POMIPo Valley Model Intercomparison

Exercise

CAMx model overview

In cooperation with AMA - MI

Ispra - March 7, 2008 G. Pirovano - CESI Ricerca

CAMx Overview

CAMx v. 4.5 (Environ International Corporation, Ca)

Eulerian photochemical transport and dispersion model

– grid configuration: horizontal - cartesian projections and geodetic (lat/lon)

vertical - generic terrain following (w is internally computed)

1- and 2-way nesting allowed

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

– vertical advection/diffusion scheme: fully implicit

– emissions: Diffuse (1st level) and point emissions

– dry deposition: resistance scheme

– wet deposition: both gas and particle; within and below cloud

– Plume in Grid (Pig) submodel implemented

– Nesting Two way flexible nesting implemented

Ispra - March 7, 2008 G. Pirovano - CESI Ricerca

CAMx Overview

CAMx v. 4.5 (Environ International Corporation, Ca)

Eulerian photochemical transport and dispersion model

– chemical modules:• gas phase: SAPRC99 / CB-IV / CB-05• gas phase integrator: CMC / IEH / LSODE• thermod. equilibrium: ISORROPIA• SOA: SOAP (Strader et al., 1998)

– aerosol dynamic: Coarse/Fine modes or size bin approach

– chemical species: Crustal, Primary Organic, Elemental Carbon

(primary)SO4

=, NO3-, NH4

+, H2O, Na+, Cl-, SOA (secondary)

Ispra - March 7, 2008 G. Pirovano - CESI Ricerca

CAMx Probing tools

OSAT - PSATOzone/Particulate Source Apportionment Technology

PSATPM10

S1

S2

Other

PSAT Advantages• Time saving (one simulation)

• Mass consistency

• Fully traceable

• Tracks sulfate, nitrate, organics, primary groups

• Tracks by category + region

Ispra - March 7, 2008 G. Pirovano - CESI Ricerca

CAMx Simulations outline

– Meteorology:• Horizontal Interpolation onto the output grid (if needed)• Aggregation of vertical levels (only over PBL) - No Interpolation• Kv Computation: TKE / Similarity theory (e.g. CMAQ approach)• Water Content: 3D prognostic fields / derived from rainfall rate

– Boundary Conditions: • Horizontal and vertical interpolation of the large scale fields onto CAMx grid• Chemical speciation and size disaggregation

Ispra - March 7, 2008 G. Pirovano - CESI Ricerca

CAMx Simulations outline

– Anthropogenic emissions:• Application of SMOKE emission model• Speciation and lumping of NMVOC• Speciation and size disaggregation of PM emissions

– Sea salt emissions: • CAMx pre-processor, function of wind speed

– Biogenic Emissions: • EPA’s BEIS, GloBEIS, MEGAN (supports CB05 and SOA updates in

v4.5)

Ispra - March 7, 2008 G. Pirovano - CESI Ricerca

CAMx Simulations outline

– Further analysis (optional):

•CB-05 versus CB-IV•2-way nesting versus 1-way nesting•PSAT analysis