Why are we modeling ozone?
- Health Standards for ozone. At each monitor:
  - Older 1-hour peak 120 ppb ozone NAAQS, 4th highest in 3 years
  - New 8-hour average 80 ppb ozone NAAQS, 3 year average
- Role of Feds, Role of States.
  - Feds set National Ambient Air Quality Standards based on health
  - States must monitor air quality and if violating NAAQS, must
    create a plan to meet them.
  - Feds must approve the plan.
- NC's observed air quality.
  - Where are the monitors?
  - What's NC's ozone air quality?
Where does ozone come from?
- Ozone totally a secondary pollutant.
- To control ozone must control its precursors.
  - NOx comes from any combustion, from soils
  - VOCs come from many human activities (fuels, solvents,
    cooking, paints); also are emitted in large amounts by vegetation, 5 times man's emission in East US.
  - AQ Conceptual Model
How can we control precursor sources?
- Feds have mobile sources (ie, cars, trucks),
  States have point (ie, utilities) and
  area sources (ie, industry and houses).
- State must do a State Implementation Plan that includes:
  - Must model historic episode (1996) = Basecase
  - Must forecast emissions (growth, existing regs) to future year (2007) = Future Basecase
  - If NAAQS not meet,
    must try additional model controls until met = Future Control case
  - State must pass enforceable regulations based on model results.
  - State must sent plan to EPA for approval.

What is needed to model ozone?
- Full meteorological fields of temperature, wind speed and direction, moisture, solar radiation, clouds, rain, mixing magnitudes
  - Terrian, land use, soil moisture, vegetation cover
  - Meteorological observations at surface and aloft
- Emissions of NOx, VOC, CO by source sector type per cell per hour:
  - Mobile, on-road, eg, cars, trucks, SUVs, buses
  - Mobile, non-road, eg, construction, trains, planes, recreational
  - Point, elevated, eg, energy generation utilities
  - Point, low-level, eg, large industrial sources
  - Area, eg, numereous small sources
  - Biogenic, eg, trees, vegetation, soil
- Chemical reaction and mass transport model

How does the Met Model work?
- Met modeling was done with the Mesoscale Meteorology 5 (MM5), a community, research quality model developed at NCAR/Penn State.

How does the Chemistry Model work?
- Chemistry and transport was done with NCSC's Multiscale Air Qualty SImulation Platform, a community, very flexible multi-processes model developed at NCSC with EPA/NOAA help.