California Regional PMCalifornia Regional PM1010/PM/PM2.52.5 Air Quality Air Quality

Study (CRPAQS) Technical UpdateStudy (CRPAQS) Technical Update

John G. Watson (johnw@dri.edu)John G. Watson (johnw@dri.edu)Philip M. RothPhilip M. Roth

Karen L. MaglianoKaren L. Magliano

Central California Air Quality Studies Policy Central California Air Quality Studies Policy CommitteeCommittee

February 25, 2005February 25, 2005

ObjectivesObjectives• Review PMReview PM2.52.5 levels during CRPAQS levels during CRPAQS

monitoringmonitoring

• Present findings from data analysis Present findings from data analysis projectsprojects

• Identify some of the future challengesIdentify some of the future challenges

Central California is a PMCentral California is a PM2.52.5 non-attainment non-attainment

areaarea

The California Regional PMThe California Regional PM1010/PM/PM2.52.5 Air Air

Quality Study (CRPAQS) Quality Study (CRPAQS) • Period: Dec. 2, 1999 –

Feb. 3, 2001

• Frequency: Every 6th day (Daily 24-hr mass measurement at Fresno and Bakersfield)

• Location: 5 PM2.5 anchor sites and 32 satellite sites

• Anchor sites: Bethel Island (BTI), Sierra Nevada Foothill (SNFH) , Fresno (FSF), Angiola (ANG), Bakersfield (BAC).

• Winter IOP periods:–Dec. 15-18, 2000–Dec. 26-28, 2000–Jan. 4-7, 2001–Jan. 31–Feb. 3, 2001

BTI

ANG

BAC

SNFH

FSF

Time Integrated SamplersTime Integrated Samplers

Dual-channel sequential filter

sampler(Desert Research Institute, Reno,

NV)

RAAS-400 PM2.5 speciation

sampler(Andersen

Instruments, Smyrna, GA)

RAAS-100 single-channel PM2.5

FRM sampler (Andersen Instruments,

Smyrna, GA)

MiniVol filter sampler

(Airmetrics, Springfield, OR)

27

133

020406080

100120140

01/01/2001

PM

2.5 m

ass

µg/m

3

70

9

0

10

20

30

40

50

60

70

80

01/01/2001

PM2.

5 m

ass

in µ

g/m

3

77

9

0

10

20

30

40

50

60

70

80

90

01/07/2001

PM

2.5

mas

s in

µg

/m3

Longitude

Annual average and maximum PMAnnual average and maximum PM2.52.5 concentrations concentrations (6(6thth day sampling) day sampling)

(2/1/2000 – 1/31/2001)

BTI SNFH

BAK

70

9

24

148

0

20

40

60

80

100

120

140

160

01/01/2001

PM

2.5 m

ass

in µ

g/m

3 FSF

Max

Annual Average

19

123

0

20

40

60

80

100

120

140

01/07/2001

PM

2.5

mas

s in

µg

/m3

ANG

PMPM2.5 2.5 seasonal distributionseasonal distribution

Winter

FallSummer

Spring

Longitude Longitude

Annual PMAnnual PM2.52.5 chemical composition chemical composition

10%

9%33%

11%

5%

3% 6%

23%

BTI (9.12 µg/m3)9%

7%

46%

10%

1%

4%5%

18%

SNFH(9.22

µg/m3)

FSF (20.27

µg/m3)

7%45%

8%

1%5% 6%

2%

26%

7%

11%

27%

4%

2%

12%2%

35%

ANG (20.40 µg/m3)6%

9%

34%

7%

1%9% 2%

32%

BAK (27.44

µg/m3)

Sulfate

Nitrate

Ammonium

OM

EC

Salt

Crustal

Trace

BAK (27.44

µg/m3)

Summer and winter nitrate (NOSummer and winter nitrate (NO33--))

• Low NO3- found in

summer (<3.5 µg/m3) (Note: different scales)

• Nitrate highest near urban areas.

Summer

Winter

• High NO3- found in

winter.

• Nitrate high throughout SJV.

Summer and winter organic carbon (OC)Summer and winter organic carbon (OC)

• Uniform OC in the southeastern valley. Highest OC near a dairy.

• Elevated OC at urban centers, especially near the Fresno Supersite. OC in rural areas was lower in winter than in summer.

Summer

Winter

Fresno Feedlot

Summer and winter elemental carbon (EC)Summer and winter elemental carbon (EC)

• Higher EC around urban centers.

• Elevated EC found near the Fresno Supersite and Bakersfield. Rural sites show limited summer-winter contrast.

Summer

WinterE C

E C

Wood smoke marker (levoglucosan) highest at Wood smoke marker (levoglucosan) highest at urban sitesurban sites

Annual Avg Winter Avg*FEL 6 26CHL 7 32YOSE 9 38EDW 12 52OCW 14 58HELM 19 81PIXL 19 82ANGI 23 98COP 32 138BAC 49 209BTI 50 215SNF 57 244SJ4 58 247S13 63 269LVR 68 291FEDL 75 323M14 101 433FRS 121 521SDP 128 551FSF 202 868

Levoglucosan Concentrations (ng/m3)

* Predicted concentration based on mass concentration measurements

Annual OC Distribution

Diurnal Variation During Diurnal Variation During IOP 3 IOP 3

(Jan. 4-7, 2001)(Jan. 4-7, 2001)Blue=Organics (1.4)Blue=Organics (1.4)

Black=EC (IMPROVE)Black=EC (IMPROVE)Red=Amm. NitrateRed=Amm. Nitrate

Yellow=Amm. SulfateYellow=Amm. SulfateBrown=SoilBrown=Soil

Bethel Island

-10

0

10

20

30

40

50

60

70

0000-0500

0500-1000

1000-1300

1300-1600

1600-2400

0000-2400

Time of Day (PST)

Con

cent

ratio

n (µ

g/m

3 )

Sierra Nevada Foothills

-10

0

10

20

30

40

50

60

70

0000-0500

0500-1000

1000-1300

1300-1600

1600-2400

0000-2400

Time of Day (PST)

Con

cent

ratio

n (µ

g/m

3 )

Fresno

-20

0

20

40

60

80

100

120

140

0000-0500

0500-1000

1000-1300

1300-1600

1600-2400

0000-2400

Time of Day (PST)

Con

cent

ratio

n (µ

g/m

3 )

Angiola

-20

0

20

40

60

80

100

0000-0500

0500-1000

1000-1300

1300-1600

1600-2400

0000-2400

Time of Day (PST)

Bakersfield

-20

0

20

40

60

80

100

0000-0500

0500-1000

1000-1300

1300-1600

1600-2400

0000-2400

Time of Day (PST)

Regional- and Urban-Scale InfluencesRegional- and Urban-Scale Influences

BethelBethelDatesDates IslandIsland FoothillsFoothills FresnoFresno AngiolaAngiolaBakersfieldBakersfield

IOP 1IOP 1Dec. 15-18Dec. 15-18 mixmix carboncarbon mixmix nitratenitrate mixmix

IOP 2IOP 2Dec. 26-28Dec. 26-28 carboncarbon carboncarbon carboncarbon nitratenitrate mixmix

IOP 3IOP 3Jan. 4-7Jan. 4-7 nitratenitrate nitratenitrate mixmix nitratenitrate nitratenitrate

IOP 4IOP 4Jan. 31-Feb. 1Jan. 31-Feb. 1 nitratenitrate mixmix carboncarbon nitratenitrate carboncarbon

Composition varies throughout dayComposition varies throughout dayHypothesis of nitrate mixing from aloftHypothesis of nitrate mixing from aloft

0

20

40

60

80

100

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Hour (PST)

Nit

rate

& B

lack

Car

bo

n (µ

g/m

3 )

PA

H (

rela

tive

un

its)

0

5

10

15

20

25

Tem

per

atu

re (

°C)

Nitrate PAH Black Carbon1 Black Carbon7 Temperature

1/9/00

0

5

10

15

20

2512 15 18 21 0 3 6 9 12 15 18 21 0 3 6 9 12 15 18 21 0 3 6 9 12 15 18 21 0 3 6 9

12/27/2000 12/28/2000 12/29/2000 12/30/2000 12/31/2000

Time (PST) and Date

NO

3 C

on

cen

trat

ion

(u

g/m

3)

0

20

40

60

80

100

NO

an

d O

zon

e C

on

cen

trat

oin

(p

pb

)

NO3 Ozone NO

Night

Night Night

Night

Angiola tower nitrate confirms hypothesisAngiola tower nitrate confirms hypothesis

0

10

20

30

40

50

60

70

80

Bethel Island Fresno Bakersfield Angiola Sierra Nevada

Location

Co

nce

ntr

atio

n (

ug

m-N

/m3)

PM25 NO3

HNO3

NO2 &Other NOy

NO

HNO3 data were not available at Bethel Island and Bakersfield

Substantial amounts of excess NOSubstantial amounts of excess NOxx, even at , even at

non-urban sites non-urban sites Is HNOIs HNO33 NO NOxx or VOC limited? or VOC limited?

Fog increases deposition and PM removalFog increases deposition and PM removal

Ultrafine particles are directly emitted and form from Ultrafine particles are directly emitted and form from atmospheric reactionsatmospheric reactions

(Fresno, CA, 3/29/2003)(Fresno, CA, 3/29/2003)

Hour

0 1 2 3 4 5 6 7 8 9 1011121314151617181920212223

Dia

me

ter (n

m)

10

100

0 10000 20000 40000 50000 30000

Vehicle Exhaust, Residential Heating and Cooking

Photochemical Nucleation

Vehicle Exhaust

Par

ticl

e D

iam

eter

(n

m)

dN/dlogDp (number cm-3)

Elevated OElevated O33 and PM and PM2.52.5 rarely occur together rarely occur togetherFresno, hourly dataFresno, hourly data

Spring

WinterFall

Summer

CRPAQS results confirm focus on reducing CRPAQS results confirm focus on reducing emissions from many sources and pollutantsemissions from many sources and pollutants

• What has been doneWhat has been done– Oil heaters switched from crude oil to natural gas, Oil heaters switched from crude oil to natural gas,

added SCRadded SCR

– Extensive controls and offsets on new industrial Extensive controls and offsets on new industrial sourcessources

– Residential and prescribed burning rulesResidential and prescribed burning rules

– Improved on-road pollution controls and Improved on-road pollution controls and inspection and maintenanceinspection and maintenance

– Unpaved surface stabilizationUnpaved surface stabilization

– Agricultural conservation management plansAgricultural conservation management plans

– Dairy permitting programDairy permitting program

CRPAQS results confirm focus on reducing CRPAQS results confirm focus on reducing emissions from many sources and pollutantsemissions from many sources and pollutants

– Oil heaters switched from crude oil to natural gas, Oil heaters switched from crude oil to natural gas, added SCRadded SCR

– Extensive controls and offsets on new industrial Extensive controls and offsets on new industrial sourcessources

– Residential and prescribed burning rulesResidential and prescribed burning rules– Improved on-road pollution controls and Improved on-road pollution controls and

inspection and maintenanceinspection and maintenance– Unpaved surface stabilizationUnpaved surface stabilization– Agricultural conservation management plansAgricultural conservation management plans– Lower sulfur diesel fuelsLower sulfur diesel fuels– Tighter emission standards for on-road and off-Tighter emission standards for on-road and off-

road diesel enginesroad diesel engines

CRPAQS activitiesCRPAQS activities

• 20052005– Finalize data analysis projectsFinalize data analysis projects

– Begin weight of evidence/reconciliation analysis.Begin weight of evidence/reconciliation analysis.

– Complete model development and evaluationComplete model development and evaluation

• 20062006– Complete weight of evidence/reconciliation Complete weight of evidence/reconciliation

analysisanalysis

– Complete emissions projections and control Complete emissions projections and control strategy modelingstrategy modeling

CRPAQS scientific contributionsCRPAQS scientific contributions

• More than 20 technical presentations at February More than 20 technical presentations at February supersite meeting, Atlanta, GAsupersite meeting, Atlanta, GA

• More than 50 technical publications. More in More than 50 technical publications. More in progressprogress

• Development and testing of new continuous Development and testing of new continuous monitoring instrumentsmonitoring instruments

• Refined conceptual models of air quality Refined conceptual models of air quality evolution in valleys and foggy conditionsevolution in valleys and foggy conditions

• Refined conceptual model of ultrafine particle Refined conceptual model of ultrafine particle formation with low sulfur conditionsformation with low sulfur conditions

Current StandardsIndicator Ave. Time Conc. Statistical Form

PM10 24 hr 150 not to exceed more than 1/yr Annual 50 arithmetic mean

PM2.5 24 hr 65 3 yr average of 98th percentile Annual 15 3 yr average of arithmetic mean

Proposed Range of Standards

PM10-2.5 24 hr 65 – 75 at 98th percentile or: 75 – 85 at 99th percentile

Annual 30 at 98th percentile or: 35 at 99th percentile

PM2.5 24 hr 25 – 35 at 99th percentile Annual 15

or: 24 hr 35 – 40 (at 98th percentile?) Annual 12 – 14

The target is changingThe target is changingEPA Staff PaperEPA Staff Paper

Remaining questionsRemaining questions

• Is nitrate limited by ammonia levels in sub-Is nitrate limited by ammonia levels in sub-regions during late summer and fall?regions during late summer and fall?

• Is nitric acid formation limited by VOCs or NOIs nitric acid formation limited by VOCs or NOxx??

• Will population and vehicle use growth offset Will population and vehicle use growth offset emissions reductions per unit?emissions reductions per unit?

• Will unidentified high emitters dominate overall Will unidentified high emitters dominate overall emissions?emissions?