A. Brut - Academia.edu (original) (raw)

Papers by A. Brut

Research paper thumbnail of Pollution transport and exchange during ESCOMPTE, 2nd IOP

Research paper thumbnail of Quality assessment of the MAJA atmospheric correction processor over a farmland area with a new operational in-situ ROSAS station

Le Centre pour la Communication Scientifique Directe - HAL - Université Paris Descartes, May 23, 2022

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Research paper thumbnail of Comparisons of pullution events during the ESCOMPTE 2001 campaign : sea-breeze and synoptic wind conditions

Research paper thumbnail of Turbulent Structure of the Surface Layer Above Open Sea

Research paper thumbnail of Determination of turbulent parameters in the atmospheric boundary layer with an UHF wind profiler. Comparison with in situ measurements

Research paper thumbnail of Seasonal and interannual variations of the upper ocean energetics between Tasmania and Antarctica

Deep Sea Research Part I: Oceanographic Research Papers, 2003

Nine years of Topex/Poseidon and ERS satellite altimetry and XBT data from the SURVOSTRAL program... more Nine years of Topex/Poseidon and ERS satellite altimetry and XBT data from the SURVOSTRAL program were used to analyze the seasonal and interannual variations of the eddy energetics in terms of its spatial distribution and relation with the upper ocean heat content. Eddy kinetic energy is calculated in two frequency bands one associated with transient and the other with low-frequency variability. The two eddy components have distinct geographical distribution. At the SURVOSTRAL line, the transient eddy energy is twice the low-frequency energy, with maximum transient energy occurring during the austral summer period and maximum low-frequency energy in winter. The site is one of growing eddy energy. Eddy momentum flux is northward over the SURVOSTRAL line, and the summertime eddy heat flux is poleward across the Subantarctic and Subtropical Fronts, and equatorward either side of the fronts. Eddy fluxes are strongly influenced by their position relative to the bathymetry and the mean current.

Research paper thumbnail of High-resolution simulations of vegetation growth over France between 1994-2007: Analysis of its inter-annual variation

Research paper thumbnail of A Surface Albedo Product at High Spatial Resolution from a Combination of SENTINEL-2 and LANDSAT-8 Data: The Role of Surface Radiative Forcing from Agriculture Areas as a Major Contributor to an Abatement of Carbon Emission

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2019

Satellite Sentinel-2 offers a global coverage of the Earth surface at the frequency of a few days... more Satellite Sentinel-2 offers a global coverage of the Earth surface at the frequency of a few days with pixel size ranging from 10 to 60 meters. Such spatio-temporal resolution fosters an advanced research in agricultural area notably. The role of the surface albedo as a mean to reduce the surface radiative forcing in link to agriculture practice is a real concern. A high resolution (HR) surface albedo is now generated routinely from the observations of satellites Sentinel-2A &-2B for the time being plus Landsat in the near future. The methodology inherited from the Global Land Service of Copernicus is presented with some preliminary results.

Research paper thumbnail of Predicting water balance of wheat and crop rotations with a simple model: AqYield

Agricultural and Forest Meteorology

Research paper thumbnail of N2O flux measurements over an irrigated maize crop: A comparison of three methods

Agricultural and Forest Meteorology

Research paper thumbnail of Observed volatilization fluxes of S-metolachlor and benoxacor applied on soil with and without crop residues

Environmental Science and Pollution Research, 2016

Volatilization may represent a major dissipation pathway for pesticides applied to soils or crops... more Volatilization may represent a major dissipation pathway for pesticides applied to soils or crops, and these losses may be modified by soil surface conditions or in the presence of plant residues. This paper investigates the effect of surface conditions on volatilization through experimental results. The two experiments consisted of volatilization flux measurements for 3 days after an application of S-metolachlor together with benoxacor: one with two wind tunnels to compare the effect of the presence of crop residues on the soil on volatilization losses and another one at the field scale from bare soil without crop residues. Volatilization fluxes were large immediately after application (between 77 and 223 ng m s for S-metolachlor depending on experimental conditions), decreasing down to a few nanograms per square meter per second on the last day. Volatilization fluxes followed a diurnal cycle driven by environmental conditions. The losses found for both compounds were in accordance with their physicochemical properties. The crop residue on the soil surface modified soil surface conditions-primarily the soil water content essentially, the degradation of S-metolachlor, and the dynamics of volatilization loss.

Research paper thumbnail of dolman 2006 BAMS

Research paper thumbnail of Water and energy budget monitoring over an agricultural landscape from optical scintillometer and TIR remote sensing data using a SVAT model

The purpose of this paper is to present an application combining remote sensing and modeling appr... more The purpose of this paper is to present an application combining remote sensing and modeling approaches for water and energy surface exchanges monitoring at high resolution over an agricultural landscape. This study takes advantage of using high spatial resolution data in the visible and thermal infrared (TIR) domains and at-ground eXtra Large Aperture Scintillometer (XLAS) sensible heat flux measurements. Actually,

Research paper thumbnail of Combining the effect of crops surface albedo variability on the radiative forcing together with crop GHG budgets calculated from in situ flux measurements in a life cycle assessment approach: methodology and results

Research paper thumbnail of Modélisation du Transfert radiatif Atmosphérique dans le modele DART

ABSTRACT Le modèle DART (Discrete Anisotropic Radiative Transfer) simule le transfert radiatif (T... more ABSTRACT Le modèle DART (Discrete Anisotropic Radiative Transfer) simule le transfert radiatif (T.R.) 3D dans le système "Terre – Atmosphère". Les paysages terrestres sont urbains ou naturels, avec relief. DART opère dans le domaine optique de l'ultraviolet à l'infrarouge thermique. Il simule des images de télédétection spatiale, pour toute configuration instrumentale et expérimentale (direction de visée, résolution spatiale, etc.). Il simule aussi des spectres et le bilan radiatif 3D. La précision radiométrique est un objectif essentiel de DART. Cette précision implique une modélisation précise du couplage "Terre - Atmosphère". Récemment, le T.R. atmosphérique a fait l'objet d'une grande amélioration en terme de précision et de flexibilité. Son algorithme s'appuie sur un échantillonnage spécifique de l'atmosphère et sur des fonctions de transfert atmosphérique pour réduire les temps de calcul. Ainsi, comparé au modèle atmosphérique ModTran, la précision de DART, en terme d'erreur relative, est passée de 6.5% à 1.3%.

Research paper thumbnail of Aggregation and disaggregation of synthetic L-band soil moisture data over South-western France in preparation of SMOS

ABSTRACT For the preparation of the soil moisture and ocean salinity (SMOS) mission, due for laun... more ABSTRACT For the preparation of the soil moisture and ocean salinity (SMOS) mission, due for launch in 2008, a synthetic study for the aggregation and disaggregation of L-band brightness temperature fields is currently being undertaken for a 5-year period (2000-2005) over south-western France. The observed soil moisture is derived from offline simulations obtained from the Meteo-France land surface model ISBA-A-gs. The radiative transfer model L-MEB is used to estimate the corresponding brightness temperature at 8 km resolution, with a large number of possible incidence angles for each time step. Aggregation of the distributed information is then undertaken by simulating overpasses of SMOS over the region. Finally, the disaggregation method is an extension of the approach presented by Merlin et al. (2005).

Research paper thumbnail of 3D-modeling of the surface energy budget in an urban area

Cities are now at the heart of many environmental studies: energetic issues, pollution or local m... more Cities are now at the heart of many environmental studies: energetic issues, pollution or local meteorology are topics that can affect the comfort of their inhabitants. As cities are built with a large variety of materials with heterogeneous canopies, radiative effects can strongly influence the 3D heat transfer within the canopy. For instance, the study of the urban heat island

Research paper thumbnail of Air–sea exchanges in the equatorial area from the EQUALANT99 dataset: Bulk parametrizations of turbulent fluxes corrected for airflow distortion

Quarterly Journal of the Royal Meteorological Society, 2005

Turbulent fluxes of momentum, sensible heat and water vapour were calculated using both the eddy ... more Turbulent fluxes of momentum, sensible heat and water vapour were calculated using both the eddy covariance (EC) and the inertial dissipation (ID) methods applied to data collected on board the research vessel La Thalassa during 40 days of the EQUALANT99 oceanographic campaign. The aim of this experiment was to establish accurate parametrizations of air-sea fluxes for the equatorial Atlantic area from a large dataset. However, the accuracy of turbulent fluxes measured aboard ships is strongly affected by the distortion of airflow patterns generated by obstacles such as the ship and mast. For the EQUALANT99 experiment, the effects of airflow distortion were estimated using physical simulations in a water channel. To reproduce the conditions of the campaign, a neutral boundary layer was simulated in the water channel and a detailed model of the ship La Thalassa was built. Correction coefficients for the mean wind speed were evaluated from these physical simulations. They show a dependence on both the azimuth angle of the flow (i.e. the horizontal direction of the flow with respect to the ship's longitudinal axis) and the angle of incidence of the wind. The correction for airflow distortion was applied to the measured wind speed and also included in the flux computation using the ID method. Compared with earlier studies which applied a single correction per flux sample, it appears that our results for the corrected transfer coefficients present greater dependence on neutral wind speed than the previous parametrizations; the method also shows encouraging results, with a decrease in the scatter of the transfer coefficients parametrization. However, the distortion could not be corrected for in the fluxes calculated using the EC method, because this technique integrates a wide range of turbulence scales for which the airflow distortion cannot be simulated in a water channel. Fluxes computed using the ID and EC methods are presented and compared in order to determine which method, in the configuration of the EQUALANT99 experiment, provides the best resulting transfer coefficients. According to the results, fluxes of momentum and latent heat computed by ID were better for deriving the drag and humidity coefficients. The EC method seemed better adapted to calculate sensible-heat fluxes than the ID method, although a high scatter remained on the Stanton neutral number.

Research paper thumbnail of P3. 6 Comparison of Pollution Events During the Escompte 2001 Campaign: Sea-Breeze and Synoptic Wind Conditions

ams.confex.com

The ESCOMPTE experiment was dedicated to the study of pollution events. A brief description of th... more The ESCOMPTE experiment was dedicated to the study of pollution events. A brief description of this program is presented in the companion paper (Moppert et al.) which is devoted to the description of the thermodynamic environment including the vertical ...

Research paper thumbnail of Regional transport and dilution during high-pollution episodes in southern France: Summary of findings from the Field Experiment to Constraint Models of Atmospheric Pollution and Emissions Transport (ESCOMPTE)

Journal of Geophysical Research, 2007

Research paper thumbnail of Pollution transport and exchange during ESCOMPTE, 2nd IOP

Research paper thumbnail of Quality assessment of the MAJA atmospheric correction processor over a farmland area with a new operational in-situ ROSAS station

Le Centre pour la Communication Scientifique Directe - HAL - Université Paris Descartes, May 23, 2022

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Research paper thumbnail of Comparisons of pullution events during the ESCOMPTE 2001 campaign : sea-breeze and synoptic wind conditions

Research paper thumbnail of Turbulent Structure of the Surface Layer Above Open Sea

Research paper thumbnail of Determination of turbulent parameters in the atmospheric boundary layer with an UHF wind profiler. Comparison with in situ measurements

Research paper thumbnail of Seasonal and interannual variations of the upper ocean energetics between Tasmania and Antarctica

Deep Sea Research Part I: Oceanographic Research Papers, 2003

Nine years of Topex/Poseidon and ERS satellite altimetry and XBT data from the SURVOSTRAL program... more Nine years of Topex/Poseidon and ERS satellite altimetry and XBT data from the SURVOSTRAL program were used to analyze the seasonal and interannual variations of the eddy energetics in terms of its spatial distribution and relation with the upper ocean heat content. Eddy kinetic energy is calculated in two frequency bands one associated with transient and the other with low-frequency variability. The two eddy components have distinct geographical distribution. At the SURVOSTRAL line, the transient eddy energy is twice the low-frequency energy, with maximum transient energy occurring during the austral summer period and maximum low-frequency energy in winter. The site is one of growing eddy energy. Eddy momentum flux is northward over the SURVOSTRAL line, and the summertime eddy heat flux is poleward across the Subantarctic and Subtropical Fronts, and equatorward either side of the fronts. Eddy fluxes are strongly influenced by their position relative to the bathymetry and the mean current.

Research paper thumbnail of High-resolution simulations of vegetation growth over France between 1994-2007: Analysis of its inter-annual variation

Research paper thumbnail of A Surface Albedo Product at High Spatial Resolution from a Combination of SENTINEL-2 and LANDSAT-8 Data: The Role of Surface Radiative Forcing from Agriculture Areas as a Major Contributor to an Abatement of Carbon Emission

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2019

Satellite Sentinel-2 offers a global coverage of the Earth surface at the frequency of a few days... more Satellite Sentinel-2 offers a global coverage of the Earth surface at the frequency of a few days with pixel size ranging from 10 to 60 meters. Such spatio-temporal resolution fosters an advanced research in agricultural area notably. The role of the surface albedo as a mean to reduce the surface radiative forcing in link to agriculture practice is a real concern. A high resolution (HR) surface albedo is now generated routinely from the observations of satellites Sentinel-2A &-2B for the time being plus Landsat in the near future. The methodology inherited from the Global Land Service of Copernicus is presented with some preliminary results.

Research paper thumbnail of Predicting water balance of wheat and crop rotations with a simple model: AqYield

Agricultural and Forest Meteorology

Research paper thumbnail of N2O flux measurements over an irrigated maize crop: A comparison of three methods

Agricultural and Forest Meteorology

Research paper thumbnail of Observed volatilization fluxes of S-metolachlor and benoxacor applied on soil with and without crop residues

Environmental Science and Pollution Research, 2016

Volatilization may represent a major dissipation pathway for pesticides applied to soils or crops... more Volatilization may represent a major dissipation pathway for pesticides applied to soils or crops, and these losses may be modified by soil surface conditions or in the presence of plant residues. This paper investigates the effect of surface conditions on volatilization through experimental results. The two experiments consisted of volatilization flux measurements for 3 days after an application of S-metolachlor together with benoxacor: one with two wind tunnels to compare the effect of the presence of crop residues on the soil on volatilization losses and another one at the field scale from bare soil without crop residues. Volatilization fluxes were large immediately after application (between 77 and 223 ng m s for S-metolachlor depending on experimental conditions), decreasing down to a few nanograms per square meter per second on the last day. Volatilization fluxes followed a diurnal cycle driven by environmental conditions. The losses found for both compounds were in accordance with their physicochemical properties. The crop residue on the soil surface modified soil surface conditions-primarily the soil water content essentially, the degradation of S-metolachlor, and the dynamics of volatilization loss.

Research paper thumbnail of dolman 2006 BAMS

Research paper thumbnail of Water and energy budget monitoring over an agricultural landscape from optical scintillometer and TIR remote sensing data using a SVAT model

The purpose of this paper is to present an application combining remote sensing and modeling appr... more The purpose of this paper is to present an application combining remote sensing and modeling approaches for water and energy surface exchanges monitoring at high resolution over an agricultural landscape. This study takes advantage of using high spatial resolution data in the visible and thermal infrared (TIR) domains and at-ground eXtra Large Aperture Scintillometer (XLAS) sensible heat flux measurements. Actually,

Research paper thumbnail of Combining the effect of crops surface albedo variability on the radiative forcing together with crop GHG budgets calculated from in situ flux measurements in a life cycle assessment approach: methodology and results

Research paper thumbnail of Modélisation du Transfert radiatif Atmosphérique dans le modele DART

ABSTRACT Le modèle DART (Discrete Anisotropic Radiative Transfer) simule le transfert radiatif (T... more ABSTRACT Le modèle DART (Discrete Anisotropic Radiative Transfer) simule le transfert radiatif (T.R.) 3D dans le système "Terre – Atmosphère". Les paysages terrestres sont urbains ou naturels, avec relief. DART opère dans le domaine optique de l'ultraviolet à l'infrarouge thermique. Il simule des images de télédétection spatiale, pour toute configuration instrumentale et expérimentale (direction de visée, résolution spatiale, etc.). Il simule aussi des spectres et le bilan radiatif 3D. La précision radiométrique est un objectif essentiel de DART. Cette précision implique une modélisation précise du couplage "Terre - Atmosphère". Récemment, le T.R. atmosphérique a fait l'objet d'une grande amélioration en terme de précision et de flexibilité. Son algorithme s'appuie sur un échantillonnage spécifique de l'atmosphère et sur des fonctions de transfert atmosphérique pour réduire les temps de calcul. Ainsi, comparé au modèle atmosphérique ModTran, la précision de DART, en terme d'erreur relative, est passée de 6.5% à 1.3%.

Research paper thumbnail of Aggregation and disaggregation of synthetic L-band soil moisture data over South-western France in preparation of SMOS

ABSTRACT For the preparation of the soil moisture and ocean salinity (SMOS) mission, due for laun... more ABSTRACT For the preparation of the soil moisture and ocean salinity (SMOS) mission, due for launch in 2008, a synthetic study for the aggregation and disaggregation of L-band brightness temperature fields is currently being undertaken for a 5-year period (2000-2005) over south-western France. The observed soil moisture is derived from offline simulations obtained from the Meteo-France land surface model ISBA-A-gs. The radiative transfer model L-MEB is used to estimate the corresponding brightness temperature at 8 km resolution, with a large number of possible incidence angles for each time step. Aggregation of the distributed information is then undertaken by simulating overpasses of SMOS over the region. Finally, the disaggregation method is an extension of the approach presented by Merlin et al. (2005).

Research paper thumbnail of 3D-modeling of the surface energy budget in an urban area

Cities are now at the heart of many environmental studies: energetic issues, pollution or local m... more Cities are now at the heart of many environmental studies: energetic issues, pollution or local meteorology are topics that can affect the comfort of their inhabitants. As cities are built with a large variety of materials with heterogeneous canopies, radiative effects can strongly influence the 3D heat transfer within the canopy. For instance, the study of the urban heat island

Research paper thumbnail of Air–sea exchanges in the equatorial area from the EQUALANT99 dataset: Bulk parametrizations of turbulent fluxes corrected for airflow distortion

Quarterly Journal of the Royal Meteorological Society, 2005

Turbulent fluxes of momentum, sensible heat and water vapour were calculated using both the eddy ... more Turbulent fluxes of momentum, sensible heat and water vapour were calculated using both the eddy covariance (EC) and the inertial dissipation (ID) methods applied to data collected on board the research vessel La Thalassa during 40 days of the EQUALANT99 oceanographic campaign. The aim of this experiment was to establish accurate parametrizations of air-sea fluxes for the equatorial Atlantic area from a large dataset. However, the accuracy of turbulent fluxes measured aboard ships is strongly affected by the distortion of airflow patterns generated by obstacles such as the ship and mast. For the EQUALANT99 experiment, the effects of airflow distortion were estimated using physical simulations in a water channel. To reproduce the conditions of the campaign, a neutral boundary layer was simulated in the water channel and a detailed model of the ship La Thalassa was built. Correction coefficients for the mean wind speed were evaluated from these physical simulations. They show a dependence on both the azimuth angle of the flow (i.e. the horizontal direction of the flow with respect to the ship's longitudinal axis) and the angle of incidence of the wind. The correction for airflow distortion was applied to the measured wind speed and also included in the flux computation using the ID method. Compared with earlier studies which applied a single correction per flux sample, it appears that our results for the corrected transfer coefficients present greater dependence on neutral wind speed than the previous parametrizations; the method also shows encouraging results, with a decrease in the scatter of the transfer coefficients parametrization. However, the distortion could not be corrected for in the fluxes calculated using the EC method, because this technique integrates a wide range of turbulence scales for which the airflow distortion cannot be simulated in a water channel. Fluxes computed using the ID and EC methods are presented and compared in order to determine which method, in the configuration of the EQUALANT99 experiment, provides the best resulting transfer coefficients. According to the results, fluxes of momentum and latent heat computed by ID were better for deriving the drag and humidity coefficients. The EC method seemed better adapted to calculate sensible-heat fluxes than the ID method, although a high scatter remained on the Stanton neutral number.

Research paper thumbnail of P3. 6 Comparison of Pollution Events During the Escompte 2001 Campaign: Sea-Breeze and Synoptic Wind Conditions

ams.confex.com

The ESCOMPTE experiment was dedicated to the study of pollution events. A brief description of th... more The ESCOMPTE experiment was dedicated to the study of pollution events. A brief description of this program is presented in the companion paper (Moppert et al.) which is devoted to the description of the thermodynamic environment including the vertical ...

Research paper thumbnail of Regional transport and dilution during high-pollution episodes in southern France: Summary of findings from the Field Experiment to Constraint Models of Atmospheric Pollution and Emissions Transport (ESCOMPTE)

Journal of Geophysical Research, 2007