CESI Research

Centre

D.E.A. Università degli studi di Brescia

Mobility and Environmental

Agency of Milan

Toulouse, 5-6/05/2004

Cesare Pertot - Environmental Studies, CESI Milanopertot@cesi.it

D.S.T.A.Università degli studi

Amedeo Avogadro

Modeling SystemModeling System

Topography Land UseECMWF /ARPEGE/ALADIN

Wind, Temperature,geopotential and relative

Hum.profiles

RAMS

CAMxor

TCAM

MOCAGE modelconcentrations

BOUNDY

Initial and boundary conditions

3-dimensional pollutant

Concentrationpatterns

EMISSIONPROCESSOR

ESCOMPTEhourly gridded emissions

Emission fields3D wind and temperature fields

turbulence parameters

VOC profiles

NASA dataozone column

density,turbidity

ARPEGE/ALADINCloud cover and

precipitationfields

CAMx v. 4.03 (Environ International Corporation, Ca)Eulerian photochemical transport and dispersion model

Model DescriptionModel Description

– grid configuration: horizontal - geographical and cartesian projectionsvertical - generic (w is internally computed)nesting allowed

– horizontal advection scheme: Bott (Bott A., 1989) or Piecewise Parabolic Method (PPM) (Colella & Woodward, 1984)

– vertical advection and diffusion scheme: fully implicit– chemical modules:

• gas phase: SAPRC99 / CB-IV and CMC / IEH integrator• Thermod. Equilibrium: ISORROPIA• SOA: SOAP (Strader et al., 1998)

– dry deposition: Resistance scheme– wet deposition: both gas and particle; within and below cloud– Plume in Grid (Pig) submodel implemented

Model DescriptionModel DescriptionTCAM• transport and deposition:

– terrain-following coordinates system– variable vertical spacing– advection-diffusion scheme (Chapeau function)– resistance-based dry deposition algorithm

• chemical module:– lumped molecule approach (SAPRC-90, SAPRC-97, COCOH-97)– lumped structure approach (CBIV-90)

• aerosol module: fixed moving approach– condensation/evaporation– termodynamic equilibrium – nucleation– acqueous chemistry

• numerical integrator: qssa, Implicit-Explicit Hybrid (IEH)• time resolution: one-hour temporal resolution• wet deposition: yes

MeteorologyMeteorology

– prognostic model based on:• nonhydrostatic, compressible equations of atmospheric dynamics and

thermodynamics• conservation equations (water vapor, liquid and ice hydrometeor mixing

rateos)

– may operate from global to sub-microscale scale (Two-way interactive nesting)– includes:

• parameterisations accounting for turbolent diffusion, solar/terrestrial radiation, moist processes, kinematic terrain effects, cumulus convection (Weissbluth), sensible/latent heat fluxes

• LEAF-2 model (John Lee) storage and vertical exchange of water and energy in multiple soil layers

• TOPMODEL, hydrology model based on Darcy Law for lateral downslope transport

• automatic seasonal variation of SST and vegetation parameters– allows parallel computation on a MIMD computer architecture

RAMS v.4.4 (Colorado State Univ. - ASTER Div. of Mission Res. Corp.)Regional Atmospheric Modeling System

Model configurationModel configuration

ESCOMPTE free run - IOP2 - from 21/06 to 26/06– 3 nested grids:

• 30 km cell size, covering the whole France• 10 km cell size• 3,3 km cell size covering Escompte domain

– input data: 3D six-hourly ECMWF analysis fields– no data assimilation– convective analysis performed only on largest grid– nudging performed only on boundary and top domain

Results - wind field (50 m a.g.l.)Results - wind field (50 m a.g.l.)

• Sea/land breeze regimes• Terrain features effects

Results - wind field (500 m a.g.l.)Results - wind field (500 m a.g.l.)

• Synoptic wind rotation

Results - temperature field (50 m a.g.l.)Results - temperature field (50 m a.g.l.)

• strong temperature gradients at coastal boundaries• influence of Camargue

Comparisons - Temperature Profiles - RS IMKComparisons - Temperature Profiles - RS IMK• Good agreement between obs. And mod. profiles• Good agreement between obs. and SST data during nighttime, differencies during day time• Inversion even during daytime in RAMS profile over water

Comparisons - Wind Speed Profiles - RS IMKComparisons - Wind Speed Profiles - RS IMK

• Wind variability correctly reproduced • Overestimation of WS in lower levels in some cases

Comparisons - Wind Dir. Profiles - RS IMKComparisons - Wind Dir. Profiles - RS IMK

Comparisons - Profiles - RS 4MComparisons - Profiles - RS 4M

• Over land ground temperature correctly reproduced