modeling of ammonia and pm 2.5 concentrations associated with emissions from agriculture
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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 27695 7th Annual CMAS Conference October 6-8, 2008. - PowerPoint PPT PresentationTRANSCRIPT
Modeling of Ammonia and PM2.5 Concentrations Associated with Emissions from Agriculture
Megan Gore, D.Q. Tong, V.P. Aneja, and M. HouyouxDepartment of Marine, Earth & Atmospheric SciencesNorth Carolina State UniversityRaleigh, NC 27695
7th Annual CMAS Conference October 6-8, 2008
Outline
٥ Introduction – Ammonia in North Carolina (NC)
٥ Model Configuration
٥ Preliminary Results
٥O3, NH3, PM2.5, NH4+
٥ Conclusions
٥ Future Work
NH3
Why do we care about Ammonia?
Elevated levels of NHx (=NH3 + NH4+) can
lead to:
٥Nitrogen enrichment and eutrophication in aquatic ecosystems
٥ Impacts on crop and forest production
٥Particulate matter (PM) formation
٥Visibility degradation
٥Odor
Nitrogen Emissions in N.C.NH3 Agricultural Sources
Total ~ 40% of Nitrogen
138,843 NH3 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 NH3(aq) + H20 NH4OH(aq)
٥ NH3(g) + H2SO4(aq) NH4HSO4(aq)
٥ NH3(g) + NH4HSO4(aq) [NH4]2SO4(s or aq)
٥ NH3(g) + HNO3(g) NH4NO3(s or aq)
٥ NH3(g) + HCl(g) NH4Cl(s or aq)
٥ NH3(g) + OH·(g) N·H2(g) + H2O(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. Canada36 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 – NH3 Emissions turned off
ppbv
Preliminary Results Ozone
July Base Run – Ozone
Monthly Average
July Reduced Run* – Ozone
Monthly Average
*Reduced Run – NH3 Emissions turned off
ppbv
Preliminary Results – NH3
January Base Run – NH3
Monthly Average
January Reduced Run* – NH3
Monthly Average
*Reduced Run – NH3 Emissions turned off
ppbv
Preliminary Results – NH3
July Base Run – NH3
Monthly Average
July Reduced Run* – NH3
Monthly Average
*Reduced Run – NH3 Emissions turned off
ppbv
Preliminary Results PM2.5
January Base Run – PM2.5
Monthly Average
January Reduced Run* – PM2.5
Monthly Average
*Reduced Run – NH3 Emissions turned off
Preliminary Results PM2.5
Base Run – January 2002, NC
Monthly Average
Preliminary Results PM2.5
Reduced Run – January 2002, NC
Monthly Average
Preliminary Results PM2.5
July Base Run – PM2.5
Monthly Average
July Reduced Run* – PM2.5
Monthly Average
*Reduced Run – NH3 Emissions turned off
Preliminary Results PM2.5
Base Run – July 2002, NC
Monthly Average
Preliminary Results PM2.5
Reduced Run – July 2002, NC
Monthly Average
Preliminary Results–NH4+ Aerosol
January Base Run – NH4+
Monthly Average
January Reduced Run – NH4+
Monthly Average
*Reduced Run – NH3 Emissions turned off
Preliminary Results–NH4+ Aerosol
July Base Run – NH4+
Monthly Average
July Reduced Run – NH4+
Monthly Average
*Reduced Run – NH3 Emissions turned off
Conclusions
٥ Agricultural NH3 emissions have a significant impact on PM2.5 and NH4 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 – NH3
Base Run – January 2002, NC
Monthly Average
ppbv
Preliminary Results – NH3
Reduced Run – January 2002, NC
Monthly Average
Preliminary Results – NH3
Difference Between Base Run and Reduced Run
January 2002, NC - Monthly Average
ppbv
Preliminary Results – NH3
Base Run – July 2002, NC
Monthly Average
ppbv
Preliminary Results – NH3
Reduced Run – July 2002, NC
Monthly Average
Preliminary Results – NH3
Difference Between Base Run and Reduced Run
July 2002, NC - Monthly Average
ppbv
Preliminary Results PM2.5
Difference Between Base Run and Reduced Run
January 2002, NC - Monthly Average
Preliminary Results PM2.5
Difference Between Base Run and Reduced Run
July 2002, NC - Monthly Average
Preliminary Results–NH4+ Aerosol
Base Run – January 2002, NC
Monthly Average
Preliminary Results–NH4+ Aerosol
Reduced Run – January 2002, NC
Monthly Average
Preliminary Results–NH4+ Aerosol
Difference Between Base Run and Reduced Run
January 2002, NC - Monthly Average
Preliminary Results–NH4+ Aerosol
Base Run – July 2002, NC
Monthly Average
Preliminary Results–NH4+ Aerosol
Reduced Run – July 2002, NC
Monthly Average
Preliminary Results–NH4+ Aerosol
Difference Between Base Run and Reduced Run
July 2002, NC - Monthly Average