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animation:seminaires:2017:accueil [2017/03/10 10:09]
cicaluga
animation:seminaires:2017:accueil [2017/05/09 14:28] (Version actuelle)
cicaluga
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 ====== Séminaires/​Colloquium 2017 ====== ====== Séminaires/​Colloquium 2017 ======
 +
 +===== Dynamics of eddy-driven jets and macroturbulent scales in the atmosphere =====
 +{{:​cbp_ens.jpeg?​nolink&​200 |}}**15 mai 2017 de 11h00 à 12h00** \\
 +COLLOQUIUM Centre Blaise Pascal-Laboratoire de Physique \\
 +Grande salle du CBP (LR6 C 023), ENS Lyon, France \\
 +
 +**Yohai KASPI  **, Weizmann Institute
 + \\
 +
 +Organisateurs : \\ 
 +
 +  * Antoine Venaille (Laboratoire de Physique, ENS de Lyon) \\
 +  * Cerasela Calugaru (Centre Blaise Pascal, ENS de Lyon, France) \\
 +   
 +
 +**Abstract :** \\ 
 +We study the dynamics of eddy-driven jets using a high-resolution idealized atmospheric general circulation model (GCM), where we systematically vary Earth’s rotation rate, and thus allow a clear separation between the subtropical and eddy-driven jets. We find that due to asymmetries in baroclinicity across the jet, eddy-driven jets tend to migrate poleward. Furthermore,​ the migrating jets allow a latitude-by-latitude analysis of the macroturbulent scales controlling the jets. We find that over a wide range of eddy scales and latitudes the jet width scales with the Rhines scale. This is analyzed through partitioning of the barotropic energy spectrum to the role of eddy-mean and eddy-eddy interactions,​ in transferring energy up- and down-scale. We find that this can explain the observed energy spectrum in the atmosphere. Finally, the role of eddy-eddy interactions is analyzed through comparison to simulations where they are omitted.
 +
  
 ===== Computational photochemistry of complex molecular systems ===== ===== Computational photochemistry of complex molecular systems =====
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   * Ivan Rivalta (Laboratoire de Chimie, ENS de Lyon) \\   * Ivan Rivalta (Laboratoire de Chimie, ENS de Lyon) \\
   * Cerasela Calugaru (Centre Blaise Pascal, ENS de Lyon, France) \\   * Cerasela Calugaru (Centre Blaise Pascal, ENS de Lyon, France) \\
 +   
 +**(25 participants)**
  
 **Abstract :** \\  **Abstract :** \\ 
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   * David Loffreda (Laboratoire de Chimie, ENS de Lyon) \\   * David Loffreda (Laboratoire de Chimie, ENS de Lyon) \\
   * Cerasela Calugaru (Centre Blaise Pascal, ENS de Lyon, France) \\   * Cerasela Calugaru (Centre Blaise Pascal, ENS de Lyon, France) \\
 +
 +**(22 participants)**
  
 The knowledge of the composition and surface structure of nanoalloy particles is crucial to explain their catalytic performance. In addition, the bonding of adsorbates may, in some cases, induce modifications in local atomic composition and surface structure, changing the activity and selectivity of the catalyst. These facts were observed for Au-Pd nanoparticles (1,2). Indeed, although the gold surface enrichment is predicted to be thermodynamically favorable under vacuum conditions (3) , a reversed segregation of Pd as a more active component to the surface is reported to occur in the presence of adsorbates (4,​5). ​ The knowledge of the composition and surface structure of nanoalloy particles is crucial to explain their catalytic performance. In addition, the bonding of adsorbates may, in some cases, induce modifications in local atomic composition and surface structure, changing the activity and selectivity of the catalyst. These facts were observed for Au-Pd nanoparticles (1,2). Indeed, although the gold surface enrichment is predicted to be thermodynamically favorable under vacuum conditions (3) , a reversed segregation of Pd as a more active component to the surface is reported to occur in the presence of adsorbates (4,​5). ​
animation/seminaires/2017/accueil.1489136986.txt.gz · Dernière modification: 2017/03/10 10:09 par cicaluga