National Park Service

U.S. Department of the Interior

Air Resources Division

Annual Data Summary

2004

Gaseous Pollutant Monitoring Program

Ozone, Sulfur Dioxide, Meteorological Observations
 Report No. NPS D-1644 

This Annual Data Summary was prepared under NPS Contract C2350010840 by: 

Air Resource Specialists, Inc. 

1901 Sharp Point Drive, Suite E 

Fort Collins, Colorado 80525 

Telephone: (970) 484-7941 

Fax: (970) 484-3423 

For additional copies of this report contact: 

Air Resource Specialists, Inc. 

1901 Sharp Point Drive, Suite E 

Fort Collins, Colorado 80525 

Telephone: (970) 484-7941 

Fax: (970) 484-3423 

E-Mail: air-imc@air-resource.com

or 

National Park Service Denver Service Center 

Technical Information Center 

12795 W. Alameda Parkway 

Denver, CO 80225-0287 

Telephone: (303) 969-2130 

E-Mail: TIC_requests@nps.gov

or 

The report can be downloaded from 

http://www2.nature.nps.gov/air/monitoring/ads/ADSReport.cfm
i

TABLE OF CONTENTS 

Section Page

FOREWARD iv 

1.0 INTRODUCTION 1-1 

2.0 NETWORK DESCRIPTION 2-1 

 2.1 GPMP Network Monitoring 2-1 

 2.2 Cooperating Programs 2-1 

3.0 DATA SUMMARIES 3-1 

 3.1 Data Collection 3-1 

 3.2 Ozone Data Summaries 3-6 

 3.2.1 Annual Ozone Summaries 3-6 

 3.2.2 Ozone Violation Summaries 3-14 

 3.2.3 Long-Term Ozone Trends 3-18 

 3.2.4 Resource Injury Indices 3-27 

 3.3 Sulfur Dioxide Data Summaries 3-32 

 3.4 Meteorological Data Summaries 3-34 

4.0 PRECISION AND ACCURACY OF OZONE MEASUREMENTS 4-1 

LIST OF FIGURES

Figure Page

2-1 2004 Monitoring Sites, National Park Service Gaseous Pollutant 

 Monitoring Program 2-3 

3-1 Annual Fourth Highest 8-Hour Average Ozone Concentrations (in ppb), 

 2004, National Park Service Gaseous Pollutant Monitoring Program 3-11 

3-2 Annual Number of Days with 8-Hour Average Ozone Values >= 85 ppb, 

 2004, National Park Service Gaseous Pollutant Monitoring Program 3-12 

3-3 Annual Second Highest 1-Hour Average Ozone Concentrations (in ppb), 

 2004, National Park Service Gaseous Pollutant Monitoring Program 3-13 

3-4 Ozone Violation Summary Ranking, 3-Year Average 4th Highest Daily 

 Maximum 8-Hour Average Ozone Concentrations (ppb), 2004, National 

 Park Service Gaseous Pollutant Monitoring Program 3-17 

3-5 Total NOX Emissions for Point and Mobile Sources in the United States 3-19 

3-6 NOX Emissions Density 3-19 
LIST OF FIGURES (continued)

Figure Page

3-7 Trends in NOX Emissions for Eastern States 3-20 

3-8 Comparison of 3-Year Rolling Average 4th Highest Daily Maximum 8-Hour 

 Average Ozone Concentration for Selected Eastern Parks 3-21 

3-9 Ozone Trends for Great Smoky Mountains NP and Cowpens NB 3-21 

3-10 Ozone Trends in Eastern Parks 3-23 

3-11 Ozone Trends in Western Parks 3-24 

3-12 Trends in Number of 8-Hour Average Ozone Exceedances 3-25 

3-13 Annual 3-Month Maximum Sum06 Exposure Index, 2004, National Park 

 Service Gaseous Pollutant Monitoring Program 3-31 

LIST OF TABLES

Table Page

2-1 Site Specifications, 2004, National Park Service Gaseous Pollutant 

 Monitoring Program 2-4

3-1 Data Collections Statistics by Site, 2004, National Park Service Gaseous 

 Pollutant Monitoring Program 3-2 

3-2 Network Summary of Data Collections Statistics, 2004, National Park Service 

 Gaseous Pollutant Monitoring Program 3-5 

3-3 Summary of Ozone Data by Site, Highest Daily 8-Hour Average Maximum 

 Concentrations (ppb), 2004, National Park Service Gaseous Pollutant 

 Monitoring Program 3-8 

3-4 Summary of Ozone Measurements from Portable Ozone Monitoring Stations 

 (POMS), Highest Daily 8-Hour Average Maximum Concentrations (ppb), 2004, 

 National Park Service Gaseous Pollutant Monitoring Program 3-10 

3-5 Ozone Violation Summary, 3-Year Average 4th Highest Daily Maximum 8-Hour 

 Average Ozone Concentration (ppb), 1997 - 2004, National Park Service Gaseous 

 Pollutant Monitoring Program 3-15 

3-6 Summary of Indices for Resource Injury (SUM06, W126, and N100), 2004, 

 National Park Service Gaseous Pollutant Monitoring Program 3-29 

3-7 Summary of Sulfur Dioxide Data by Site, 2004, National Park Service Gaseous 

 Pollutant Monitoring Program 3-33 

ii
LIST OF TABLES (continued)

Table Page

3-8 Summary of Selected Meteorological Data by Site, 2004, National Park Service 

 Gaseous Pollutant Monitoring Program 3-35 

4-1 Ozone Analyzer Precision and Accuracy Summary, 2004, National Park Service 

 Gaseous Pollutant Monitoring Program 4-2 

4-2 Ozone Analyzer Precision and Accuracy Overall Network Summary, 2004, 

 National Park Service Gaseous Pollutant Monitoring Program 4-8 

 

iii
Foreword 

National Park Service 

Gaseous Pollutant Monitoring Program 

2004 Annual Report 

This annual data summary report includes data from all Gaseous Pollutant Monitoring 

Program (GPMP) stations. Several parks with state operated stations are also included. Air 

quality and meteorological data from these sites for 2004 have been collected, validated, and 

made available to the Environmental Protection Agency (EPA), the parks, and the public. The 

data summarized in this report, as well as data from previous years, can now be accessed and 

viewed graphically on the National Park Service (NPS) Air Resources Division (ARD) Web site 

(http://www2.nature.nps.gov/air/data/). This report also presents several measures of how well 

the network has functioned (data precision, accuracy, and collection rates), and contains 

summaries related to the pollutant National Ambient Air Quality Standards and thresholds for 

resource injury. 

Changes in 2004 

Over the past year there has been an increase in the amount of information on the 

National Park Service Air Resources Division’s Web site. Because of this increase, this year’s 

annual data summary does not include pollutant or wind roses. These plots can be created 

interactively for any period of time on the Web at http://www2.nature.nps.gov/air/data/. 

2004 saw an increase in the number of portable ozone monitoring systems (POMS) 

operated by the NPS. These POMS serve as the “baseline monitoring” function described in the 

1991 NPS Monitoring Strategy (http://www2.nature.nps.gov/air/Monitoring/docs/1991trend.pdf). 

POMS were used in 11 locations in 2004. Data from these sites are included in many of the 

summaries in this report and the hourly data are available on the Web site. At least 14 POMS 

stations will be deployed in 2005 and anywhere from 3-5 stations will move each year. If your 

park has an interest in deploying a POMS, please contact John Ray at NPS ARD. 

In 2004 and 2005, budget constraints led to some changes in the monitoring network. 

Ozone monitoring was discontinued at some sites where outside funding is no longer available, 

where ozone concentrations are low, or where multiple stations existed within the same park 

unit. Ozone monitoring was discontinued in either 2004 or 2005 at the following parks: Hawaii 

Volcanoes, Olympic, Sequoia/Kings Canyon, and Everglades National Parks. Passive ozone 

monitoring also ended at about 20 locations in 2004, although several of these parks have 

separately funded passive ozone sampling for 2005. 

iv
Highlights in 2004 

 

During 2004, most sites realized fewer exceedances of the ozone standard than in 2003. 

An exceedance occurs when an 8-hour average ozone concentration is equal to or greater than 85 

ppb. Five sites in three western parks had greater than four exceedances in 2004: 

Park/Site 

4th Highest DailyMaximum 8-Hour 

Avg. O3 Concentration (ppb) 

Number of 

Exceedances

Joshua Tree 102 31 

Sequoia and Kings Canyon – Ash Mountain 99 52 

Sequoia and Kings Canyon – Lower Kaweah 95 24 

Sequoia and Kings Canyon – Lookout Point 95 50 

Yosemite – Turtleback Dome 89 8 

 

Areas that exceeded the standard in recent years, but not in 2004 include: Acadia NP, 

Mammoth Cave NP, Cowpens NM, and Rocky Mountain NP. The trends section of this report 

provides some possible explanation for this decrease in ozone concentrations. Exceedances can 

lead to a violation of the National Ambient Air Quality Standard (NAAQS) for ozone. A 

violation of the NAAQS occurs when the three year average of the fourth highest daily 

maximum is greater than or equal to 85 ppb. The sites listed above, plus five others violated the 

3-year standard in 2004; two less than in 2003. 

Special Studies in 2004 

Each year several special air quality studies are conducted in individual parks. The 

objectives of these studies fall under the following monitoring objectives of the GPMP: 

 • Provide data for atmospheric model development and evaluation. 

 • Identify pollutants which may injure park natural resources or affect human health by 

measuring these pollutants and correlating observed effects on resources to ambient 

levels of pollutants. 

Yellowstone National Park - Monitoring of carbon monoxide (CO) and fine particulates (PM2.5) 

was conducted in two locations to relate snowmobile usage to ambient air quality. Over the last 

couple of years, CO and PM2.5 levels at locations with high snowmobile activity has declined. 

Detailed emission data from snowmobiles and snowcoaches were collected using remote sensing 

and portable instrumentation. Separate reports will be prepared for these studies. The park plans 

to use these data in modeling and in the revision to the Winter Use Plan. 

Great Smoky Mountains National Park - Blount County, TN, is on the eastern boundary of the 

park and has no ozone monitoring stations. The county health department and the NPS worked 

together on a project using passive ozone samplers to characterize ozone concentrations at six 

locations around the park. A spatial distribution model was developed. 

Cumberland-Piedmont - The Cumberland-Piedmont network within the Inventory and 

Monitoring Program conducted passive ozone sampling and portable ozone monitoring at 28 

v
locations in 14 parks during the Summer of 2004. For many of these parks, the passive sampling 

was the first direct measurement of ozone concentrations. Results will be compared to the 

nearest ozone monitors and to the Air Atlas estimates. 

Yosemite National Park - An enhanced monitoring station is located within Yosemite Valley to 

compare ozone concentrations in the valley to those from the regular monitoring station at a 

higher elevation within the park. Data have shown that ozone is lower in the valley, especially at 

night. Another objective of the station is to track changes in nitrogen oxides (NOx) and carbon 

monoxide (CO) within the valley as transportation modes change. During the winter some very 

high concentrations of NOx were observed, suggesting boundary-layer trapping of emissions 

from a point source within Yosemite Valley. 

Network Quality Assurance 

Overall data capture for NPS ozone monitoring continues to be high (93.3%) and exceeds 

NPS objectives and EPA requirements. The Quality Assurance Project Plan (QAPP) and the 

Quality Management Plan (QMP) were completely revised in 2004 

(http://www2.nature.nps.gov/air/Monitoring/network.cfm#procedures). These documents, as 

well as the individual Standard Operation Procedures (SOPs), define how monitoring at NPS 

units is performed and describes the procedures used to process and validate the data. 

The GPMP acknowledges and thanks the many park employees who perform the 

majority of the air quality monitoring by keeping the stations operational and working on air 

quality issues. 

Dr. John D. Ray 

GPMP Program Manager 

NPS Air Resources Division 

Denver, CO 

303-969-2820 

john_d_ray@nps.gov 

vi
1.0 INTRODUCTION 

 The overall purpose of the National Park Service (NPS) Gaseous Pollutant Monitoring 

Program (GPMP) is to monitor the status and trends of ambient air quality conditions in national 

park units. This purpose is outlined by the Clean Air Act of 1963 (including the 1970, 1977, and 

1990 amendments) and the Organic Act of 1916, which assign the federal land managers the 

responsibility of protecting the natural resources in national parks. Several monitoring 

objectives have been derived from this purpose: 

Primary Monitoring Objectives 

Gaseous Pollutant Monitoring Program 

• Establish baseline concentrations of air pollution in national park units 

• Assess trends in air quality 

• Determine compliance with national ambient air quality standards 

• Provide data for the development and revision of national and regional air pollution control 

policies that are protective of park resources 

• Provide data for atmospheric model development and evaluation 

• Identify air pollutants that may injure or damage park natural resources, measure these 

pollutants, and correlate observed effects on resources to ambient levels of pollutants 

 Other NPS monitoring objectives call for the collection of data to support the National 

Park Service's required involvement in both the development of state air quality control plans, 

and the evaluation of permit applications for new or expanding air pollution sources wishing to 

locate near park units. The Clean Air Act gives federal land managers an affirmative 

responsibility to protect air quality related values in Class I areas and to assess whether new 

sources will have an adverse impact on park unit resources and values. Information on air quality 

levels in NPS units can also be used to evaluate the performance of atmospheric models that 

simulate how pollutants are transported into park units, and predict impacts on the park units 

caused by air pollution sources. 

 To meet these objectives the NPS Air Resources Division (ARD) has established a 

network of stations to monitor ozone (O3), sulfur dioxide (SO2), carbon monoxide (CO), oxides 

of nitrogen (NOx), particulate matter (PM), and meteorological conditions in the parks. This data 

summary report presents only O3, SO2, and meteorological data. Other gas and particulate 

monitoring are performed at several sites for specific air quality studies. Ozone, meteorological, 

and some SO2 monitoring methods and quality assurance procedures adopted by the GPMP 

network were developed in accordance with the EPA regulations of 40 CFR, Part 58, Appendix 

D, which, although addressing primarily health-effects based monitoring in areas of high 

population, are generally pertinent to the GPMP. These design criteria allow for the direct 

comparison of NPS collected data with that collected by the EPA, and state and local air 

pollution control agencies. 

 As a supplement to the basic network, the ARD also conducts shorter-term air quality 

monitoring including passive ozone, portable ozone, and special studies monitoring in selected 

parks. In addition, the ARD cooperates with other national and state programs that monitor 

ambient gases, meteorology, deposition chemistry, particulate matter, and visibility. 

1-1
 Data collected by this network are incorporated in the EPA Air Quality System (AQS) 

database, which is a national database of air quality data collected throughout the country. These 

data are also stored in the NPS ARD’s Information Management Center (IMC), and publicly 

available through the NPS ARD’s Web site at 

http://www2.nature.nps.gov/air/Monitoring/network.cfm#data 



1-2
2.0 NETWORK DESCRIPTION 

 The NPS air quality monitoring strategy has focused primarily on Class I areas defined 

by the Clean Air Act amendments of 1977. The Gaseous Pollutant Monitoring Program network 

consists of individual stations located in national park units throughout the United States. The 

NPS also participates with other agencies in cooperative monitoring programs. This section 

describes the GPMP network and cooperating programs. 

2.1 GPMP NETWORK MONITORING 

 During 2004, fifty-nine (59) monitoring sites in forty-six (46) units of the National Park 

System conducted some combination of ozone, sulfur dioxide, and meteorological monitoring. 

The locations of the sites that operated during the year are presented on the map in Figure 2-1. 

The parameters monitored at each park unit are indicated with colored flags. The CASTNet flag 

identifies sites where the NPS operates Clean Air Status and Trend Network monitoring systems 

in cooperation with the EPA’s CASTNet program to quantify dry atmospheric deposition. The 

enhanced gaseous and/or particulates flag indicates that the NPS sponsors additional or highresolution gaseous or particulate monitoring at the park. Monitoring agencies and park units 

with more than one monitoring site are indicated. Site specifications, including site names, 

abbreviations, AQS identification numbers, locations, and monitored parameters are listed in 

Table 2-1. 

 In addition to monitoring for regulatory compliance, the NPS added non-certified 

portable ozone monitoring systems (POMS) to the GPMP in 2003. These sites employ portable 

non-reference, non-equivalent method ozone and meteorological monitoring stations, generally 

configured for solar and battery power. The POMS are intended for short-term seasonal use at 

locations where reference method monitoring has not occurred or is not practical. Throughout 

this report, POMS site names in tables and figures have been underlined to distinguish them from 

monitoring sites meeting all EPA guidelines. 

2.2 COOPERATING PROGRAMS 

 Data from cooperating programs are reported by those programs and are not included in 

this report. The exception to that is ozone, sulfur dioxide, and meteorology collected in NPS 

units by state agencies which supplement the data collected by the GPMP. 

State Programs

 The NPS cooperates with a number of state agencies. At some sites, state air quality 

agencies provide measurement and operations support, and data are generally shared directly 

among cooperating agencies. Relevant ozone, sulfur dioxide, and meteorological data submitted 

by states to the EPA AQS are retrieved for inclusion in this report. Throughout this report, stateoperated and reported monitoring site names in tables and figures are indicated in italics. 

CASTNet

 Most GPMP stations operate in a cooperative effort with the EPA Clean Air Status and 

Trends Network (CASTNet). Weekly integrated particulate samples are collected on filter packs 

at CASTNet sites. The samples are analyzed for ambient atmospheric nitrates, sulfates, 

ammonium, sulfur dioxide, and nitric acid, and the results are used to estimate atmospheric dry 

deposition. More information is available at the CASTNet Web site: http://www.epa.gov/castnet. 

2-1
Passive Ozone

 To expand the spatial sampling of ozone in national parks, the Research and Monitoring 

Branch, (RMB) of the NPS ARD adopted the use of low-cost passive ozone samplers. Weekly 

integrated ozone concentrations are measured in the parks during the ozone season, typically late 

spring through early fall. Operators change the ozone badges weekly and mail them to a contract 

laboratory for analysis. The results are compiled and reported by the RMB. 

IMPROVE

 The Interagency Monitoring of Protected Visual Environments (IMPROVE) is a 

consortium of federal and state agencies which conduct visibility monitoring in Class I areas, 

including national parks. A number of instruments are used to monitor visibility, including: 

 • Aerosol samplers, which collect 24-hr integrated particle samples every 3 days on a 

series of filter media. Filters are later analyzed for PM2.5 and PM10 mass, elements, 

ions, and carbon. 

 • Transmissometers, which directly measure the atmospheric light extinction over a 

sight path of several kilometers. 

 • Nephelometers, which perform point optical measurements of the scattering 

component of atmospheric light extinction. 

 • Cameras which document the appearance of a scene as viewed through the 

atmosphere. Digital images from many sites are posted to the Internet along with 

relevant air quality data and other information in near real-time for public viewing. 

More information is available at the IMPROVE Web site: http://vista.cira.colostate.edu/improve. 

NADP/NTN and NADP/MDN

 The National Atmospheric Deposition Program/National Trends Network (NADP/NTN) 

includes wet deposition monitoring at over 250 sites nationwide. The NADP network has been 

collecting data for over 20 years, and is coordinated from the Program Office at the Illinois State 

Water Survey in Champaign, Illinois. Data for all major ions are available in concentrations and 

depositions expressed by kilograms/hectare. The National Atmospheric Deposition Program/ 

Mercury Deposition Network (NADP/MDN) includes wet mercury deposition monitoring at 

over 80 sites nationwide. More information about both of these programs is available at the 

NADP Web site: http://nadp.sws.uiuc.edu/. 

2-2
Figure 2-1

2004 Monitoring Sites

National Park Service Gaseous Pollutant Monitoring Program

* Park units with more than one site are indicatedwith (x) following the park unit name, where xrepresents the number of sites within the unit.

OzoneMeteorology

CASTNet Filter Pack

Sulfur Dioxide

Enhanced Gaseous and/or Particulates

Parameters Operating agency key:

plain text = site operated by the National Park Service

italics = site operated by a state agency

underline = National Park Service operated

portable ozone system (POMS)

Acadia (2)

Badlands

Big Bend

Big South Fork

Black Canyon of the Gunnison Canyonlands

Cape Cod

Chamizal

Chiricahua

Channel Islands

Congaree 

Cowpens

Craters of the Moon

Denali

Death Valley

Everglades

Glacier

Great Basin

Grand Canyon (2) Great Smoky Mountains (5)

Gulf Islands

Hawaii Volcanoes (2)

Isle Royale

Joshua Tree

Kobuk Valley

Lake Mead

Lassen Volcanic

Little River Canyon

Mammoth Cave (2)

Mesa Verde

Mount Rainier (2)

North Cascades

Olympic (2)

Petrified Forest

Pinnacles

Rocky Mountain

Russell Cave

Saguaro

Sequoia/Kings Canyon (3) Shenandoah

Theodore Roosevelt

Voyageurs

Wind Cave

Yellowstone (2)

Yosemite (2)

Zion

2-3
Table 2-1

National Park Unit

Elev.

(m)

Longitude Latitude

NPS

Abbr.

Site Name State

CASTNet

Abbr.

AQS ID

Number

SO2

O3

Years1

VWD2 SWS3 TMP RH

Site Specifications

2004

National Park Service Gaseous Pollutant Monitoring Program

X 44.3472 23-009-0102 466 68.2278 Cadillac Mountain ME Acadia ACAD-CM 10 X X X

X 44.3769 23-009-0103 158 68.2608 McFarland Hill ME Acadia ACAD-MH ACA416 7 X X X

X 43.7436 46-071-1001 739 101.9414 Visitor Center SD Badlands BADL-VC 8 X X X

X 29.3022 48-043-0101 1052 103.1772 K-Bar Ranch Road TX Big Bend BIBE-KB BBE401 15 X X X

X 36.4725 451 84.6806 Portable Ozone TN Big South Fork BISO-PT 2 X X X

X 38.5803 2408 107.7167 Portable Ozone CO Black Canyon of the Gunnison BLCA-PT 2 X X X

X 41.9769 25-001-0002 40 70.0164 Cape Cod MA Cape Cod CACO-XX 18 X X X

X 38.4586 49-037-0101 1809 109.8211 Island in the Sky UT Canyonlands CANY-IS CAN407 13 X X X

X 31.7656 48-141-0044 1128 106.455 Chamizal TX Chamizal CHAM-XX 13 X X X

X 32.0092 04-003-8001 1570 109.3892 Entrance Station AZ Chiricahua CHIR-ES CHA467 14 X X X

34.0164 06-083-2012 0 120.05 Santa Rosa Island CA Channel Islands CHIS-XX 8

33.8147 45-079-0021 34 80.7811 Congaree Bluff SC Congaree COSW-BL 5 X

35.1303 45-021-0002 296 81.8164 Cowpens SC Cowpens COWP-XX 17

X 43.4606 16-023-0101 1815 113.5622 Visitor Center ID Craters of the Moon CRMO-VC 13 X X X

X 63.7258 02-290-0003 661 148.9633 Headquarters AK Denali DENA-HQ DEN417 18 X X X

X 36.5092 06-027-0101 125 116.8481 Park Village CA Death Valley DEVA-PV DEV412 12 X X X

X 25.3911 12-086-0030 2 80.6806 Beard Center FL Everglades EVER-BC EVE419 21 X X X

X 48.5103 30-029-8001 976 113.9956 West Glacier Horse Stables MT Glacier GLAC-WG GLR468 13 X X X

X 39.0053 32-033-0101 2060 114.2158 Maintenance Yard NV Great Basin GRBA-MY GRB411 12 X X X

X 36.0597 04-005-8001 2073 112.1822 The Abyss AZ Grand Canyon GRCA-AS GRC474 12 X X X

X 36.2828 1433 113.0958 Portable Ozone AZ Grand Canyon GRCA-PT 2 X X X

X 35.6042 47-009-0102 564 83.7831 Cades Cove TN Great Smoky Mountains GRSM-CC 12 X X X

X 35.5619 47-155-0102 2021 83.4981 Clingmans Dome TN Great Smoky Mountains GRSM-CD 12 X X X

X 35.6967 47-155-0101 1243 83.6086 Cove Mountain TN Great Smoky Mountains GRSM-CM 17 X X X

X 35.6331 47-009-0101 793 83.9422 Look Rock TN Great Smoky Mountains GRSM-LR GRS420 17 X X X

35.59 37-087-0036 1500 83.0775 Purchase Knob NC Great Smoky Mountains GRSM-PK 10

X 30.3183 7 87.2553 Portable Ozone FL Gulf Islands GUIS-PT 1 X X X

X 19.4203 15-001-0007 1123 155.2881 Observatory HI Hawaii Volcanoes HAVO-OB X X X X

2-4
National Park Unit

Elev.

(m)

Longitude Latitude

NPS

Abbr.

Site Name State

CASTNet

Abbr.

AQS ID

Number

SO2

O3

Years1

VWD2 SWS3 TMP RH

Table 2-1 (cont.)

Site Specifications

2004

National Park Service Gaseous Pollutant Monitoring Program

X 19.4308 15-001-0005 1215 155.2578 Visitor Center HI Hawaii Volcanoes HAVO-VC X X X X

X 48.1083 347 88.6064 Portable Ozone MI Isle Royale ISRO-PT 3 X X X

X 34.0714 06-071-9002 1244 116.3906 Yucca Valley CA Joshua Tree JOTR-YV JOT403 12 X X X

X 67.0931 02-290-0004 88 157.8689 Ambler AK Kobuk Valley KOVA-AM KVA428 X X X

X 36.0194 881 114.0686 Portable Ozone AZ Lake Mead LAME-PT 2 X X X

X 40.5403 06-089-3003 1756 121.5764 Manzanita Lake Maint. Area CA Lassen Volcanic LAVO-ML LAV410 18 X X X

34.4603 441 85.5972 Portable Ozone AL Little River Canyon LIRI-PT 1

X 37.1319 21-061-0501 243 86.1478 Houchin Meadow KY Mammoth Cave MACA-HM MAC426 8 X X X

X 37.1864 258 86.0411 Portable Ozone KY Mammoth Cave MACA-PT 1 X X X

X 37.1983 08-083-0101 2165 108.4903 Maintenance Yard CO Mesa Verde MEVE-MY MEV405 12 X X X

X 46.7958 1067 121.8842 Portable Ozone WA Mount Rainier MORA-PT 1 X X X

X 46.7583 53-053-1010 415 122.1244 Tahoma Woods WA Mount Rainier MORA-TW MOR409 14 X X X

X 48.5397 53-057-0013 109 121.4472 Marblemount Ranger Station WA North Cascades NOCA-MM NCS415 9 X X X

X 47.9706 1543 123.5028 Portable Ozone WA Olympic OLYM-PT 1 X X X

X 48.0975 53-009-0012 125 123.4256 Visitor Center WA Olympic OLYM-VC OLY421 20 X X X X

X 34.8225 04-017-0119 1723 109.8919 Horse Barn AZ Petrified Forest PEFO-HB PET427 3 X X X

X 36.485 06-069-0003 335 121.1556 East Entrance Station CA Pinnacles PINN-ES PIN414 18 X X X

X 40.2778 08-069-0007 2743 105.5453 Longs Peak Ranger Station CO Rocky Mountain ROMO-LP ROM406 18 X X X

34.9811 215 85.81 Portable Ozone AL Russell Cave RUCA-PT 1

X 32.1744 04-019-0021 938 110.7364 Pima County AZ Saguaro SAGU-PC 13 X X X

X 36.4894 06-107-0009 457 118.8269 Ash Mountain CA Sequoia and Kings Canyon SEKI-AS 6 X X X

X 36.5658 06-107-0006 1890 118.7772 Lower Kaweah CA Sequoia and Kings Canyon SEKI-LK 21 X X X

X 36.4292 06-107-0008 1225 118.7625 Lookout Point CA Sequoia and Kings Canyon SEKI-LP SEK402 8 X X X

X 38.5231 51-113-0003 1073 78.4347 Big Meadows VA Shenandoah SHEN-BM SHN418 22 X X X X

X 46.8947 38-007-0002 850 103.3778 Visitor Center ND Theodore Roosevelt THRO-VC THR422 7 X X X X

X 48.4128 27-137-0034 429 92.8292 Sullivan Bay MN Voyageurs VOYA-SB VOY413 9 X X X

X 43.5578 46-033-0132 1292 103.4839 Visitor Center SD Wind Cave WICA-VC WNC429 X X X

X 44.5597 56-039-1011 2400 110.4006 Water Tank WY Yellowstone YELL-WT YEL408 9 X X X

2-5
National Park Unit

Elev.

(m)

Longitude Latitude

NPS

Abbr.

Site Name State

CASTNet

Abbr.

AQS ID

Number

SO2

O3

Years1

VWD2 SWS3 TMP RH

Table 2-1 (cont.)

Site Specifications

2004

National Park Service Gaseous Pollutant Monitoring Program

X 37.7431 06-043-0033 1219 119.5939 Merced River CA Yosemite YOSE-MR 3 X X X

X 37.7133 06-043-0003 1605 119.7061 Turtleback Dome CA Yosemite YOSE-TD YOS404 12 X X X

X 37.1983 49-053-0130 1213 113.1506 Dalton's Wash UT Zion ZION-DW 1 X X X

# active park units: 46 # active park sites: 59

1. The values in this column represent the number of years an ozone analyzer has been operational at the site.

2. Cape Cod reports wind direction as scalar wind direction rather than vector wind direction.

italics

underline

= site operated by a state agency

= site operated by the National Park Service, but consisting of

non-EPA certified portable instrumentation

Operating agency key: Key:

plain text = site operated by the National Park Service O3 = Ozone Analyzer

SO2 = Sulfur Dioxide Analyzer

VWD = Vector Wind Direction

SWS = Scalar Wind Speed

TMP = Ambient Temperature

RH = Relative Humidity

RNF = Precipitation

W

3. Saguaro reports wind speed as vector wind speed rather than scalar wind speed.

4. A filter pack is a part of the CASTNet network and is used to measure dry deposition using the "inferential method". This method combines air quality concentration data w

and land use functions to compute deposition velocities. Ambient air is drawn across the filter at either 3.0 or 1.5 liters per minute. The filter is then analyzed in a lab to yield w

particulate sulfate (SO4

2-

), particulate nitrate (NO3

-

), particulate ammonium (NH4

+), sulfur dioxide (SO2), and nitric acid (HNO3 ). In some cases, the positive ions Na+, K+, Ca2

from the filter samples.

2-6
3.0 DATA SUMMARIES 

 Ground-level ozone and sulfur dioxide are regulated under the Clean Air Act, the 

comprehensive federal law that regulates air quality in the United States. Among other things, 

the Clean Air Act requires the U.S. EPA to set standards for “criteria pollutants”. These 

standards, known as the National Ambient Air Quality Standards (NAAQS), define the national 

targets for acceptable concentrations of each of the criteria pollutants. For each pollutant, EPA 

has developed two NAAQS standards: 

 • The “primary standard,” which is intended to protect public health, including the 

health of “sensitive” populations such as asthmatics, children, and the elderly. 

 • The “secondary standard,” which is intended to prevent damage to the environment 

and property, including protection against decreased visibility, damage to animals, 

crops, vegetation, and buildings. 

 This section presents 2004 data summaries for the NPS GPMP. Data collection statistics 

for all sites are presented first, followed by data summaries for ozone, sulfur dioxide, and 

meteorological parameters. In these data summary products, site names of EPA-certified sites 

operated by the NPS are indicated with plain text, site names of EPA-certified sites operated by 

state agencies are written in italics, and site names of portable ozone monitoring systems 

(POMS) operated by the NPS are underlined. 

3.1 DATA COLLECTION 

 Table 3-1 presents data collection statistics for each parameter by site and presents the 

overall network average by parameter. The network average valid data collection for ozone was 

93.3% , and for sulfur dioxide was 86.7% . 

 Table 3-2 presents a network summary of data collection statistics by parameter. Annual 

and quarterly network average statistics are presented, along with the number and percentage of 

NPS operated (including POMS) and state operated sites which met the minimum EPA data 

collection criteria of 75%. For 2004, 48 of 55 ozone sites and 5 of 6 sulfur dioxide sites met or 

exceeded the annual EPA criteria. 

3-1
National Park Unit

Parameter Code

National Park Service Gaseous Pollutant Monitoring Program

2004

Data Collections Statistics by Site

Table 3-1

D

% 

WET

% valid1

RNF

% valid1

RH

% valid1

TMP

% valid1 % valid1 % valid1

O3

% valid1

Site Name

SO2

% valid1

VWD2 SWS3

Acadia -9-999.0 -999.0 99.2 99.2 99.2 99.2 -999.0 99.2 Cadillac Mountain

Acadia 99.7 92.7 99.8 99.9 99.9 99.9 -999.0 99.4 McFarland Hill

Badlands -9-999.0 76.3 99.7 99.5 97.7 75.8 -999.0 99.5 Visitor Center

Big Bend 90.6 99.1 99.4 99.3 97.8 97.8 -999.0 98.9 K-Bar Ranch Road

Big South Fork -9-999.0 100.0 100.0 100.0 99.5 99.5 -999.0 72.4 Portable Ozone

Black Canyon of the Gunnison -9-999.0 99.9 99.9 99.9 99.9 99.9 -999.0 43.7 Portable Ozone

Cape Cod -9-999.0 -999.0 98.7 99.1 93.0 99.0 -999.0 97.5 Cape Cod 

Canyonlands 99.3 99.3 99.5 91.9 99.7 99.7 -999.0 98.1 Island in the Sky

Chamizal -9-999.0 -999.0 99.9 99.9 99.9 99.9 -999.0 99.5 Chamizal 

Chiricahua 95.7 98.6 99.2 99.3 99.1 91.8 -999.0 99.2 Entrance Station

Channel Islands -9-999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 84.5 Santa Rosa Island

Congaree -9-999.0 -999.0 -999.0 -999.0 -999.0 -999.0 99.4 99.3 Congaree Bluff

Cowpens -9-999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 99.2 Cowpens 

Craters of the Moon -9-999.0 -999.0 93.9 98.0 98.8 73.1 -999.0 94.2 Visitor Center

Denali 98.5 99.8 98.6 99.9 99.8 99.8 -999.0 99.7 Headquarters

Death Valley 98.8 98.7 99.5 98.6 99.3 99.3 -999.0 95.0 Park Village

Everglades 86.2 95.5 85.8 98.3 95.2 95.2 -999.0 94.8 Beard Center

Glacier 99.4 99.1 99.8 99.7 96.2 96.2 -999.0 92.3 West Glacier Horse Stables

Great Basin 98.4 98.3 99.0 98.9 97.9 97.9 -999.0 97.8 Maintenance Yard

Grand Canyon 71.5 99.0 98.2 99.6 99.5 99.5 -999.0 99.1 The Abyss

Grand Canyon -9-999.0 99.9 99.9 99.9 99.9 99.9 -999.0 58.8 Portable Ozone

Great Smoky Mountains -9-999.0 98.1 97.9 97.9 99.1 99.1 -999.0 96.4 Cades Cove

Great Smoky Mountains -9-999.0 97.6 95.4 95.3 93.5 93.2 -999.0 97.5 Clingmans Dome

Great Smoky Mountains -9-999.0 99.6 99.5 99.5 98.9 98.9 -999.0 96.2 Cove Mountain

Great Smoky Mountains 98.7 98.7 98.2 99.2 99.2 99.2 -999.0 98.9 Look Rock

Great Smoky Mountains -9-999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 93.3 Purchase Knob

Gulf Islands -9-999.0 100.0 100.0 100.0 100.0 100.0 -999.0 88.8 Portable Ozone

Hawaii Volcanoes -9-999.0 99.6 95.5 100.0 99.9 99.9 88.3 -999.0 Observatory

3-2
Table 3-1 (cont.)

National Park Unit

Parameter Code

National Park Service Gaseous Pollutant Monitoring Program

2004

Data Collections Statistics by Site

D

% 

WET

% valid1

RNF

% valid1

RH

% valid1

TMP

% valid1 % valid1 % valid1

O3

% valid1

Site Name

SO2

% valid1

VWD2 SWS3

Hawaii Volcanoes -9-999.0 99.3 99.7 99.7 99.6 99.6 99.6 -999.0 Visitor Center

Isle Royale -9-999.0 100.0 100.0 100.0 100.0 100.0 -999.0 92.3 Portable Ozone

Joshua Tree 99.1 98.8 99.8 88.4 99.6 99.6 -999.0 99.1 Yucca Valley

Kobuk Valley 172.4 44.4 72.8 100.0 100.0 44.4 -999.0 -999.0 Ambler

Lake Mead -9-999.0 100.0 100.0 100.0 100.0 100.0 -999.0 69.8 Portable Ozone

Lassen Volcanic 97.0 98.4 99.0 99.0 97.6 97.4 -999.0 98.5 Manzanita Lake Maint. Area

Little River Canyon -9-999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 91.8 Portable Ozone

Mammoth Cave 99.3 99.3 99.1 99.4 99.9 97.9 -999.0 99.7 Houchin Meadow

Mammoth Cave -9-999.0 100.0 100.0 100.0 100.0 100.0 -999.0 72.5 Portable Ozone

Mesa Verde 99.3 99.3 100.0 99.7 99.7 62.8 -999.0 99.3 Maintenance Yard

Mount Rainier -9-999.0 99.9 99.9 100.0 99.9 99.9 -999.0 70.3 Portable Ozone

Mount Rainier 92.7 99.2 98.2 99.8 98.2 92.7 -999.0 98.5 Tahoma Woods

North Cascades 98.8 98.6 99.2 99.1 98.5 95.6 -999.0 98.0 Marblemount Ranger Station

Olympic -9-999.0 100.0 100.0 100.0 100.0 100.0 -999.0 100.0 Portable Ozone

Olympic 99.5 98.8 100.0 81.8 100.0 100.0 99.0 81.1 Visitor Center

Petrified Forest 99.3 98.9 99.9 99.8 47.7 47.7 -999.0 93.4 Horse Barn

Pinnacles 94.8 97.7 98.4 98.3 97.0 97.0 -999.0 95.7 East Entrance Station

Rocky Mountain 91.7 99.3 99.9 99.9 99.4 98.7 -999.0 99.9 Longs Peak Ranger Station

Russell Cave -9-999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 95.9 Portable Ozone

Saguaro -9-999.0 -999.0 99.9 99.9 99.5 99.3 -999.0 99.0 Pima County

Sequoia and Kings Canyon -9-999.0 98.9 99.5 99.5 99.5 99.5 -999.0 81.6 Ash Mountain

Sequoia and Kings Canyon -9-999.0 97.2 99.1 98.9 98.9 98.9 -999.0 92.8 Lower Kaweah

Sequoia and Kings Canyon 98.2 98.2 98.9 98.8 98.8 98.8 -999.0 87.6 Lookout Point

Shenandoah 96.6 97.7 97.9 97.8 97.8 95.6 77.2 96.3 Big Meadows

Theodore Roosevelt 97.7 97.6 98.2 98.2 92.6 92.6 57.9 58.3 Visitor Center

Voyageurs 99.5 99.3 99.8 98.1 92.9 92.9 -999.0 98.3 Sullivan Bay

Wind Cave 87.3 99.5 99.7 99.8 99.7 99.7 -999.0 -999.0 Visitor Center

Yellowstone 34.4 99.0 99.2 99.3 99.3 99.3 -999.0 96.4 Water Tank

3-3
Table 3-1 (cont.)

National Park Unit

Parameter Code

National Park Service Gaseous Pollutant Monitoring Program

2004

Data Collections Statistics by Site

D

% 

WET

% valid1

RNF

% valid1

RH

% valid1

TMP

% valid1 % valid1 % valid1

O3

% valid1

Site Name

SO2

% valid1

VWD2 SWS3

Yosemite -9-999.0 97.2 95.2 95.4 96.3 96.3 -999.0 90.7 Merced River

Yosemite 76.5 95.2 90.9 99.0 97.0 97.0 -999.0 98.8 Turtleback Dome

Zion -9-999.0 98.8 94.8 94.7 99.2 99.2 -999.0 94.4 Dalton's Wash

Average Network Data Collection

Operating agency key:

plain text

italics

underline

= site operated by the National Park Service

= site operated by a state agency

= site operated by the National Park Service, but consisting of 

non-EPA certified portable instrumentation

93.3 86.7 94.5 97.3 98.2 98.1 97.3 93.0 

1. The percent is calculated against the number possible. Percent valid can be less than 100% due to routine maintenance, power failures, audits or other circumstances where t

collect data. Percent valid can also be less than 100% due to influencing factors such as instrument error, operator error, timing problems, flow issues, and other factors that a

calculating percent valid for O3 and SO2, calibration events were removed from the number possible.

2. Cape Cod reports wind direction as scalar wind direction rather than vector wind direction.

Key:

SWS = Scalar Wind Speed

TMP = Ambient Temperature

RH = Relative Humidity

RNF = Precipitation

WO3 = Ozone Analyzer

SO2 = Sulfur Dioxide Analyzer

VWD = Vector Wind Direction

3. Saguaro reports wind speed as vector wind speed rather than scalar wind speed.

3-4
Calendar

Quarter

Network Data

Collection Statistic1 Units 

O3 SO2 VWD SWS TMP RH RNF WET DTP 

Parameter Code

Table 3-2

Network Summary of Data Collections Statistics

2004

National Park Service Gaseous Pollutant Monitoring Program

Annual Annual Network Average % 93.3 86.7 94.5 97.3 98.2 98.1 97.3 93.0 96.1 

No. Sites>=75% Valid No. Sites (%) 48 (87%) (83%) 5 49 (93%) 52 (98%) 53 (100%) 52 (98%) 47 (98%) 26 (90%) 28 (9

No. Sites <75% Valid No. Sites (%) 7 (13%) (17%) 1 4 (8%) 1 (2%) 0 (0%) 1 (2%) 1 (2%) 3 (10%) 1 (

1 Quarterly Network Average % 92.3 82.3 98.4 98.6 98.7 97.6 96.4 95.2 96.7 

No. Sites >=75% Valid No. Sites (%) 36 (90%) (83%) 5 41 (100%) 41 (100%) 41 (100%) 40 (98%) 36 (97%) 26 (96%) 27 (9

No. Sites <75% Valid No. Sites (%) 4 (10%) (17%) 1 0 (0%) 0 (0%) 0 (0%) 1 (2%) 1 (3%) 1 (4%) 1 (

2 Quarterly Network Average % 93.9 85.4 95.1 97.6 98.7 99.3 99.1 95.5 97.7 

No. Sites >=75% Valid No. Sites (%) 49 (94%) (83%) 5 48 (94%) 50 (98%) 50 (98%) 51 (100%) 46 (100%) 27 (96%) 27 (9

No. Sites <75% Valid No. Sites (%) 3 (6%) (17%) 1 3 (6%) 1 (2%) 1 (2%) 0 (0%) 0 (0%) 1 (4%) 1 (

3 Quarterly Network Average % 91.9 81.6 91.9 95.8 98.3 97.6 98.2 87.2 97.0 

No. Sites >=75% Valid No. Sites (%) 50 (91%) (67%) 4 49 (93%) 52 (98%) 52 (98%) 51 (96%) 48 (100%) 24 (83%) 28 (9

No. Sites <75% Valid No. Sites (%) 5 (9%) (33%) 2 4 (8%) 1 (2%) 1 (2%) 2 (4%) 0 (0%) 5 (17%) 1 (

4 Quarterly Network Average % 95.4 97.4 93.2 97.4 97.2 97.8 95.2 94.5 93.1 

No. Sites >=75% Valid No. Sites (%) 42 (98%) (100%) 6 41 (95%) 42 (98%) 42 (98%) 43 (100%) 37 (95%) 27 (93%) 27 (9

No. Sites <75% Valid No. Sites (%) 1 (2%) (0%) 0 2 (5%) 1 (2%) 1 (2%) 0 (0%) 2 (5%) 2 (7%) 2 (

Key:

O3 = Ozone Analyzer

SO2 = Sulfur Dioxide Analyzer

VWD = Vector Wind Direction

1. Network data collection statistics include: 1) the percent of valid hourly averages for each parameter across the network; 2) the number and percent of sites wh

requirement of 75% valid data capture; and 3) the number and percent of sites which failed to meet 75% valid data capture.

SWS = Scalar Wind Speed

TMP = Ambient Temperature

RH = Relative Humidity

RNF = Precipitation

WET = Wetness Sensor

DTP = Delta Temperature

SOL = Solar Radition

FLOW = Filter Pack Flow Rate05

3-5
3.2 OZONE DATA SUMMARIES 

 Ground-level ozone, produced by the reaction of nitrogen oxides (NOx) and volatile 

organic compounds (VOCs) in the presence of sunlight, is one of the most widespread pollutants 

affecting vegetation and public health in the U.S. Although ozone is principally viewed as an 

urban problem, ozone and its precursor emissions can travel long distances, resulting in elevated 

ozone levels in national parks. Combustion processes from power plants, automobiles, and 

industries are the main anthropogenic emitters of NOX. Vehicles, industries, and natural 

vegetation emit VOCs. 

 Exposure to ozone affects human health, causing acute respiratory problems, aggravation 

of asthma, temporary decreases in lung capacity in some adults, inflammation of lung tissue, and 

impairment of the body’s immune system. Ozone also affects vegetation in national parks. 

Research shows that some plants are more sensitive than humans to ozone and that effects on 

plants occur well below the EPA National Ambient Air Quality Standard (NAAQS). 

 The NAAQS primary standard for ozone is 0.08 ppm over an 8-hour period. An 

exceedance of the standard occurs when an 8-hour average ozone concentration is greater than or 

equal to 85 ppb. An exceedance of the standard is not the same as a violation. A violation 

occurs when the 3-year average of the fourth highest daily maximum 8-hour average ozone 

concentration equals or exceeds 85 ppb. The secondary ozone standard defined by the EPA is 

the same as the primary standard. 

 To quantify ozone exposure to plants, various indices other than the primary and 

secondary standards are often used. These indices, described further in Section 3.2.4, are 

believed to be biologically relevant because they take into account both peak ozone 

concentrations and cumulative exposure to ozone. 

3.2.1 Annual Ozone Summaries 

 Table 3-3 summarizes O3 measurements with respect to the daily 8-hour average 

maximum concentrations at each EPA-certified monitoring site. The five highest 8-hour average 

maximum ozone concentrations are listed, as well as the total number of days with exceedances 

of the NAAQS 8-hour standard (8-hour average ozone values greater than or equal to 85 ppb). 

The fourth highest value column and the number of days column are both color-coded to identify 

sites where the 4th highest 8-hour average ozone value exceeded the 8-hour standard during 

2004. Note that other sites may have experienced fewer than four exceedances of the 8-hour 

standard but are not color coded. 

In 2004, 11 sites exceeded the 8-hour standard, as compared to 18 sites in 2003. From 

2003 to 2004, 18 sites had a decrease in the number of days with an exceedance of the 8-hour 

standard and only 2 sites had an increase. 

 Table 3-4 presents similar information for the non-EPA certified (portable) sites. Ozone 

summary statistics from POMS should be compared to EPA standards for reference purposes 

only. 

3-6
 The map in Figure 3-1 presents the annual fourth highest 8-hour average ozone 

concentrations for all network sites listed in Tables 3-3 and 3-4. Ozone values for EPA-certified 

sites are color-coded to represent values below (green) and above (orange and red) the national 

standard. Data from portable sites (no color) are included for reference only. 

 The map in Figure 3-2 presents the annual number of days which exceeded the 8-hour 

standard for all network sites listed in Tables 3-3 and 3-4. The data points are color-coded to 

distinguish between sites that did not exceed NAAQS (green) and those that did (orange and 

red). Data from portable sites (no color) are included for reference only. 

 The map in Figure 3-3 presents the annual second highest 1-hour average ozone 

concentrations for all network sites. Ozone values for EPA-certified sites are color-coded to 

represent 4 distinct levels. Ozone values from portable sites (no color) are included for reference 

only. 

3-7
# Days with 8-Hour

Average O3 Values

>=85 ppb1 National Park Unit

1st

Site Name Highest

Valid Number

of Days

2nd

Highest

3rd

Highest

4th

Highest1

5th

Highest

Table 3-3

Summary of Ozone Data by Site

Highest Daily 8-Hour Average Maximum Concentrations (ppb)

2004

National Park Service Gaseous Pollutant Monitoring Program

Acadia Cadillac Mountain 172 84 83 82 82 80 0

Acadia McFarland Hill 363 79 77 76 73 73 0

Badlands Visitor Center 361 66 66 63 63 62 0

Big Bend K-Bar Ranch Road 358 63 63 62 61 60 0

Cape Cod Cape Cod 181 107 89 85 83 80 3

Canyonlands Island in the Sky 355 77 75 74 72 72 0

Chamizal Chamizal 362 78 75 74 73 72 0

Chiricahua Entrance Station 360 73 72 72 70 70 0

Channel Islands Santa Rosa Island 323 93 86 76 75 73 2

Congaree Congaree Bluf 357 86 70 69 67 66 1 

Cowpens Cowpens 359 75 73 70 68 67 0

Craters of the Moon Visitor Center 341 65 65 64 63 63 0

Denali Headquarters 362 64 60 56 52 51 0

Death Valley Park Village 334 81 79 79 79 78 0

Everglades Beard Center 339 73 66 65 64 64 0

Glacier West Glacier Horse Stables 333 56 55 54 54 53 0

Great Basin Maintenance Yard 346 82 77 77 72 72 0

Grand Canyon The Abyss 359 77 76 74 72 72 0

Great Smoky Mountains Cades Cove 230 70 68 67 66 66 0

Great Smoky Mountains Clingmans Dome 176 83 83 78 76 74 0

Great Smoky Mountains Cove Mountain 347 86 84 77 74 74 1

Great Smoky Mountains Look Rock 357 86 85 83 82 80 2

Great Smoky Mountains Purchase Knob 202 78 75 71 71 70 0

Joshua Tree Yucca Valley 359 107 107 106 102 101 31

Lassen Volcanic Manzanita Lake Maint. Area 351 73 70 68 68 67 0

Mammoth Cave Houchin Meadow 364 72 72 70 70 70 0

Mesa Verde Maintenance Yard 360 73 71 69 69 68 0

Mount Rainier Tahoma Woods 355 64 64 64 63 62 0

North Cascades Marblemount Ranger Station 352 57 54 54 52 51 0

Olympic Visitor Center 293 52 51 50 49 49 0

Petrified Forest Horse Barn 317 84 72 71 71 70 0

Pinnacles East Entrance Station 345 83 79 78 77 76 0

Rocky Mountain Longs Peak Ranger Station 364 76 74 74 73 72 0

Saguaro Pima County 360 75 74 73 73 72 0

Sequoia and Kings Canyon Ash Mountain 269 103 103 102 99 98 52

Sequoia and Kings Canyon Lower Kaweah 298 99 98 95 95 92 24

Sequoia and Kings Canyon Lookout Point 307 101 98 97 95 95 50

Shenandoah Big Meadows 341 87 77 76 75 74 1

Theodore Roosevelt Visitor Center 210 61 56 55 55 55 0

3-8
Table 3-3 (cont.)

# Days with 8-Hour

Average O3 Values

>=85 ppb1 National Park Unit

1st

Site Name Highest

Valid Number

of Days

2nd

Highest

3rd

Highest

4th

Highest1

5th

Highest

Summary of Ozone Data by Site

Highest Daily 8-Hour Average Maximum Concentrations (ppb)

2004

National Park Service Gaseous Pollutant Monitoring Program

Voyageurs Sullivan Bay 350 65 64 62 61 59 0

Yellowstone Water Tank 339 62 62 61 60 60 0

Yosemite Merced River 329 71 69 69 69 68 0

Yosemite Turtleback Dome 357 124 121 92 89 87 8

Zion Dalton's Wash 314 80 78 77 74 73 0

Operating agency key: Color shading key:

plain text

italics = site operated by a state agency

= site operated by the National Park Service 4th highest 8-hr. avg.

= 85 - 104 ppb ozone concentration

>105 ppb ozone concentration

# days with 8-hr. avg. >= 85 ppb

= 4 - 10 days

>10days

1. The primary and secondary National Ambient Air Quality Standard for ozone is 0.08 ppm over an 8-hour period. (An exceedance of the

standard occurs when an 8-hour average ozone concentration is greater than or equal to 85 ppb. A violation of the standard occurs when 

the 3-year average of the fourth highest daily maximum 8-hour average ozone concentration equals or exceeds 85 ppb.) Exceedances of 

the standard are highlighted here in orange or red.

Note: The color coding break points follow the color categories used on the EPA's AIRNOW Web Site (www.airnow.gov).

3-9
# Days with

8-Hour Average O3

Values >=85 ppb1 National Park Unit

1st

Highest

Valid Number

of Days

2nd

Highest

3rd

Highest

4th

Highest1

5th

Highest

Table 3-4

Highest Daily 8-Hour Average Maximum Concentrations (ppb)

2004

National Park Service Gaseous Pollutant Monitoring Program

Summary of Ozone Measurements from Portable Ozone Monitoring Systems (POMS)1

Site Name

Big South Fork Portable Ozone 94 65 65 64 63 62 0

Black Canyon of the Gunnison Portable Ozone 56 91 80 80 80 79 1

Grand Canyon Portable Ozone 69 77 76 74 73 72 0

Gulf Islands Portable Ozone 35 96 89 84 78 76 2

Isle Royale Portable Ozone 129 65 64 58 58 58 0

Lake Mead Portable Ozone 155 89 86 80 80 78 2

Little River Canyon Portable Ozone 18 68 65 62 60 60 0

Mammoth Cave Portable Ozone 68 68 65 64 63 58 0

Mount Rainier Portable Ozone 89 75 74 66 63 62 0

Olympic Portable Ozone 127 59 58 57 56 56 0

Russell Cave Portable Ozone 20 51 46 45 43 43 0

2. The primary and secondary National Ambient Air Quality Standard for ozone is 0.08 ppm over an 8-hour period. (An exceedance of the

standard occurs when an 8-hour average ozone concentration is greater than or equal to 85 ppb. A violation of the standard occurs when 

the 3-year average of the fourth highest daily maximum 8-hour average ozone concentration equals or exceeds 85 ppb.) 

1. The GPMP POMS do not meet EPA standards for regulatory monitoring. However, ozone summary statistics from portable systems 

can be compared to EPA standards for reference purposes.

3-10
Figure 3-1

Annual Fourth Highest 8-Hour Average Ozone Concentrations (in ppb)

2004

National Park Service Gaseous Pollutant Monitoring Program

* Park units with more than one site are indicated with (x) following the parkunit name, where x represents the number of sites within the unit. At unitswhere more than one site exists, the highest value from all sites was reported.

Big South

Black Canyon of the Gunnison

Grand Canyon

Gulf Islands

Isle Royale

Lake Mead

Mammoth Cave

Little River Canyon

Olympic

Russell Cave

Acadia (2)

Badlands

Big Bend

Canyonlands

Cape Cod

Chamizal

Chiricahua

Channel Islands

Congaree 

Cowpens

Craters of the Moon

Denali

Death Valley

Everglades

Glacier

Great Basin

Grand Canyon

Great Smoky Mountains (5)

Joshua Tree

Lassen Volcanic

Mammoth Cave Mesa Verde

Mount Rainier

Mount Rainier

North Cascades

Olympic

Petrified Forest

Pinnacles

Rocky Mountain

Saguaro

Sequoia/Kings Canyon (3) Shenandoah

Theodore Roosevelt

Voyageurs

Yellowstone

Yosemite (2)

Zion

63

80

73

78

58

80

60

63

63

56

43

Legend

0 - 84 ppbozone concentration85 - 105 ppbozone concentration

> 105 ppbozone concentration

Portable site

Operating agency key:

plain text = site operated by the National Park Service

italics

underline

= site operated by a state agency

 = National Park Service operatedportable ozone system (POMS)

82

63

61

72

83

73

70

75

67

68

63

52

79

64

54

72

72

82 102

68

70

69

63

52 49

71

77

73

73

99

75

55

61

60

89

74

3-11
Figure 3-2

Annual Number of Days with 8-Hour Average Ozone Values >= 85 ppb

2004

National Park Service Gaseous Pollutant Monitoring Program

* Park units with more than one site are indicated with (x) following the parkunit name, where x represents the number of sites within the unit. At unitswhere more than one site exists, the highest value from all sites was reported.

Gulf Islands

Acadia (2)

Badlands

Big Bend

Big South

Black Canyon of the Gunnison

Canyonlands

Cape Cod

Chamizal

Chiricahua

Channel Islands

Congaree 

Cowpens

Craters of the Moon

Denali

Death Valley

Everglades

Glacier

Great Basin

Grand Canyon

Grand Canyon

Great Smoky Mountains (5)

Isle Royale

Joshua Tree

Lake Mead

Lassen Volcanic

Little River Canyon

Mammoth Cave

Mammoth Cave Mesa Verde

Mount Rainier

Mount Rainier

North Cascades

Olympic

Olympic

Petrified Forest

Pinnacles

Rocky Mountain

Russell Cave

Saguaro

Sequoia/Kings Canyon (3) Shenandoah

Theodore Roosevelt

Voyageurs

Yellowstone

Yosemite (2)

Zion

0

1

0

2

0

2 0

0

0

0

0

55

Legend

0 - 3 days4 - 10 days

> 10 days

Portable site

65

Operating agency key:

plain text = site operated by the National Park Serviceitalicsunderline

= site operated by a state agency

 = National Park Service operated portable ozone system (POMS)

0

0

0

0

3

0

0

2

1

0

0

0

0

0

0

0

0

2 31

0

0

0

0

0 0

0

0

0

0

52

1

0

0

0

8

0

3-12
Figure 3-3

Annual Second Highest 1-Hour Average Ozone Concentrations (in ppb)

2004

National Park Service Gaseous Pollutant Monitoring Program

* Park units with more than one site are indicated with (x) following the parkunit name, where x represents the number of sites within the unit. At unitswhere more than one site exists, the highest value from all sites was reported.

Acadia (2)

Badlands

Big Bend

Big South

Black Canyon of the Gunnison

Canyonlands

Cape Cod

Chamizal

Chiricahua

Channel Islands

Congaree 

Cowpens

Craters of the Moon

Denali

Death Valley

Everglades

Glacier

Great Basin

Grand Canyon

Grand Canyon

Great Smoky Mountains (5)

Gulf Islands

Isle Royale

Joshua Tree

Lake Mead

Lassen Volcanic

Little River Canyon

Mammoth Cave

Mammoth Cave Mesa Verde

Mount Rainier

Mount Rainier

North Cascades

Olympic Olympic

Petrified Forest

Pinnacles

Rocky Mountain

Russell Cave

Saguaro

Sequoia/Kings Canyon (3) Shenandoah

Theodore Roosevelt

Voyageurs

Yellowstone

Yosemite (2)

Zion

73

92

83

106

68

92

77

71

101

60

57

55

Legend

0 - 50 ppbozone concentration

51 - 100 ppbozone concentration101 - 150 ppbozone concentration

Portable site

Operating agency key:

plain text = site operated by the National Park Service

italics

underline

= site operated by a state agency

 = National Park Service operatedportable ozone system (POMS)

>150 ppbozone concentration

100

68

65

79

111

105

78

98

102

81

68

65

84

77

56

84

81

93 128

78

79

79

81

66 58

86

91

85

84

112

91

62

67

65

128

82

3-13
3.2.2 Ozone Violation Summaries

 Table 3-5 presents an ozone violation summary for all 3-year periods over the last ten 

years, with violations indicated in orange and red. A violation of the standard occurs when the 

3-year average of the fourth highest daily maximum 8-hour average ozone concentration equals 

or exceeds 85 ppb. Table values in parentheses indicate that the EPA data completeness 

requirement for the 3-year period was not met. However, annual fourth highest daily maximum 

8-hour ozone concentrations greater than or equal to 85 ppb for calendar years not meeting the 

EPA data completeness requirement are included in the NAAQS violation computation. 

 In 2004, 10 sites within 6 national park units were in violation of the NAAQS 8-hour 

standard, whereas in 2003, 13 sites within 7 units violated the standard. 

 Figure 3-4 presents a ranked list of sites based on the 2002 – 2004 ozone violation 

summary data presented in the first column of Table 3-5. 

3-14
Table 3-5

Ozone Violation Summary

3-Year Average 4th Highest Daily Maximum 8-Hour Average Ozone Concentration1 (pp

1997 - 2004

National Park Service Gaseous Pollutant Monitoring Program

Site Name 2002 - 2004 2001 - 2003 2000 - 2002 1999 - 2001 1998 - 2000 1997 - 1999 1National Park Unit

Acadia Cadillac Mountain 88 94 93 89 87 (89) 

Acadia McFarland Hill 80 87 84 85 83 (90) 

Badlands Visitor Center (64) (67)

Big Bend K-Bar Ranch Road 62 62 (62) (63) 66 65 

Cape Cod Cape Cod 88 95 93 96 89 (95) 

Canyonlands Island in the Sky 72 70 (71) (71) 73 70 

Chamizal Chamizal 78 79 81 75 (79) (76) 

Chiricahua Entrance Station 70 69 69 70 70 68 

Channel Islands Santa Rosa Island 68 64 (65) (66) (66) 66 

Congaree Congaree Bluff 74 77 77 (74) (73)

Cowpens Cowpens 80 84 87 87 92 93 

Craters of the Moon Visitor Center 67 (65) (63) (63) 66 (64) 

Denali Headquarters 53 54 49 49 48 53 

Death Valley Park Village 80 81 81 79 80 79 

Everglades Beard Center (62) (60) (60) 64 68 68 

Glacier West Glacier Horse Stables 55 53 49 48 51 47 

Great Basin Maintenance Yard 72 70 72 72 73 72 

Grand Canyon The Abyss 74 74 73 72 73 73 

Great Smoky Mountains Cades Cove 73 76 79 81 (85) (83) 

Great Smoky Mountains Clingmans Dome (87) (92) (98) (98) (102) (98) 

Great Smoky Mountains Cove Mountain 86 92 96 96 101 (100) 

Great Smoky Mountains Look Rock 91 92 94 96 104 104 

Great Smoky Mountains Purchase Knob 82 86 88 87 90 90 

Joshua Tree Yucca Valley 106 99 94 92 102 109 

Lassen Volcanic Manzanita Lake Maint. Area 71 72 74 77 78 76 

Mammoth Cave Houchin Meadow 77 80 84 88 94 (92) 

Mesa Verde Maintenance Yard 68 67 69 69 70 (66) 

Mount Rainier Tahoma Woods 63 61 56 60 57 51 

North Cascades Marblemount Ranger Station 51 50 46 48 46 43 

Olympic Visitor Center 40 39 39 44 43 43 

3-15
Table 3-5 (cont.)

Ozone Violation Summary

3-Year Average 4th Highest Daily Maximum 8-Hour Average Ozone Concentration1 (pp

1997 - 2004

National Park Service Gaseous Pollutant Monitoring Program

Site Name 2002 - 2004 2001 - 2003 2000 - 2002 1999 - 2001 1998 - 2000 1997 - 1999 1National Park Unit

Petrified Forest Horse Barn (66) (64) (55)

Pinnacles East Entrance Station 80 81 81 (79) (82) 82 

Rocky Mountain Longs Peak Ranger Station 82 81 78 74 77 74 

Saguaro Pima County (75) (76) (54) (33) (33) (33) 

Sequoia and Kings Canyon Ash Mountain (105) (107) (105) (104) (105) (105)

Sequoia and Kings Canyon Lower Kaweah 101 101 98 (94) (93) (96) 

Sequoia and Kings Canyon Lookout Point (102) (104) (103) (103) (102) (102) 

Shenandoah Big Meadows 82 87 85 87 93 96 

Theodore Roosevelt Visitor Center 60 61 59 58 (57) (56) 

Voyageurs Sullivan Bay 64 65 (64) 67 68 70 

Yellowstone Water Tank 63 65 65 67 67 65 

Yosemite Merced River (67) (66) (72)

Yosemite Turtleback Dome 90 90 89 86 88 86 

Zion Dalton's Wash (74)

# Park Units with Violations:

# Sites with Violations:

1. The primary and secondary National Ambient Air Quality Standard for ozone is 0.08 ppm over an 8-hour period. (An exceedance of the standard occurs when 

concentration is greater than or equal to 85 ppb. A violation of the standard occurs when the 3-year average of the fourth highest daily maximum 8-hour average o

or exceeds 85 ppb.) Violations of the standard are highlighted here in orange and red.

Operating agency key:

( ) Note: A number in parenthesis () indicates that data completeness was not met. The primary standard requires 90 percent data completeness, on average, durin

single year within the period having less than 75 percent data completeness. This data completeness requirement would have to be satisfied in order to determine 

met at a monitoring site. However, calendar years with less than 75 percent data completeness are included in the computation if the annual fourth-highest daily 

concentration is greater than the level of the standard. A site could be found not to have met the standard with less than complete data.

plain text

italics

= site operated by the National Park Service

= site operated by a state agency

Color shading key:

4th highest 8-hr. avg.

= 85 - 104 ppb ozone concentration

>=105 ppb ozone concentration

6

10

7

13

8

13

9

15

9

15

9

15

3-16
Figure 3-4

Ozone Violation Summary Ranking

National Park Service Gaseous Pollutant Monitoring Program

2002 - 2004

3-Year Average 4th Highest Daily Maximum 8-Hour Average Ozone Concentrations (ppb)

0 20 40 60 80 100 120

Joshua Tree - Yucca Valley

Sequoia and Kings Canyon - Ash Mountain

Sequoia and Kings Canyon - Lookout Point

Sequoia and Kings Canyon - Lower Kaweah

Great Smoky Mountains - Look Rock

Yosemite - Turtleback Dome

Acadia - Cadillac Mountain

Cape Cod

Great Smoky Mountains - Clingmans Dome

Great Smoky Mountains - Cove Mountain

Great Smoky Mountains - Purchase Knob

Rocky Mountain - Longs Peak Ranger Station

Shenendoah - Big Meadows

Acadia - McFarland Hill

Cowpens

Death Valley - Park Village

Pinnacles - East Entrance Station

Chamizal

Mammoth Cave - Houchin Meadow

Saguaro - Pima County

 Congaree - Congaree Bluff

Grand Canyon - The Abyss

Zion - Dalton's Wash

Great Smoky Mountains - Cades Cove

Canyonlands - Island in the Sky

Great Basin - Maintenance Yard

Lassen Volcanic - Manzanita Lake Maintenance Area

Chiricahua - Entrance Station

Channel Islands - Santa Rosa Island

Mesa Verde - Maintenance Yard

Craters of the Moon - Visitor Center

Yosemite - Merced River

Petrified Forest - Horse Barn

Badlands - Visitor Center

Voyageurs - Sullivan Bay

Mount Rainier - Tahoma Woods

Yellowstone - Water Tank

Big Bend - K-Bar Ranch Road

Everglades - Beard Center

Theodore Roosevelt - Visitor Center

Glacier - West Glacier Horse Stables

Denali - Headquarters

North Cascades - Marblemount Ranger Station

Olympic - Visitor Center

Ozone Concentration (ppb)

85 ppb or greater 

violates the 8-hr 

ozone National 

Ambient Air 

Quality Standard

3-17
3.2.3 Long-Term Ozone Trends 

Ozone is monitored not only to determine when air quality conditions are unacceptable, 

but also to see how the conditions are changing. Changes in ozone should relate to factors that 

control its concentration, such as precursor emissions, climate variability, changing transport 

patterns, global transport, and short-term events such as wildfires. Over broad regions, if 

precursor emission changes are large enough and persistent, then a change in ozone 

concentrations can be observed. 

Determining ozone trends is an important monitoring network objective. It is also 

difficult, because trends are often poorly defined and interpretation is complicated by such 

factors as pollutant emission rates, which are constantly changing, and annual climate variations, 

which can dominate ozone production and transport factors. A commonly used trend technique 

is linear regression. This method has several limitations, including the expectation of a 

consistent geometric progression. Comparisons of the linear trend and the time series plots of 

ozone can be helpful. At some monitoring sites trends are evident while at other sites 

fluctuations are large and the trend line may be dominated by a small number of points. 

 When considering ozone trends it is important to recall that ozone is formed in sunlight 

by the reaction of nitrogen oxides (NOx) and reactive volatile organic compounds (VOCs). In 

most non-urban areas in the eastern U.S., the availability of NOx to react with VOCs is the 

limiting factor in the production of ozone. Most non-urban areas are therefore classified as NOxlimited (EPA, 1998; OTAG, 1997; SOS, 1995; Tong, 2005). Therefore, trends in NOx emissions 

can be reasonably expected to relate to trends in ozone production. Figure 3-5 shows the change 

in NOx emissions from both point and mobile sources over time in the United States. NOx levels 

decrease in the 1970s and 1980s, are stable throughout the 1990s, and decrease again after 2000. 

Since NOx is a precursor of ozone it is expected that ozone trends might follow a similar pattern, 

which is what the EPA discovered in a review of all the ozone monitoring stations in the U.S. 

(http://www.epa.gov/airtrends/). Areas of significant NOx emissions density from the latest full 

inventory (1999) can be seen across much of the eastern U.S. Figure 3-6 indicates that the 

distribution of NOx emissions is uneven, so regional and local differences in ozone can be 

expected. Also, specific control programs were initiated in the eastern U.S. (NOx SIP Call, for 

example) so that relatively greater NOx reductions have occurred in the East. 

3-18
Figure 3-5 

Total NOx Emissions for Point and Mobile Sources in the United States 

Figure 3-6 

NOx Emissions Density 

Source: EPA NOx emissions table by year (http://www.epa.gov/airtrends/pdfs/NOXNational.pdf)

NOx emissions density based on the EPA 1999 emission inventory. Reductions in NOx emissions would be 

expected to be unevenly distributed just as the sources are. Regional patterns are expected, especially in the 

Midwest, coastal Northeast, and Southeast. 

NOx Emissions in the U.S.

0

2

4

6

8

10

12

14

197019751980198519901991199219931994199519961997199819992000200120022003

NOx Emissions

(millions of tons/year)

NOx Point Sources Mobile Sources

3-19
In 1999 NOx emissions changed dramatically in the Midwest and in portions of the South 

due to the implementation of NOx emission controls on several large point sources. Figure 3-7 

highlights the eight eastern states with the largest NOx reductions from 1996 through 2003. 

Consequently, ozone concentrations in the national parks surrounding these areas appear to 

respond to the lower NOx emissions. Figure 3-8 presents ozone timelines for selected eastern 

U.S. park units. Ozone concentrations peaked in 1999-2000 at Mammoth Cave NP, Great 

Smoky Mountains NP, Shenandoah NP, and Cowpens National Battlefield (NB). Since then, 

ozone concentrations in these areas have decreased. Modeling indicates these parks are NOxlimited in ozone formation (Tong, 2005), but climate variability cannot be ruled out since recent 

years have been cooler and wetter than average. 

Ozone trends display similar patterns within regions. The EPA Ozone Report for 2003

http://www.epa.gov/air/airtrends/aqtrnd04/ozone.html reports that several parks follow the 

same patterns as nearby major urban areas. For example, as shown in Figure 3-9, Great 

Smoky Mountains NP follows the trends for nearby Knoxville and farther away Nashville, TN; 

Cowpens NB follows the changes in ozone of Charlotte, NC. 

Figure 3-7 

Trends in NOx Emissions for Eastern States 

States with the largest reductions in NOx from point sources includes KY, TN, and NC. 

Source: Figure 20 from EPA “The Ozone Report, 2003” 

(http://www.epa.gov/air/airtrends/aqtrnd04/2003ozonereport/closer.pdf#page=6) 

KY NC TN

Trends in NOx Emissions for Eastern States with

Largest Reductions in NOx from Electric Utilities 

1996 1997 1998 1999 2000 2001 2002 2003 

Millions of Tons NOX

9 

8 

7 

6 

5 

4 

3 

2 

1 

0 

3-20
Figure 3-8 

Comparison of 3-Year Rolling Average 4th Highest Daily Maximum 

8-Hour Average Ozone Concentration for Selected Eastern Parks 

Time series plot of ozone concentrations at eastern U.S. national park units. The red line indicates the 8-hour 

NAAQS. The parks with thicker lines follow a similar pattern, with a peak in 1999-2000 and decreasing ozone after 

that. The parks with dashed lines appear to have a different pattern.

Figure 3-9 

Ozone Trends for Great Smoky Mountains NP and Cowpens NB 

Ozone trends for Great Smoky Mountains NP and Cowpens NB follow the patterns of nearby major urban areas. 

This shows the regional nature of ozone concentrations and trends. (Ozone units in ppm). 

Source: Figure 21 from EPA “The Ozone Report, 2003”. 

0.00

0.02

0.04

0.06

0.08

0.10

0.12

199219931994199519961997199819992000200120022003

3-yr Avg 4th Hi Max 8hr Ozone (ppm)

Knoxville

Great Smoky Mtn - Look Rock

Nashville

0.00

0.02

0.04

0.06

0.08

0.10

0.12

199219931994199519961997199819992000200120022003

3-yr Avg 4th Hi Max 8hr Ozone (ppm)

Cowpens

Charlotte, NC

50

60

70

80

90

100

110

199019911992199319941995199619971998199920002001200220032004

4th Highest Maximum 8-Hour Average Ozone (ppb)

Shenandoah Great Smoky Mtns-Look Rock

Mammoth Cave Cowpens

Congaree Swamp Everglades

Acadia

3-21
Three-year rolling averages of the 4th highest 8-hour ozone concentration time series 

plots and linear regression trends for eastern parks are plotted surrounding the map in Figure 3-

10. Similar information for western parks is presented in Figure 3-11. The correlation 

coefficient (R2

) represents how well the data fit the linear model and the p value gives the 

statistical significance of the trend. The closer the R2

 value is to 1, the better the data fit the 

linear regression, and p values less than 0.05 represent a high significance. In each plot, the 

regression trend arrows indicate an increase, a decrease, or no change in ozone levels. The blue 

line on each graph marks the level of the National Ambient Air Quality Standard (NAAQS) for 

ozone which is based on a three year average of the annual 4th highest daily maximum 8-hr 

average ozone concentration. Each park shows considerable variation in annual ozone 

concentrations, which is reflected in the low R2 values and the poor statistical significance 

associated with the linear regression trends for most of the eastern parks. 

A possible explanation for this variability is that ozone increased during much of the 

1990s and then decreased after 1999-2000 at four of the eastern U.S. parks (as displayed in 

Figure 3-8). Linear regression shows an increasing trend at Congaree NP. While parks in the 

mid-atlantic and south eastern states show no trends or increasing trends, the parks in New 

England show decreasing trends. At Acadia NP, a decreasing trend is observed through at least 

1996. After 1996 ozone has remained nearly constant or slightly increased. The monitoring 

station at Acadia moved across the road in 1998, which may have affected the ozone record for 

this site.

Compared to the East, the West has a lower density of emission sources (Figure 3-6) and 

has not benefited from NOx reductions to the extent that the eastern U.S. has. Ozone data at most 

western parks display less year-to-year variability as well as less variability over several years 

than eastern parks. The linear regression trends for selected western parks are shown in Figure 

3-11. Joshua Tree and Sequoia-Kings Canyon NPs have seen major swings in ozone 

concentrations over time. These changes should be assessed in conjunction with trends at the 

upwind urban areas that dominate the area’s air quality. While the California parks show 

decreasing or no trends, much of the central western parks have increasing ozone trends. 

3-22
Figure 3-10 

Ozone Trends in Eastern Parks 

Ozone concentrations and linear regression trends for selected eastern parks. Arrows in the boxes give the direction of the trend. 

90807060

110100

Mean(3yr_avg4thHI_8hr, ACAD)

1988

1990

1992

1994

1996

1998

2000

2002

2004

Year

Acadia 

Slope = - 0.46  R2 = 0.28 

p = 0.015

90807060

110100

Mean(3yr_avg4thHI_8hr, CACO)

1988

1990

1992

1994

1996

1998

2000

2002

2004

Cape Cod 

Year

Slope = - 1.04  R2 = 0.58 

 p = 0.0006 

90807060

) 110

100

Mean(3yr_avg4thHI_8hr, COSW

1988

1990

1992

1994

1996

1998

2000

2002

2004

Year

90807060

110100

Mean(3yr_avg4thHI_8hr, SVBM)

1988

1990

1992

1994

1996

1998

2000

2002

2004

Year

Shenandoah 

Slope = 0.48  R2 = 0.29 

 p = 0.015 

90807060

110100

Mean(3yr_avg4thHI_8hr, COWP)

1988

1990

1992

1994

1996

1998

2000

2002

2004

Year

Cowpens 

Slope = 0.39  R2 = 0.14 

 p = 0.17 

Congaree

Slope = 0.56  R2 = 0.48 

p = 0.0003

90807060

110100

Mean(3yr_avg4thHI_8hr, GSCD)

1988

1990

1992

1994

1996

1998

2000

2002

2004

Year

Great Smoky Mountains 

Slope = 1.18  R2 = 0.23 

 p = 0.156 

Regression 

Increasing O3 trend 

Decreasing O3 trendNo trend 

Clingmans Dome

90807060

) 110

100

Mean(3yr_avg4thHI_8hr, MACA

1988

1990

1992

1994

1996

1998

2000

2002

2004

Year

Mammoth Cave 

Slope = - 0.26  R2 = 0.04 

 p = 0.45 

90807060

110100

Mean(3yr_avg4thHI_8hr, GSLR)

1988

1990

1992

1994

1996

1998

2000

2002

2004

Year

Look Rock

Great Smoky Mountains 

Slope = 0.62  R2 = 0.31 

 p = 0.017 

McFarland Hill

3-23
80

7060504030

Mean(3yr_avg4thHI_8hr, YELL) 20

1988

1990

1992

1994

1996

1998

2000

2002

2004

Year

90807060

110100

Mean(3yr_avg4thHI_8hr, YOTD) Yosemite 

90807060

) 110

100

Mean(3yr_avg4thHI_8hr, ROMO

1988

1990

1992

1994

1996

1998

2000

2002

2004

Year

Regression Trends 

Increasing O3 trend Decreasing O3 trendNo trend 

90807060

110100

Mean(3yr_avg4thHI_8hr, PINN) Pinnacles Slope = -0.31 R2 = 0.31 p = 0.025 

Yellowstone 

Slope = 0.46  R2 = 0.45 

 p = 0.0042 

Slope = - 0.22  R2 = 0.12 

 P = 0.26 

Rock

y Mountain 

Slope = 0.83  R2 = 0.77 

 p = 0.001 

90807060

110100

Mean(3yr_avg4thHI_8hr, JOTR)

1988

1990

1992

1994

1996

1998

2000

2002

2004

Year

Joshua Tree 

Slope = -0.044 R2 = 0.001 

 p = 0.89 

Mesa Verde 

Slope = 0.65  R2 = 0.56 

 p = 0.013 

90807060

) 110

100

Mean(3yr_avg4thHI_8hr, GRCA

1988

1990

1992

1994

1996

1998

2000

2002

2004

Year

Grand Canyon 

Slope = 0.98  R2 = 0.70 

 p = 0.001 

Ozone concentrations and linear regression trends for selected western parks. Arrows in the boxes give the direction of the trend. 

2004

2002

2000

1998

1996

1994

1990

1988

90807060

110100

Mean(3yr_avg4thHI_8hr, SELK)

1988

1990

1992

1994

1996

1998

2000

2002

2004

Sequoia 

Lower Kaweah

Slope = 0.003  R2 = 0.00004 

 p = 0.98 

1992

2004

2002

2000

1998

1996

1994

1992

1990

1988

Figure 3-11 

Ozone Trends in Western Parks 

3-24
Another useful statistic that indicates the frequency of and potential trend in poor air 

quality is the number of exceedances per year. An exceedance is defined as an occurrence where 

the daily maximum 8-hour average ozone concentration is greater than or equal to 85 ppb. Two 

examples are given in Figure 3-12; Great Smoky Mountains NP (Look Rock) and Joshua Tree 

NP both have very high numbers of exceedances and as a result often issue ozone advisories to 

the public when the air quality is expected to exceed the NAAQS for ozone. There is much more 

year-to-year variability in the number of exceedances than there is in the 4th highest 8-hr average 

concentration. The patterns look different than those in Figure 3-10 and 3-11, yet it is clear that 

the ozone concentrations continue to be above the NAAQS standard and the number of 

exceedances per year are quite high. 

Figure 3-12 

Trends in Number of 8-Hour Average Ozone Exceedances 

Trend plots for the number of ozone exceedances at Great Smoky Mountains and Joshua Tree National Parks. 

Compare to concentration plots in Figure 3-10 and 3-11. 

Ideally, trends should indicate changes attributable to changes in emissions, control 

strategies, and changes in other human activities. However, because of weather variability that 

also affects ozone concentrations, only large changes in emissions or activities that happen 

abruptly are likely to result in obvious changes in ozone concentrations. Some areas in the 

eastern U.S. now seem to be responding to NOx emission reductions as predicted by researchers 

and computer modeling. This is good news for future predictions of air quality in eastern parks 

and something to be tracked carefully. 

Great Smoky Mountains – Look Rock

y = 0.5377x - 1060.4

R2 = 0.0908

0

5

10

15

20

25

30

35

40

19841986198819901992199419961998200020022004

Number of exceedances/year

Joshua Tree National Park

y = -0.1847x + 400.46

R2

 = 0.0044

0

10

20

30

40

50

60

70

80

19841986198819901992199419961998200020022004

Number of exceedances/year

3-25
 More information related to ozone trends in national parks can be found on the Web at 

these sites: 

Annual 4th highest 8-hr concentrations in parks 

http://www2.nature.nps.gov/air/monitoring/docs/2005_ParkO3Conc.pdf

Annual NAAQS exceedence counts in parks 

http://www2.nature.nps.gov/air/Monitoring/docs/2005_O3_ParkExceedDays.pdf

Performance measures (GPRA report on trends) 

http://www2.nature.nps.gov/air/who/npsPerfMeasures.cfm 

Ozone interpolation maps as 5-year averages (Air Atlas) 

http://www.nps.nsm.du.edu/website/AirAtlas9903/viewer.htm

References 

Environmental Protection Agency (EPA) (1998). Finding of Significant Contribution and 

Rulemakings for Certain States in the Ozone Transport Assessment Group Region. 

http://www.epa.gov/ttn/naaqs/ozone/rto/sip/index.html (June 30, 2005). 

Ozone Transport Assessment Group (OTAG) (1997). OTAG Technical Supporting Document, 

http://www.epa.gov/ttn/naaqs/ozone/rto/otag/finalrpt/ (June 30, 2005). 

Southern Oxidants Study (SOS), Ed.: Chameides, W.L and E.B. Cowling (1995). The State of 

the Southern Oxidants Study (SOS): Policy-Relevant Findings in Ozone Pollution Research 

1988-1994. http://www2.ncsu.edu/ncsu/CIL/southern_oxidants/index.html (June 30, 2005). 

Tong, D. Q., D. Kang, V.P. Aneja, and J. D. Ray (2005). Reactive nitrogen oxides in the 

southeast US national parks: source identification, origin, and process budget, Atmos. Environ., 

39, 315-327. http://www2.nature.nps.gov/air/Studies/enhanced.cfm#refs (June 30, 2005). 

3-26
3.2.4 Resource Injury Indices 

To quantify ozone exposure to plants, various indices other than the NAAQS primary and 

secondary standards are often used. These indices, defined below, take into account both peak 

ozone concentrations and cumulative exposure to ozone. 

 • SUM06 – A cumulative index that is calculated as the maximum 3-month sum of the 

0800-2000 hourly average ozone concentrations equal to or greater than 0.06 ppm (60 

ppb). The units of this index are ppm-hr. Several thresholds have been developed for 

SUM06 (Heck and Cowling, 1997): 

 No risk to ozone sensitive vegetation 0 - 7 ppm-hr 

 Higher risk to ozone sensitive vegetation 8 - 16 ppm-hr 

 Highest risk to ozone sensitive vegetation > 16 ppm-hr 

 • W126 – A cumulative index that is calculated as the sum of the 0800-2000 weighted 

hourly ozone concentrations during the EPA-designated ozone season, where a 

weighting function is used to give increasing significance (weights between 0 and 1) 

to concentrations of ozone greater than 0.040 ppm (40 ppb), and no weight to 

concentrations below 0.040 ppm (40 ppb). Units of this index are ppm-hr. 

 • N100 – The number of hours with ozone concentrations greater than or equal to 0.10 

ppm (100 ppb). This index is reported without units. The N100 index is often 

considered along with the W126 in assessing the possible impact of the exposure. 

Several thresholds have been developed for W126 and N100 (Lefohn et al, 1997): 

 W126 N100

Highly Sensitive Species 5.9 ppm-hr 6 

Moderately Sensitive Species 23.8 ppm-hr 51 

Low Sensitivity 66.6 ppm-hr 135 

 Table 3-6 presents the ozone exposure indices summary statistics for 2004. Summaries 

for portable ozone sites are included for reference only. Since portable sites are deployed for 

short-term seasonal use, there may be significant biases in SUM06, W126, and N100 exposure 

indices calculated from their data. These statistics were not calculated for sites that were 

operational for less than three months during the year. In 2004 these sites were Gulf Islands 

National Seashore, Little River Canyon National Preserve, and Russell Cave National 

Monument. 

 The map in Figure 3-13 presents the annual 3-month maximum SUM06 exposure index 

for all network sites listed in Table 3-6. Index values are color-coded to represent three distinct 

levels of cumulative exposure. Data from portable sites (no color) are included for reference 

only. The Sum06 risk thresholds are relative and not absolute. 

 Ozone effects depend not only on ozone exposure, but on other factors that may 

ameliorate or magnify the extent of ozone injury, including soil moisture, presence of other air 

pollutants, insects or diseases, and other environmental stresses. A high SUM06 exposure in a 

drought year, for example, may not result in vegetation injury because stomatal closure to 

prevent moisture loss will also prevent ozone uptake. 

3-27
 In evaluating risk to vegetation from ozone, it is useful to consider not only the SUM06 

but also the W126 and N100 exposures. If more than one exposure indices is above the 

threshold for effects, the potential for injury increases. 

 In 2004, assessments were completed to evaluate the potential for ozone injury to 

vegetation at many national park service units. The assessments are available at 

http://www2.nature.nps.gov/air/Pubs/ozone.cfm 

Information on ozone-sensitive plant species is 

available at http://www2.nature.nps.gov/air/Pubs/pdf/BaltFinalReport1.pdf. 

References 

Heck, W.W. and E.B. Cowling. 1997. The Need for a Long-Term Cumulative Secondary 

Ozone Standard – An Ecological Perspective. Environmental Management. January. 

Lefohn, A.S., W. Jackson, D. Shadwick, and H.P. Knudsen. 1997. Effect of Surface Ozone 

Exposures on Vegetation Grown in the Southern Appalachian Mountains: Identification of 

Possible Areas of Concern. Atmospheric Environment 31(11):1695-1708. 

3-28
National Park Unit Site Name N1003 O3 %

Valid

SUM061

(ppm-hr)

W1262

(ppm-hr)

Table 3-6

Summary of Indices for Resource Injury (SUM06, W126, and N100) 

2004

National Park Service Gaseous Pollutant Monitoring Program

Acadia Cadillac Mountain 99.2 12.9 20.7 3

Acadia McFarland Hill 99.4 5.9 17.0 0

Badlands Visitor Center 99.5 4.6 15.9 0

Big Bend K-Bar Ranch Road 98.9 3.6 21.9 0

Big South Fork Portable Ozone 72.4 2.7 7.0 0

Black Canyon of the Gunnison Portable Ozone 43.7 41.0 51.7 0

Cape Cod Cape Cod 97.5 17.8 23.3 7

Canyonlands Island in the Sky 98.1 24.2 51.9 0

Chamizal Chamizal 99.5 11.7 19.6 4

Chiricahua Entrance Station 99.2 24.7 39.9 0

Channel Islands Santa Rosa Island 84.5 8.8 19.9 1

Congaree Congaree Bluff 99.3 8.3 13.0 2

Cowpens Cowpens 99.2 8.9 15.7 0

Craters of the Moon Visitor Center 94.2 7.4 27.6 0

Denali Headquarters 99.7 0.9 8.6 0

Death Valley Park Village 95.0 69.8 74.2 0

Everglades Beard Center 94.8 4.6 10.6 0

Glacier West Glacier Horse Stables 92.3 0.0 5.3 0

Great Basin Maintenance Yard 97.8 25.1 40.8 0

Grand Canyon The Abyss 99.1 35.5 55.0 0

Grand Canyon Portable Ozone 58.8 8.6 22.8 0

Great Smoky Mountains Cades Cove 96.4 7.1 13.9 0

Great Smoky Mountains Clingmans Dome 97.5 34.9 46.5 0

Great Smoky Mountains Cove Mountain 96.2 30.1 54.3 0

Great Smoky Mountains Look Rock 98.9 37.3 65.0 0

Great Smoky Mountains Purchase Knob 93.3 26.1 32.3 0

Isle Royale Portable Ozone 92.3 1.6 4.7 0

Joshua Tree Yucca Valley 99.1 108.1 140.2 70

Lake Mead Portable Ozone 91.4 58.9 52.4 0

Lassen Volcanic Manzanita Lake Maint. Area 98.5 19.5 28.0 0

Mammoth Cave Houchin Meadow 99.7 10.9 22.1 0

Mammoth Cave Portable Ozone 72.5 3.1 4.4 0

Mesa Verde Maintenance Yard 99.3 16.0 44.2 0

Mount Rainier Portable Ozone 70.3 4.2 5.6 2

Mount Rainier Tahoma Woods 98.5 1.8 4.2 0

North Cascades Marblemount Ranger Station 98.0 0.5 2.5 0

Olympic Portable Ozone 100.0 0.1 4.6 0

Olympic Visitor Center 81.1 0.0 1.6 0

Petrified Forest Horse Barn 93.4 33.1 42.4 0

Pinnacles East Entrance Station 95.7 18.5 29.3 0

Rocky Mountain Longs Peak Ranger Station 99.9 34.0 58.0 0

Saguaro Pima County 99.0 22.6 43.3 0

3-29
Table 3-6 (cont.)

National Park Unit Site Name N1003 O3 %

Valid

SUM061

(ppm-hr)

W1262

(ppm-hr)

Summary of Indices for Resource Injury (SUM06, W126, and N100) 

2004

National Park Service Gaseous Pollutant Monitoring Program

Sequoia and Kings Canyon Ash Mountain 81.6 65.0 122.5 57

Sequoia and Kings Canyon Lower Kaweah 92.8 97.2 96.3 17

Sequoia and Kings Canyon Lookout Point 87.6 120.7 133.7 45

Shenandoah Big Meadows 96.3 20.5 41.6 0

Theodore Roosevelt Visitor Center 58.3 0.6 4.3 0

Voyageurs Sullivan Bay 98.3 1.4 11.9 0

Yellowstone Water Tank 96.4 2.6 24.3 0

Yosemite Merced River 90.7 11.0 16.2 0

Yosemite Turtleback Dome 98.8 97.9 109.0 12

Zion Dalton's Wash 94.4 41.1 48.2 0

Operating agency key:

plain text

italics

underline

= site operated by the National Park Service

= site operated by a state agency

= site operated by the National Park Service, but consisting of non-EPA certified protable instrumentation

1. SUM06 exposure index represents the sum of all hourly ozone concentrations equaling or exceeding 0.06 ppm. The value reported 

here represents a three month maximum value for the year. Units are ppm-hr.

2. W126 exposure index represents the sum of all hourly ozone concentrations where each concentration is weighted by a function that 

gives greater emphasis to the higher hourly concntrations while still including the lower ones. Units are ppm-hr. For more information 

on the W126 exposure index go to http://www2.nature.nps.gov/air/maps/AirAtlas/air_quality_glossary.pdf

3. N100 represents the number of hourly ozone concentrations greater than or equal to 0.100 ppm (100 ppb).

3-30
Acadia (2)

Badlands

Big Bend

Big South

Black Canyon of the Gunnison

Canyonlands

Cape Cod

Chamizal

Chiricahua

Channel Islands

Congaree 

Cowpens

Craters of the Moon

Denali

Death Valley

Everglades

Glacier

Great Basin

Grand Canyon

Grand Canyon

Great Smoky Mountains (5)

Isle Royale

Lake Mead

Joshua Tree

Lassen Volcanic

Mammoth Cave

Mammoth Cave Mesa Verde

Mount Rainier

Mount Rainier

North Cascades

Olympic

Olympic

Petrified Forest

Pinnacles

Rocky Mountain

Saguaro

Sequoia/Kings Canyon (3) Shenandoah

Theodore Roosevelt

Voyageurs

Yellowstone

Yosemite (2)

Zion

Legend

0 - 7 ppm-hr8 - 16 ppm-hr

> 16 ppm-hr

Operating agency key:

plain text = site operated by the National Park Serviceitalicsunderline

= site operated by a state agency

 = National Park Service operatedportable ozone system (POMS) Portable site

13

5

4

24

18

12

25

9

8

9

7

1

70

5

0

25

36

37 108

20

11

16

2

1 0

33

19

34

23

121

21

1

1

3

98

41

3

41

9

2

59 3

4

0

Figure 3-13

Annual 3 Month Maximum Sum06 Exposure Index

2004

National Park Service Gaseous Pollutant Monitoring Program

* Park units with more than one site are indicated with (x) following the parkunit name, where x represents the number of sites within the unit. At unitswhere more than one site exists, the highest value from all sites was reported.

3-31
3.3 SULFUR DIOXIDE DATA SUMMARIES 

 Sulfur dioxide (SO2) is a criteria pollutant that over time undergoes chemical 

transformations in the atmosphere to form aqueous sulfur compounds, such as sulfuric acid, and 

particulate sulfate that can lead to environmental and health effects. Both sulfur dioxide and fine 

particulate sulfate can cause respiratory problems. Sulfur dioxide and acidic sulfate deposited on 

the earth’s surface can affect aquatic and terrestrial ecosystems. Sulfur compounds are a major 

constituent of acid rain and sulfate is one of the particulate species responsible for visibility 

degradation and regional haze. 

 The Primary National Ambient Air Quality Standards for sulfur dioxide are an annual 

arithmetic mean of 0.03 ppm (34 ppb) and a 24-hour mean of 0.14 ppm (144 ppb), not to be 

exceeded more than once per year. The secondary NAAQS is a 3-hour mean of 0.50 ppm (549 

ppb), not to be exceeded more than once per year. Table 3-7 summarizes sulfur dioxide 

measurements for comparison to these standards and lists the number of exceedances for each. 

Maximum hourly concentrations for each site are also presented in the table for reference. 

 At Hawaii Volcanoes National Park sulfur dioxide data are collected using a lower range 

and an upper range. The lower range does not capture values higher than 999 ppb, but is 

considered to be an EPA equivalency method. The upper range captures values above 999 ppb 

accurately, but is not an EPA reference method. Data presented in this report were collected 

using the upper range to give a more accurate representation of sulfur dioxide values. 

3-32
Highest Daily 24-Hour

Average Concentrations2 (ppb)

Hig

Av

Highest Daily Maximum 3-Hour

Average Concentration3 (ppb)

National Park Unit Site Name

Annual

Arithmetic

Mean (ppb)1

1st

Highest

2nd

Highest

3rd

Highest

4th

Highest

No. of days

with 24-Hour

Avgerage

 >= 145 ppb

1st

Highest

2nd

Highest

3rd

Highest

4th

Highest

No. of days

with 3-Hour

Maximum

>= 550 ppb

1st

Highe

Table 3-7

Summary of Sulfur Dioxide Data by Site

2004

National Park Service Gaseous Pollutant Monitoring Program

Congaree Congaree Bluff 1 0 10 9 7 7 81 55 0 32 31 29

Hawaii Volcanoes * Observatory 20 1 181 144 140 140 987 

535 0 527 501 441

Hawaii Volcanoes * Visitor Center 10 0 143 136 129 106 785 

545 0 416 404 362

Olympic * Visitor Center 1 0 5 5 4 4 24 

14 0 12 11 10

Shenandoah * Big Meadows 2 0 11 10 9 8 31 

18 0 16 16 16

Theodore Roosevelt Visitor Center 0 0 2 2 2 2 16 6 0 4 4 4

1. The primary annual National Ambient Air Quality Standard for sulfur dioxide is an annual arithmetic mean of 0.03 ppm. (A value greater than 0.03 ppm, 34 ppb

standard.) (40 CFR 50.4.)

2. The primary daily National Ambient Air Quality Standard for sulfur dioxide is 0.14 ppm over a 24-hour period not to be exceeded more than once per year. (A 

144 ppb, or 365 μg/m3 exceeds the standard.) (40 CFR 50.4.)

3. The secondary National Ambient Air Quality Standard for sulfur dioxide is 0.5 ppm over a 3-hour period not to be exceeded more than once per year. (A valu

ppb, or 1300 μg/m3 exceeds the standard.) (40 CFR 50.5.)

*This site collected sulfur dioxide data using an instrument or a range that is not an EPA reference method.

plain text

italics = site operated by a state agency

Operating agency key:

= site operated by the National Park Service

Color shading key:

>34 ppb annual arithmetic mean, >144 ppb 24-hour averag

3-33
3.4 METEOROLOGICAL DATA SUMMARIES 

 Meteorological data collected along with air quality parameters are used to better 

understand the local conditions and transport of air pollutants. In addition, meteorological data 

are essential for air quality deposition modeling efforts. Refer to Table 2-1 for a list of 

meteorological parameters collected at each site. 

 Table 3-8 presents a summary of selected meteorological data for all sites. The 

parameters included are wind speed, ambient temperature, relative humidity, and precipitation. 

3-34
National Park Unit Site Name

AAverage Maximum Minimum

Relative Humidity

(%)

Average Maximum Minimum

Table 3-8

Summary of Selected Meteorological Data by Site

2004

National Park Service Gaseous Pollutant Monitoring Program

Average

Ambient Temperature

(degrees C)

Wind Speed

(Scalar1)

(m/s)

18 100 84 -0.2 27.5 13.8 6.3 Acadia Cadillac Mountain

14 100 70 -26.8 30.8 6.2 3.2 Acadia McFarland Hill

8 99 56 -22.5 38.4 10.3 4.1 Badlands Visitor Center

5 100 50 -6.0 38.1 19.5 3.4 Big Bend K-Bar Ranch Road

28 100 82 -0.5 31.7 20.6 0.6 Big South Fork Portable Ozone

8 99 39 -2.5 30.0 15.1 2.2 Black Canyon of the Gunnison Portable Ozone

22 100 80 -21.1 27.9 8.9 2.7 Cape Cod Cape Cod 

2 99 41 -11.0 32.6 10.7 2.8 Canyonlands Island in the Sky

4 98 39 -6.8 38.5 18.8 3.3 Chamizal Chamizal 

6 100 45 -7.5 34.6 15.1 3.1 Chiricahua Entrance Station

6 100 54 -21.2 31.7 6.3 3.4 Craters of the Moon Visitor Center

11 99 67 -36.8 27.6 0.2 1.4 Denali Headquarters

2 100 21 5.0 47.8 26.0 3.8 Death Valley Park Village

26 100 77 7.0 33.8 23.4 2.2 Everglades Beard Center

14 98 74 -36.3 32.1 5.8 1.1 Glacier West Glacier Horse Stables

5 98 46 -15.6 31.0 8.8 2.7 Great Basin Maintenance Yard

4 100 44 -9.8 30.1 10.4 2.8 Grand Canyon The Abyss

5 95 29 4.5 37.8 23.3 2.8 Grand Canyon Portable Ozone

8 100 77 -16.5 30.8 13.3 1.2 Great Smoky Mountains Cades Cove

3 100 92 -5.0 19.6 12.2 3.5 Great Smoky Mountains Clingmans Dome

2 100 75 -17.7 24.7 10.7 4.5 Great Smoky Mountains Cove Mountain

16 100 72 -15.8 28.1 13.1 2.4 Great Smoky Mountains Look Rock

41 96 75 19.0 32.8 27.3 3.5 Gulf Islands Portable Ozone

27 100 86 9.1 25.9 16.4 4.7 Hawaii Volcanoes Observatory

41 100 91 8.4 24.8 16.1 3.4 Hawaii Volcanoes Visitor Center

27 100 72 1.3 26.5 13.8 5.7 Isle Royale Portable Ozone

3-35
Table 3-8 (cont.)

National Park Unit Site NameAAverage Maximum Minimum

Relative Humidity

(%)

Average Maximum Minimum

Summary of Selected Meteorological Data by Site

2004

National Park Service Gaseous Pollutant Monitoring Program

Average

Ambient Temperature

(degrees C)

Wind Speed

(Scalar1)

(m/s)

4 100 37 -3.5 35.9 14.7 3.9 Joshua Tree Yucca Valley

24 98 75 -41.5 28.8 -0.1 2.5 Kobuk Valley Ambler

5 78 18 8.3 41.5 27.9 4.0 Lake Mead Portable Ozone

8 99 60 -15.1 28.0 7.4 2.0 Lassen Volcanic Manzanita Lake Maint. Area

14 100 72 -16.2 31.4 14.1 1.8 Mammoth Cave Houchin Meadow

32 98 80 6.0 33.7 21.9 0.5 Mammoth Cave Portable Ozone

5 97 41 -13.6 30.7 10.0 2.9 Mesa Verde Maintenance Yard

15 99 75 2.0 32.3 13.6 0.6 Mount Rainier Portable Ozone

12 100 83 -8.9 34.5 9.5 1.0 Mount Rainier Tahoma Woods

14 100 84 -9.5 36.4 10.4 1.3 North Cascades Marblemount Ranger Station

19 100 74 -1.4 25.8 10.2 0.8 Olympic Portable Ozone

22 100 81 -9.7 30.5 10.1 0.9 Olympic Visitor Center

3 99 43 -13.5 33.4 12.6 3.8 Petrified Forest Horse Barn

4 98 61 -4.7 39.1 14.6 2.2 Pinnacles East Entrance Station

5 99 53 -24.8 25.0 3.8 2.7 Rocky Mountain Longs Peak Ranger Station

1 96 30 -0.5 40.0 21.2 2.8 Saguaro Pima County

5 100 51 -0.9 38.5 17.1 2.5 Sequoia and Kings Canyon Ash Mountain

6 99 59 -11.0 28.6 9.1 1.7 Sequoia and Kings Canyon Lower Kaweah

7 99 52 -5.9 33.6 12.8 4.3 Sequoia and Kings Canyon Lookout Point

4 100 73 -21.4 25.6 8.2 2.5 Shenandoah Big Meadows

7 100 64 -31.2 36.6 6.3 5.2 Theodore Roosevelt Visitor Center

3-36
Table 3-8 (cont.)

National Park Unit Site NameAAverage Maximum Minimum

Relative Humidity

(%)

Average Maximum Minimum

Summary of Selected Meteorological Data by Site

2004

National Park Service Gaseous Pollutant Monitoring Program

Average

Ambient Temperature

(degrees C)

Wind Speed

(Scalar1)

(m/s)

18 100 71 -35.5 30.7 3.6 2.8 Voyageurs Sullivan Bay

7 100 53 -24.1 35.7 9.5 3.0 Wind Cave Visitor Center

11 100 68 -27.1 25.5 1.6 1.6 Yellowstone Water Tank

5 99 65 -8.4 35.7 10.3 0.5 Yosemite Merced River

2 99 42 -8.5 31.0 11.2 4.0 Yosemite Turtleback Dome

5 100 36 -6.6 38.9 16.6 2.8 Zion Dalton's Wash

Operating agency key:

plain text = site operated by the National Park Service

underline = site operated by the National Park Service, but consisting of non-EPA certified portable instrumentation

italics = site operated by a state agency

1. Saguaro reports wind speed as vector wind speed rather than scalar wind speed.

Note: Dashed lines represent no data available for that particular parameter at that site.

3-37
4.0 PRECISION AND ACCURACY OF OZONE MEASUREMENTS 

 Ozone analyzers are automatically challenged daily with known zero and span 

concentrations. Most sites also undergo an automatic daily precision check. At a few sites, 

precision checks are performed weekly. All EPA reference method ozone sites operate both an 

analyzer (with ozone generator) and calibrator on site. The daily zero, span, and precision values 

are measured by both instruments, providing an independent reference to the on-site 

measurements. The NPS goal is for precision checks to fall within ± 10% of the calibration gas 

concentration. 

 Routine quality assurance multipoint calibrations of the GPMP ozone analyzers and 

calibrators are performed by the site operators monthly, and by the NPS-contracted network field 

specialists upon initial installation and every six months thereafter. Network field specialists 

perform their quality assurance checks using an ozone transfer standard (traceable to a NISTcertified primary standard). The NPS goal is for these accuracy checks to fall within ± 10% of 

the transfer standard gas concentrations. For more information on quality assurance within the 

network, please refer to the Quality Management Plan (QMP) and the Quality Assurance Project 

Plan (QAPP) which can be found on the Web at: 

http://www2.nature.nps.gov/air/Monitoring/network.cfm#procedures.

 Table 4-1 presents a summary of ozone analyzer precision results and semiannual 

accuracy results, by quarter, for 2004. Results are color-coded to indicate ideal performance (no 

shading), acceptable performance (yellow), and unacceptable performance (red). Accuracy 

results are presented only for NPS-operated sites, and typically include 2 entries for the year. 

 Table 4-2 presents a network summary of ozone analyzer precision and accuracy, by 

quarter, for 2004. Included in the table are the number of sites whose precision and accuracy 

checks fell within ± 5%, ± 10%, and outside of ± 10%. 

4-1
Upper 95%

Probability

Limit

Avg. Absolute

Percent

Difference

National Park Unit

Table 4-1

Ozone Analyzer Precision and Accuracy Summary

2004

Site Name

Calendar

Quarter

Precision Ac

6

Lower 95%

Probability

Limit

6 3,4

Required No.

of Precision

Checks Met?1

National Park Service Gaseous Pollutant Monitoring Program

Accuracy Check

Performed During

the Quarter?2

Avg

D

Acadia Cadillac Mountain 1

2 N 2.4 0.0 1.2 N

3 N 2.5 -0.1 1.2 Y

4

Acadia McFarland Hill 1 N 4.1 -5.3 0.6 Y

2 N 6.7 -4.4 1.2 Y

3 N 1.9 -0.7 0.6 Y

4 N N

Badlands Visitor Center 1 Y 2.6 -4.7 1.0 Y

2 N 1.0 -4.5 1.7 Y

3 N 3.3 -5.8 1.2 Y

4 Y 0.8 -3.1 1.2 Y

Big Bend K-Bar Ranch Road 1 Y 5.4 -2.2 1.6 Y

2 N 1.6 -2.0 0.2 Y

3 N -1.0 -4.4 2.7 Y

4 Y 0.0 -7.9 4.0 Y

Cape Cod Cape Cod 1

2 N 3.7 1.7 2.7 Y

3 N 4.9 -3.5 0.7 Y

4

Canyonlands Island in the Sky 1 N 1.1 -3.8 1.3 Y

2 N -0.9 -3.7 2.3 Y

3 Y 4.0 -5.2 0.6 Y

4 Y 11.2 -2.0 4.6 N

Chamizal Chamizal 1 N -0.8 -2.9 1.9 Y

2 N 1.6 -4.7 1.6 Y

3 N 0.2 -3.5 1.7 Y

4 N 1.9 -4.5 1.3 Y

Chiricahua Entrance Station 1 N 1.3 -0.7 0.3 Y

2 Y 0.9 -0.8 0.1 Y

3 N 0.7 -1.4 0.3 Y

4 Y 1.6 -1.8 0.1 Y

Channel Islands Santa Rosa Island 1 N 0.7 -1.5 0.4 N

2 N 1.4 -1.1 0.1 Y

3 N 2.6 -2.3 0.1 Y

4 N 7.1 -5.4 0.8 Y

4-2
Upper 95%

Probability

Limit

Avg. Absolute

Percent

Difference

Table 4-1 (cont.)

National Park Unit

Ozone Analyzer Precision and Accuracy Summary

2004

Site Name

Calendar

Quarter

Precision Ac

6

Lower 95%

Probability

Limit

6 3,4

Required No.

of Precision

Checks Met?1

National Park Service Gaseous Pollutant Monitoring Program

Accuracy Check

Performed During

the Quarter?2

Avg

D

Congaree Congaree Bluff 1 N 5.4 -3.9 0.7 N

2 N 6.5 -4.0 1.3 N

3 N 4.3 0.2 2.2 N

4 N 9.1 -4.9 2.1 N

Cowpens Cowpens 1 N 8.8 -15.6 3.4 Y

2 N 12.9 -11.3 0.8 Y

3 N 4.8 -3.2 0.8 N

4 N 8.3 -9.3 0.5 N

Craters of the Moon Visitor Center 1 Y 4.0 -8.9 2.4 Y

2 N 5.4 2.5 4.0 Y

3 N 5.3 -1.5 1.9 Y

4 N 4.0 -4.0 0.0 Y

Denali Headquarters 1 N 0.7 -1.1 0.2 Y

2 Y 2.1 -2.6 0.2 Y

3 Y 0.6 -1.7 0.6 Y

4 N -0.7 -2.8 1.8 Y

Death Valley Park Village 1 Y -3.1 -10.8 6.9 N

2 N -2.5 -9.7 6.1 Y

3 Y 4.1 -6.7 1.3 Y

4 Y 3.2 -5.0 0.9 Y

Everglades Beard Center 1 N 4.5 -6.5 1.0 Y

2 N 1.1 -7.1 3.0 Y

3 Y 7.5 -9.6 1.1 Y

4 N 5.0 -4.6 0.2 Y

Glacier West Glacier Horse Stables 1 N 1.7 -3.1 0.7 Y

2 Y 4.8 -2.7 1.0 Y

3 Y 5.1 -1.2 2.0 Y

4 N 5.3 -1.5 1.9 Y

Great Basin Maintenance Yard 1 Y 1.5 -7.6 3.0 Y

2 N 2.7 -1.9 0.4 Y

3 Y 1.9 -1.9 0.0 Y

4 Y 3.2 -2.0 0.6 Y

Grand Canyon The Abyss 1 N 1.3 -1.5 0.1 Y

2 Y 2.9 -0.1 1.4 Y

3 N 2.2 -0.4 0.9 Y

4 Y 2.1 -2.5 0.2 Y

4-3
Upper 95%

Probability

Limit

Avg. Absolute

Percent

Difference

Table 4-1 (cont.)

National Park Unit

Ozone Analyzer Precision and Accuracy Summary

2004

Site Name

Calendar

Quarter

Precision Ac

6

Lower 95%

Probability

Limit

6 3,4

Required No.

of Precision

Checks Met?1

National Park Service Gaseous Pollutant Monitoring Program

Accuracy Check

Performed During

the Quarter?2

Avg

D

Great Smoky Mountains Cades Cove 1 N 1.4 -6.4 2.5 Y

2 Y 2.1 -5.2 1.5 Y

3 N 2.4 -2.3 0.0 Y

4 Y 2.9 -2.7 0.1 Y

Great Smoky Mountains Clingmans Dome 1

2 N 8.2 -7.7 0.3 Y

3 N 8.7 -7.2 0.7 N

4 Y 2.9 -2.1 0.4 Y

Great Smoky Mountains Cove Mountain 1 N 5.0 -6.5 0.8 Y

2 Y 12.2 -8.9 1.7 Y

3 N 5.9 -1.2 2.3 Y

4 Y 2.7 -2.1 0.3 Y

Great Smoky Mountains Look Rock 1 N 1.1 -3.2 1.0 Y

2 Y 8.9 -3.5 2.7 Y

3 N 5.9 -2.7 1.6 Y

4 Y 3.4 -2.2 0.6 Y

Great Smoky Mountains Purchase Knob 1

2 N 2.4 -0.9 0.8 Y

3 N 2.2 -1.1 0.6 Y

4 N 2.9 -1.3 0.8 Y

Joshua Tree Yucca Valley 1 N 1.3 -3.3 1.0 Y

2 Y 2.2 -3.5 0.7 Y

3 N -0.3 -5.3 2.8 Y

4 Y 0.7 -4.6 2.0 Y

Lassen Volcanic Manzanita Lake Maint. Area 1 N 7.2 -10.7 1.8 Y

2 N -2.8 -6.8 4.8 Y

3 Y -0.4 -6.7 3.6 Y

4 N -1.1 -5.7 3.4 Y

Mammoth Cave Houchin Meadow 1 N 2.3 -1.6 0.4 Y

2 Y 3.9 -0.3 1.8 Y

3 N 6.4 -2.0 2.2 Y

4 N 6.8 -1.8 2.5 Y

4-4
Upper 95%

Probability

Limit

Avg. Absolute

Percent

Difference

Table 4-1 (cont.)

National Park Unit

Ozone Analyzer Precision and Accuracy Summary

2004

Site Name

Calendar

Quarter

Precision Ac

6

Lower 95%

Probability

Limit

6 3,4

Required No.

of Precision

Checks Met?1

National Park Service Gaseous Pollutant Monitoring Program

Accuracy Check

Performed During

the Quarter?2

Avg

D

Mesa Verde Maintenance Yard 1 N 2.9 -2.4 0.3 Y

2 Y 8.1 -2.5 2.8 Y

3 N 13.0 1.1 7.0 Y

4 Y 1.3 -1.3 0.0 Y

Mount Rainier Tahoma Woods 1 N 2.6 -6.6 2.0 Y

2 Y -2.2 -8.2 5.2 Y

3 N -1.2 -9.8 5.5 Y

4 Y 2.4 -10.5 4.1 Y

North Cascades Marblemount Ranger Station 1 N -3.5 -10.7 7.1 N

2 Y -1.4 -10.8 6.1 Y

3 N -2.4 -9.3 5.9 Y

4 Y -0.7 -10.5 5.6 Y

Olympic Visitor Center 1 N 4.0 -7.4 1.7 Y

2 Y 2.5 -7.3 2.4 Y

3 N 3.3 -7.5 2.1 Y

4 Y 0.9 -10.6 4.8 Y

Petrified Forest Horse Barn 1 N 2.5 -6.4 1.9 Y

2 Y 1.9 -1.2 0.3 Y

3 N 1.9 -1.8 0.0 Y

4 Y 2.4 -3.8 0.7 Y

Pinnacles East Entrance Station 1 N 2.6 -2.9 0.2 Y

2 N 1.5 -2.4 0.4 Y

3 Y 2.4 -2.0 0.2 Y

4 N 0.1 -3.1 1.5 Y

Rocky Mountain Longs Peak Ranger Station 1 Y 3.9 -2.3 0.8 Y

2 N 5.6 2.2 3.9 Y

3 Y 4.9 1.4 3.1 Y

4 N 6.1 -3.0 1.6 Y

Saguaro Pima County 1 N 2.5 -0.6 1.0 Y

2 N 1.3 -1.3 0.0 N

3 N 2.5 -2.8 0.2 N

4 N 1.9 -0.3 0.8 Y

4-5
Upper 95%

Probability

Limit

Avg. Absolute

Percent

Difference

Table 4-1 (cont.)

National Park Unit

Ozone Analyzer Precision and Accuracy Summary

2004

Site Name

Calendar

Quarter

Precision Ac

6

Lower 95%

Probability

Limit

6 3,4

Required No.

of Precision

Checks Met?1

National Park Service Gaseous Pollutant Monitoring Program

Accuracy Check

Performed During

the Quarter?2

Avg

D

Sequoia and Kings Canyon Ash Mountain 1 Y 1.4 -2.1 0.3 Y

2 N 2.5 -3.9 0.7 Y

3 Y 1.6 -3.9 1.2 Y

4 N 2.6 -2.6 0.0 Y

Sequoia and Kings Canyon Lower Kaweah 1 Y 4.0 -3.5 0.2 Y

2 N 2.0 -3.6 0.8 Y

3 Y 1.9 -3.5 0.8 Y

4 N 1.1 -2.0 0.5 Y

Sequoia and Kings Canyon Lookout Point 1 Y 2.2 -11.7 4.8 Y

2 N 0.6 -8.4 3.9 Y

3 Y 2.7 -8.1 2.7 N

4 N -0.5 -12.4 6.4 Y

Shenandoah Big Meadows 1 N 0.8 -1.5 0.4 Y

2 N 2.5 -1.5 0.5 Y

3 Y -1.3 -5.0 3.2 Y

4 Y 4.5 -3.3 0.6 Y

Theodore Roosevelt Visitor Center 1

2 N 2.0 -0.5 0.7 Y

3 N 5.0 -8.4 1.7 Y

4 N 1.9 -6.6 2.4 Y

Voyageurs Sullivan Bay 1 N -1.1 -2.9 2.0 Y

2 Y -0.9 -3.5 2.2 Y

3 N -1.6 -3.8 2.7 Y

4 Y -1.4 -3.2 2.3 Y

Yellowstone Water Tank 1 N -0.6 -4.4 2.5 Y

2 Y 0.3 -3.7 1.7 Y

3 Y 0.6 -2.5 0.9 Y

4 N 0.0 -5.1 2.5 Y

Yosemite Merced River 1 Y 2.9 -1.4 0.8 Y

2 N 0.2 -1.9 0.9 Y

3 Y 0.5 -1.9 0.7 Y

4 N 0.1 -2.3 1.1 Y

4-6
Upper 95%

Probability

Limit

Avg. Absolute

Percent

Difference

Table 4-1 (cont.)

National Park Unit

Ozone Analyzer Precision and Accuracy Summary

2004

Site Name

Calendar

Quarter

Precision Ac

6

Lower 95%

Probability

Limit

6 3,4

Required No.

of Precision

Checks Met?1

National Park Service Gaseous Pollutant Monitoring Program

Accuracy Check

Performed During

the Quarter?2

Avg

D

Yosemite Turtleback Dome 1 N 1.0 -2.6 0.8 Y

2 N 1.3 -3.1 0.9 Y

3 Y 2.1 -1.8 0.1 Y

4 N 1.9 -2.1 0.1 Y

Zion Dalton's Wash 1 N 1.6 -2.7 0.5 Y

2 Y 0.9 -2.5 0.8 Y

3 N -1.3 -2.9 2.1 Y

4 Y -0.9 -3.0 1.9 Y

Operating agency key:

plain text

italics

underline

= site operated by the National Park Service

= site operated by a state agency

= site operated by the National Park Service, but consisting of non-EPA 

certified portable instrumentation

Color shading key:

Ideal: indicates a percent difference within +/-5% or a pro

Acceptable: indicates a percent difference between +/-5.1-

between +/-10.1-15%

Unacceptable: indicates a percent difference greater than +

greater than +/-15%

1. Precision checks are required by the Environmental Protection Agency (EPA) of all pollutant analyzers collecting data which are to be submitted to the EPA A

precision check is performed by challenging the pollutant analyzer with a known concentration of gas from the pollutant transfer standard. This precision check 

every 14 days of monitoring operation. The percent difference between the analyzer and the transfer standard is then calculated.3 According to NPS Standard O

pollutant analyzer must respond within 10% of the transfer standard.

2. Accuracy checks are required by the Environmental Protection Agency (EPA) of all pollutant analyzers collecting data which are to be submitted to the EPA A

accuracy check is performed by challenging the pollutant analyzer with a known concentration of gas from the pollutant transfer standard at several different po

between the analyzer and the transfer standard is then calculated.3 According to NPS Standard Operating Procedures, the pollutant analyzer must respond within 

All accuracy checks reported here were performed by the reporting organization and not by an outside auditor.

3. Percent Difference = ((analyzer - transfer std)/transfer std)x100

4. Average Absolute Percent Difference is the mean of the absolute value of all individual precision check percent differences during the quarter, or the mean o

percent differences from each point challenged during an accuracy check.

5. Maximum Percent Difference is the highest percent difference from the points of a multipoint (or accuracy) calibration. A positive value indicates the anlyzer 

indicates the anlyzer read low.

6. Upper/Lower 95% Probability Limits = (Average Percent Difference)+/-(1.96)(Standard Deviation of precision check percent differences in the quarter). The 

the interval having a 95% chance of containing the true average percent difference. Probability limits must be within +/-15%.

4-7
National Park Service Gaseous Pollutant Monitoring Program

Ozone Analyzer Precision and Accuracy Overall Network Summary

2004

# Operational

Sites

# Sites within

+/- 5%

# Sites within

+/- 5.1 - 10%

# Sites >

+/- 10%

# Sites within

+/- 5%

# Sites with

+/- 5.1 - 10%

Accuracy2

Average Absolute Perce

Calendar

Quarter

Precision1

Average Absolute Percent Difference

Table 4-2

39 37 2 0 9 1 1

44 41 3 0 16 1 2

44 41 3 0 15 1 3

42 39 2 0 14 4 4

1. Precision checks are required by the Environmental Protection Agency (EPA) of all pollutant analyzers collecting data which are to be submitted to the EPA A

precision check is performed by challenging the pollutant analyzer with a known concentration of gas from the pollutant transfer standard. This precision check 

every 14 days of monitoring operation. The percent difference between the analyzer and the transfer standard is then calculated. According to NPS Standard Op

pollutant analyzer must respond within 10% of the transfer standard.

2. Accuracy checks are required by the Environmental Protection Agency (EPA) of all pollutant analyzers collecting data which are to be submitted to the EPA Ai

accuracy check is performed by challenging the pollutant analyzer with a known concentration of gas from the pollutant transfer standard at several different poi

between the analyzer and the transfer standard is then calculated. According to NPS Standard Operating Procedures, the pollutant analyzer must respond within 1

4-8