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
Comparison of High-Cloud Characteristics as Estimated by Selected Spaceborne Observations and Ground-Based Lidar Datasets
2009
Auteurs : Gérard BROGNIEZ, Patrick CHERVET, Martial HAEFFELIN, Martial HAEFFELIN, Olga LADO-BORDOWSKY, Yohann MORILLE, Yohann Morille, Frédéric PAROL, Jacques PELON, Artemio PLANA-FATTORI, Antoine Roblin, Geneviève SEZE, Claudia STUBENRAUCH, Claudia STUBENRAUCH et G. Sèze
Masquer le résumé
The characterization of high clouds as performed from selected spaceborne observations is assessed in this article by employing a number of worldwide ground-based lidar multiyear datasets as reference. Among the latter, the ground lidar observations conducted at Lannion, Bretagne (48.7°N, 3.5°W), and Palaiseau, near Paris [the Site Instrumental de Recherche par Télédétection Atmosphérique (SIRTA) observatory: 48.7°N, 2.2°E], both in France, are discussed in detail. High-cloud altitude statistics at these two sites were found to be similar. Optical thicknesses disagree, and possible reasons were analyzed. Despite the variety of instruments, observation strategies, and methods of analysis employed by different lidar groups, high-cloud optical thicknesses from the Geoscience Laser Altimeter System (GLAS) on board the Ice, Cloud and land Elevation Satellite (ICESat) were found to be consistent on the latitude band 40°-60°N. Respective high-cloud altitudes agree within 1 km with respect to those from ground lidars at Lannion and Palaiseau; such a finding remains to be verified under other synoptic regimes. Mean altitudes of high clouds from Lannion and Palaiseau ground lidars were compared with altitudes of thin cirrus from the Television and Infrared Observation Satellite (TIROS) Operational Vertical Sounder (TOVS) Path-B 8-yr climatology for a common range of optical thicknesses (0.1-1.4). Over both sites, the annual altitude distribution of thin high clouds from TOVS Path-B is asymmetric, with a peak around 8-9.5 km, whereas the distribution of high clouds retrieved from ground lidars seems symmetric with a peak around 9.5-11.5 km. Additional efforts in standardizing ground lidar observation and processing methods, and in merging high-cloud statistics from complementary measuring platforms, are recommended.
Keywords :
TIROS operational vertical sounder ; Polar orbiting satellite ; Space remote sensing ; statistical analysis ; Altitudinal distribution ; Climatology ; Remote sensing by laser beam ; Radar altimetry ; altimetry ; Lidar ; Ground based measurement ; Radar observation ; TIROS satellites ; Satellite observation ; Measurement technique ; High altitude ; clouds ;
Source : Pascal - INIST  

Validation of GOMOS-Envisat vertical profiles of O3, NO2, NO3, and aerosol extinction using balloon-borne instruments and analysis of the retrievals
2008
Auteurs : Frédérique Auriol, Jean-Yves Balois, Gwenaël Berthet, Colette Brogniez, Valery Catoire, Michel Chartier, Philippe François, Bertrand Gaubicher, F. Goutail, J.-P. Pommereau, Jean-Baptiste Renard, Claude Robert et Christian Verwaerde
Masquer le résumé
The UV-visible Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument onboard Envisat performs nighttime measurements of ozone, NO2, NO3 and of the aerosol extinction, using the stellar occultation method. We have conducted a validation exercise using various balloon-borne instruments in different geophysical conditions from 2002 to 2006, using GOMOS measurements performed with stars of different magnitudes. GOMOS and balloon-borne vertical columns in the middle stratosphere are in excellent agreement for ozone and NO2. Some discrepancies can appear between GOMOS and balloon-borne vertical profiles for the altitude and the amplitude of the concentration maximum. These discrepancies are randomly distributed, and no bias is detected. The accuracy of individual profiles in the middle stratosphere is 10 % for ozone and 25 % for NO2. On the other hand, the GOMOS NO3 retrieval is difficult and no direct validation can be conducted. The GOMOS aerosol content is also well estimated, but the wavelength dependence can be better estimated if the aerosol retrieval is performed only in the visible domain. We can conclude that the GOMOS operational retrieval algorithm works well and that GOMOS has fully respected its primary objective for the study of the trends of species in the middle stratosphere, using the profiles in a statistical manner. Some individual profiles can be partly inaccurate, in particular in the lower stratosphere. Improvements could be obtained by reprocessing some GOMOS transmissions in case of specific studies in the middle and lower stratosphere when using the individual profiles.
Keywords :
Validation ; balloon ; stratosphere
Source : HAL  

Aerosol complexity in megacities: From size-resolved chemical composition to optical properties of the Beijing atmospheric particles
2009
Auteurs : Helene CACHIER, H. Cachier, Oleg DUBOVIK, Benjamin GUINOT, B. Guinot, Marc MALLET, JEAN CLAUDE ROGER, J.C. Roger et TONG YU
Masquer le résumé
[1] ] Megacities need adapted tools for the accurate modeling of aerosol impacts. For this purpose a new experimental data processing has been worked out for Beijing aerosols as case study. Size-resolved aerosol particles were extensively sampled during winter and summer 2003 and subsequently fully chemically characterized. The product is an aerosol model presenting a new particle pattern (mode number, size and chemistry) without any prerequisite constrain either on the mode number or on each mode chemical composition. Six modes were found and five of them consistently appear as internally mixed particles organized around a black carbon or a dust core coated by organic and/or inorganic material. Data were checked by robust comparisons with other experimental data (particle number, sunphotometer-derived derived data). We found the presence of two accumulation modes in different internal mixing and optical calculations show that the Beijing aerosol single scattering albedo (wo # 0.90) is significantly higher than expected. Such an approach would allow realistic modeling of atmospheric particle impacts under complex situations.
Keywords :
albedo ; Mixing ; mixing ; accumulation ; photometry ; inorganic materials ; drill cores ; dust ; Soot ; models ; Summer ; Winter ; case studies ; data processing ; Modeling ; particles ; optical properties ; chemical composition ; Complexity ; aerosols ;
Source : Pascal - INIST  

First ground-based infrared solar absorption measurements of free tropospheric methanol (CH3OH) : Multidecade infrared time series from Kitt Peak (31.9°N 111.6°W): Trend, seasonal cycle, and comparison with previous measurements
2009
Auteurs : Linda CHIOU, Hervé HERBIN, Emmanuel MAHIEU et Curtis P. RINSLAND
Masquer le résumé
[1] Atmospheric CH3OH (methanol) free tropospheric (2.09-14-km altitude) time series spanning 22 years has been analyzed on the basis of high-spectral resolution infrared solar absorption spectra of the strong ν8 band recorded from the U.S. National Solar Observatory on Kitt Peak (latitude 31.9°N, 111.6°W, 2.09-km altitude) with a 1 -m Fourier transform spectrometer (FTS). The measurements span October 1981 to December 2003 and are the first long time series of CH3OH measurements obtained from the ground. The results were analyzed with SFIT2 version 3.93 and show a factor of three variations with season, a maximum at the beginning of July, a winter minimum, and no statistically significant long-term trend over the measurement time span.
Keywords :
Long term ; Winter ; Fourier transformation ; latitude ; Solar observatory ; absorption spectra ; altitude ; seasonal variations ; trend-surface analysis ; Time series ; Methanol ; troposphere ; absorption ;
Source : Pascal - INIST  

Delivery of aerosol products for assimilation and environmental use
DAEDALUS
2003 - 2005

Sujets :
Resources of the Sea, Fisheries, Forecasting, Meteorology, Environmental Protection
Participants :
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE FRANCE
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
Research

URA 0713 - LABORATOIRE D'OPTIQUE ATMOSPHÉRIQUE Laboratoire d'Optique Atmosphérique (URA 713) UER de Physique Fondamentale Université de Lille 59655
FRANCE
ROYAL NETHERLANDS METEOROLOGICAL INSTITUTE NEDERLAND
ROYAL NETHERLANDS METEOROLOGICAL INSTITUTE
Other

P.O. Box 201 10,Wilhelminalaan 10 3730 AE
NEDERLAND
BELGIAN INSTITUTE FOR SPACE AERONOMY BELGIQUE-BELGIË
BELGIAN INSTITUTE FOR SPACE AERONOMY
Research,Other

3,Ringlaan 3 1180
BELGIQUE-BELGIË
NORWEGIAN INSTITUTE FOR AIR RESEARCH NORGE
NORWEGIAN INSTITUTE FOR AIR RESEARCH
Research,Other

P.O. Box 100 Instituttveien 18 2027
NORGE
NETHERLANDS ORGANISATION FOR APPLIED SCIENTIFIC RESEARCH - TNO NEDERLAND
NETHERLANDS ORGANISATION FOR APPLIED SCIENTIFIC RESEARCH - TNO
Research,Other

TNO PHYSICS AND ELECTRONICS LABORATORY P.B. 6031 63,Oude Waalsdorperweg 63 2509 JG
NEDERLAND
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
UNIVERSIDADE DE EVORA PORTUGAL
UNIVERSIDADE DE EVORA
Education

CENTRO DE GEOFISICA DE EVORA PO Box 94 Rua Romao Ramalho 59 7000-671
PORTUGAL
COMMISSION OF THE EUROPEAN COMMUNITIES ITALIA
COMMISSION OF THE EUROPEAN COMMUNITIES
Research

INSTITUTE FOR ENVIRONMENT AND SUSTAINABILITY CLIMATE CHANGE UNIT Via Enrico Fermi 1 21020
ITALIA
Laboratoire d'Optique Atmosphèrique
Laboratoire d'Optique Atmosphèrique


Royal Netherlands Meteorological Institute
Royal Netherlands Meteorological Institute


Belgian Institute for Space Aeronomy
Belgian Institute for Space Aeronomy


Norwegian Institute for Air Research
Norwegian Institute for Air Research


NETHERLANDS ORGANISATION FOR APPLIED SCIENTIFIC RESEARCH
NETHERLANDS ORGANISATION FOR APPLIED SCIENTIFIC RESEARCH


Hide objectives
Atmospheric aerosols affect human health, continental and marine ecosystems, visibility, and the Earth's climate, requiring dedicated monitoring of their properties. DAEDALUS is a focused project to make an inventory of existing data relevant to aerosol monitoring, assess the users' needs at the European level interims of troposphere and stratospheric aerosol properties, evaluate the scientific, technical, and institutional efforts needed to meet the users' needs, match the available aerosol data products with the information needed by the group of users, and improve methodologies for making optimal use of satellite data and for assimilating aerosol data in transport models. DAEDALUS will provide the necessary impetus for designing long-term sustainable and fully operational European monitoring of aerosol properties at regional and global scales over sea and over land, as foreseen in GMES.

Source : Cordis  

Cirrus microphysical properties and their effect on radiation : survey and integration into climate models using combined satellite observations (CIRAMOSA)
CIRAMOSA
2001 - 2003

Sujets :
Measurement Methods, Environmental Protection, Resources of the Sea, Fisheries, Meteorology, Forecasting
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
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE FRANCE
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
Research

URA 0713 - LABORATOIRE D'OPTIQUE ATMOSPHÉRIQUE Laboratoire d'Optique Atmosphérique (URA 713) UER de Physique Fondamentale Université de Lille 59655
FRANCE
ECOLE NORMALE SUPERIEURE FRANCE
ECOLE NORMALE SUPERIEURE
Education,Research

LABORATOIRE DE METEOROLOGIE DYNAMIQUE Rue Lhomond 24 75231
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
SECRETARY OF STATE FOR DEFENCE - MINISTRY OF DEFENCE UNITED KINGDOM
SECRETARY OF STATE FOR DEFENCE - MINISTRY OF DEFENCE
Research

METEOROLOGICAL OFFICE HADLEY CENTRE FOR CLIMATE PREDICTION AND RESEARCH Fitzroy Road, Metz Office EX1 3PB
UNITED KINGDOM
Laboratoire de Météorologie Dynamique
Laboratoire de Météorologie Dynamique


Laboratoire d'Optique Atmosphèrique
Laboratoire d'Optique Atmosphèrique


Hide objectives
The radiation effect due to changes of microphysical properties within cirrus clouds can be very important. We will provide a long-term survey of these properties, together with cirrus macrophysical properties, and then establish a compilation of correlations between them and the state of the atmosphere. This information is essential for the understanding of changes in clouds expected by a global climate change. Satellite instruments measuring radiation with a good spectral resolution as well as multi-angular measurements of polarized reflectance used with newly developed retrieval algorithms are now capable to give this information over the whole globe. Extensive care will be taken of the validation of the retrieved cirrus properties by intercomparison with data sets from regional measurement campaigns. Models for climate prediction can profit from the outcome of this proposal by using the most appropriate correlations in their radiation codes.

Source : Cordis  

Validation of ACE-FTS v2.2 methane profiles from the upper troposphere to the lower mesosphere
2008
Auteurs : P. BARON, P. F. Bernath, T. Blumenstock, C. D. Boone, Colette Brogniez, Valery Catoire, M. Coffey, M. De Mazière, P. Duchatelet, D. W. T. Griffith, James W. HANNIGAN, N. B. JONES, I. KRAMER, Y. Kasai, E. Mahieu, G. L. Manney, C. Piccolo, C. Randall, Claude Robert, C. Senten, K. Strong, J. R. Taylor, C. Tétard, C. Vigouroux, K. A. Walker et S. Wood
Masquer le résumé
The ACE-FTS (Atmospheric Chemistry Experiment – Fourier Transform Spectrometer) solar occultation instrument that was launched onboard the Canadian SCISAT-1 satellite in August 2003 is measuring vertical profiles from the upper troposphere to the lower mesosphere for a large number of atmospheric constituents. Methane is one of the key species. The version v2.2 data of the ACE-FTS CH4 data have been compared to correlative satellite, balloon-borne and ground-based Fourier transform infrared remote sensing data to assess their quality. The comparison results indicate that the accuracy of the data is within 10% in the upper troposphere – lower stratosphere, and within 25% in the middle and higher stratosphere up to the lower mesosphere (<60 km). The observed differences are generally consistent with reported systematic uncertainties. ACE-FTS is also shown to reproduce the variability of methane in the stratosphere and lower mesosphere.
Keywords :
Source : HAL  





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