Réseau NDSC-France NDACC P. Keckhut Coordinateur du NDACC-France LATMOS / IPSL

Objectifs Scientifiques Etude de la variabilité et détection des changements d’origine anthropique Fournir une base de référence notamment pour la validation des expériences spatiales Permettre des études de processus. Détection des Changements de la Stratosphère Network for the Detection of Stratospheric Changes First discussions 1986, implementation in 1991

Instruments LIDAR profiles –Raman lidar measuring water vapor –Differential Absorption Lidar (DIAL) measuring O3 –Backscatter lidars measuring aerosol –Raman and Rayleigh lidars measuring temperature MICROWAVE RADIOMETERS –Ozone, water vapor, and ClO profiles UV/VISIBLE SPECTROMETERS –Column abundance of ozone, NO2, and, at some latitudes, OClO and BrO FTIR SPECTROMETERS –Column abundances of a broad range of species including ozone, HCl, NO, NO2, ClONO2, and HNO3 DOBSON/BREWER SONDES –Ozone total column SONDES –Ozone profiles and Aerosol profile UV radiation at the ground

Validation des instruments du réseau Intercomparaisons –Déplacement des instruments sur un même site. –Comparaisons successives à partir d’un instrument mobile. –Utilisation d’expériences spatiales comme transfert géographique. Tests d’algorithme –Signaux artificiels –Echanges de données brutes OZONE TEMPERATURE Intercomparaison Sondes ballon

Contribution Française Constitué de 5 stations primaires et de nombreues stations secondaires Contribution Française: ALOMAR (69°N), Station Alpine (44°N), La Réunion (21°S), Dumont D’Urville (67°S), Réseau SAOZ Réseau NDSC depuis SO INSU depuis Données publiques après 2 ans bases de données hébergées à la NOAA. Exercises d’intercomparaisons. Financements : INSU, IPEV, MATE, ADEME, CNES, Collectivités locales.

NDACC Goals Detecting trends in overall atmospheric composition and understanding their impacts on the stratosphere and troposphere, Studying atmospheric composition variability at interannual and longer timescales, Establishing links and feedbacks between climate change and atmospheric composition, Calibrating and validating space-based measurements of the atmosphere, Supporting process-focused scientific field campaigns, and Testing and improving theoretical models of the atmosphere.

NDACC Organization The NDACC Steering Committee consists of two co-chairs, pairs of PIs representing each of the Working Groups, Independent Scientists who are appointed to act as peer reviewers, and ex-officio members from important NDACC funding agencies. Science Team Representatives –Dobson & Brewer –FTIR –LIDAR –Microwave –Ozonesondes & Aerosol Sondes –Satellite –Spectral UV –Theory & Analysis –UV/Visible –Peer and Ex-Officio Representatives

OHP temperature evolution in winter 1996/97

Gravity waves

Gravity waves in Doppler wind zonal meridional

Mesospheric inversions

Ozone trends Multiregression analysis Linear decrease of 5-10%/decade Good agreement between Lidar, Umcker and SAGE Lack of long data series in the lower stratosphere Probable discontinuities in ozonosonde series Coll. M. Guirlet et S. Godin Origine of the ozone depletion in the lower stratosphere at mid-latitude ?

Vortex evolution in December 1997

Example of polar filament simulated by the high-resolution transport model MIMOSA (Hauchecorne et al., 2002, Godin et al., 2002) Study of polar filaments

Synergie sol-espace Valider les expériences spatiales Assurer la continuité d’expériences spatiales successives et estimer des tendances à l’échelle globale HALOE GOMOS NCEP/LIDAR à 1hPa