Nitrate Discussion WRAP Meeting – Tucson, AZ January 10/11, 2006 Joe Adlhoch - Air Resource Specialists, Inc.

Overview How much of baseline regional haze in WRAP states is due to nitrate? How much of baseline regional haze in WRAP states is due to nitrate? What are the historical trends in nitrate concentrations? What are the historical trends in nitrate concentrations? What are the contributions of natural and manmade emissions to nitrate? What are the contributions of natural and manmade emissions to nitrate? How are emissions expected to change by 2018? How are emissions expected to change by 2018? How is visibility expected to change? How is visibility expected to change? How does this compare with the glidepath? How does this compare with the glidepath? Selected case studies Selected case studies

IMPROVE Monitoring Locations

Baseline Extinction: 20% Worst Days

Baseline Extinction: 20% Best Days

Baseline Nitrate: 20% Worst Days

Historical Trends in 20% Worst Days: Total and Nitrate Extinction 16 year trends (1989 – 2004) required 12 complete years of data 16 year trends (1989 – 2004) required 12 complete years of data 8 year trends (1997 – 2004) required 6 complete years of data 8 year trends (1997 – 2004) required 6 complete years of data Theil slopes (Mm -1 /yr) calculated for all sites with sufficient data Theil slopes (Mm -1 /yr) calculated for all sites with sufficient data P-values of 0.2 required to identify trend as significant P-values of 0.2 required to identify trend as significant Changes in monitoring or analytical protocol over the years may affect trends Changes in monitoring or analytical protocol over the years may affect trends

16-yr Trends 8-yr Trends

Historical Trends, 20% Worst Days Mount Rainier NP 16-yr decrease in Bext 8-yr increase in NO3 16-yr decrease in NO3

Historical Trends, 20% Worst Days Chiricahua NM 16-yr increase in NO3 8-yr increase in Bext

Historical Trends, 20% Worst Days Redwood NP 16-yr decrease in Bext 16-yr decrease in NO3

Historical Trends, 20% Worst Days Rocky Mountain NP 8-yr increase in Bext 8-yr increase in NO3

Anthropogenic and Natural NOx Emissions by State (Plan02)

Total WRAP Region SO2 and NOx Emissions (2002, 2018, and difference)

All NOx Emissions

Gridded Model Results for Annual Average Nitrate Mass Annual average modeled mass (not 20% worst days) Annual average modeled mass (not 20% worst days) 2002 and and 2018 Difference (2018 – 2002) Difference (2018 – 2002) Ratio (2018/2002) Ratio (2018/2002)

Modeled 2002 NO3 Modeled 2018 NO3

Baseline and Projected 2018 Extinction: 20% Worst Days 2000 – 2004 Baseline ExtinctionProjected 2018 Extinction

Baseline and Projected 2018 Nitrate Extinction: 20% Worst Days 2000 – 2004 Baseline Nitrate Extinction Projected 2018 Nitrate Extinction

Baseline dv and Projected 2018 dv Reduction: 20% Worst Days 2000 – 2004 Baseline DeciviewsProjected 2018 Deciview Reduction

Variation in Baseline Deciview Values

Percent of 2018 Target Reduction Achieved

Hells Canyon, OR/ID

2002 NOx Emissions: Hells Canyon

2018 NOx Reductions: Hells Canyon

Model Comparison: Hells Canyon, OR

Hells Canyon, OR/ID2002 IMPROVE Data 2002 Model Results

2018 Model Changes: Hells Canyon, OR

Baseline Variability (dv) Baseline Variability by Species Glide Path: Hells Canyon, OR/ID

Medicine Lakes, MT

2002 NOx Emissions: Medicine Lakes

2018 NOx Reductions: Medicine Lakes

Model Comparison: Medicine Lakes, MT

Medicine Lakes, MT2002 IMPROVE Data 2002 Model Results

2018 Model Changes: Medicine Lakes

Baseline Variability (dv) Baseline Variability by Species Glide Path: Medicine Lakes, MT

Agua Tibia, CA

2002 NOx Emissions: Agua Tibia

2018 NOx Reductions: Agua Tibia

Model Comparison: Agua Tibia, CA

Agua Tibia, CA2002 IMPROVE Data 2002 Model Results

2018 Model Changes: Agua Tibia, CA

Baseline Variability (dv) Baseline Variability by Species Glide Path: Agua Tibia, CA