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Impact of solar UV variability on sudden stratospheric warming with LMDz-Reprobus. A. Hauchecorne 1 , S. Bekki 1 , M. Marchand 1 , C. Claud 2 , P. Keckhut 1 , F. Lefèvre 1 , D. Cugnet 1 , S. Lefebvre 1 , F. Lott 2 , G. Thuillier 1 LATMOS, CNRS, UVSQ, UPMC
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Impact of solar UV variability on sudden stratospheric warming with LMDz-Reprobus A. Hauchecorne1, S. Bekki1, M. Marchand1, C. Claud2, P. Keckhut1, F. Lefèvre1, D. Cugnet1, S. Lefebvre1, F. Lott2, G. Thuillier1 LATMOS, CNRS, UVSQ, UPMC Laboratoire de Météorologie Dynamique, CNRS, UPMC, Ecole Polytechnique
Sun-atmosphere link:possible mechanisms Total solar irradiance: change surface and tropospheric temperature Solar UV: O3 production stratospheric temperature change in atmospheric circulation: amplification mechanism ? Particle precipitations (SPE, GCR, EPP) - SPE and EPP in auroral zone: NOx and HOx atmospheric chemistry - GCR modulated by solar wind: condensation nuclei clouds atmospheric chemistry chemistry
CCM LMDz-Reprobus Dynamics and transport LMDz: • Extended version of the LMDz 4th generation GCM (Lott et al.) • Tropospheric version largely used in the french community • LMDz is the atmospheric component of the IPSL Earth System model (Dufresne et al.) Chemistry Reprobus: • Chemistry-transport model (Lefèvre et al.) • Chemical families Ox, NOx, HOx, ClOx, BrOx et CHOx chemistry. • Heterogeneous reactions: on aerosols and PSC particles • PSC sedimentation (dehydration and denitrification) : irreversible vertical transfer of HNO3 and H2O
Zonal mean temperature LMDZ-Reprobus Meteorological analysis ERA40
LMDz-Reprobus 30 years simulations: Minimum and maximum solar conditions for the 11-year solar cycle All the other forcings are kept constant: SSTs, sea ice, stratospheric aerosols, CFCs, GHGs
Difference in polar temperature (K) 90°S 90°N MIN MAX DIF
LMDz-Reprobus solar max – solar min January February Wind Temperature
LMDz Reprobus solar max – solar min Temperature Ozone
Stratosphere-troposphere dynamical coupling From Baldwin and Dunkerton, JASTP, 2005
Conclusion • The solar UV variability mechanism has been tested in LMDz-Reprobus • There is an impact onstratospheric dynamics (sudden stratospheric warming) • Future plans • Impact on the troposphere • Comparison with other models CMAM, SOCOL, IGCM-FASTOC • Common work on the evaluation of different solar forcings • (TSI, UV, GCR, SPE, EEP)