NH3 Emissions for Regional Air Quality Modeling

Motivation and QuestionsMotivation

NH3 plays a key role in secondary aerosol formation—impact on health & regional hazeNH3 deposits readily and contributes to N deposition in pristine ecosystems

QuestionsWhat are the major sources of NH3 within the region?For the major sources, what are the uncertainties in the emission factors?For the major sources, how well do we know the activity levels?For the major sources, how do environmental or operating practices affect emission rates?NH3 emissions are uncertain, but how sensitive are model results to these uncertainties? Is near-source NH3 deposition an issue within a grid modeling framework?

Atmosphere/biosphere Nitrogen Cycle

Anthropogenic Tg NH3 / year

Domesticated animals 21 – 29

Fertilizer 6 - 9

Biomass burning 2 – 6

Fossil fuel 0.3 – 2

Miscellaneous 0 - 7

Total Anthropogenic 30 – 50

Natural 15 – 23

Total 45 - 75

Source Type NH3 (tons/yr)

Ag Fertilizer Application 12,659

Cattle & calves operations 12,462

Dairy operations 5,718

Other animals 4,957

Biogenic sources 4,082

Waste treatment 2,602

Industrial Processes 1,392

Stationary Fuel Combustion 306

Waste burning 111

Solvent Use 0

WA Total 44,289

NEI NH3 Emissions for Washington

Fertilizer NH3 emissions factors(Chinkin et al. 2003)

A. NH3---Battye-12(1%)--CMU-1%--Corsi-49(12-121)-EEA-4%

Beef and dairy cattle NH3 emission factors (lb/head/year; Chinkin et al. 2003)

Dairy 48 to 74 lb/head/yr Beef 29 to 88 lb/head/yr

Recent Feedlot Emission Results (Flesch et al., 2007)

Spring and summer 0.15 kg/head/day

Extrapolated annual emission factor:

55 kg/head/yr or 120 lb/head/yr

Recent EI adjustments: Columbia River Gorge Visibility Modeling Analysis (Environ, 2007)

Comparison of 2002 NEI and Environ NH3 GIS EI

(1) Ammonia emissions from confined area feeding operations (CAFO), such as dairies, were understated by factors of 1.5 to approximately 3, depending on the type of manurehandling conducted at each (i.e., flush, scrape, drylot/pasture, or deep-pit);(2) Ammonia emissions from fertilizer application were understated by upwards of a factor of three for anhydrous and aqueous ammonia application sources, and by a factor of 2.5for nitrogen solution fertilizer application sources.

Tomorrow’s Air Quality: AIRPACT-3 Daily Forecast System

MM5 numerical mesoscalemeteorological model (UW)SMOKE: Sparse Matrix Operating Kernalfor Emissions processing.CMAQ: Community Multi-scale Air Quality model:

O3 & toxics chemistry with 72 species and 214 reactions

Aerosol dynamics & chemistry in Aitken, accumulation, & coarse modes

Deposition of N, S, O3, & Hg species

12 km x 12 km grid cells, 21 layers

Forecast to 64 hours daily

Runs in ~1 hour on 4 nodes of a linuxcluster

PM speciesNitratesSulfatesOrganic aerosolsWind-Blown Dust (soon)PM2.5 total mass

Airpact Terrain ht.

Daisy-chain Initial Conditions

Dynamic Boundary Conditions: spatial & temporal details

2005 anthropogenic emissions (SMOKE)

Wild and Prescribed Fire Emissions

Gridded Emissions

Updated Biogenic Emission Model (BEIS3)

WSU Dairy NH3 Emissions Module

AIRPACT-3 Dynamic Emissions & IC/BC

MM5/MCIP Meteorology from UW Weather Forecast System

CMAQ

NH3 Emissions Dairy Module (Rumburg et al., 2006)

• based upon DOAS NH3 & tracer ratio measurements at the WSU dairy

•Housing, lagoon, and slurry application emissions

•Incorporates N balance approach and accounts for wind speed & temperature effects

Stalls Model SensitivityModel Parameter Avg. Flux Avg. Daily Peak Daily Annual

(mg cow-1 s-1) (kg day-1) (kg day-1) (kg year-1)

Base Case 5.4 20 86 7,000

pH = 8.1 10 40 170 14,000

pH = 7.5 2.7 10 47 3,700

Temperature + 2° C 6.1 24 100 8,500

Temperature - 2° C 4.6 18 80 6,400

Milk Prod. = 50 kg day

6.5 22 97 7,900

Milk Prod. = 35 kg day

4.6 20 86 7,000

Protein = 21% 6.0 23 100 8,300

Protein = 17% 4.7 18 80 6,500

Dairy Module Input Data Requirements

Column Description Type A FIPS 5-digit Integer B Site-ID 5-digit Integer C Latitude Real D Longitude Real E Number of Milking cow Integer F Number of Dry cow Integer G Number of Heifer Integer H Number of Calves Integer I Lagoon area (m^2) Real J Pit area (m^2) Real K Tank area (m^2) Real L Housing type (Scrape Barn = 1) Integer M Application type (Big Gun = 1) Integer N Application area Real O Site name Text in “quotes”

Dairy NH3 Emission Module

WA Dairy NH3 (ton/yr)

Housing 8,634

Storage 5,441

Application 4,364

Total 18,439

OR Dairy NH3 (ton/yr)

Housing 9,469

Storage 5,079

Application 3,420

Total 17,967

Source Type NH3 (tons/yr)

Ag Fertilizer Application 12,659

Cattle & calves operations 12,462

Dairy operations 5,718

Other animals 4,957

Biogenic sources 4,082

Waste treatment 2,602

Industrial Processes 1,392

Stationary Fuel Combustion 306

Waste burning 111

Solvent Use 0

WA Total 44,289

or with WSU dairy module

Dairy operations 18,439

WA Total 57,010

% increase 29%

Airpact NH3 Emissions for Washington

8

6

4

2

0

Mod

eled

(µ

g/m

3 )

86420

Measured (µg/m3)

EPA_AQS IMPROVE SWCAA

PEC50

40

30

20

10

0

Mod

eled

(µ

g/m

3 )

50403020100

Measured (µg/m3)

EPA_AQS IMPROVE SWCAA

POC

Airpact-3 Evaluation, Aug-Nov 2004 (Chen, 2007)

10

8

6

4

2

0M

odel

ed (

µg/

m3 )

1086420

Measured (µg/m3)

EPA_AQS SWCAA

PNO35

4

3

2

1

0

Mod

eled

(µ

g/m

3 )

543210

Measured (µg/m3)

EPA_AQS SWCAA

PNH420

15

10

5

0

Mod

eled

(µ

g/m

3 )

20151050

Measured (µg/m3)

EPA_AQS SWCAA

PSO4

Columbia Gorge Visibility Modeling Analyses (Environ, 2007)

Source attribution results for PNH4

Nov. 2004

Questions remainWhat are the major sources of NH3 within the region?

Fertilizer vs livestock—which is larger? Biogenic natural soil emissions—very few measurements.

For the major sources, what are the uncertainties in the emission factors?

Factor of two or more in available factorsFor the major sources, how well do we know the activity levels?

For the major sources, how do environmental or operating practices affect emission rates?

Seasonal changes, diurnal changesNH3 emissions are uncertain, but how sensitive are model results to these uncertainties--how accurate does an emission inventory need to be?

Is near-source NH3 deposition an issue within a grid modeling framework?

What is required to improve our ability to construct more accurate emission inventories for NH3?

Animal Ammonia Emissions• Pathways for NH3 emissions from animal

waste• Hydrolysis of urea in urine with urease• Anaerobic biological breakdown • organic nitrogen ® amino acids ® NH3

• Dairy cows have the largest per animal emissions (Bouwmann et al., 1997)• Developed countries ~ 20 kg NH3 cow-1 yr -1

• Developing countries ~ 8 kg NH3 cow-1 yr -1

• European measurements and farming practices• Filters, flasks, and passive samplers

Housing Emissions Model

• Calculates liquid NH3 concentration based upon cow factors– Uses milk production, dietary Na, K, and N

intake, body weight, and week of lactation -> urinary urea

– Assumes excess of urease from manure– Converts urea to ammonia-N– Partitions ammonia-N between NH3 and NH4+

based upon pH, (pH = 7.8 - lagoon pH)• Calculates volatilization based upon temperature

Lagoon Emissions Model

• Calculates lagoon ammonia-N concentration based upon temperature

• Partitions ammonia-N between NH3and NH4+ based upon pH, pH = 7.8

• Calculates volatilization based upon temperature

• Uses Gaussian plume model to calculate downwind concentrations

Lagoon Modeling600

500

400

300

200

100

0

NH

3 M

odel

ed C

once

ntra

tion

(ppb

v)

6005004003002001000

NH3 Measured Concentration (ppbv)

Normalized mean error = 21%

Stalls Modeled versus Measured Concentrations

2500

2000

1500

1000

500

0

NH

3 M

odel

ed C

once

ntra

tion

(ppb

v)

25002000150010005000

NH3 Measured Concentration (ppbv)

Normalized Mean Error = 30%

Slurry Application Modeling

600

500

400

300

200

100

0

NH

3 C

once

ntra

tion

[ppb

v]

40302010

Decay Time (Hours)

Measured Concentration Theoretical Model Empirical Model

Theoretical Model Error = 59%Empirical Model Error = 22%

Lagoon Emissions Model

pH NH3NH4+

Organic N

Bacteria Bacteria

NH3 + NH4+

Organic N

StallsNH3(g)

NH3Free Air StreamConvective Mass Transfer Coefficient hm

Temperature

Waste Application Model

Theoretical ModelSlurry volatilization from upper layer of soilSlurry infiltration - HYDRUS 1DSlurry adsorption to soil Slurry temperature - radiation & canopy light model

Empirical ModelExponential fit to the data• Useful for air quality models

Slurry Application

pH NH3NH4+Soil (-)particles

Infiltration

Adsorption

NH3Free Air StreamConvective Mass Transfer Coefficient hm

NH3(g)

Temperature

Tomorrow’s Air Quality: AIRPACT-3 Daily Forecast System

MM5 numerical mesoscalemeteorological model (UW)SMOKE: Sparse Matrix Operating Kernalfor Emissions processing.CMAQ: Community Multi-scale Air Quality model:

O3 & toxics chemistry with 72 species and 214 reactions

Aerosol dynamics & chemistry in Aitken, accumulation, & coarse modes

Deposition of N, S, O3, & Hg species

12 km x 12 km grid cells, 21 layers

Forecast to 64 hours daily

Runs in ~1 hour on 4 nodes of a linuxcluster

PM speciesNitratesSulfatesOrganic aerosolsWind-Blown Dust (soon)PM2.5 total mass

Airpact Terrain ht.

Airpact-3 Aerosol Results/

http://www.lar.wsu.edu/airpact-3

http://www.lar.wsu.edu/airpact-3/http://www.lar.wsu.edu/airpact-3

Modeling sensitivity to NH3 emissions: Columbia Gorge Modeling Analysis (Environ, 2007)

Sensitivity Runs1. Zero PGE Boardman from BART-levelemissions2. Zero ammonia emissions East of Gorge3. Zero on-road mobile emissions inPortland4. Zero major industrial (point) emissionsPortland5. Zero major point emissions in the Gorge

Motivation and QuestionsAtmosphere/biosphere Nitrogen CycleNEI NH3 Emissions for WashingtonFertilizer NH3 emissions factors(Chinkin et al. 2003)Beef and dairy cattle NH3 emission factors (lb/head/year; Chinkin et al. 2003)Recent Feedlot Emission Results (Flesch et al., 2007)Recent EI adjustments: Columbia River Gorge Visibility Modeling Analysis (Environ, 2007)Tomorrow’s Air Quality: AIRPACT-3 Daily Forecast SystemAIRPACT-3 Dynamic Emissions & IC/BCStalls Model SensitivityDairy Module Input Data RequirementsDairy NH3 Emission ModuleAirpact NH3 Emissions for WashingtonAirpact-3 Evaluation, Aug-Nov 2004 (Chen, 2007)Columbia Gorge Visibility Modeling Analyses (Environ, 2007)Questions remainAnimal Ammonia EmissionsHousing Emissions ModelLagoon Emissions ModelLagoon ModelingSlurry Application ModelingLagoon Emissions ModelWaste Application ModelSlurry ApplicationTomorrow’s Air Quality: AIRPACT-3 Daily Forecast SystemAirpact-3 Aerosol Results/Modeling sensitivity to NH3 emissions: Columbia Gorge Modeling Analysis (Environ, 2007)