both models is similar, however some small differences are still noticeable. Secondly, we analyze the impact of using MM5 and WRF on calculated PM10 and O3 concentrations. In general CHIMERE/MM5 and CHIMERE/WRF underestimate the PM10 concentrations for January. The difference in PM10 concentrations for January between CHIMERE/MM5 and CHIMERE/WRF is around a factor 1.6 (PM10 higher for CHIMERE/MM5). This difference and the larger underestimation in PM10 concentrations by CHIMERE/WRF are related to the differences in heat fluxes and the resulting PBL heights calculated by WRF. In general the PBL height by WRF meteorology is a factor 2.8 higher at noon in January than calculated by MM5. This study showed that the difference in microphysics scheme has an impact on the profile of cloud liquid water (CLW) calculated by the meteorological driver and therefore on the production of SO4 aerosol. A sensitivity analysis shows that changing the Noah Land Surface Model (LSM) for the 5-layer soil temperature model, the calculated monthly mean PM10 concentrations increase by 30%, due to the change in the heat fluxes and the resulting PBL heights. For June, PM10 calculated concentrations by CHIMERE/MM5 and CHIMERE/WRF are similar and agree with the observations. Calculated O3 values for June are in general overestimated by a factor 1.3 by CHIMERE/MM5 and CHIMRE/WRF. The reason for this is that daytime NO2 concentrations are a higher than the observations and nighttime NO concentrations (titration effect) are underestimated.

• Stochastic fields method for sub-grid scale emission heterogeneity in mesoscale atmospheric dispersion models

  Cassiani M, J. F. Vinuesa, Galmarini S, Denby B

  Atmospheric Chemistry and Physics Discussions. 01/2009;

  The stochastic fields method for turbulent reacting flows has been applied to the issue of sub-grid scale emission heterogeneity in a mesoscale model. This method is a solution technique for the probability density function (PDF) transport equation and can be seen as a straightforward extension of c... [more] The stochastic fields method for turbulent reacting flows has been applied to the issue of sub-grid scale emission heterogeneity in a mesoscale model. This method is a solution technique for the probability density function (PDF) transport equation and can be seen as a straightforward extension of currently used mesoscale dispersion models. It has been implemented in an existing mesoscale model and the results compared with Large-Eddy Simulation (LES) data devised to test specifically the effect of sub-grid scale emission heterogeneity on boundary layer concentration fluctuations. The sub-grid scale emission variability is assimilated in the model as a PDF of the emissions. The stochastic fields method shows excellent agreement with the LES data without the need of any additional model constants, nor the adjustment of the constants already used in the mesoscale model. The stochastic fields method solves transport equations of the concentration PDF for dispersing scalars and therefore it possesses the ability to handle chemistry of any complexity without closure assumptions. This study shows for the first time the feasibility of applying this method to mesoscale chemical transport models.

• The impact of MM5 and WRF meteorology over complex terrain on CHIMERE model calculations

  A. de Meij, Gzella A, Cuvelier C, Thunis P, Bessagnet B, J. F. Vinuesa, Menut L, H. M. Kelder

  Atmospheric Chemistry and Physics. 01/2009;

  The objective of this study is to evaluate the impact of meteorological input data on calculated gas and aerosol concentrations. We use two different meteorological models (MM5 and WRF) together with the chemistry transport model CHIMERE. We focus on the Po valley area (Italy) for January and June 2... [more] The objective of this study is to evaluate the impact of meteorological input data on calculated gas and aerosol concentrations. We use two different meteorological models (MM5 and WRF) together with the chemistry transport model CHIMERE. We focus on the Po valley area (Italy) for January and June 2005. Firstly we evaluate the meteorological parameters with observations. The analysis shows that the performance of both models in calculating surface parameters is similar, however differences are still observed. Secondly, we analyze the impact of using MM5 and WRF on calculated PM10 and O3 concentrations. In general CHIMERE/MM5 and CHIMERE/WRF underestimate the PMv concentrations for January. The difference in PM10 concentrations for January between CHIMERE/MM5 and CHIMERE/WRF is around a factor 1.6 (PM10 higher for CHIMERE/MM5). This difference and the larger underestimation in PM10 concentrations by CHIMERE/WRF are related to the differences in heat fluxes and the resulting PBL heights calculated by WRF. In general the PBL height by WRF meteorology is a factor 2.8 higher at noon in January than calculated by MM5. This study showed that the difference in microphysics scheme has an impact on the profile of cloud liquid water (CLW) calculated by the meteorological driver and therefore on the production of SO4 aerosol. A sensitivity analysis shows that changing the Noah Land Surface Model (LSM) in our WRF pre-processing for the 5-layer soil temperature model, calculated monthly mean PMv concentrations increase by 30%, due to the change in the heat fluxes and the resulting PBL heights. For June, PM10 calculated concentrations by CHIMERE/MM5 and CHIMERE/WRF are similar and agree with the observations. Calculated O3 values for June are in general overestimated by a factor 1.3 by CHIMERE/MM5 and CHIMERE/WRF. High temporal correlations are found between modeled and observed O3 concentrations.

• Corrigendum to "Modeling the impact of sub-grid scale emission variability on upper-air concentration" published in Atmos. Chem. Phys., 8, 141─158, 2008

  Galmarini S, Vinuesa J.-F, Martilli A

  Atmospheric Chemistry and Physics. 01/2008;

  No abstract available.

• Modeling the impact of sub-grid scale emission variability on upper-air concentration

  Galmarini S, Vinuesa J.-F, Martilli A

  Atmospheric Chemistry and Physics. 01/2008;

  The long standing issue of sub-grid emission heterogeneity and its influence to upper air concentration is addressed here and a subgrid model proposed. The founding concept of the approach is the assumption that average emission act as source terms of average concentration, emission fluctuations are... [more] The long standing issue of sub-grid emission heterogeneity and its influence to upper air concentration is addressed here and a subgrid model proposed. The founding concept of the approach is the assumption that average emission act as source terms of average concentration, emission fluctuations are source for the concentration variance. The model is based on the derivation of the sub-grid contribution of emission and the use of the concentration variance equation to transport it in the atmospheric boundary layer. The model has been implemented in an existing mesoscale model and the results compared with Large-Eddy Simulation data for ad-hoc simulation devised to test specifically the parametrization. The results show an excellent agreement of the models. For the first time a time evolving error bar reproducing the sub-grid scale heterogeneity of the emissions and the way in which it affects the concentration has been shown. The concentration variance is presented as an extra attribute to better define the mean concentrations in a Reynolds-average model. The model has applications from meso to global scale and that go beyond air quality.

• Dynamic Models for the Subgrid-Scale Mixing of Reactants in Atmospheric Turbulent Reacting Flows

  Jean-François Vinuesa, Fernando Porté-Agel

  Journal of the Atmospheric Sciences. 01/2008; 65:1692-1699..

• Dynamic LES Modeling of a Diurnal Cycle

  S. Basu, J.F. Vinuesa, A. Swift

  Journal of Applied Meteorology and Climatology. 01/2008; 47:1156-1174.

• The diurnal evolution of ²²²Rn and its progeny in the atmospheric boundary layer during the Wangara experiment

  Vinuesa J.-F, Basu S, Galmarini S

  Atmospheric Chemistry and Physics. 01/2007;

  The diurnal atmospheric boundary layer evolution of the ²²²Rn decaying family is studied using a state-of-the-art large-eddy simulation model. In particular, a diurnal cycle observed during the Wangara experiment is successfully simulated together with the effect of diurnal va... [more] The diurnal atmospheric boundary layer evolution of the ²²²Rn decaying family is studied using a state-of-the-art large-eddy simulation model. In particular, a diurnal cycle observed during the Wangara experiment is successfully simulated together with the effect of diurnal varying turbulent characteristics on radioactive compounds initially in a secular equilibrium. This study allows us to clearly analyze and identify the boundary layer processes driving the behaviour of ²²²Rn and its progeny concentrations. An activity disequilibrium is observed in the nocturnal boundary layer due to the proximity of the radon source and the trapping of fresh ²²²Rn close to the surface induced by the weak vertical transport. During the morning transition, the secular equilibrium is fast restored by the vigorous turbulent mixing. The evolution of ²²²Rn and its progeny concentrations in the unsteady growing convective boundary layer depends on the strength of entrainment events.

• The diurnal evolution of ²²²Rn and its progeny in the atmospheric boundary layer during the Wangara experiment

  Vinuesa J.-F, Basu S, Galmarini S

  Atmospheric Chemistry and Physics Discussions. 01/2007;

  The diurnal atmospheric boundary layer evolution of the ²²²Rn decaying family is studied by using a state-of-the-art large-eddy simulation model. In particular, a diurnal cycle observed during the Wangara experiment is successfully simulated together with the effect of diurnal... [more] The diurnal atmospheric boundary layer evolution of the ²²²Rn decaying family is studied by using a state-of-the-art large-eddy simulation model. In particular, a diurnal cycle observed during the Wangara experiment is successfully simulated together with the effect of diurnal varying turbulent characteristics on radioactive compounds in a secular equilibrium. This study allows us to clearly analyze and identify the boundary layer processes driving the ²²²Rn and its progeny concentration behaviors. The activity disequilibrium observed in the nocturnal boundary layer is due to the proximity of the radon source and the trapping of fresh ²²²Rn close to the surface induced by the weak vertical transport. During the morning transition, the secular equilibrium is fast restored by the vigorous turbulent mixing. The evolution of ²²²Rn and its progeny concentration in the unsteady growing convective boundary layer depends on the strength of entrainment events.

• Modelling the impact of sub-grid scale emission variability on upper-air concentration

  Galmarini S, Vinuesa J.-F, Martilli A

  Atmospheric Chemistry and Physics Discussions. 01/2007;

  The long standing issue of sub-grid emission heterogeneity and its influence to upper air concentration is addressed here and a subgrid model proposed. The founding concept of the approach is the assumption that average emission acts as source terms of average concentration, while emission fluctuati... [more] The long standing issue of sub-grid emission heterogeneity and its influence to upper air concentration is addressed here and a subgrid model proposed. The founding concept of the approach is the assumption that average emission acts as source terms of average concentration, while emission fluctuations are source for the concentration variance. The model is based on the derivation of the sub-grid contribution of emission and the use of the concentration variance equation to transport it in the atmospheric boundary layer. The model has been implemented in an existing mesoscale model and the results compared with Large-Eddy Simulation data for ad-hoc simulation devised to test specifically the parametrization. The results show and excellent agreement of the models. For the first time a time evolving error bar reproducing the sub-grid scale heterogeneity of the emissions and the way in which it affects the concentration has been shown. The concentration variance is presented as an extra attribute to better define the mean concentrations in a Reynolds-average model. The model has applications from meso to global scale and that go beyond air quality.

• Characterization of the ²²²Rn family turbulent transport in the convective atmospheric boundary layer

  Vinuesa J.-F, Galmarini S

  Atmospheric Chemistry and Physics. 01/2007;

  The combined effect of turbulent transport and radioactive decay on the distribution of ²²²Rn and its progeny in convective atmospheric boundary layers (CBL) is investigated. Large eddy simulation is used to simulate their dispersion in steady state CBL and in unsteady conditi... [more] The combined effect of turbulent transport and radioactive decay on the distribution of ²²²Rn and its progeny in convective atmospheric boundary layers (CBL) is investigated. Large eddy simulation is used to simulate their dispersion in steady state CBL and in unsteady conditions represented by the growth of a CBL within a pre-existing reservoir layer. The exact decomposition of the concentration and flux budget equations under steady state conditions allowed us to determine which processes are responsible for the vertical distribution of ²²²Rn and its progeny. Their mean concentrations are directly correlated with their half-life, e.g. ²²²Rn and ²¹⁰Pb are the most abundant whereas ²¹⁸Po show the lowest concentrations. ²²²Rn flux decreases linearly with height and its flux budget is similar to the one of inert emitted scalar, i.e., a balance between on the one hand the gradient and the buoyancy production terms, and on the other hand the pressure and dissipation at smaller scales which tends to destroy the fluxes. While ²²²Rn exhibits the typical bottom-up behavior, the maximum flux location of the daughters is moving upwards while their rank in the ²²²Rn progeny is increasing leading to a typical top-down behavior for ²¹⁰Pb. We also found that the relevant radioactive decaying contributions of ²²²Rn short-lived daughters (²¹⁸Po and ²¹⁴Pb) act as flux sources leading to deviations from the linear flux shape. In addition, while analyzing the vertical distribution of the radioactive decay contributions to the concentrations, e.g. the decaying zone, we found a variation in height of ²²²Rn daughters' radioactive transformations. Under unsteady conditions, the same behaviors reported under steady state conditions are found: deviation of the fluxes from the linear shape for ²¹⁸Po, enhanced discrepancy in height of the radioactive transformation contributions for all the daughters. In addition, ²²²Rn and its progeny concentrations decrease due to the rapid growth of the CBL. The analysis emphasizes the crucial role of turbulent transport in the behavior of ²²²Rn n morning concentrations, in particular the ventilation at the top of the boundary layer that leads to the dilution of ²²²Rn by mixing with radon low concentration air.

• Characterization of the 222Rn family turbulent transport in the convective atmospheric boundary layer

  Vinuesa, J. -F., S. Galmarini

  Atmospheric Chemistry and Physics. 01/2007; 7:697-712.

• Impacts of using reformulated and oxygenated fuel blends on the regional air quality of the upper Rhine valley

  Vinuesa J.-F, Mirabel Ph, Ponche J.-L

  Atmospheric Chemistry and Physics. 01/2006;

  The effects of using three alternative gasoline fuel blends on regional air quality of the upper Rhine valley have been investigated. The first of the tested fuels is oxygenated by addition of ethyl-tertio-butyl ether (ETBE), the second is based on a reformulation of its composition and the third on... [more] The effects of using three alternative gasoline fuel blends on regional air quality of the upper Rhine valley have been investigated. The first of the tested fuels is oxygenated by addition of ethyl-tertio-butyl ether (ETBE), the second is based on a reformulation of its composition and the third on is both oxygenated and reformulated. The upper Rhine valley is a very sensitive region for pollution episodes and several meteorological and air quality studies have already been performed. High temporal and spatial emission inventories are available allowing relevant and realistic modifications of the emission inventories. The calculation period, i.e., 11 May 1998, corresponds to a regional photochemical ozone pollution episode during which ozone concentrations exceeded several times the information threshold of the ozone directive of the European Union (180 μg m^-3 as 1 hourly average). New emission inventories are set up using specific emission factors related to the alternative fuels by varying the fraction of gasoline passenger cars (from 50% to 100%) using the three fuel blends. Then air quality modeling simulations are performed using these emission inventories over the upper Rhine valley. The impact of alternative fuels on regional air quality is evaluated by comparing these simulations with the one using a reference emission inventory, e.g., where no modifications of the fuel composition are included. The results are analyzed by focusing on peak levels and daily averaged concentrations. The use of the alternative fuels leads to general reductions of ozone and volatile organic compounds (VOC) and increases of NO_x levels. We found different behaviors related to the type of the area of concern i.e. rural or urban. The impacts on ozone are enhanced in urban areas where 15% reduction of the ozone peak and daily averaged concentrations can be reached. This behavior is similar for the NO_x for which, in addition, an increase of the levels can be noted in urban plumes over rural areas. The most important decreases of the total VOC levels are mainly located over rural areas (more than 5% reduction of the levels except in urban plumes). By comparing these results with those from a local study related to the air quality of Strasbourg, we estimate that the regional contribution to the urban air quality of Strasbourg allows an enhancement of the results by using alternative fuel blends at the regional scale.

• Subgrid-scale modeling of reacting scalar fluxes in large-eddy simulations of atmospheric boundary layers

  Jean-François Vinuesa, Fernando Porté-Agel, Sukanta Basu, Rob Stoll

  12/2005;

  In large-eddy simulations of atmospheric boundary layer turbulence, the lumped coefficient in the eddy-diffusion subgrid-scale (SGS) model is known to depend on scale for the case of inert scalars. This scale dependence is predominant near the surface. In this paper, a scale-dependent dynamic SGS mo... [more] In large-eddy simulations of atmospheric boundary layer turbulence, the lumped coefficient in the eddy-diffusion subgrid-scale (SGS) model is known to depend on scale for the case of inert scalars. This scale dependence is predominant near the surface. In this paper, a scale-dependent dynamic SGS model for the turbulent transport of reacting scalars is implemented in large-eddy simulations of a neutral boundary layer. Since the model coefficient is computed dynamically from the dynamics of the resolved scales, the simulations are free from any parameter tuning. A set of chemical cases representative of various turbulent reacting flow regimes is examined. The reactants are involved in a first-order reaction and are injected in the atmospheric boundary layer with a constant and uniform surface flux. Emphasis is placed on studying the combined effects of resolution and chemical regime on the performance of the SGS model. Simulations with the scale-dependent dynamic model yield the expected trends of the coefficients as function of resolution, position in the flow and chemical regime, leading to resolution-independent turbulent reactant fluxes.

• Revisiting the Local Scaling Hypothesis in Stably Stratified Atmospheric Boundary Layer Turbulence: an Integration of Field and Laboratory Measurements with Large-eddy Simulations

  Sukanta Basu, Fernando Porté-Agel, Efi Foufoula-Georgiou, Jean-François Vinuesa, Markus Pahlow

  09/2005;

  The `local scaling' hypothesis, first introduced by Nieuwstadt two decades ago, describes the turbulence structure of stable boundary layers in a very succinct way and is an integral part of numerous local closure-based numerical weather prediction models. However, the validity of this hypothesi... [more] The `local scaling' hypothesis, first introduced by Nieuwstadt two decades ago, describes the turbulence structure of stable boundary layers in a very succinct way and is an integral part of numerous local closure-based numerical weather prediction models. However, the validity of this hypothesis under very stable conditions is a subject of on-going debate. In this work, we attempt to address this controversial issue by performing extensive analyses of turbulence data from several field campaigns, wind-tunnel experiments and large-eddy simulations. Wide range of stabilities, diverse field conditions and a comprehensive set of turbulence statistics make this study distinct.

• Emission scenarios for air quality management and applications at local and regional scales including the effects of the future European emission regulation (2015) for the upper Rhine valley

  Ponche J.-L, Vinuesa J.-F

  Atmospheric Chemistry and Physics Discussions. 01/2004;

  Air quality modeling associated with emission scenarios has become an important tool for air quality management. The set-up of realistic emission scenarios requires accurate emission inventories including the whole methodology used to calculate the emissions. This means a good description of the sou... [more] Air quality modeling associated with emission scenarios has become an important tool for air quality management. The set-up of realistic emission scenarios requires accurate emission inventories including the whole methodology used to calculate the emissions. This means a good description of the source characteristics including a detailed composition of the emitted fluxes. Two main approaches are used. The so-called bottom-up approach that relies on the modification of the characteristics of the sources and the top-down approach whose goal is generally to reach standard pollutant concentration levels. This paper is aimed at providing a general methodology for the elaboration of such emission scenarios and giving examples of applications at local and regional scales for air quality management. The first example concerns the impact of the installation of the urban tramway in place of the road traffic in the old centre of Strasbourg. The second example deals with the use of oxygenated and reformulated car fuels on local (Strasbourg urban area) and regional (upper Rhine valley) scales. Finally, we analyze in detail the impacts of the incoming European emission regulation for 2015 on the air quality of the upper Rhine valley.

• Length dependence of the electronic transparence (conductance) of a molecular wire

  C. Joachim, J. F. Vinuesa

  EPL (Europhysics Letters). 01/1996; 33:635-640.

• Introducing effective reaction rates to account for the inefficient mixing of the convective boundary layer

  J.-F. Vinuesa, J. Vilà-Guerau de Arellano

  Atmospheric Environment.

  The convective boundary layer (CBL) is characterised by narrow vigorous thermals (updraft motions) surrounded by relatively large subsidence motions. In such a flow, reactants are normally segregated and their chemical transformations depend on the ability of atmospheric turbulence to mix them. This... [more] The convective boundary layer (CBL) is characterised by narrow vigorous thermals (updraft motions) surrounded by relatively large subsidence motions. In such a flow, reactants are normally segregated and their chemical transformations depend on the ability of atmospheric turbulence to mix them. This process is particularly important when the time-scale of the chemical transformation is similar to the turbulent characteristic time scale. For large atmospheric models, the segregation occurs at scales smaller than the grid length. As a result, instantaneous and homogeneous mixing of the reactants is normally assumed. This paper is aimed at the study of this assumption and to apply a parameterisation of an effective reaction rate accounting for the inefficient mixing due to convective turbulence in the CBL. We simulate a growing CBL with two models that use different physical assumptions. The first one, the so-called mixed-layer model, assumes an instantaneous and homogeneous mixing of the reactants in the boundary layer (BL). The second one, a three-dimensional large eddy simulation (LES) model, explicitly solves atmospheric turbulent motions and describes the heterogeneity of the mixing due to the turbulent characteristics of the CBL. By comparing their results in a simple case, i.e. a second-order chemical reaction, we show that the heterogeneous mixing due to convective turbulence has an important impact on the chemical transformations by slowing down the reaction rate. By introducing effective reaction rates through a parameterisation which accounts for this inefficient mixing, the mixed-layer model results improve significantly. We extend our study to a chemical mechanism that accounts for the ozone formation and depletion in the CBL. We show that the reaction rate can be slowed down or increased depending on whether the reactants are transported in opposite directions or not. We propose coefficients to be used to calculate the effective reaction rates in large-scale or mixed-layer models.

• Subgrid-scale modeling of reacting scalar fluxes in large-eddy simulations of atmospheric boundary layers

  J.-F. Vinuesa, F. Porté-Agel, S. Basu, R. Stoll

  In large-eddy simulations of atmospheric boundary layer turbulence, the lumped coefficient in the eddy-diffusion subgrid-scale (SGS) model is known to depend on scale for the case of inert scalars. This scale dependence is predominant near the surface. In this paper, a scale-dependent dynamic SGS mo... [more] In large-eddy simulations of atmospheric boundary layer turbulence, the lumped coefficient in the eddy-diffusion subgrid-scale (SGS) model is known to depend on scale for the case of inert scalars. This scale dependence is predominant near the surface. In this paper, a scale-dependent dynamic SGS model for the turbulent transport of reacting scalars is implemented in large-eddy simulations of a neutral boundary layer. Since the model coefficient is computed dynamically from the dynamics of the resolved scales, the simulations are free from any parameter tuning. A set of chemical cases representative of various turbulent reacting flow regimes is examined. The reactants are involved in a first-order reaction and are injected in the atmospheric boundary layer with a constant and uniform surface flux. Emphasis is placed on studying the combined effects of resolution and chemical regime on the performance of the SGS model. Simulations with the scale-dependent dynamic model yield the expected trends of the coefficients as function of resolution, position in the flow and chemical regime, leading to resolution-independent turbulent reactant fluxes.

• Revisiting the local scaling hypothesis in stably stratified atmospheric boundary-layer turbulence: An integration of field and laboratory measurements with large-eddy simulations

  S. Basu, F. Porté-Agel, E. Foufoula-Georgiou, J.-F. Vinuesa, M. Pahlow

  The 'local scaling' hypothesis, first introduced by Nieuwstadt two decades ago, describes the turbulence structure of the stable boundary layer in a very succinct way and is an integral part of numerous local closure-based numerical weather prediction models. However, the validity of this hy... [more] The 'local scaling' hypothesis, first introduced by Nieuwstadt two decades ago, describes the turbulence structure of the stable boundary layer in a very succinct way and is an integral part of numerous local closure-based numerical weather prediction models. However, the validity of this hypothesis under very stable conditions is a subject of ongoing debate. Here, we attempt to address this controversial issue by performing extensive analyses of turbulence data from several field campaigns, wind-tunnel experiments and large-eddy simulations. A wide range of stabilities, diverse field conditions and a comprehensive set of turbulence statistics make this study distinct.