Responses to SO2 NOx NH3 Reeductions

2018 Responses to Domain-wide SO2/NOx/NH3 Reductions: 

2018 Responses to Domain-wide SO2/NOx/NH3 Reductions Talat Odman*, Yongtao Hu, Alper Unal, and Ted Russell School of Civil & Environmental Engineering Georgia Institute of Technology VISTAS Meeting August 25, 2004

Overview: 

Overview 2018-OTB (B1) vs. 2018-OTW (B2a) Responses to 30% SO2/NOx/NH3 reductions: Regional perspective OTB vs. OTW responses: How different are they? PM2.5 response vs. extinction response Are the responses additive? Class I area vs. Urban area responses Site specific responses

2018-OTW vs. 2018-OTB: 

2018-OTW vs. 2018-OTB

2018 OTB & OTW Summary: 

2018 OTB & OTW Summary July: SO4 is about 1/2 of PM2.5 NO3 is very small OC is about 1/4 of PM2.5 2018-OTW SO4 is about 2/3 of 2018-OTB SO4 2018-OTW PM2.5 is about 25% less than 2018-OTB PM2.5 January: SO4 is small NO3 is about 1/3 of PM2.5 OC is about 1/4 of PM2.5 2018-OTW NO3 is less than 2018-OTB SO4 2018-OTW PM2.5 is slightly less than 2018-OTB PM2.5

July 17, 2018 OTB & OTW: 

July 17, 2018 OTB & OTW

SO4 (July): 

SO4 (July)

NO3 (July): 

NO3 (July)

OC (July): 

OC (July)

Jan. 5, 2018 OTB & OTW: 

Jan. 5, 2018 OTB & OTW

SO4 (Jan.): 

SO4 (Jan.)

NO3 (Jan.): 

NO3 (Jan.)

OC (Jan.): 

OC (Jan.)

Responses to 30% SO2/NOx/NH3 Reductions: 

Responses to 30% SO2/NOx/NH3 Reductions

Response Summary: 

Response Summary July: Regionally, SO2 control is the most effective SO4 responds almost linearly to SO2 reductions January: Regionally, NH3 control is the most effective NO3 responds sub-linearly to NH3 reductions

July 17: 

July 17 2018 OTB 30% NOx 30% SO2 30% NH3

SO4 to 30% SO2 (July): 

SO4 to 30% SO2 (July)

Jan. 5: 

Jan. 5 2018 OTB 30% NOx 30% SO2 30% NH3

NO3 to 30% NH3 (Jan.): 

NO3 to 30% NH3 (Jan.)

OTB vs. OTW Response: 

OTB vs. OTW Response

Summary: 

Summary In general, OTB and OTW responses of PM2.5 are similar. This is more so for January when PM2.5 levels for OTB and OTW are much closer Responses are slightly larger for 2018-OTB Ranking of responses to different controls are very similar.

PM2.5 Responses to 30% SO2 Reduction (July 17) : 

PM2.5 Responses to 30% SO2 Reduction (July 17)

PM2.5 Responses to 30% NH3 Reduction (Jan. 5) : 

PM2.5 Responses to 30% NH3 Reduction (Jan. 5)

OTB & OTW Responses at Shenandoah (July): 

OTB & OTW Responses at Shenandoah (July)

OTB & OTW Responses at Shenandoah (Jan.): 

OTB & OTW Responses at Shenandoah (Jan.)

OTB & OTW Responses at Great Smoky Mountains (July): 

OTB & OTW Responses at Great Smoky Mountains (July)

OTB & OTW Responses at Great Smoky Mountains (Jan.): 

OTB & OTW Responses at Great Smoky Mountains (Jan.)

PM2.5 vs. Bext Response: 

PM2.5 vs. Bext Response

Summary: 

Summary July: Bext responses to 30% NOx and 30% SO2 reductions are larger than PM2.5 responses to the same controls Bext response to 30% NH3 reduction is smaller than PM2.5 response to the same control Recall that Bext formula does not directly contain NH4 January: Bext responses are slightly larger than PM2.5 responses

PM2.5 and Bext at Shenandoah (July): 

PM2.5 and Bext at Shenandoah (July)

PM2.5 and Bext at Shenandoah (Jan.): 

PM2.5 and Bext at Shenandoah (Jan.)

PM2.5 and Bext at Great Smoky Mountains (July): 

PM2.5 and Bext at Great Smoky Mountains (July)

PM2.5 and Bext at Great Smoky Mountains (Jan.): 

PM2.5 and Bext at Great Smoky Mountains (Jan.)

Are the responses additive?: 

Are the responses additive?

Summary: 

Summary In general, responses to 30% SO2, NOx and NH3 reductions are additive. Adding individual responses may slightly overestimate the combined response.

NOx and NH3 Controls (Jan.): 

NOx and NH3 Controls (Jan.)

SO2, NOx and NH3 Controls (Jan.): 

SO2, NOx and NH3 Controls (Jan.)

Class I Area vs. Urban Area Responses: 

Class I Area vs. Urban Area Responses

Responses at Class I - Urban Area Pairs: 

Responses at Class I - Urban Area Pairs Looked at 4 pairs: Cohotta – Atlanta, GA Cape Romain – Charleston, SC Great Smoky Mountains – Knoxville, TN Dolly Sods - Charleston, WV Class I – urban area pairs display similar responses. Relative response is generally larger in Class I area Ranking of responses to different controls is generally the same

Cohotta-Atlanta Responses (July): 

Cohotta-Atlanta Responses (July)

Cohotta-Atlanta Responses (Jan.): 

Cohotta-Atlanta Responses (Jan.)

Cape Romain–Charleston Responses (July): 

Cape Romain–Charleston Responses (July)

Cape Romain–Charleston Responses (Jan.): 

Cape Romain–Charleston Responses (Jan.)

Great Smoky Mountains–Knoxville Responses (July): 

Great Smoky Mountains–Knoxville Responses (July)

Great Smoky Mountains–Knoxville Responses (Jan.): 

Great Smoky Mountains–Knoxville Responses (Jan.)

Dolly Sods-Charleston, WV Responses (July): 

Dolly Sods-Charleston, WV Responses (July)

Dolly Sods-Charleston, WV Responses (Jan.): 

Dolly Sods-Charleston, WV Responses (Jan.)

Site Specific Responses: 

Site Specific Responses

Conclusion: 

Conclusion 2018-OTW PM2.5 is about 25% less than 2018-OTB PM2.5 in July. The two are much closer in January. SO2 controls are most effective in July while NH3 controls are most effective in January. OTB and OTW responses of PM2.5 are similar. PM2.5 and Bext responses are similar. Responses are generally additive. Responses at Class I – urban area pairs are similar. Response magnitudes vary from site to site.