# Presentation: 275965

## Lessons Learned:

**Lessons Learned:**
**One-Atmosphere Photochemical Modeling **
**in Southeastern U.S.**

**Presentation from Southern Appalachian Mountains Initiative**
**to Meeting of Regional Planning Organizations**
**December 3, 2002**

## SAMI Atmospheric Modeling

- Unique Contributions:
- Demonstrated fully-integrated one-atmosphere model
- ozone, aerosols, and deposition
- “performance comparable to or better than recent applications of CMAQ or REMSAD”

## In 1997 selected to use:
RAMS-3B meteorological model
EMS-95 emissions model
Urban to Regional Multi-scale (URM) air quality model
variable grid (12-km over Southern Appalachian Mountains)   
SAPRC chemical mechanism for gases
ISORROPIA for aerosols
Reactive Scavenging Module for deposition
Decoupled Direct Method for sensitivity to emissions changes

- RAMS-3B meteorological model
- EMS-95 emissions model
- Urban to Regional Multi-scale (URM) air quality model
- variable grid (12-km over Southern Appalachian Mountains)
- SAPRC chemical mechanism for gases
- ISORROPIA for aerosols
- Reactive Scavenging Module for deposition
- Decoupled Direct Method for sensitivity to emissions changes

**SAMI Atmospheric Model**

## SAMI Atmospheric Modeling Domain

- Georgia Institute of Technology

## SAMI Atmospheric Modeling

- Unique Contributions:
- Selected episodes to represent annual and seasonal air quality measures
- based on meteorology characterized for 5-year period
- 9 episodes in Feb, Mar, Apr, May, Jun, Jul, Aug
- Lesson learned:  prioritize computational power: greater spatial resolution or longer time periods?

## SAMI Atmospheric Model:             Lessons Learned

- Emissions Inventory uncertainties:
- especially NH3, primary OC; non-road, area sources
- Meteorological Model performance:
- clouds and precipitation affect chemistry and deposition
- wind speed and direction, mixing heights affect transport

## SAMI Atmospheric Model:             Lessons Learned

- Air Quality Observations limited spatially and temporally:
- PM2.5 data, especially NH4
- wet and dry deposition data
- vertical profiles for initial and boundary conditions

## SAMI Atmospheric Model: Lessons Learned

- Photochemical Model Performance:
- SO4 and OC best performance (+/- 50%), largest components of PM2.5
- overpredict NO3, soil, and EC; small components
- SO4 not fully neutralized by NH4, atmosphere NH4- limited
- need better measures: NH3, NH4, primary vs secondary  OC

## URM Model Performance - Fine Particle Mass  Great Smoky Mtns

- 2/01/01

**SO4**

**NO3**

**NH4**

**ORG**

**EC**

**SOIL**

**0**

**10.0**

**20.0**

**30.0**

**Concentration **

**(********g/m3)**

**Class 5**

**Class 4**

**Class 3**

**Class 2**

**Class 1**

** ****2/09/94   3/24/93   4/26/95   8/04/93   8/07/93   8/11/93  7/12/95  7/31/91   7/15/95**

**Modeled (left)          IMPROVE (right)**

## URM Model Performance:  Sulfate Fine Particle Mass

**July 1995**

**May 1995**

**May 1993**

**March 1993**

**February 1994**

**July 1991**

**June 1992**

**August 1993**

**April 1995**

**URM Model Performance:  Sulfate Fine Particle Mass**

**+ 50%**

**- 50%**

**(based on data from 3-10 IMPROVE sites in 12, 24, and 48 km grids)**

## URM Model Performance:  PM2.5 Mass

**July 1995**

**May 1995**

**May 1993**

**March 1993**

**February 1994**

**July 1991**

**June 1992**

**August 1993**

**April 1995**

**URM Model Performance:  PM2.5 Mass**

**URM  Modeled Concentration (********g/m3)**

**IMPROVE Measurements (********g/m3)**

**+ 50%**

**- 50%**

**(based on data from 3-10 IMPROVE sites in 12, 24, and 48 km grids)**

## Wet Ammonium Deposition Normalized Percent Bias

**Normalized Percent Bias**

**(based on data from 9-14 NADP wet deposition sites in 12, 24, and 48 km grids)**

## SAMI Atmospheric Modeling

- Unique Contributions:
- To assess effects, used modeled relative change in air quality to adjust measured air quality:
- visibility
- ozone effects to forests
- acid deposition effects to streams and forests
- Lesson learned:  bound relative reduction factor by model performance

## SAMI Atmospheric Modeling

- Unique Contributions:
- Used direct sensitivity analyses to evaluate state contributions to Class I areas
- Decoupled Direct Method (DDM-3D)
- evaluated responses to 10% change in emissions
- Lessons learned:
- trust relative contributions rather than absolute
- daily source contributions from DDM compare favorably to daily back trajectories

## DDM Sensitivity Performance

**Gaseous**
**Species**

**Aerosol **
**Species**

**Wet **
**Deposition**
**Species**

**SO2**

**NOx**

**NH3**

**VOCs**

**Ozone**

- Good

- Good

**SO2**

- Good

**NH3**

- Good

**SO4**

- Good

- Good

**NO3**

- Good

- Poor

- Good

**NH4**

- Good

- Good

- Fair

- Good

**OC**

- Good

- Good

**EC**

**SOIL**

**PM2.5**

- Good

- Good

- Poor

- Good

**SO4**

- Good

**NO3**

- Poor

- Good

- Poor

- Good

**NH4**

- Poor

- Poor

- Poor

- Poor

- Fair

## Slide 16

## Slide 17

## Annual SO4 Fine Particles Response to 10% Reduction in 

**SO2 Emissions from 2010 A2 strategy**

**SO4 Fine Particle Response (%)**

**-8.0**

**-6.0**

**-4.0**

**-2.0**

**0.0**

**Sipsey, AL**

**Cohutta, GA**

**Joyce Kilmer,**
**NC**

**Great Smoky**
**Mtn, TN **

**Shining**
**Rock, NC**

**Linville**
**Gorge, NC**

**James River **
**Face, VA**

**Shenanhoah,**
** ****VA**

**Otter Creek,**
** ****WV**

**Dolly Sods,**
**WV**

** ****Non-SAMI states**

**SAMI states**

## Appendix

## Sulfate Aerosol Normalized Percent Bias

**Sulfate Aerosol Normalized Percent Bias**

- -100

- -50

- 0

- 50

- 100

- 150

**Normalized Percent Bias**

**(based on data from 3-10 IMPROVE sites in 12, 24, and 48 km grids)**

## Ammonium Aerosol Normalized Percent Bias

**Ammonium Aerosol Normalized Percent Bias**

- -60

- -40

- -20

- 0

- 20

- 40

- 60

- 80

- 100

- 120

**7/12/1995**

**7/15/1995**

**7/19/1999**

**5/24/1995**

**5/27/1995**

**5/12/1993**

**5/15/1993**

**3/24/1993**

**3/27/1993**

**3/31/1993**

**2/9/1994**

**2/12/1994**

**4/26/1995**

**4/29/1995**

**5/3/1995**

**6/24/1992**

**6/27/1992**

**8/4/1993**

**8/7/1993**

**8/11/1993**

**7/24/1991**

**7/27/1991**

**7/31/1991**

**Normalized Mean Bias**

**(based on data from 3-10 IMPROVE sites in 12, 24, and 48 km grids)**

## Organic Aerosol Normalized Percent Bias

**Organic Aerosol Normalized Percent Bias**

**-60**

**-40**

**-20**

**0**

**20**

**40**

**60**

**80**

**100**

**120**

**7/12/1995**

**7/15/1995**

**7/19/1999**

**5/24/1995**

**5/27/1995**

**5/12/1993**

**5/15/1993**

**3/24/1993**

**3/27/1993**

**3/31/1993**

**2/9/1994**

**2/12/1994**

**4/26/1995**

**4/29/1995**

**5/3/1995**

**6/24/1992**

**6/27/1992**

**8/4/1993**

**8/7/1993**

**8/11/1993**

**7/24/1991**

**7/27/1991**

**7/31/1991**

**Normalized Percent Bias**

**(based on data from 3-10 IMPROVE sites in 12, 24, and 48 km grids)**

## Nitrate Aerosol Normalized Percent Bias

**Nitrate Aerosol Normalized Percent Bias**

- -50

- 0

- 50

- 100

- 150

- 200

- 250

**7/12/1995**

**7/15/1995**

**7/19/1999**

**5/24/1995**

**5/27/1995**

**5/12/1993**

**5/15/1993**

**3/24/1993**

**3/27/1993**

**3/31/1993**

**2/9/1994**

**2/12/1994**

**4/26/1995**

**4/29/1995**

**5/3/1995**

**6/24/1992**

**6/27/1992**

**8/4/1993**

**8/7/1993**

**8/11/1993**

**7/24/1991**

**7/27/1991**

**7/31/1991**

**Normalized Percent Bias**

**(based on data from 3-10 IMPROVE sites in 12, 24, and 48 km grids)**

## PM 2.5 Normalized Percent Bias

**-100**

**-50**

**0**

**50**

**100**

**150**

**200**

**2/9/94**

**3/24/93**

**3/31/93**

**4/29/95**

**5/15/93**

**5/24/95**

**6/24/92**

**7/24/91**

**7/31/91**

**7/15/95**

**8/4/93**

**8/11/93**

**Normalized Bias (%)**

- Normalized Bias of +/- 50% is potential criteria for aerosol model performance

**(based on data from 3-10 IMPROVE aerosol sites in 12, 24, and 48 km grids)**

**2/12/94**

**3/27/93**

**4/26/95**

**5/12/93**

**5/21/95**

**5/27/95**

**6/27/92**

**7/27/91**

**7/12/95**

**7/19/95**

**8/7/93**

## Aerosol Model Performance

**Modeled on Left,     IMPROVE On Right**

**URM Model Results vs. Observations for July 15, 1995**

**PM 2.5 (********g/m3****)**

**0.0**

**10.0**

**20.0**

**30.0**

**40.0**

**Aerosol Model Performance**

**Sipsey,**
**AL**

**Great**
**Smoky **
**Mtns.,TN**

**Shining **
**Rock, **
**NC**

**James **
**River **
**Face, VA**

**Shenandoah,**
**VA**

**Dolly **
**Sods, WV**

- 2/01/01

**SO4**

**NO3**

**NH4**

**ORG**

**EC**

**SOIL**

## Wet Sulfate Deposition Normalized Percent Bias  

- -30

- -25

- -20

- -15

- -10

- -5

- 0

- 5

- 10

**July 11-18,**

**1995**

**May 23-30,**

**1995**

**May 11-18,**

**1993**

**March 23-**

**30, 1993**

**Feb 8-15,**

**1994**

**April 26 -**

**May 3,**

**1995**

**August 3-**

**11, 1993**

**June 24-29,**

**1992**

**July 23-30,**

**1991**

**Normalized Percent Bias **

**(based on data from 9-14 NADP wet deposition sites in 12, 24, and 48 km grids)**

## Confidence Levels in SAMI 1990 Base Year inventory

**Confidence Levels in SAMI ****1990 Base Year inventory**