LOA - Laboratoire d'Optique Atmosphèrique - UMR 8518

France Centre de recherche public
Accréditation CIR
Contact principal
Téléphone : 33(0)3 20 43 45 32
Mail : direction-loa@univ-lille1.fr
Adresse :
Bât. P5
59655 Villeneuve d'Ascq
France
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Description
(Extrait du site web)
Activité Générale :

L'optique atmosphérique cherche à modéliser la propagation à travers l'atmosphère de la lumière visible reçue du soleil et de la lumière infrarouge émise par l'ensemble des surfaces et de l'atmosphère terrestres. Les travaux menés au LOA dans ce domaine s'insèrent dans l'étude globale du climat.

Un premier objectif est de quantifier le rôle de ce rayonnement visible et infrarouge dans les échanges énergétiques de la planète, en particulier de préciser le rôle des nuages dans le bilan radiatif de la terre dont ils constituent un facteur essentiel.

Un second axe de recherche porte sur la caractérisation à l'échelle du globe de différents paramètres qui sont en relation directe avec l'évolution climatique (nuages, aérosols, surfaces), en utilisant principalement l'observation satellitaire.
Les travaux menés dans ce contexte mettent en oeuvre:

* La conception de logiciels permettant de simuler le transfert du rayonnement, à l'aide de modèles du système terre - atmosphère.
* L'analyse d'observations acquises par les capteurs satellitaires existants, le plus souvent sous forme d'images traitées sur ordinateur, et la conception d'expériences satellitaires nouvelles.
* La réalisation de campagnes d'observation de terrain, utilisant des appareillages développés par le laboratoire, mis en oeuvre au sol ou à partir d'avions ou de ballons stratosphériques, et destinés à valider les modèles ou à mettre en évidence les processus atmosphériques.

Le LOA est une unité Mixte de Recherches (UMR/CNRS 8518). Il fait partie de la Fédération de Recherches (FR1818) Milieux naturels et anthropisé Flux et dynamique.

Quelques documents de Laboratoire d'Optique Atmosphèrique
Validation of ACE-FTS N2O measurements
2008
Auteurs : P. F. Bernath, T. Blumenstock, C. D. Boone, Valery Catoire, M. Coffey, P. DEMOULIN, E. DUPUY, M. De Mazière, P. Duchatelet, N. Glatthor, D. W. T. Griffith, James W. HANNIGAN, M. Höpfner, N. B. JONES, Kenneth W. JUCKS, J. J. Jin, T. E. Kerzenmacher, H. Kuellmann, J. Kuttippurath, A. Lambert, J. C. MCCONNELL, S. MIKUTEIT, Donal P. MURTAGH, E. Mahieu, J. Mellqvist, J. Notholt, C. Piccolo, P. Raspollini, M. Ridolfi, Claude Robert, M. Schneider, Otto Schrems, K. Semeniuk, C. Senten, G. P. Stiller, A. Strandberg, K. Strong, Matthew TOOHEY, J. R. Taylor, C. Tétard, J. Urban, K. A. Walker, T. Warneke, M. A. Wolff et S. Wood
Masquer le résumé
The Atmospheric Chemistry Experiment (ACE), also known as SCISAT, was launched on 12 August 2003, carrying two instruments that measure vertical profiles of atmospheric constituents using the solar occultation technique. One of these instruments, the ACE Fourier Transform Spectrometer (ACE-FTS), is measuring volume mixing ratio (VMR) profiles of nitrous oxide (N2O) from the upper troposphere to the lower mesosphere at a vertical resolution of about 3–4 km. In this study, the quality of the ACE-FTS version 2.2 N2O data is assessed through comparisons with coincident measurements made by other satellite, balloon-borne, aircraft, and ground-based instruments. These consist of vertical profile comparisons with the SMR, MLS, and MIPAS satellite instruments, multiple aircraft flights of ASUR, and single balloon flights of SPIRALE and FIRS-2, and partial column comparisons with a network of ground-based Fourier Transform InfraRed spectrometers (FTIRs). Overall, the quality of the ACE-FTS version 2.2 N2O VMR profiles is good over the entire altitude range from 5 to 60 km. Between 6 and 30 km, the mean absolute differences for the satellite comparisons lie between -42 ppbv and +17 ppbv, with most within ±20 ppbv. This corresponds to relative deviations from the mean that are within ±15%, except for comparisons with MIPAS near 30 km, for which they are as large as 22.5%. Between 18 and 30 km, the mean absolute differences are generally within ±10 ppbv, again excluding the aircraft and balloon comparisons. From 30 to 60 km, the mean absolute differences are within ±4 ppbv, and are mostly between -2 and +1 ppbv. Given the small N2O VMR in this region, the relative deviations from the mean are therefore large at these altitudes, with most suggesting a negative bias in the ACE-FTS data between 30 and 50 km. In the comparisons with the FTIRs, the mean relative differences between the ACE-FTS and FTIR partial columns are within ±6.6% for eleven of the twelve contributing stations. This mean relative difference is negative at ten stations, suggesting a small negative bias in the ACE-FTS partial columns over the altitude regions compared. Excellent correlation (R=0.964) is observed between the ACE-FTS and FTIR partial columns, with a slope of 1.01 and an intercept of -0.20 on the line fitted to the data.
Keywords :
Source : HAL  

High spectral resolution remote sensing for earth's weather and climate studies
1993 - 1995

Sujets :
Coordination, Cooperation, Education, Training
Participants :
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE FRANCE
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
Other,Research

UPR 1211 - LABORATOIRE DE METEOROLOGIE DYNAMIQUE Ecole Polytechnique 91128
FRANCE
FREIE UNIVERSITAET BERLIN DEUTSCHLAND
FREIE UNIVERSITAET BERLIN
Education

INSTITUT FUER WELTRAUMWISSENSCHAFTEN (WE4) - FACHBEREICH GEOWISSENSCHAFTEN Fabeckstrasse 69 14195
DEUTSCHLAND
COUNCIL FOR THE CENTRAL LABORATORY OF THE RESEARCH COUNCILS UNITED KINGDOM
COUNCIL FOR THE CENTRAL LABORATORY OF THE RESEARCH COUNCILS
Research,Other

RUTHERFORD APPLETON LABORATORIES Chilton OX11 0QX
UNITED KINGDOM
UNIVERSITE PIERRE ET MARIE CURIE - PARIS VI FRANCE
UNIVERSITE PIERRE ET MARIE CURIE - PARIS VI
Education

SERVICE D'ARONOMIE PO Box 121 Place Jussieu 4 Tour 15 75230
FRANCE
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF LILLE FRANCE
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF LILLE
Education

UMR 8518 - LABORATOIRE D'OPTIQUE ATMOSPHÉRIQUE Bètiment P5 59655
FRANCE
Laboratoire de Météorologie Dynamique
Laboratoire de Météorologie Dynamique


Laboratoire d'Optique Atmosphèrique
Laboratoire d'Optique Atmosphèrique



Source : Cordis  

Comparison of high cloud characteristics as estimated by selected spaceborne observations and ground-based lidar datasets
2009
Auteurs : Gérard BROGNIEZ, P. CHERVET, Martial Haeffelin, O. Lado-Bordowsky, Yohann Morille, Frédéric PAROL, J. Pelon, A. Plana-Fattori, A. Roblin, C.J. Stubenrauch et G. Sèze
Pas de résumé disponible
Keywords :
Source : HAL  

Impact of sea-surface dust radiative forcing on the oceanic primary production: A 1D modeling approach applied to the West African coastal waters
2009
Auteurs : Malik CHAMI, Malik Chami, P. DUBUISSON, Philippe DUBUISSON, Bernard GENTILI, Bernard Gentili, Marc Mallet, Richard SEMPERE et Richard Sempere
Masquer le résumé
[1] The impact of the dust sea-surface forcing (DSSF) on the oceanic Primary Production (PP) is investigated here by using 1D modelling approach coupling an atmospheric radiative transfer model and a simple PP model. Simulations reveal that dust are able to induce a significant decrease of PP due to the attenuation of light by about 15-25% for dust optical depth (DOD) larger than 0.6-0.7 (at 550 nm). For DOD lower than ∼0.2-0.3, the influence of dust on PP is weak (∼5%). In addition to DOD, the important role played by dust single scattering albedo (DSSA) is also shown. Realistic applications over the Senegal coast are studied using SeaWiFS and AERONET observations. The analysis showed that PP could be reduced by about 15-20% during the spring period. This study highlights that dust/light interactions need to be parameterized in coupled ocean-atmosphere models used to estimate PP at regional scales.
Keywords :
Africa ; Senegal ; West Africa ; Regional scope ; Ocean-atmosphere model ; ocean-atmosphere interaction ; Spring(season) ; springs ; SeaStar satellite ; albedo ; Optical thickness ; attenuation ; simulation ; coupling ; Coastal water ; one-dimensional models ; primary productivity ; Forcing ; radiative transfer ; dust ; Sea surface ;
Source : Pascal - INIST  

European Stratospheric Monitoring Stations in the ALPS II
ESMOS/ALPS II
1996 - 1998

Sujets :
Forecasting, Environmental Protection, Measurement Methods, Meteorology
Participants :
BELGIAN INSTITUTE FOR SPACE AERONOMY BELGIQUE-BELGIË
BELGIAN INSTITUTE FOR SPACE AERONOMY
Research,Other

3,Ringlaan 3 1180
BELGIQUE-BELGIË
Centre National de la Recherche Scientifique (CNRS) FRANCE
Centre National de la Recherche Scientifique (CNRS)
Non Commercial

Institut National des Sciences de l'Univers Observatoire de Bordeaux (INSU 6) BP 89 Université de Bordeaux 33270
FRANCE
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE FRANCE
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
Research

UPR 3501 - SERVICE D'AÉRONOMIE BP 3 Route des Gètines 92371
FRANCE
FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V. DEUTSCHLAND
FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Research

INSTITUT FUER ATMOSPHAERISCHE UMWELTFORSCHUNG EV Kreuzeckbahnstrasse 19 82467
DEUTSCHLAND
UNIVERSITY OF BERNE SCHWEIZ/SUISSE/SVIZZERA
UNIVERSITY OF BERNE
Education,Other

INSTITUTE OF APPLIED PHYSICS 5,Sidlerstrasse 5 3012
SCHWEIZ/SUISSE/SVIZZERA
UNIVERSITÀ DEGLI STUDI - L'AQUILA ITALIA
UNIVERSITÀ DEGLI STUDI - L'AQUILA
Education,Other

DIPARTIMENTO DI FISICA Via Vetoio 10, Coppito 67010
ITALIA
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF LILLE FRANCE
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF LILLE
Education

UMR 8518 - LABORATOIRE D'OPTIQUE ATMOSPHÉRIQUE Bètiment P5 59655
FRANCE
UNIVERSITE DE LIEGE BELGIQUE-BELGIË
UNIVERSITE DE LIEGE
Education

INSTITUTE OF ASTROPHYSICS AND GEOPHYSICS GROUPE INFRA-ROUGE DE PHYSIQUE ATMOSPHERIQUE ET SOLAIRE 5,Allee du 6 Aout, Bat. B5c 4000
BELGIQUE-BELGIË
NORWEGIAN INSTITUTE FOR AIR RESEARCH NORGE
NORWEGIAN INSTITUTE FOR AIR RESEARCH
Research,Other

P.O. Box 100 Instituttveien 18 2027
NORGE
Laboratoire d'Optique Atmosphèrique
Laboratoire d'Optique Atmosphèrique


Belgian Institute for Space Aeronomy
Belgian Institute for Space Aeronomy


Norwegian Institute for Air Research
Norwegian Institute for Air Research


Hide objectives
To expand the intensive co-ordinated ground-based observations to provide climatological measurements of ozone total amounts and vertical profiles, aerosol vertical distributions, ClO vertical profiles, NO2, NO, reservoirs and long-lived tracers total amounts; - to study the coherence of the ozone vertical profiles database recorded since the mid-eighties. The problem of the possible meteorological bias in the ozone profile retrieved from lidars in the low stratosphere will be addressed; - to identify the processes which drive the variability of ozone over the Alps in the low and middle stratosphere by coupling the ozone vertical profiles obtained at different sites and using dynamical tracers (trajectories, potential temperatures and vorticies); - to study the nitrogen and chlorine budgets with ground-based and satellite measurements to test and validate the stratospheric models; - to assess the impact of heterogeneous chemistry processes on the partitioning of stratospheric species by using ground-based and satellite data combined with 2-D and 3-D modelling studies; - to compare the time series of stratospheric species now available from the Alpine stations with long-term simulation over the last decade; - to contribute to stratospheric studies on the connections of mid-latitude changes with high and low latitudes; - to validate satellite measurements of stratospheric species performed by GOME and possibly ADEOS; - to finalise intercomparisons for aerosol and ClO retrieval methods.

Source : Cordis  

Statistical approaches to error identification for plane-parallel retrievals of optical and microphysical properties of three-dimensional clouds : Bayesian inference
2009
Auteurs : H. W. BARKER, N. FERLAY, P. GABRIEL, D. O'BRIEN et G. L. STEPHENS
Masquer le résumé
[1] This paper addresses the effects of three-dimensional (3-D) radiative transfer on the retrieval of optical depth for inhomogeneous stratiform liquid water clouds from passive satellite imagery. A nonparametric Bayesian classifier is developed to identify locations in a scene where plane-parallel retrievals fail to meet the requirements of a criterion that dictates a specified level of accuracy. Receiver operating characteristics are introduced that provide useful metrics that assess the quality of the error identification procedure as functions of illumination-viewing geometry. By fixing droplet effective radii, distributions of errors for retrieved optical depth are estimated at a scale of 120 m. These estimates suggest the best performance that can be expected for optical depth retrievals when 3-D radiative transfer cannot be ignored. The developments in this paper were made possible through the use of Monte Carlo radiative transfer simulations on stratiform clouds that were generated by a cloud system-resolving model. Plane-parallel retrievals employ the CloudSat optical depth retrieval algorithm.
Keywords :
Retrieval algorithm ; models ; Stratiform cloud ; simulation ; Monte Carlo analysis ; performances ; Effective radius ; droplets ; geometry ; Illumination ; quality ; accuracy ; imagery ; satellites ; Optical thickness ; radiative transfer ; Bayes methods ; Water cloud ; errors ;
Source : Pascal - INIST  

Estimating the altitude of aerosol plumes over the ocean from reflectance ratio measurements in the O2 A-band.
2009
Auteurs : David Antoine, Philippe DUBUISSON, D. Dessailly et L. Duforet
Pas de résumé disponible
Keywords :
Source : HAL  





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