Treasure Valley Ozone Precursor Study, July – September 2007

Ozone-VOC-NOx isopleth

PAMS target list

Treasure Valley Airshed Nox - 2005 EI

48.5%

20.6%

6.6%

3.7%

3.4%

3.3%

2.6%

2.5%

2.4%

1.8%4.5%

Mobile

NonRoad Mobile

Industrial Coal Boilers

Industrial Wood Boilers

Biogenics

Industrial NG Boilers

Military Aircraft

Diesel Line Haul Locomotives

Residential NG Furnaces

Open Burning Res Household Waste

Other (<2%)

Treasre

Valley

Treasure Valley Airshed VOC

58%

8%

6%

4%

3%

3%

2%2%

2%1%

1%1%1%1%1%1%0%0%0%0%0%0%0%0%0%0%0%0%0%0%0%0%

Biogenics from EPA

Mobile Total

NonRoad Mobile Total

Gasoline Related Activities

Trans Maint Degrease: Cold Cleaning

Auto Dealers Degrease: Cold Cleaning

Emulsif ied Asphalt

Residential Woodstoves/Fireplaces

Architectural Surface Coating

Electronic Open Top Degreasing

Surface Coating Plastic Products

Auto Repair Degreasing: Cold Cleaning

Consumer Personal Care Products

Consumer Pesticide Application

Open Burning Res Household Waste

Traff ic Markings

Dry Cleaning

Aircraft Surface Coating

Misc Repair Degreasing: Cold Cleaning

Consumer Auto Products

Electronic Degreasing: Cold Cleaning

Consumer Processes

Ind Machinery Open Top Degreasing

R il d S f C ti

2004 Ozone Saturation Study (Ogawa Passive Samplers)

2007 Study – Monitoring Sites

0

10

20

30

40

50

60

70

0 3 6 9 12 15 18 21Hour

Ozo

ne C

onc

(ppb

v)

PAR NNUWHP MOUITD WHTSTL

Spatial/temporal variation of ozone

Urban background ~ 33ppbv

Uniform temporal variation

0

10

20

30

40

50

60

0 3 6 9 12 15 18 21Time

Ozo

ne, N

O a

nd N

O2

(ppb

v)

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

VO

Cs (

ppbv

)

NO NO2 O3Butane isoButane t2PenteneBenzene Toluene Hexeneo-Xylene

1

10

100

0 3 6 9 12 15 18 21Time

Win

d sp

eed

and

tem

pera

ture

0

90

180

270

360

450

540

630

Win

d di

rect

ion,

sola

r rad

iatio

n an

d re

lativ

e hu

mid

ity

Wind speedTemp.%RHSolar RadiationWind direction

Ozone-VOC-NOx, meteorology and topography

0

10

20

30

40

50

60

0 3 6 9 12 15 18 21Time

Ozo

ne a

nd N

O c

onc.

(ppb

v)

NO ThuO3 ThuNO SunO3 Sun

ThursdaytNO=O3

SundaytNO=O3

tO3acc

0

3

6

9

12

15

18

21

Mon Tue Wed Thu Fri Sat SunDay

Tim

e

0

1

2

3

4

5

6

7

8

Ozo

ne a

cc. r

ate

(ppb

/hr)

tNO=O3 tO3acc Rate

Ozone inhibition and accumulation

•Weekday vs. weekend effect

•Role of precursor reductions

0.1

1

10

100

Sun Mon Tue Wed Thu Fri SatDay of week

VO

C/N

Ox

ratio

ITDSt. Lukes

VOC/NOx = 5.5

Regional sources of ozone and its precursors

State Number of fires Burnt area (in acres)

Idaho 26 2,113,227

Nevada 16 512,012

Oregon 21 454,728

Washington 12 172,739

California 18 421,924

Montana 22 549,933

July 10-14, 2007

Lessons LearnedSize (and resources) of field studies may vary (coordinate with

modeling efforts)Both local and regional characteristics should be addressed

• Local and regional characteristics of ozone sources and impacts• Continental background• Ozone precursors defines the conditions of photochemistry and

provide directions for future efforts• Meteorology and topography defines the spatial and temporal

variation• Local sources (and for non-stagnant conditions) are responsible

for significant increase of ozone concentrations• Stagnant conditions and regional events/sources add on ozone

(and its precursors) concentrations

Data analysis and modelingMonitoring ↔ Data Analysis ↔ Modeling

1. “Traditional” ozone data analysis

2. Integration of regional meteorology and air mass trajectories- backward trajectories to determine if “high-ozone” air mass intercepted an area or large point source

- forward trajectories to determine whether or not contaminated plumes (e.g wildfires) are mixed with surface air.