March 3, 2004 EAS 4/8803 1

EAS 4/8803: Experimental Methods in AQWeeks 8 - 11:

Air Quality Management (AQM)Clean Air Act (History, Objectives, NAAQS)Emissions and Atmospheric Trends (Links)Principal Measurement Techniques (O3, NOx, CO, SO2, Pb, PM)

Measurement of CO (Exp 5)NDIR Method (Interferences, Stability, DL, Precision, Accuracy)

Controlling O3

Why controlling O3 (Agriculture, Health)Photochemical Processes (NOx vs VOC sensitivities, limitations)Ambient Measurements and Trends (World, USA, GA)

Measurement of O3 (Exp 6)UV Absorption (Interferences, Stability, DL, Precision, Accuracy)

March 3, 2004 EAS 4/8803 2

Comparison of 1970 and 2002 Emissions

EPA 454/K-03-001, Latest Findings on National Air Quality, August 2003, www.epa.gov/airtrends

March 3, 2004 EAS 4/8803 3

Link: Emissions Air QualityCAUTION!!

• Most emissions are estimated NOT measured (uncertainty).

• Most monitors located in urban environments (representation).

• Some APs are formed in atmosphere via secondary reactions (PM, O3).

• Secondary reactions have different sensitivities (to precursors) and yields: P(O3), P(SOA).

• Meteorology plays underlying role (BL dynamics, radiation, rainfall).

EPA 454/K-03-001, Latest Findings on National Air Quality, August 2003, www.epa.gov/airtrends

March 3, 2004 EAS 4/8803 4

Success: Emissions Reductions Despite Growth

EPA 454/K-03-001, Latest Findings on National Air Quality, August 2003, www.epa.gov/airtrends

CO, NOx, VOC, SO2, PM, Pb

March 3, 2004 EAS 4/8803 5

Emissions/AQ Trends: SO2

AQ

Emissions Sources (2001)

Potential Risks and Effects• Breathing impairment

• Respiratory, cardiovascular {PM}• Precursor for PM

•Acidification (soils, waters)• Corrosion (bldgs, monuments)

• Visibility

March 3, 2004 EAS 4/8803 6

SO2 SO4= in Greater Atlanta for July 2001

34.4

34.2

34.0

33.8

33.6

33.4

33.2

33.0

32.8

32.6

32.4

-85.0 -84.5 -84.0 -83.5 -83.0 -82.5 -82.0

Atlanta

FAQS ASACA sites significant point sources point sources w/ CO:NOx > 1

20x20 km

Griffin

Macon

Augusta

Columbus

N

E

S

W6 12

SO2*3 (ppbv)

SO4= (µgm-3)

WS*2 (m/s) WD (%)

N

E

S

W6 12

SO2*2 (ppbv)

WS*2 (m/s) WD (%)

50

40

30

20

10

0

SO4= -G

RF

SO

2-G

RF

SO

2-A

TL (

µgm

-3)

00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00 00:00Time (EST)

March 3, 2004 EAS 4/8803 7

Emissions/AQ Trends: NOx (NO+NO2)

AQ

Emissions

Sources (2001)

Potential Risks and Effects• Airway, lung function

• Respiratory illness, infection• Precursor for O3 and PM

•Acid deposition (nutrient loss)• Eutrophication (algae bloom)

• Visibility

March 3, 2004 EAS 4/8803 8

Emissions/AQ Trends: CO

AQ

Emissions

Sources (2001)

Potential Risks and Effects• Blood-O2 deficiency

• Cardiovascular (angina pectoris)• Visual, neurological impairment

• Role in P(O3) via HOx cycle (slow)

March 3, 2004 EAS 4/8803 9

Passenger Car Light Truck Sum/AvgMileage (mi) 12,500 14,000 26,500

Fuel Economy (mi/gal) 21.5 17.2 19.2

PC LT AvgFuel Consumed (gal/mi) 0.047 0.058 0.053

Emission Rate (g/mi) HC 2.80 3.51 3.18CO 20.90 27.70 24.49

NOx 1.39 1.81 1.61CO2 415.90 522.10 472.01

PC LT SumVMT (mi/day) 56,603,774 63,396,226 120,000,000

Fuel Consumed (gal/day) 2,632,734 3,685,827 6,318,561Emission Rate (t/day) HC 158 223 381

CO 1,183 1,756 2,939NOx 79 115 193CO2 23,542 33,099 56,641

US Average for July 2000

Metro Atlanta Daily Totals

US Annual Average

Strategies for Metropolitan Atlanta's Regional Transportation and Air Quality (SMARTRAQ)

13-County Metro Atlanta: 120 Mio VMT daily

Source: EPA Office of Transportation and Air Quality, "Average Annual

Emissions and Fuel Consumption for Passenger Cars and Light Trucks“, see

http://www.epa.gov/otaq/consumer/f00013.htm

March 3, 2004 EAS 4/8803 10

Atlanta August 1999: Average Diurnal Profile

March 3, 2004 EAS 4/8803 11

Source – Receptor Considerations: CO/NOyAtlanta JST

Air mass arriving at Griffin has significantly higher CO/NOy ratio in summer than in winter:Loss of more abundant summertime HNO3 due to surface deposition!

Griffindownwind

300

250

200

150

100

CO

(p

pbv)

302520151050

NOy (ppbv)

Northerly flowexcl SO2 >3 ppbvJul 2001slope = 31.1 +-1.51intcept= 106 +-4r = 0.77Jan 2002slope = 7.2 +-0.45intcept= 159 +-4r = 0.74

1400

1200

1000

800

600

400

200

0

CO

(p

pbv)

200150100500

NOy (ppbv)

August 1999slope = 6.3 +-0.08intcept= 189 +-5r = 0.81December 2001slope = 6.5 +-0.09intcept= 129 +-8r = 0.94

July 2001slope = 9.0 +-0.18intcept= 86 +-7r = 0.88

Higher intercept points to elevated regional background CO! Long-range transport of wild fires’ plumes (see SOS’95)? Or other high-CO/low-NOx sources?

March 3, 2004 EAS 4/8803 12

Regional CO vs Burn Activity in GA

140

160

180

200

220

240

Dec-02 Jan-03 Feb'03 Mar'03 Apr'03 May'03 June'03Month

CO

(p

pbv)

0

5,000

10,000

15,000

20,000

25,000

Bur

ned

Acr

es

Ft Benning (acr)Surr Region (acr)Rest of GA/10 (acr)Ft Gordon (acr)Surr Region (acr)CO bkgrd (ppbv)

Monthly average CO background level derived from CO/NOy regressions at OLC (left) in comparison with prescribed burn areas at Forts Benning and Gordon, their surrounding

counties, and the rest of Georgia (only 10% of true area plotted!).

March 3, 2004 EAS 4/8803 13

32.9 28.8 31.5 29.7

34.432.7 32.2 39.3

10.811.0 9.1

9.0

15.918.3 17.1

19.73.6 7.4 7.8

0.4

2.4 1.8 2.3 1.90.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

7:00 12:00 17:00 23:00Time of Day (CST)

VOC

Avg

Con

tribu

tion

(%)

0

10

20

30

40

50

60

70

80

90

100

Diesel Ex Gasoline Ex Evap GasolineRefinery Fug Primers & Enamel Biogenics

Emissions/AQ Trends: VOC

AQ in Pensacola

Emissions

Sources (2001)excl BHC

Potential Risks and Effects• Multitude of species

• Some toxic (aromatics, FCHCs)• Some vital precursors for O3

March 3, 2004 EAS 4/8803 14

VOC Emissions from Prescribed Burning

Mixing ratios enhanced above local background at Fort Gordon TA21.Fuel: 230 acres of 2 year rough of pine needles, leaves, and woody debris.

0.0

0.1

1.0

10.0

100.0

1000.0

10000.0

100000.0

FLaming (3 h) Smoldering (6 h)

ppm

v, p

pbv

CO2/COx (%) CO2 CO CH4 AlkanesAlkenes Aromatics Halog HC Biog HC Org NO3

March 3, 2004 EAS 4/8803 15

PB Emission Rate Estimates for Aromatics (C>6)Comparison with Mobile Sources

0

1

10

100

1000

10000

Flaming Smoldering Gas Diesel Flaming Smoldering Gas Diesel

Fort Gordon Richmond Fort Benning Muscogee

Emis

sion

s (k

g/bu

rn/d

ay)

Toluene m-Xylene p-Xylene o-Xylene 3-Ethyltoluene4-Ethyltoluene 2-Ethyltoluene Isopropylbenzene Propylbenzene Ethylbenzene

Average emissions per burn (~500 acres) compare with daily mobile emissions !3-, and 4-Ethyltoluene higher during smoldering,

2-Ethyltoluene, Isopropyl-, and Ethyl-benzene highest for gasoline fueled vehicles.

March 3, 2004 EAS 4/8803 16

Emissions/AQ Trends: Primary PM10

AQ

Emissions

Sources (2001)

Potential Risks and Effects• Heart (arrhythmias, attacks)

• Respiratory (asthma, bronchitis)

• Among elderly and young• Vegetation (ecosystem)

• Buildings, Materials• Visibility

March 3, 2004 EAS 4/8803 17

Emissions/AQ Trends: Primary PM2.5

AQ

Emissions

Sources (2001)

Potential Risks and Effects• Heart (arrhythmias, attacks)

• Respiratory (asthma, bronchitis)

• Among elderly and young• Vegetation (ecosystem)

• Buildings, Materials• Visibility

March 3, 2004 EAS 4/8803 18

Mas

s Em

issi

on R

ate

(g/k

g of

bio

mas

s bur

ned)

0123456789

101112131415

Carbonyls Cyclic compounds Branched Alkanes n-Alkynes Aromatics n-Alkanes n-Alkenes

Pinu

s tae

da

Tsug

a hete

roph

ylla

Pinu

s pon

dero

sa

MHFF

FPSP

WGLP

Biomass Litter CompositesMHFF… mixed hardwood (oak) forest foliageFPSP… Florida palmetto & slash pineWGLP… wiregrass & longleaf pine

Direct (Primary) PM Emissions from Foliar Fuel Combustion in LabHays, Geron et al., ES&T 36, 2281-2295, 2002

March 3, 2004 EAS 4/8803 19

POC

PBS High-Vol Sampling and GC/MS AnalysesQuantification of >100 Particle-phase Organic Compounds

RetenePimaric acidAbietic acidSandaracopimaric acidLevoglucosan

0

100

200

300

400

500

600

700

2/5/03 12:00 2/5/03 17:00 2/5/03 22:00 2/6/03 3:00 2/6/03 8:00Sample Start Time [EST]

Con

cent

ratio

n (n

g m

-3)

n-Alkanes Hopanes Steranes PAHs Resin acids Arom carboxy acidsOther compounds Levoglucosan Branched alkanesn-Alkanoic acids Alkenoic acids Alkanedioic acids

Five consecutive 5-h samples taken at OLC between February 5th 1200 and 6th 1300

March 3, 2004 EAS 4/8803 20

Influence from February 5th Burn: Source Apportionment

1200

1000

800

600

400

200

0

CO

(ppbv) PB (acres)

2/2 2/3 2/4 2/5 2/6Sun Mon Tue (m/dd) Wed Thu

60

50

40

30

20

10

0

NO

NO

y O

3 (p

pbv)

16

12

8

4

0

PM2.5

(g m-3) Un-ID Others LOA OOE OC EC NH4+ NO3- SO4=

8

4

0WS

(m s

-1)0.00

-20

-10

0

10

20

amb T (C

)

Low P front moving through GA on 3rd and 4th, with cold dry air moving in behind it from NE, causing below normal T under clear skies. Prescribed burning of 937 acres on 2/5 1200 at ~28 km to east, smoldering until 2/6 am. 0

1

2

3

4

5

6

7

8

2/5 1200 2/5 1700 2/5 2200 2/6 0300 2/6 0800Sample Start Time (EST)

Org

anic

Car

bon

(ug

m-3

)Diesel exhaust Gasoline exhaust Wood combustionVegetative detritus Other OC

Nighttime avg 53% wood

?

March 3, 2004 EAS 4/8803 21

?

VOCs

PMNOx

O3, SOA

Toxics

COCO2

March 3, 2004 EAS 4/8803 22

Secondary organic aerosol (SOA):Organic compounds, some highly oxygenated, residing in the

aerosol phase as a function of atmospheric reactions that occur in either gas or particle phases.

SOA formation mainly depends on:Emissions & forming potential of precursors

aromatics (BTX, aldehydes, carbonyls)terpenes (mono-, sesqui-)other biogenics (aldehydes, alcohols)

Presence of other initiating reactantsO3, OH, NO3, sunlight, acid catalysts

Mechanisms (with half hr to few hr yields):Gas-to-particle conversion/partitioning

e.g. terpene oxidationHeterogeneous reactions

aldehydes via hydration and polymerization, forming hemiacetal/acetal in presence of alcohols

Particle-phase reactionsacetal formation catalytically accelerated by particle sulfuric acid (Jang and Kamens, ES&T, 2001)

March 3, 2004 EAS 4/8803 23

Seasonal PM2.5 Mass, Composition & [O3-max] Relationships with Prescribed Burning

January May 2003

0

5

10

15

20

25

Jan

Feb

Mar

, 1st

Mar

, 2nd

Apr, 1

st

Apr, 2

ndM

ay

Period

PM (

g m

-3)

0

10

20

30

40

50

60

70

80

90

100

O3 (ppbv)

Others [NH4+] [NO3-] [SO4-2] EC LOA OC OOE Max O3

OM/OC 1.9 1.5 2.2 1.6 1.9 2.1 2.0

Higher PM mass and OM/OC with higher [O3] later in the season

No burn 935 acres 1256 3770 4006 504 251

March 3, 2004 EAS 4/8803 24

Potential P(SOA) Estimates for Aromatics (C>6) Emitted by Prescribed Burning

Comparison with Mobile Sources

0

10

20

30

40

50

60

70

80

90

100

Flaming Smoldering Gas Diesel Flaming Smoldering Gas DieselFort Gordon Richmond Fort Benning Muscogee

P(SO

A)-F

ract

ion

(%)

Toluene m+p-Xylene o-Xylene 3-Ethyltoluene 4-Ethyltoluene2-Ethyltoluene Isopropylbenzene Propylbenzene Ethylbenzene

Contribution to P(SOA) potential is highest for Toluene from flaming and Xylenes from smoldering, minimal for 2-Ethyltoluene.

March 3, 2004 EAS 4/8803 25

Other (Inorganic) Secondary PM FormationSecondary formation is a function of many factors including: concentrations of precursors, other gaseous reactive species (e.g., O3, OH), atmospheric conditions, and cloud or fog droplet interactions. Gas-to-particle conversion (oxidation) SO2(g) HOSO3 H2SO4 + 2NH3 (NH4)2SO4

NOx(g) HNO3 + NH3 NH4NO3

Heterogeneous reactions

(R7)

R6)(

R5)(

)4R()(

2422

123

233

322

2222

SOOSO

SOHHSO

HSOHOHSO

OHSOOHgSO

March 3, 2004 EAS 4/8803 26

24.3 +-9.3

32%

3%

13%2%

19%

18%

4%

1%

8%

27.6 +-11.6

31%

2%

10%

21%

22%

5%

0%

8%

1%

SO4=NO3-NH4+ECOCOOELOAOthersUnID

15.9 +-6.9

20%

7%

12%

1%31%

6%

10%

1%

12%

Fall-99 Winter-99/00

20.1 +-15.2

20%

8%

11%

0%29%

16%

2%

2%

12%

10.6 +-3.6

21%

11%

12%1%

31%

5%

6%

1%

12%

12.2 +-4.7

18%

10%

11%

2%35%

5%

4%

1%

14%

PM2.5 Seasonal Comparison: Suburban vs Rural

Summer-99

Rural Dixon

SuburbanHendersonville

• Differences in composition are insignificant regionally but not seasonally• Differences in mass related to different BL dynamics and SOA (Un-ID)

March 3, 2004 EAS 4/8803 27

PM2.5 Mass Balance and Maximum Hourly Ozone

0

10

20

30

40

50

60

Atla

nta

H.v

ille

Dix

on

H.v

ille

Dix

on

H.v

ille

Dix

on

Mac

on

Aug

usta

Col

umbu

s

LaPo

rte

W.T

ower

Grif

fin

Grif

fin

PM2.

5 (

g

m-3

)

0

20

40

60

80

100

120

O3-h m

ax (ppbv)

SO4= NO3- NH4+ EC OC OOE LOA Others UnID O3-h max

Summer-99 Fall-99 Winter-99/00 Summer-00 Jul-01 Jan-02

Comparison of Seasonal and Regional Averages: PM2.5 & O3

• Seasonal [PM2.5]-mass /-SO4= / [O3] correlation: high in summer, low in fall & winter

• Houston TexAQS measurements governed by local emissions, episodes and meteorology• BL dynamics contributing to sub-regional differences between H.ville & Dixon

• Unidentified [PM2.5] mass highest and most variable in summer (SOA)

March 3, 2004 EAS 4/8803 28

Summertime PM2.5 – Max(O3) Relationship

Tighter correlation in July 2001.“Downwind” Griffin site offset to higher PM2.5 mass.

August 99 in Atlanta was hotter, dryer, more polluted with O3-precursor species.

March 3, 2004 EAS 4/8803 29

Seasonal & Regional Comparison of PM2.5 Composition

Summer Months

Regional Difference: Higher OM/OC and OC/EC at more rural site!Seasonal Difference: Lower OM/OC and (higher) OC/EC in winter.

More SOA in August 99? More oxygenated POCs away from Atlanta?

Winter Months

March 3, 2004 EAS 4/8803 30

PM2.5 Wind Roses: Seasonal Differences Across GAIndications for Regional Transport?

Period 2001+ 02MAY-OCT NOV-APR

34.4

34.2

34.0

33.8

33.6

33.4

33.2

33.0

32.8

32.6

32.4

32.2

32.0

-85.5 -85.0 -84.5 -84.0 -83.5 -83.0 -82.5 -82.0

Atlanta

FAQS measurement sites GA-EPD monitoring sites coal burning power plants point sources w/ CO:NOx > 1

20x20 km

N

E

S

W9 18

µg m-3

15.813.4Griffin

N

E

S

W9 18

µg m-3

16.715.5Macon SBP

N

E

S

W9 18

µg m-3

Columbus OLC 16.6 19.3

N

E

S

W9 18

µg m-3

15.014.2Augusta RP

N

E

S

W18 36

µg m-3

36.8

Aug’99

March 3, 2004 EAS 4/8803 31

…Similarity to Daytime O3

Period 2001+ 02MAY-OCT NOV-APR

34.4

34.2

34.0

33.8

33.6

33.4

33.2

33.0

32.8

32.6

32.4

32.2

32.0

-85.5 -85.0 -84.5 -84.0 -83.5 -83.0 -82.5 -82.0

Atlanta

FAQS measurement sites GA-EPD monitoring sites coal burning power plants point sources w/ CO:NOx > 1

20x20 km

N

E

S

W30 60

ppb38.228.5Macon SBP

N

E

S

W30 60

ppb

Columbus OLC 30.7 19.8

N

E

S

W30 60

ppb30.222.2Augusta RP

N

E

S

W30 60

ppb44.236.1Griffin

N

E

S

W60 120

ppb

106

Aug’99

March 3, 2004 EAS 4/8803 32

Emissions/AQ Trends: O3

old 1h NAAQS

Secondary Product !!

Potential Risks and Effects• Acute health (respiration, asthma)

• Chronic health (obstructive pulmonary)

• Vegetation damage (chlorophyll)• Agriculture (crop & forest yields)

• Materials deterioration

new 8h NAAQS

March 3, 2004 EAS 4/8803 33

Photochemical Processes Leading to O3 and PM

SOA

NOz

An Assessment of Tropospheric Ozone Pollution, A North American Perspective, NARSTO, National Acad. Press, 2000.

March 3, 2004 EAS 4/8803 34

Ground-level Ozone Formation

Volatile Organic Compounds (VOCs)

Nitrogen Oxides (NOx)

Fuels, Paints, Solvents, &

Vegetation

Combustion Processes

Ozone (O3)Smog+