Western Ozone Conference

• Understand the nature, causes and trends of ozone in the western U.S. outside CA

• Identify additional assessment work needed to better characterize ozone

• Identify the policy development needed to address the problem

Overview

• Summarize Conference Information

• Discuss Conclusions

• Discuss Recommendations

Conference Overview

• Regulatory Overview– Federal– Early Action Compacts

• Regional Trends– Regional Monitoring Modeling– Mobile Controls

• Case Studies– NM, CO, WA, OR, ID Modeling– WY, AZ, NM Monitoring

• Special topics– Gas Production– Fire

• Not a uniquely important region in terms of impact

• Several studies in North Pacific region over last 2 decades

Why focus on Asian Emissions, North Pacific and US West Coast?

30

25

20

15

10

5

0An

thro

po

ge

nic

NO

x E

mis

sio

ns

(Tg

/ye

ar)

20001995199019851980

North America

Asia+ 5.0 %/year

Europe

• Asian emissions increased significantly over period of studies - Look for parallel change in ambient levels

70

60

50

40

30

20

O3 (pp

bv)

20001996199219881984

CITE 1C

ITCT 2K2

Lassen VolcanicNational Park

Elevated Data setsSites slope O3 2000 r2

(ppbv/yr) (ppbv)Lassen 0.46 ± 0.39 45.8 ± 2.4 0.36Aircraft 0.51 55.3

60

50

40

30

20

10

O3 (pp

bv)

20001996199219881984

Pt. Arena

TrinidadHead

Cheeka Peak

Point ReyesNational Sea Shore

RedwoodNational Park

Marine Boundary Layer Data Sets sites slope O3 2000 r2

(ppbv/yr) (ppbv) 4 sea-level 0.50 ± 0.36 39.9 ± 3.3 0.44 All 5 0.78 ± 0.28 42.9 ± 2.4 0.68

(Data selected to avoid North American influence)

Conclusion: Along the U.S. west coast, springtime O3 has increased by ≈ 0.5 ppbv/yr, i.e. ≈10 ppbv in 20 years or ≈1-1.5 %/yr

Increasing background ozone during spring on the west coast of North America, Jaffe et al., Geophys. Res. Letters, 30, 2003

Springtime mean O3 levels have increased

Summary: In springtime

Impact of Asian Emissions on the Photochemistry of the North Pacific Troposphere

• Asian emissions have increased by ≈ 5% / year over last 20 years

• O3 levels in Eastern Pacific have increased by ≈ 1-1.5 % / year

• PAN levels in Eastern Pacific have increased by ≈ 3-4 % / year

• Pacific photochemistry has become less efficient sink for O3

Caveat: Based on very few “background” data of short time span. 1985 Pt. Arena data are only early PAN and VOC measurements collected over 10 day period

Decreasing Trend, p<=0.15

Decreasing Trend, p>0.15

Increasing Trend, p<=0.15

Increasing Trend, p>0.15

No Trend

Insufficient Data

Trends in Annual 4th-Highest 8-Hour Ozone Average, 1993-2002

Acadia

Big Bend

Cape Cod

Canyonlands

Chamizal

Chiricahua

Channel Islands

Congaree Swamp

Cowpens

Craters of the Moon

Death Valley

Everglades

Glacier

Great Basin

Grand CanyonGreat Smoky MtnsJoshua Tree

Lassen Volcanic

Mammoth CaveMesa Verde

Mount Rainier

North Cascades

Olympic

Pinnacles

Rocky Mountain

Saguaro

Sequoia

Shenandoah

Theodore Roosevelt

Voyageurs

Yellowstone

Yosemite

Denali

55

42

48

N ational Park Service O zone M onitoring N etw ork2002 4th H ighest Daily M axim um 8-Hour O zone Concentrations

(parts per b illion)

<= 84 ppb

85 - 95 ppb

>= 96 ppb

Voyageurs

OlympicNorth Cascades

Mt. Rainier

Glacier

Theo. Roosevelt

Yellowstone

Rocky Mountain

Hawaii Volcanoes

Denali

Virgin Islands

MammothCave Shenandoah

Acadia

Cape Cod

Congaree Swamp

Cowpens

Great SmokyMountains

Big Bend

Chamizal

Mesa Verde

Everglades

LassenVolcanic

Yosemite

Pinnacles

Joshua Tree

Sequoia

Craters of theMoon

Saguaro

Great BasinCanyon-

lands

Grand Canyon

Chiricahua

DeathValley

ChannelIslands

100

62

93

72

8969

66

82

93

69

83

55

52

74

79103

107

75

8570

52

4427

86

87

77

109

86

62

65

66

93

How do ozone concentrations in national parks compare with nearby urban areas?

Ozone Trends at Rocky Mountain NP and Front Range Cities, 1993 - 2002

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1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

An

nu

al 4

th H

igh

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ly M

axim

um

8-h

ou

r O

zon

e, p

pb

Rocky Mountain Rocky Flats (08-059-0006) Arvada (08-059-0002) Denver (08-031-0014)

Boulder (08-013-0011) Colorado Springs (08-041-0013) Ft Collins (08-069-1004)

Rocky Flats

Boulder

Denver

Arvada

Rocky Mt NP

Colorado Springs

Ft Collins

85 ppb

Note: Arvada, Colorado Springs, Denver show a statistically significant increase in 4th highest daily maximum 8-hour ozone (p<0.10)

1993-2002 Mar-Sep Diurnal Ozone PatternsRocky Mountain National Park and Selected Urban Monitoring Sites

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Hour of the Day

Ozo

ne

Co

nce

ntr

atio

n, p

pb

Rocky Mountain NP

Arvada (08-059-0002)

Ft. Collins (08-069-1004)

Denver (08-031-0014)

Rocky Flats (08-0006-1004)

Do diurnal patterns of ozone differ from parks to nearby urban areas?

1993-2002 Jan-Dec Diurnal Ozone PatternsAt Grand Canyon NP, Saguaro NP, and Selected Urban Monitoring Sites

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ntr

atio

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pb

Phoenix (04-013-1004)

Las Vegas (32-003-0016)Tucson (04-019-1011)

Saguaro NP

Grand Canyon NP

Expected Ozone Trends – Federal Emissions Reductions

• Heavy Duty Engine & Diesel Sulfur– Issued in 2001– Emissions standards for heavy-duty trucks and buses, plus

fuel sulfur limits– 95% less NOx emissions from category– Effective in model year 2006/07, phase in (09/10)

• NonRoad Engine & Diesel Sulfur – Proposed in 2003, Expected final in April 2004 – Emissions standards for construction, agricultural, and

industrial equipment– 90% less NOx emissions from category– Effective in model year 2008, phase in through 2014

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AZ CO ID OR UT

State / Base Case

Per

cent

Cha

nge

(%)

2020 B

2020 C

2030 B

2030 C

Expected Ozone Trends – Future NOx Emissions Changes

Expected Ozone Trends – NonRoad Modeling Analyses

• Most portions of the western U.S. are projected to have a reduction of 2-10 ppb in peak 8-hr ozone levels by 2020

• Greater reductions in majority of CA

• Disbenefits in LA, SF, DEN (small) & PHX (small)

Legend

53 - 70

71 - 79

80 - 84

85 - 89

90 - 94

95 - 129

Number of Counties

(97)

(108)

(151)

(71)

(67)

Nonroad (CAMX) 8 hour

(27)

1999-2001 Design Values

1999-2001 Eight Hour Ozone Design Values

Projected 2020 Eight Hour Ozone Design Values

Legend

DV2020B

43 - 70

71 - 79

80 - 84

85 - 89

90 - 94

95 - 133

Number of Counties

(154)

(39)

(16)

(9)

(5)

Nonroad (CAMX) 8 hour

(299)

2020 Base Design Values

50556065707580859095

100

2001-2003

2020 B 2020 C 2030 B 2030 C

Maricopa

Pima

Expected Ozone Trends – NR Modeling: Arizona

Expected Ozone Trends – NR Modeling: Colorado

50556065707580859095

100

2001-2003

2020 B 2020 C 2030 B 2030 C

Jefferson

Larimer

Expected Ozone Trends – NR Modeling: Nevada

50

55

6065

70

75

80

8590

95

100

2001-2003 2020 B 2020 C 2030 B 2030 C

Clark

Expected Ozone Trends – NR Modeling: New Mexico

50556065707580859095

100

2001-2003

2020 B 2020 C 2030 B 2030 C

Bernalillo

Dona Ana

San Juan

Expected Ozone Trends – NR Modeling: Oregon

50556065707580859095

100

2001-2003

2020 B 2020 C 2030 B 2030 C

Clackamas

Columbia

Lane

Marion

Expected Ozone Trends – NR Modeling: Utah

50556065707580859095

100

2001-2003

2020 B 2020 C 2030 B 2030 C

Davis

Salt Lake

Utah

Weber

Expected Ozone Trends – NR Modeling: Washington

50556065707580859095

100

2001-2003

2020 B 2020 C 2030 B 2030 C

Clark

King

Pierce

Thurston

Expected Ozone Trends – NonRoad Modeling Analyses

• 8-hour ozone levels are generally expected to decrease slightly in the Western U.S. over the next 10-25 years– Decrease of ~ 5%: Albuquerque, Denver, Phoenix,

Salt Lake City, Tucson, & rural areas– Larger decreases: Portland, Seattle – Model results uncertain (your results may vary)– Certain Western U.S. cities are likely to maintain

design values near/just below the NAAQS over the next 0-20 years w/o local control

• – will depend on year-to-year meteorological variability.

CMAQ Western U.S. Ozone Modeling – 1996 Application

• Model performance evaluation indicated greater negative bias in the western U.S. in the summer than in 36/12 CAMx

– Mean normalized bias = -11.7%– Normalized gross error = 23.2 %– East US (annual): bias = -1.2%; error

= 18.6%– West US (annual): bias = -26.5%;

error = 29.9%– East US (summer): bias = 0.8%;

error = 18.7%– West US (summer): bias = -27.0%;

error = 30.5%

2007 Emission Reduction Sensitivity Analysis

• Across-the-Board 10% reduction in anthropogenic emissions in DMA + Weld County (plus on-road and off-road reductions).

• Key Findings:– Modeled ozone stiff response to local emission

reductions (i.e., ozone not very responsive to local emission controls)

– VOC control in DMA is more effective than NOx control in DMA

• 10% VOC control in DMA results in 0.3-0.4 ppb ozone reduction at Rocky Flats North monitor

• 10% NOx control in DMA results in 0.4 ppb ozone increase at Rocky Flats North monitor

Denver Ozone Source Apportionment

• Source Apportionment results currently under review by State and Denver RAQC, report not yet available

• Preliminary results suggest the following:– A majority (~75% to 85%) of the peak 8-hour ozone

concentrations at the Rocky Flats monitor come from outside of the Denver Metropolitan Area (DMA)

– For sources in the DMA, on-road mobile sources are most important followed by non-road mobile sources

• Helps explain why modeling results are so stiff in response to local controls

1-Hr Ozone Model Performance, Error – Goal < 35%Mean Normalized Gross Error in 1- Hr Ozone, (%).

0.0

5.0

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20.0

25.0

30.0

35.0

40.0

04-Jun

05-Jun

06-Jun

07-Jun

08-Jun

Average

Gro

ss E

rror

, %

4 Km Domain12 Km Domain36 km DomainSan Juan Basin

Overall Conclusions Western US O3 Modeling

• Ozone downwind of smaller “urban” areas in western U.S. tends to be underestimated– Seen in recent EACs (CAMx) and Regional Visibility

modeling (CMAQ)– Regional buildup of ozone understated

• Contributing factors:– Missing emissions

• UCI Oil&Gas, many small unpermitted sources• Missing biogenic emissions/understated reactivity• Mobile Source fleet type different from national average

– Meteorological Modeling More Challenging

2002 Denver Metro and Statewide

VOC EI with Biogenic Emissions

Point Sources7 %

Point Sources-F lash15 %

Area Sources11 %

N on-R oad (exhaust)7 %

N on-R oad (evaporative)1 %

M obile Sources (exhaust)9 %

M obile Sources (evaporative)8 %

B iogenic43 %

D e n ve r EAC -2 0 0 2 H yd ro ca rb o n Em issio n s fo r th e D e n ve r A re a + W e ld C o u n ty w ith B iog e n ic Em issio n s

(To ta l H C =8 9 3 tp d )

Point Sources2 %

Point Sources-F lash2 %

Area Sources3 %

N on-R oad (exhaust)2 %N on-R oad (evaporative)0 %

M obile Sources (exhaust)2 %

M obile Sources (evaporative)2 %

B iogenic88 %

D e n ve r EAC -2 0 0 2 S ta te w id e H yd ro ca rb o n Em issio n s+ B io g e n ic Em issio n s a n d W ild fire

(To ta l H C = 7 3 7 8 tp d )

MT Emission InventoryCoal Bed Methane Sources

MT Emission InventoryConventional Oil & Gas Sources

July 19, 2002

10:15 am

SVR = 130 km

O3 = 78 ppb

11:45 am

SVR = 54 km

O3 = 86 ppb

July 19, 2002 (3:00-3:45 pm)

SVR = 58 km O3 = 96 ppb (highest O3 value in 2002)

Maximum Daily 1- Hour Ozone Measurements, July - August, 2000

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pp

m o

zon

e

Beach

Bountiful

Cottonwood

Herriman

Highland

Hawthorne

Logan

North Ogden

North Provo

Spanish Fork

Washington Terrace

West Valley

O3 1 Hr Max. Entire Wasatch Front - Aug '02

28-A

ug

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ug

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ug

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ug

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Day of the Month

O3

pp

m

Brigham City Logan Bountiful Salt Lake Beach Hawthorn West Vall Harriman

West Prov Highland Spanish F Washingto North Ogd

Conclusions

• Future not clear/national view may need refinement • Many examples, but lack of regional understanding of:

– Background, natural, rural/urban, transport/local, regional, subregional-Elevated urban ozone not well synchronized with rural ozone

• Better analysis of existing situation needed• ID policy goals – attainment, maintenance,

transport/local, rural/urban, regional/subregional• Coordinate/leverage resources• High background levels – limited local control options

Recommendations

• Modeling– Biogenics, meteorology– One atmosphere model

• Monitoring – Work with existing data – Better collaboration– Better spatial coverage– Collect speciated VOC and NO

Recommendations (cont.)

• Early Action Compacts– Encourages proactive assessment/action-to identify/address

problems before they become nonattainment areas– Continue to make option available

• Forecasting – continue federal support• IAQR – understand effect on ozone• Oil and gas – getting better understanding of emissions• Fire/ozone

– Resolve fire/ozone episode relationship/documentation – Resolve monitor interference question

Questions?

?