Modeling of Ammonia and PM 2.5 Concentrations Associated with Emissions from Agriculture Megan Gore, D.Q. Tong, V.P. Aneja, and M. Houyoux Department of Marine, Earth & Atmospheric Sciences North Carolina State University Raleigh, NC th Annual CMAS Conference October 6-8, 2008

Outline ٥ Introduction – Ammonia in North Carolina (NC) ٥ Model Configuration ٥ Preliminary Results ٥ O 3, NH 3, PM 2.5, NH 4 + ٥ Conclusions ٥ Future Work NH 3

Why do we care about Ammonia? Elevated levels of NH x (=NH 3 + NH 4 + ) can lead to: ٥ Nitrogen enrichment and eutrophication in aquatic ecosystems ٥ Impacts on crop and forest production ٥ Particulate matter (PM) formation ٥ Visibility degradation ٥ Odor

Nitrogen Emissions in N.C. NH 3 Agricultural Sources Total ~ 40% of Nitrogen 138,843 NH 3 tons/yr Swine 68,540 (49%) Cattle 24,952 (18%) Broilers 13,669 (10%) Turkeys 16,486 (12%) Fertilizer 8,720 (6%) Other 6,476 (5%) (Aneja et al., 1998)

Hog Farms in N.C.

Ammonia Atmospheric Chemistry Atmospheric Reactions: ٥ NH 3 (aq) + H 2 0 NH 4 OH(aq) ٥ NH 3 (g) + H 2 SO 4 (aq) NH 4 HSO 4 (aq) ٥ NH 3 (g) + NH 4 HSO 4 (aq) [NH 4 ] 2 SO 4 (s or aq) ٥ NH 3 (g) + HNO 3 (g) NH 4 NO 3 (s or aq) ٥ NH 3 (g) + HCl(g) NH 4 Cl(s or aq) ٥ NH 3 (g) + OH · (g) N · H 2 (g) + H 2 O(g)

Model Configuration ٥ Model: Community Multi-Scale Air Quality (CMAQ) Model ٥ Episode: January 1 – December 31, 2002 ٥ Domain:Continental U.S., N. Mexico, S. Canada 36 km, 24 layers ٥ Meteorology: MM5 - Pleim-Xiu Land Surface module on ٥ Emissions: 2002 National Emissions Inventory ٥ I/B Conditions: MOZART-2 for lateral BC ٥ Gas-phase mechanism: Carbon Bond (CB05) ٥ Aerosol module: AE4

Preliminary Results Ozone space January Base Run – Ozone Monthly Average January Reduced Run* – Ozone Monthly Average *Reduced Run – NH 3 Emissions turned off ppbv

Preliminary Results Ozone July Base Run – Ozone Monthly Average July Reduced Run* – Ozone Monthly Average *Reduced Run – NH 3 Emissions turned off ppbv

Preliminary Results – NH 3 January Base Run – NH 3 Monthly Average January Reduced Run* – NH 3 Monthly Average *Reduced Run – NH 3 Emissions turned off ppbv

Preliminary Results – NH 3 July Base Run – NH 3 Monthly Average July Reduced Run* – NH 3 Monthly Average *Reduced Run – NH 3 Emissions turned off ppbv

Preliminary Results PM 2.5 January Base Run – PM 2.5 Monthly Average January Reduced Run* – PM 2.5 Monthly Average *Reduced Run – NH 3 Emissions turned off

Preliminary Results PM 2.5 Base Run – January 2002, NC Monthly Average

Preliminary Results PM 2.5 Reduced Run – January 2002, NC Monthly Average

Preliminary Results PM 2.5 July Base Run – PM 2.5 Monthly Average July Reduced Run* – PM 2.5 Monthly Average *Reduced Run – NH 3 Emissions turned off

Preliminary Results PM 2.5 Base Run – July 2002, NC Monthly Average

Preliminary Results PM 2.5 Reduced Run – July 2002, NC Monthly Average

Preliminary Results–NH 4 + Aerosol January Base Run – NH 4 + Monthly Average January Reduced Run – NH 4 + Monthly Average *Reduced Run – NH 3 Emissions turned off

Preliminary Results–NH 4 + Aerosol July Base Run – NH 4 + Monthly Average July Reduced Run – NH 4 + Monthly Average *Reduced Run – NH 3 Emissions turned off

Conclusions ٥ Agricultural NH 3 emissions have a significant impact on PM 2.5 and NH 4 aerosol predicted concentrations

Future Work  Additional model runs turning off emissions from the various agricultural sectors  Evaluate the effect of ammonia emissions of aerosol composition  Model evaluation using observed values of pollutants  Meteorological analysis

Acknowledgements ٥ USDA ٥ USEPA ٥ NCSU Air Quality Research Group

Atmospheric emissions, transport, transformation & deposition of trace gases *Indirect deposition is direct deposition to land followed by runoff or seepage through groundwater to a surface water body.

Preliminary Results Ozone Base Run – January 2002, NC Monthly Average ppbv

Preliminary Results Ozone Reduced Run – January 2002, NC Monthly Average ppbv

Preliminary Results Ozone Difference Between Base Run and Reduced Run January 2002, NC - Monthly Average ppbv

Preliminary Results Ozone Base Run – July 2002, NC Monthly Average ppbv

Preliminary Results Ozone Reduced Run – July 2002, NC Monthly Average

Preliminary Results Ozone Difference Between Base Run and Reduced Run January 2002, NC - Monthly Average ppbv

Preliminary Results – NH 3 Base Run – January 2002, NC Monthly Average ppbv

Preliminary Results – NH 3 Reduced Run – January 2002, NC Monthly Average

Preliminary Results – NH 3 Difference Between Base Run and Reduced Run January 2002, NC - Monthly Average ppbv

Preliminary Results – NH 3 Base Run – July 2002, NC Monthly Average ppbv

Preliminary Results – NH 3 Reduced Run – July 2002, NC Monthly Average

Preliminary Results – NH 3 Difference Between Base Run and Reduced Run July 2002, NC - Monthly Average ppbv

Preliminary Results PM 2.5 Difference Between Base Run and Reduced Run January 2002, NC - Monthly Average

Preliminary Results PM 2.5 Difference Between Base Run and Reduced Run July 2002, NC - Monthly Average

Preliminary Results–NH 4 + Aerosol Base Run – January 2002, NC Monthly Average

Preliminary Results–NH 4 + Aerosol Reduced Run – January 2002, NC Monthly Average

Preliminary Results–NH 4 + Aerosol Difference Between Base Run and Reduced Run January 2002, NC - Monthly Average

Preliminary Results–NH 4 + Aerosol Base Run – July 2002, NC Monthly Average

Preliminary Results–NH 4 + Aerosol Reduced Run – July 2002, NC Monthly Average

Preliminary Results–NH 4 + Aerosol Difference Between Base Run and Reduced Run July 2002, NC - Monthly Average