1 AirWare : AirWare : C OMPREHENSIVE A IR QUALITY M ODEL WITH E X TENSIONS VERSION 4.30, PBM DDr. Kurt Fedra Environmental Software & Services GmbH A-2352 Gumpoldskirchen AUSTRIA DDr. Kurt Fedra Environmental Software & Services GmbH A-2352 Gumpoldskirchen AUSTRIA

2 CAMxCAMx CAMx simulates the emission, dispersion, chemical reaction, and removal of pollutants in the troposphere by solving the pollutant continuity equation for each chemical species (l) on a system of nested three- dimensional grids.

3 CAMxCAMx The Eulerian continuity equation describes the time dependency of the average species concentration (cl) within each grid cell volume as a sum of all of the physical and chemical processes operating on that volume.

4 Where: C l = concentration of chemical species l V H = horizontal wind vector  = net vertical entrainment rate  = atmospheric density K = turbulent diffusion CAMx basic structure:

5 CAMx (simple version) Regular terrain-following 3D grid, supports nesting; Describes conservative substances, particulates and aerosols, various alternative chemistry mechanisms including complete photochemistry (ozone). Regular terrain-following 3D grid, supports nesting; Describes conservative substances, particulates and aerosols, various alternative chemistry mechanisms including complete photochemistry (ozone).

6 CAMx model grid: 2 level nesting: 1 km master domain (240*180) 1 km master domain (240*180) up to 9 sub- domains (city level, km at 250m) up to 9 sub- domains (city level, km at 250m) 8 vertical layers. 8 vertical layers.

7 CAMx Performance Performance independent of the number of (gridded) sources; Depends on: horizontal and vertical extent and resolution of the model domain, run duration 24 hours Cyprus (240*180*8, 9 sub- domains of 20*20 km 250m) conservative  3 hours 24 hours Cyprus, ozone (CBM IV, no sub- domain nesting  10 hours. Performance independent of the number of (gridded) sources; Depends on: horizontal and vertical extent and resolution of the model domain, run duration 24 hours Cyprus (240*180*8, 9 sub- domains of 20*20 km 250m) conservative  3 hours 24 hours Cyprus, ozone (CBM IV, no sub- domain nesting  10 hours.

8 CAMxCAMx The Eulerian continuity equation describes the time dependency of the average species concentration (cl) within each grid cell volume as a sum of all of the physical and chemical processes operating on that volume.

9 CAMx implementation Used for scheduled runs: Daily 24 hour forecasts (SO2, NOx, PM10) Hourly now-casts (waiting for real-time data assimilation, nudging the initial conditions with monitoring data. Used for scheduled runs: Daily 24 hour forecasts (SO2, NOx, PM10) Hourly now-casts (waiting for real-time data assimilation, nudging the initial conditions with monitoring data.

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22 AirWare R5.3 PBM photochemical box model DDr. Kurt Fedra Environmental Software & Services GmbH A-2352 Gumpoldskirchen AUSTRIA DDr. Kurt Fedra Environmental Software & Services GmbH A-2352 Gumpoldskirchen AUSTRIA

23 PBM photochemical box model Simple, fast and efficient numerical model for urban scale ( km) photochemical smog. Initial and boundary conditions can be taken from the daily regional ozone forecasts by CAMx. Input data include: –Meteorology (temperature, wind speed, mixing height, insolation/cloud cover) can be taken from the MM5 weather forecasts; –Dynamic (hourly) emission data of NOx and VOC are taken from the city domain level emission scenarios Simple, fast and efficient numerical model for urban scale ( km) photochemical smog. Initial and boundary conditions can be taken from the daily regional ozone forecasts by CAMx. Input data include: –Meteorology (temperature, wind speed, mixing height, insolation/cloud cover) can be taken from the MM5 weather forecasts; –Dynamic (hourly) emission data of NOx and VOC are taken from the city domain level emission scenarios

24 PBM photochemical box model Simple representation: Variable volume (vertical movement of the mixing layer), well mixed reactive cell (box); Transport and dispersion of pollutants through the cell; Dynamic emission of primary precursor species; Chemical transformations into intermediate and secondary products. Simple representation: Variable volume (vertical movement of the mixing layer), well mixed reactive cell (box); Transport and dispersion of pollutants through the cell; Dynamic emission of primary precursor species; Chemical transformations into intermediate and secondary products.

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26 PBM photochemical box model Simulation runs: Daily forecast runs for the period from –05:00 LST (at/around/before sunrise) –23:00 LST (after sunset Hourly model output. Speed/efficiency of the model makes it ideal for stochastic/ensemble simulations: probability of exceedances of daily/next day ozone warning and alert levels. Simulation runs: Daily forecast runs for the period from –05:00 LST (at/around/before sunrise) –23:00 LST (after sunset Hourly model output. Speed/efficiency of the model makes it ideal for stochastic/ensemble simulations: probability of exceedances of daily/next day ozone warning and alert levels.

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28 PBM data requirements: Meteorology (hourly): Date, location Wind speed Mixing height (can be simulated) Ambient air temperature Solar radiation or UV radiation (can be simulated if cloud cover is known) Cloud cover, amount and (optional) height Meteorology (hourly): Date, location Wind speed Mixing height (can be simulated) Ambient air temperature Solar radiation or UV radiation (can be simulated if cloud cover is known) Cloud cover, amount and (optional) height

29 PBM data requirements: Air Quality data: Initial conditions (concentrations) Boundary conditions/concentrations: upwind monitoring station ? Observed concentrations (optional) Hydrocarbon speciation factors for –Initial concentrations –Boundary conditions –Observed concentrations Air Quality data: Initial conditions (concentrations) Boundary conditions/concentrations: upwind monitoring station ? Observed concentrations (optional) Hydrocarbon speciation factors for –Initial concentrations –Boundary conditions –Observed concentrations

30 PBM reactivity classes: Non-reactives (NONR) Ethylene (ETH) Olefins/alkenes, minus ethylene (OLE) Paraffins/alkanes, minus methane (PAR) Formaldehyde (FOR) Other aldehyde species (ALD) Toluene (TOL) Other aromatic species (ARO) Non-reactives (NONR) Ethylene (ETH) Olefins/alkenes, minus ethylene (OLE) Paraffins/alkanes, minus methane (PAR) Formaldehyde (FOR) Other aldehyde species (ALD) Toluene (TOL) Other aromatic species (ARO)

31 PBM data requirements: Emissions (hourly): CO (area, point sources) NOx (area, line, point sources) THC (total hydrocarbon) emissions NMHC (non-Methane compounds) NO2/NOx ratio in emissions (0.1) CH4/THC ratio in emissions Emissions (hourly): CO (area, point sources) NOx (area, line, point sources) THC (total hydrocarbon) emissions NMHC (non-Methane compounds) NO2/NOx ratio in emissions (0.1) CH4/THC ratio in emissions

32 PBM model dynamics: Mixing height growth: option to interpolate between minimum and maximum; Photolytica rate constants: diurnal variation of photolytica rate constants based on theoretical clear-sky insolation and attenuation based on cloud cover or oberserved insolation; Chemical kinetics: 63 reactions and 41 chemical species in 8 hydrocarbon classes (Demerjian generalized chemical kinetics) Mixing height growth: option to interpolate between minimum and maximum; Photolytica rate constants: diurnal variation of photolytica rate constants based on theoretical clear-sky insolation and attenuation based on cloud cover or oberserved insolation; Chemical kinetics: 63 reactions and 41 chemical species in 8 hydrocarbon classes (Demerjian generalized chemical kinetics)

33 PBM model governing equation:

34 PBM major assumptions: 1.Well mixed box, no significant spatial variation inside the box/surface; 2.Low wind to near stagnant conditions (< 2m/s) 3.Emission sources are homogeneously distributed within the domain; 4.Entrainment/exchange 1.laterally by advective transport 2.Vertically by rising mixing layer 5.Molecular and turbulent diffusion neglected (well mixed…) 6.Horizontal and vertical wind shear neglected. 1.Well mixed box, no significant spatial variation inside the box/surface; 2.Low wind to near stagnant conditions (< 2m/s) 3.Emission sources are homogeneously distributed within the domain; 4.Entrainment/exchange 1.laterally by advective transport 2.Vertically by rising mixing layer 5.Molecular and turbulent diffusion neglected (well mixed…) 6.Horizontal and vertical wind shear neglected.