Study (CRPAQS) Technical Update

California Regional PM 10 /PM 2.5 Air Quality
Study (CRPAQS) Technical Update
John G. Watson (johnw@dri.edu)
Philip M. Roth
Karen L. Magliano
Central California Air Quality Studies Policy
Committee
February 25, 2005

Objectives
• Review PM 2.5 levels during CRPAQS
monitoring
• Present findings from data analysis
projects
• Identify some of the future challenges

Central California is a PM 2.5 non-attainment
area

The California Regional PM 10/PM
Quality Study (CRPAQS)
•Period: Dec. 2, 1999 –
Feb. 3, 2001
/PM Air 2.5 • Frequency: Every 6 th day
(Daily 24-hr mass
measurement at Fresno and
Bakersfield)
•Location: 5 PM 2.5
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
FSF
SNFH

Time Integrated Samplers
RAAS-100
single-channel PM 2.5
FRM sampler
(Andersen Instruments,
Smyrna, GA)
RAAS-400
PM 2.5 speciation
sampler
(Andersen
Instruments, Smyrna,
GA)
Dual-channel
sequential filter
sampler
(Desert Research
Institute, Reno,
NV)
MiniVol filter
sampler
(Airmetrics,
Springfield, OR)

Annual average and maximum PM 2.5 concentrations
PM 2.5 mass in µg/m 3
90
80 77
70
60
50
40
30
20
10
0
BTI
9
(6 th day sampling)
01/01/2001
01/07/2001
PM2.5 mass in µg/m 3
80
70
70
60
50
40
30
20
10
0
SNFH
9
PM2.5 mass in µg/m 3
160
148
140
FSF
120
100
80
60
40
24
20
0
01/01/2001
Max
PM 2.5 mass in µg/m 3
140
120
100
80
60
40
20
0
Annual Average
(2/1/2000 – 1/31/2001)
123
ANG
19
01/07/2001
Longitude
PM2.5 mass µg/m 3
140
120
100
80
60
40
20
0
133
BAK
27
01/01/2001

PM seasonal 2.5 distribution
Winter
Spring
Summer
Fall
Longitude
Longitude

Annual PM 2.5 chemical composition
FSF
(20.27
µg/m 3 )
8%
1%
5%
BTI (9.12 µg/m 3 )
2%
11%
33%
10%
5%3% 6% 23%
6%
26%
9%
ANG (20.40 µg/m 3 )
2%
12%
2%
4%
SNFH
4%
(9.22
5% 9%
1%
µg/m 3 )
18%
10%
7%
46%
BAK
(27.44
µg/m 3 ) 1%
35% 7%
7%
9% 2% 6%
32%
Sulfate
Nitrate
Ammonium
OM
EC
Salt
Crustal
Trace
45%
7%
27%
11%
34%
9%

Summer and winter nitrate (NO - 3 )
Summer
•Low NO 3
-
found in
summer (

Summer and winter organic carbon (OC)
Summer
• Uniform OC in the
southeastern valley.
Highest OC near a
dairy.
Fresno
Feedlot
Winter
• Elevated OC at urban
centers, especially near
the Fresno Supersite.
OC in rural areas was
lower in winter than in
summer.

Summer and winter elemental carbon (EC)
Summer
• Higher EC around
urban centers.
EC
• Elevated EC found
near the Fresno
Supersite and
Bakersfield. Rural
sites show limited
summer-winter
contrast.
Winter
EC

Wood smoke marker (levoglucosan) highest at
urban sites
Annual OC Distribution
Levoglucosan Concentrations (ng/m3)
Annual Avg Winter Avg*
FEL 6 26
CHL 7 32
YOSE 9 38
EDW 12 52
OCW 14 58
HELM 19 81
PIXL 19 82
ANGI 23 98
COP 32 138
BAC 49 209
BTI 50 215
SNF 57 244
SJ4 58 247
S13 63 269
LVR 68 291
FEDL 75 323
M14 101 433
FRS 121 521
SDP 128 551
FSF 202 868
* Predicted concentration based on mass
concentration measurements

70
60
Bethel Island
Concentration (µg/m 3 )
Concentration (µg/m 3 )
50
40
30
20
10
0
-10
70
60
50
40
30
20
10
0
0000-
0500
0500-
1000
1000-
1300
1300-
1600
Time of Day (PST)
Sierra Nevada Foothills
1600-
2400
0000-
2400
Diurnal Variation During
IOP 3
(Jan. 4-7, 2001)
Blue=Organics (1.4)
Black=EC (IMPROVE)
Red=Amm. Nitrate
Yellow=Amm. Sulfate
Brown=Soil
-10
0000-
0500
0500-
1000
1000-
1300
1300-
1600
1600-
2400
0000-
2400
Time of Day (PST)
140
120
Fresno
Angiola
Bakersfield
Concentration (µg/m 3 )
100
80
60
40
20
0
-20
0000-
0500
0500-
1000
1000-
1300
1300-
1600
1600-
2400
0000-
2400
0000-
0500
0500-
1000
1000-
1300
1300-
1600
1600-
2400
0000-
2400
0000-
0500
0500-
1000
1000-
1300
1300-
1600
1600-
2400
0000-
2400
Time of Day (PST)
Time of Day (PST)
Time of Day (PST)

Regional- and Urban-Scale Influences
Dates
Bakersfield
Bethel
Island Foothills Fresno Angiola
IOP 1
Dec. 15-18
mix
carbon
mix
nitrate
mix
IOP 2
Dec. 26-28
carbon
carbon
carbon
nitrate
mix
IOP 3
Jan. 4-7
nitrate
nitrate
mix
nitrate
nitrate
IOP 4
Jan. 31-Feb. 1 nitrate
mix
carbon
nitrate
carbon

Composition varies throughout day
Hypothesis of nitrate mixing from aloft
Nitrate PAH Black Carbon1 Black Carbon7 Temperature
100
25
1/9/00
Nitrate & Black Carbon (µg/m 3 )
PAH (relative units)
80
60
40
20
0
0
1
2
3
4
5
6
7
8
91011121314151617181920212223
Hour (PST)
20
15
10
5
0
Temperature (°C)

Angiola tower nitrate confirms hypothesis
25
100
NO3 Ozone NO
Night Night
20
Night
Night
15
10
5
80
60
40
20
0
0
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
15
18
21
0
3
6
9
NO3 Concentration (ug/m3)
NO and Ozone Concentratoin (ppb)
12/27/2000 12/28/2000 12/29/2000 12/30/2000 12/31/2000
Time (PST) and Date

Substantial amounts of excess NO x , even at
non-urban sites
Is HNO 3 NO x or VOC limited?
Concentration (ugm-N/m3)
80
70
60
50
40
30
20
PM25 NO3
HNO3
NO2 &
Other NOy
NO
10
0
Bethel Island Fresno Bakersfield Angiola Sierra Nevada
Location
HNO 3 data were not available at Bethel Island and Bakersfield

Fog increases deposition and PM removal

Ultrafine particles are directly emitted and form from
atmospheric reactions
(Fresno, CA, 3/29/2003)
Particle Diameter (nm)
100
10
Vehicle
Exhaust
Photochemical
Nucleation
Vehicle
Exhaust,
Residential
Heating and
Cooking
0 1 2 3 4 5 6 7 8 9 1011121314151617181920212223
Hour
0 10000 20000 30000
40000 50000
dN/dlogD p (number cm -3 )

Elevated O 3 and PM 2.5 rarely occur together
Fresno, hourly data
Spring
Summer
Fall
Winter

CRPAQS results confirm focus on reducing
emissions from many sources and pollutants
• What has been done
– Oil heaters switched from crude oil to natural gas,
added SCR
– Extensive controls and offsets on new industrial
sources
– Residential and prescribed burning rules
– Improved on-road pollution controls and
inspection and maintenance
– Unpaved surface stabilization
– Agricultural conservation management plans
– Dairy permitting program

CRPAQS results confirm focus on reducing
emissions from many sources and pollutants
– Oil heaters switched from crude oil to natural gas,
added SCR
– Extensive controls and offsets on new industrial
sources
– Residential and prescribed burning rules
– Improved on-road pollution controls and
inspection and maintenance
– Unpaved surface stabilization
– Agricultural conservation management plans
– Lower sulfur diesel fuels
– Tighter emission standards for on-road and off-
road diesel engines

• 2005
CRPAQS activities
– Finalize data analysis projects
– Begin weight of evidence/reconciliation analysis.
– Complete model development and evaluation
• 2006
– Complete weight of evidence/reconciliation
analysis
– Complete emissions projections and control
strategy modeling

CRPAQS scientific contributions
• More than 20 technical presentations at February
supersite meeting, Atlanta, GA
• More than 50 technical publications. More in
progress
• Development and testing of new continuous
monitoring instruments
• Refined conceptual models of air quality
evolution in valleys and foggy conditions
• Refined conceptual model of ultrafine particle
formation with low sulfur conditions

Current Standards
The target is changing
Indicator Ave. Time Conc.
EPA Staff Paper
Statistical Form
PM 10
24 hr 150 not to exceed more than 1/yr
Annual 50 arithmetic mean
PM 2.5
24 hr 65 3 yr average of 98 th percentile
Annual 15 3 yr average of arithmetic mean
Proposed Range of Standards
PM 10-2.5
24 hr 65 – 75 at 98 th percentile
or: 75 – 85 at 99 th percentile
Annual 30 at 98 th percentile
or: 35 at 99 th percentile
PM 2.5
24 hr 25 – 35 at 99 th percentile
Annual 15
or: 24 hr 35 – 40 (at 98 th percentile?)
Annual 12 – 14

Remaining questions
• Is nitrate limited by ammonia levels in sub-
regions during late summer and fall?
• Is nitric acid formation limited by VOCs or NO x ?
• Will population and vehicle use growth offset
emissions reductions per unit?
• Will unidentified high emitters dominate overall
emissions?