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Modélisation du cycle de l’ozone dans la haute troposphère : impact des NOx produits par les éclairs.
C. Mari, JP. Pinty, P. Mascart, J. Duron, C. Barthe, JP Chaboureau, F. Gheusi, M. Tressol and T. Fehr (DLR)
- Motivations - Paramétrisation des LiNOx dans Méso-NH- Applications à TOGA-COARE, TROCCINOX et STERAO- Perspectives
Méso-NH – Réunion utilisateurs -Toulouse 2005
Comprendre le bilan de l’ozone troposphérique
NOx : catalyseurs indispensables pour la production de l’O3 !
Réduire l’incertitude sur les sources de NOx
(Lee et al., 1997)
Paramétrisation des LiNOx dans Méso-NH(JP Pinty et T. Fehr)
• Lightning frequency (Price and Rind 1992) / Cloud Top Height
• IC/CG rate (Price and Rind, 1994) / Cold cloud thickness
• P(CG) = 6,7 x 1026 molecules of NO / flash, P(IC) = P(CG) / 10 (Price et al., 1997)
• LNOx in updrafts and/or in downdrafts
• Perfectly coherent with transport and scavenging
0°C
-10°C
IC
CG
Updrafts
Downdrafts
Cloud Top
Long-term simulations 1D / TOGA-COARE
Upper troposphere: Accumulation
Free troposphere:Competition LNOx vs. convective transport
PBL: Increase of NOxdue to downdraft transport of LNOx
NO2 (LiNOx) – NO2 (No LiNOx)
Long-term simulations 1D / TOGA-COARE
O3 (LiNOx) - O3 (NO LiNOx)
LNOx = local and sporadic eventbut integrated effect in space and time for ozone
Meso-NH Set-up for regional (low-resolution) simulationsEU-TROCCINOX
• One single domain (same as forecast mode)• horizontal grid: 102 x 102 points at 30 km resolution
• 72 levels: from 40 m (bottom) up to 600 m (top)
• Physics
• turbulence: CBR TKE 1D scheme
• convection: Bechtold’s scheme (incl. scavenging and LiNOx)
• microphysics: Pinty-Jabouille, subgrid cloudiness
• surface: ISBA and TEB
• radiation: ECMWF
• Initialization/coupling with ARPEGE-MOCAGE analysis
• Lagrangian tracers
• Chemistry• ReLACS scheme (37 species)
• dry deposition: Wesely
• emissions: EDGAR/GEIA (1°x1°)
(except for BB, Yevich and Logan 2003)
03/03/04Local convection flight in the afternoon
03/03/04Morning flight survey
04/03/04Aged NOx plume in the afternoon
Modelling of LNOx in MNHC at high resolution[ JP Pinty, C. Mari, C. Barthe and JP Chaboureau]
The STERAO intercomparison case[courtesy of M. Barth, NCAR)
http://box.mmm.ucar.edu/individual/barth/Chem_Convec_Intercomparison/slide1.html
Set-up of Méso-NH
• Domain
• horizontal grid : 120 x 120 points at 1 km resolution with open LBC
• 50 levels : from 70 m (bot) up to 600 m (top) with wave damping
•Physics
• transport with MPDATA scheme
• microphysics: Pinty-Jabouille
• electricity: Barthe-Pinty-Molinié
• gas scavenging & LiNOx: Mari-Pinty
• 3D turbulence (TKE): Cuxart-B-R
• Initialization
• R/S with 3 warm bubbles (3K)
• profiles of HCHO, H2O2, HNO3
• profiles of CO, NOx, O3
• 3 hour run on the 12 LINUX cluster @ LA
Ice and Wind fieldsT=1 hour @ Z=10 km
Convective Transport and scavenging
75 ppb<CO<130 ppb
Time = 1 hour Time = 2.5 hours
HNO3
http://box.mmm.ucar.edu/individual/barth/Chem_Convec_Intercomparison/slide1.html
Perspectives
● Modèle couplé transport / lessivage / éclairs / chimie dans la convection, complet et réaliste
● Tests de sensibilité 1D (stage de H. Luitjing au LA )
● Amélioration de la paramétrisation: approche plus physique, comparaison avec des simulations explicites de type STERAO (stage post-doctoral C. Barthe)