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
Consultez cette fiche en intégralité ?
Consultez cette fiche et près de 50 000 autres fiches de Centres de Recherche dans plus de 30 pays européens sur Expernova.com !

Inscrivez-vous ou contactez-nous pour une démonstration personnalisée.
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
Determination of standards for a UV-B monitoring network
1991 - 1994

Sujets :
Safety, Environmental Protection
Participants :
UNIVERSITY OF READING UNITED KINGDOM
UNIVERSITY OF READING
Education

DEPARTMENT OF METEOROLOGY, HORTICULTURE AND AGRICULTURE PO Box 217 Earley Gate 2, Whiteknights, Palmer Building RG6 2AU
UNITED KINGDOM
ARISTOTLE UNIVERSITY OF THESSALONIKI HELLAS
ARISTOTLE UNIVERSITY OF THESSALONIKI
Education

DEPARTMENT OF PHYSICS LABORATORY OF ATMOSPHERIC PHYSICS PO Box 149 Aristotle University of Thessaloniki 54006
HELLAS
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
University of Tromsø NORGE
University of Tromsø
Education

Institute of Mathematical and Physical Sciences 9037
NORGE
NATURAL ENVIRONMENT RESEARCH COUNCIL UNITED KINGDOM
NATURAL ENVIRONMENT RESEARCH COUNCIL
Research,Other

BRITISH ANTARCTIC SURVEY Madingley Road, High Cross CB3 0ET
UNITED KINGDOM
BELGIAN INSTITUTE FOR SPACE AERONOMY BELGIQUE-BELGIË
BELGIAN INSTITUTE FOR SPACE AERONOMY
Research,Other

3,Ringlaan 3 1180
BELGIQUE-BELGIË
Koninklijk Nederlands Meteorologisch Instituut NEDERLAND
Koninklijk Nederlands Meteorologisch Instituut
Non Commercial

Division of Physical Meterology PO Box 201 3730 AE
NEDERLAND
University of Cambridge UNITED KINGDOM
University of Cambridge
Education

Department of Botany Downing Street CB2 3ET
UNITED KINGDOM
LEOPOLD-FRANZENS-UNIVERSITAET INNSBRUCK ÖSTERREICH
LEOPOLD-FRANZENS-UNIVERSITAET INNSBRUCK
Education

INSTITUTE OF MEDICAL PHYSICS 44,Müllerstrasse 44 6020
ÖSTERREICH
UNIVERSITAET FUER BODENKULTUR WIEN ÖSTERREICH
UNIVERSITAET FUER BODENKULTUR WIEN
Education,Other

INSTITUT FÜR METEOROLOGIE UND PHYSIK 18,Turkenschanzstrasse 18 1180
ÖSTERREICH
Laboratoire d'Optique Atmosphèrique
Laboratoire d'Optique Atmosphèrique


Department of Meteorology
Department of Meteorology


Belgian Institute for Space Aeronomy
Belgian Institute for Space Aeronomy


Hide objectives
The overall objective of this project is to produce practical recommendations for the deployment of an integrated ultraviolet B(UVB) network throughout Europe.
Hide achievements
The main results of these campaigns are summarised below 1. Good calibration procedures are a necessary first step for accurate and reliable measurements. Careful monitoring of the lamp current ensures consistency of the calibration source, the lamp-spectrometer geometry must be rigorously maintained, and stray light within the calibration room must be excluded. 2. The spectrometer geometry and mechanical stability must allow the calibration to remain valid between the fixed conditions of the calibration room and the different instrument orientations, spatial distributions of radiation and ambient conditions in the environment. In most cases this involves at least a temperature stabilisation of sensitive parts of the spectrometer. 3. Important characteristics of the ideal spectrometer are: (a) wavelength specification. This could be achieved to an accuracy of about 0.1 to 0.3nm in many of the instruments and is acceptable unless very accurate work in the short wavelength UV-B region of the spectrum is required. (b) slit function. This determines the near field stray light from adjacent wavelengths which is attributed to the nominated wavelength of a measurement. The slit function is important where the measured spectrum changes very rapidly with wavelength, as with solar UV-B. Measuring the slit function of the spectrometers allowed the effects of different slit functions on a measurement of the sun light to be calculated. Correcting for both slit function and wavelength specification improves the comparison between instruments, especially in the UV-B. (c) far-field stray light. Radiation from wavelengths outside the region of the slit function must be rigorously excluded. if not, it provides a background measurement which limits the sensitivity of the spectroradiometer. As the solar spectrum changes by three orders of magnitude across the UV-B regions, spectrometers need stray light rejection of the same order. In general the single monochromator and diode array instruments did not have sufficient stray light rejection for measurements at the shorter UV-B wavelengths. (d) cosine response. The fore optics of each spectrometer should have a cosine response but in practice this was often far from perfect. Asymmetry in the cosine response can lead to apparent diurnal asymmetry in the measured irradiances, and different cosine errors can add to discrepancies in response between instruments. Knowing the cosine response of an instrument allows corrections to be made, but these involve assumptions about the spectral distribution of the incident radiation. In conclusion, a group of UV spectrometers has been identified which could act together to form a UV network. Other instruments require some improvement in design or operational procedures, but could achieve the level of performance set by the core group. The experiences of the campaigners have led to a greater understanding of instrument and operational requirements, which will aid newcomers to this area of research and point the way to future improvements in hardware and methodologies. A transportable lamp system has been designed and built to maintain an independent check of calibrations when instruments are isolated at their home sites.

Source : Cordis  

Numerical simulation of the 7 to 9 September 2006 AMMA mesoscale convective system: Evaluation of the dynamics and cloud microphysics using synthetic observations
2010
Auteurs : Dominique Bouniol, S. Cautenet, Philippe DUBUISSON, C. Duroure, Vincent Giraud, Alain PROTAT et Guillaume Penide
Masquer le résumé
This paper presents a numerical simulation of a Mesoscale Convective System (MCS) observed during the AMMA (African Monsoon Multidisciplinary Analysis) experiment with the BRAMS model (Brazilian Regional Atmospheric Modelling System). The aim is to document the life cycle of the MCS and to identify key cloud microphysical processes and their signatures by making use of synthetic observations calculated from the simulated fields. These observations: ARM (Atmospheric Radiation Measurement) 95 GHz equivalent radar reflectivity factor and Doppler velocity and infrared brightness temperatures in three SEVIRI (Spinning Enhanced Visible and InfraRed Imager) channels centred at 8.7, 10.6 and 12 µm are simulated using respectively Mie scattering theory and FASDOM (Fast Discrete Ordinate Method), a fast radiative transfer code. Synthetic observations and model variables are compared to various measurements from several platforms (W-band and Massachusetts Institute of Technology (MIT) ground-based Doppler radars, soundings, aircraft measurements, and Meteosat Second Generation) to evaluate the model at different scales and to identify the signatures of microphysical properties with a focus on the anvil part of the MCS. A method using both the ARM and the MIT radar data is used to identify the different regimes within the MCS. A relatively good agreement with direct comparisons is found, as well as discrepancies in the microphysical scheme parametrization that clearly need improvements (using in situ measurements). Microphysical signatures are also studied using joint radar reflectivity/Doppler-height histograms. Their analysis shows that the model tends to overplay the role of the riming processes, even in the anvil part of the MCS. Comparisons of the Particle Size Distributions (simulated and measured in situ) show the model's ability to reproduce complex PSDs (e.g. a multimodal behaviour)
Keywords :
Source : HAL  

A MULTI-WAVELENGTH INVESTIGATION OF RCW175: AN Hn REGION HARBORING SPINNING DUST EMISSION
2012
Auteurs : M. I. R. ALVES, S. CAREY, S. CASASSUS, M. COMPIEGNE, R. D. DAVIES, R. J. DAVIS, C. DICKINSON, D. ELIA, N. FLAGEY, S. MOLINARI, A. NORIEGA-CRESPO, R. PALADINI, M. Pestalozzi, S. SHENOY, E. Schisano et C. T. TIBBS
Masquer le résumé
Using infrared, radio continuum, and spectral observations, we performed a detailed investigation of the H II region RCW 175. We determined that RCW 175, which actually consists of two separate H II regions, G29.1-0.7 and G29.0-0.6, is located at a distance of 3.2 ± 0.2 kpc. Based on the observations we infer that the more compact G29.0-0.6 is less evolved than G29.1-0.7 and was possibly produced as a result of the expansion of G29.1-0.7 into the surrounding interstellar medium. We compute a star formation rate for RCW 175 of (12.6 ± 1.9) x 10-5 M yr―1, and identified six possible young stellar object candidates within its vicinity. Additionally, we estimate that RCW 175 contains a total dust mass of 215 ± 53 M. RCW 175 has previously been identified as a source of anomalous microwave emission (AME), an excess of emission at centimeter wavelengths often attributed to electric dipole radiation from the smallest dust grains. We find that the AME previously detected in RCW 175 is not correlated with the smallest dust grains (polycyclic aromatic hydrocarbons or small carbonaceous dust grains), but rather with the exciting radiation field within the region. This is a similar result to that found in the Perseus molecular cloud, another region which harbors AME, suggesting that the radiation field may play a pivotal role in the production of this new Galactic emission mechanism. Finally, we suggest that these observations may hint at the importance of understanding the role played by the major gas ions in spinning dust models.
Keywords :
Abundance ; Models ; Molecular clouds ; Polycyclic aromatic hydrocarbons ; Dust grain ; Electric dipoles ; Microwave emission ; Young stellar object ; Formation rate ; Star formation ; Interstellar matter ; HII regions ; Continuum ; dust, extinction ; HII regions ; ISM: abundances ; ISM: individual objects (RCW175, G29.1-0.7, G29.0-0.6) ;
Source : Pascal - INIST  

Previsibility of mineral dust concentrations: The CHIMERE-DUST forecast during the first AMMA experiment dry season
2009
Auteurs : Isabelle Chiapello, Laurent Menut et Cyril Moulin
Masquer le résumé
Abstract. The predictability of Northern Africa dust events is assessed using daily numerical forecast simulations for the next three days. The dust concentration fields, modeled with the CHIMERE-DUST model, were first evaluated by comparison with both AERONET surface data and OMI and SEVIRI satellite measurements. The accuracy and spread between measurements and simulations are discussed for the first short observation period of the AMMA experiment in Western Africa, between January and March 2006. The predictability of dust events was then estimated by comparing model results for different leads in a forecast mode. The model performance was evaluated with respect to its capability to forecast the surface wind speed, which is the key process for dust emission, and the transport of mineral dust near source regions and towards remote areas. It is shown that emissions forecast can vary up to 80% (close to the sources) but that the variability on forecasted dust concentrations and optical thicknesses do not exceed 40% and 20%.
Keywords :
Source : HAL  

Aerosol layer properties over Kyiv from AERONET/PHOTONS sunphotometer measurements during 2008-2009
2011
Auteurs : A.P. Cracknell, V. DANYLEVSKY, Oleg DUBOVIK, A. GRYTSAI, V. Ivchenko, Z. LI, G. Milinevsky, Goloub PHILLIPPE, M. SOSONKIN et C. A. VAROTSOS
Masquer le résumé
The AErosol RObotic NETwork (AERONET) is one of the most developed ground-based networks for aerosol monitoring. Radiative measurements (solar irradiance extinction, aureole brightness and sky light polarization) are used by the AERONET inversion retrieval technique to derive a wide variety of aerosol particle properties and parameters that are important for estimations of aerosol influences on climate change. Within the framework of scientific cooperation between Universite de Lille 1 and Taras Shevchenko National University (TSNU) of Kyiv (Kiev), a CIMEL CE 318-2 sunphotometer has been operating at Kyiv since March 2008. This article presents a preliminary analysis of the columnar aerosol properties retrieved from Kyiv sunphotometer measurements and one case study with unusual behaviour of the aerosol parameters. Version 2 of the AERONET inversion products (spectral aerosol optical thickness (AOT), the Ångström parameter (α), single-scattering albedo (SSA), size distribution and refractive index, and aerosol radiative forcing estimations) is considered in the analysis, demonstrating variability of aerosol properties and radiative forcing at the Kyiv observational site during a 1-year period.
Keywords :
Europe ; Southern Europe ; Italy ; Marches Italy ; Scientific cooperation ; frame structure ; climate change ; Estimation ; Parameter ; particles ; varieties ; techniques ; Inversion ; inverse problem ; utilization ; polarization ; Light ; brightness ; extinction ; irradiance ; solar radiation ; monitoring ; Ground based measurement ; networks ; Robotics ; 2009 ; 2008 ; properties ; aerosols ;
Source : Pascal - INIST  

Indirect radiative forcing due to aerosols over the North Atlantic region.
ACE-2: CLOUDYCOLUMN
1996 - 1998

Sujets :
Environmental Protection, Meteorology
Participants :
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE FRANCE
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
Research

URA 1357 - GROUPE D'ETUDE DE L'ATMOSPHRE MTOROLOGIQUE - GAME Avenue Gustave Coriolis 42, C.N.R. MTtTorologique 31057
FRANCE
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE FRANCE
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
Research

UMR 5560 - LABORATOIRE D'AEROLOGIE 14,Avenue Edouard Belin 14 31400
FRANCE
GERMAN AEROSPACE CENTRE DEUTSCHLAND
GERMAN AEROSPACE CENTRE
Research,Other

INSTITUTE OF ATMOSPHERIC PHYSICS Postfach 90 60 58 Muenchener Strasse 20, Oberpfaffernhofen 82234
DEUTSCHLAND
FREIE UNIVERSITAET BERLIN DEUTSCHLAND
FREIE UNIVERSITAET BERLIN
Education

INSTITUT FUER WELTRAUMWISSENSCHAFTEN (WE4) - FACHBEREICH GEOWISSENSCHAFTEN Fabeckstrasse 69 14195
DEUTSCHLAND
SECRETARY OF STATE FOR DEFENCE - MINISTRY OF DEFENCE UNITED KINGDOM
SECRETARY OF STATE FOR DEFENCE - MINISTRY OF DEFENCE
Research,Other

METEOROLOGICAL OFFICE FLIGHT RESEARCH D.E.R.A. Aerospace, Building Y 46 GU14 0LX
UNITED KINGDOM
UNIVERSITÉ BLAISE PASCAL CLERMONT-FERRAND II FRANCE
UNIVERSITÉ BLAISE PASCAL CLERMONT-FERRAND II
Education,Other

LABORATOIRE DE MÉTÉOROLOGIE PHYSIQUE BP 185 Avenue des Landais 24 63177
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
University of Manchester Institute of Science and Technology (UMIST) UNITED KINGDOM
University of Manchester Institute of Science and Technology (UMIST)
Education

Department of Pure and Applied Physics Physics Department PO Box 88 Sackville Street M60 1QD
UNITED KINGDOM
Laboratoire d'Aérologie
Laboratoire d'Aérologie


Laboratoire de Météorologie Physique
Laboratoire de Météorologie Physique


Laboratoire d'Optique Atmosphèrique
Laboratoire d'Optique Atmosphèrique


German Aerospace Center
German Aerospace Center


Hide objectives
Cloudy-Column is one of five projects which constitute the European contribution to the second Aerosol Characterisation Experiment (ACE-2) of the International Global Atmospheric Chemistry Project (IGAC). Cloudy-Column is specifically dedicated to the study of the indirect effect. The objective is to develop parameterisations of marine extended stratocumulus for climate models, that include explicitly the characteristics of the aerosol background and their effects on cloud radiative properties.

Source : Cordis  





Automated Data Collection Terms