1 Regional Haze Glossary of Visibility Acronyms, Abbreviations, and Terms

BART = Best Available Retrofit Technology

- A source emission limitation, based on the maximum degree of reduction for each pollutant, that must be achieved by sources subject to the Prevention of Significant Deterioration program.

Bext = Extinction

- The attenuation of light due to scattering and absorption as it passes through

a medium.

CEMS

- A continuous emission monitoring system (CEMS) is the total equipment necessary for

the determination of a gas or particulate matter concentration or emission rate using pollutant analyzer measurements and a conversion equation, graph, or computer program to produce results in units of the applicable emission limitation or standard.

CENRAP = Central States Regional Air Partnership , one of the five RPO s. Includes the states and tribal areas encompassed by Nebraska, Kansas, Oklahoma, Texas, Minnesota, Iowa, Missouri, Arkansas, and Louisiana. Affiliated with CenSARA.

Class I Areas

- As define d by the Clean Air Act, include national parks greater than 6,000 acres, wilderness areas and national memorial parks greater than 5,000 acres, and international parks that existed as of August 1977.

CMAQ = Community Multiscale Air Quality modeling system

.

CO = Carbon monoxide

.

Coarse M ode

- A size range of particles between 2.5 microns and 10 microns. Coarse particles are mostly composed of soils. The sum of the masses of coarse and fine particles (all particles smaller than 10 microns) is called PM 10

.

COHA = Causes of Haze Assessment

- A n online report that answers questions about the chemical components that cause regional haze, relationships of haze to meteorology, the emissions that cause haze, and the effects of previous an d future emissions reductions on the poorest and best visibility levels. ( http://www.coha.dri.edu/ )

DV = Deciview

- The unit of measurement of haze, as in the haze index (HI) defined below.

EC = Elemental carbon

.

EDMS = Emissions Data Management System

- A n emission inventory data warehouse and

web

- based application that provides a consistent approach to regional emissions tracking to meet the requirements for State Implementation Plan (SIP) and Tribal Implement ation Plan (TIP) development and periodic review and updates. The EDMS serves as a central regional emissions inventory database and associated software to facilitate the data collection efforts for regional2

modeling, 309 tracking and resulting data analy ses. The EDMS is the central repository for the data from the Western Regional Air Partnership (WRAP) region that is used initially for air quality modeling in pursuit of meeting the requirements of the United States Environmental Protection Agency's (EPA) regional haze rule (RHR). The emission inventories contained within the EDMS consist of visibility impairing pollutants that are released into the atmosphere by

different sources.

EGU = Electric Generating Unit

.

EI = Emission Inventory

.

FETS = Fire Emi ssions Tracking System

. The WRAP's Fire Emissions Tracking System (FETS) is a database with a web interface for planned and unplanned fire events. Users can view

fire data on

- screen with a mapping tool and query the database for downloads of data into mo del

ready formats and CSV or DBF formats. ( http://www.wrapfets.org/ )

FLM = Federal Land Manager

.

Fugitive Dust

- Emissions associated with anthropogenic mechanical processes affecting the release of dust and organic carbon from disturbed or undisturbed lands. These sources are computed as being spread over a spatial extent (a county or air district).

HI = Haze Index

- A measure of visibility derived from calculated light extinction measurements that is designed so that uniform changes in the haze index c orrespond to uniform incremental changes in visual perception, across the entire range of conditions from pristine to highly impaired. The haze index [in units of deciviews (dv)] is calculated directly from the total light extinction [bext expressed in in verse megameters (Mm

- 1)] as follows: HI = 10 In (b ext /10).

IMPROVE = Interagency Monitoring of PROtected Visual Environments

- A collaborative monitoring program established in the mid

- 1980s as part of the Federal Implementation Plans. IMPROVE objective s are to provide data needed to assess the impacts of new emission sources, identify existing man

- made visibility impairment, and assess progress toward the national visibility goals that define protection of the 156 Class I areas.

LADCO = Lake Michigan A ir Directors Consortium . Represents states of Illinois, Indiana, Michigan, and Wisconsin.

MANE

- VU = Mid

- Atlantic/Northeast Visibility Union

- One of the five RPOs. Includes Connecticut, Delaware, the District of Columbia, Maine, Maryland, Massachusett s, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Northern Virginia, and suburbs of Washington, D.C. The Northeast States for Coordinated Air Use Management (NESCAUM) and Mid

- Atlantic Regional Air Management Association (MARAMA) are working in cooperation with the OTC on regional haze issues.

Midwest RPO

- One of the five RPOs. Affiliated with LADCO. Includes the states and tribal areas encompassed by Illinois, Indiana, Michigan, Ohio, and Wisconsin.3

Most Impaired Days

- Data representing a subset of the annual measurements that correspond to the dirtiest, or haziest, days of the year.

Natural Conditions

- Prehistoric and pristine atmospheric states, i.e., atmospheric conditions that are not affected by human activities.

Nat ural Conditions II (NC II)

- Alternate method for calculating natural conditions. Used in conjunction with the revised IMPROVE algorithm.

Natural Fire Sources

- Combustion emissions from wildfire, wildland fire use, non

- federal rangeland burning, and mai ntenance burning activities of wildland managers. These sources are computed as daily point source events.

NH 3 = Ammonia

.

NO = Nitrous oxide

.

NO 2 = Nitrogen dioxide

- A gas consisting of one nitrogen and two oxygen atoms. It absorbs blue light and ther efore has a reddish

- brown color associated with it.

NO 3 = Nitrate

- Solid or liquid particulate matter containing ammonium nitrate [NH 4 NO 3 ] or other nitrate salts. Atmospheric nitrate aerosols are often formed from the atmospheric oxidation

of oxides of nitrogen (NOx).

NOx = Oxides of nitrogen (NO + NO 2 )

- One of the six criteria pollutants. The term used to describe the sum of nitric oxide (NO), nitric dioxide (NO 2 ), and other oxides of nitrogen, which plays a major role in the formation of ozone. The major sources of man

- made NOx emissions are high temperature combustion processes, such as those occurring in automobiles and power plants.

OC = Organic carbon

.

OMC

- Organic mass estimated from the IMPROVE organic carbon measurement (see POM)

.

PM 10 - Measure of particulate matter (pollutants from combustion and natural sources); denotes particles with a nominal size less than 10 micrometers in diameter.

PM 2.5 - Measure of particulate matter (pollutants from combustion and natural sources); denotes

par ticles smaller than 2.5 micrometers in diameter.

PMC = Coarse particulate matter (PM 10 - PM 2.5 )

.

PMFINE = Fine particulate matter (PM 2.5 )

.

PNO 3 = Particulate nitrate

.4

POA = Primary organic aerosol

.

POM = Particulate organic matter (see OMC).

Ppb = Pa rts per billion (1 in 10^9)

.

Ppm = Parts per million (1 in 10^6)

.

Ppt = Parts per trillion (1 in 10^12)

.

PRP = Preliminary Reasonable Progress.

PSAT = PM Source Apportionment Technology

- A modeling tool which performs source apportionment based on use r

- defined source groups. A source group is the combination of a geographic source region and an emissions source category. Examples of source regions include states, nonattainment areas, and counties. Examples of source categories include mobile sources

, biogenic sources, and elevated point sources.

PSD = Prevention of Significant Deterioration

- A program established by the Clean Air Act that limits the amount of additional air pollution that is allowed in Class I and Class II areas.

PSO 4 = Particulat e sulfate

.

RAVI = Reasonably Attributable Visibility Impairment

- Visibility impairment caused by a single or small number of sources.

Regional Haze

- A cloud of aerosols extending up to hundreds of miles across a region and promoting noticeably hazy con ditions. Condition of the atmosphere in which uniformly distributed aerosol obscures the entire vista irrespective of direction or point of observation. Is not easily traced visually to a single source.

REMSAD = Regulatory Modeling System for Aerosols a nd Deposition

- A numerical grid model for rapid scoping and strategy assessments for particulate matter, regional haze, PM species, and deposition of air toxins.

Residence Time

- The fraction of time an air parcel spends in a defined region (model grid c ell). Residence time maps are generated by summarizing back trajectories over a period of time of

interest.

RMC = Regional Modeling Center

. The Western Regional Air Partnership (WRAP) has implemented a regional planning process to provide the necessary technical and policy tools needed by states and tribes to comply with the CAA requirements. As part of this effort, the WRAP has established a Regional Modeling Center (RMC) at the University of California, Riverside (UCR) with assistance from ENVIRON Cor poration and the University of North

Carolina. The WRAP RMC provides assistance to State and Tribal agencies in conducting regional haze analyses over the western United States. This analysis is being performed by5

operating regional scale, three

- dimensio nal air quality models that simulate the emissions, chemical transformations, and transport of criteria pollutants and fine particulate matter (PM) and consequent effects on visibility in Class I Areas in the western US. ( http://pah.cert.ucr.edu/aqm/308/ )

Road Dust

- Emissions associated with mechanical re

- entrainment of dust materials from paved and unpaved road surfaces by vehicular traffic. These sources are computed as being spread over a spatial extent (a county or air district).

RPO = Regional Planning Organization

.

RRF = Relative Response Factor

- Estimated or expected change in aerosol species monitoring concentration between 2 different years, based on model results from both years. WRAP used 3 methods to develop relative r esponse factors (RRFs): Specific Days (designated by EPA); Quarterly Weighted; and Monthly Weighted. These methods are described in more detail under the TSS Methods page.

Sea Salt

- Particulate matter generated by wind on the ocean, approximated from m easurements of chloride or chlorine in an aerosol sampler.

SESARM = Southeast States Air Resource Managers . Affiliated with Southern Appalachian Mountain Initiative (SAMI). Represents the states of Alabama, Georgia, Kentucky, North Carolina, South Carol ina, and Tennessee.

SIP = State Implementation Plan

- A detailed description of the measures a state will use to carry out its responsibilities under the Clean Air Act.

SO 2 = Sulfur dioxide

- A gas consisting of one sulfur and two oxygen atoms. Of inter est because sulfur dioxide converts to an aerosol that is a very efficient light scatterer. Also, it can convert into acid droplets consisting primarily of sulfuric acid.

SO 4 = Sulfate

- Solid or liquid particulate matter composed of sulfuric acid [H 2 SO 4 ], ammonium bisulfate [NH 4 HSO 4 ], or ammonium sulfate [(NH 4 ) 2 SO 4 ]. Atmospheric sulfate aerosols are often formed from the atmospheric oxi dation of sulfur dioxide.

SOx = Oxides of sulfur

.

Soil

- D etermined as a sum of the masses of th o se eleme nts predominantly associated with soil (Al, Si, Ca, Fe, K, and Ti), adjusted to account for oxygen associated with the common oxide

forms. For purposes of the Regional Haze SIP, soil is considered PM 2.5

.

Substitute Data

- Some IMPROVE monitoring sites did not meet EPA Re gional Haze Rule data completeness requirements for the baseline period (2000

- 04). For these sites data were substituted for missing samples based on a methodology developed by WRAP. For more

information see http://matar.cira.colostate.edu/views/web/documents/substitutedata.aspx

.6

TSD = Technical Support Document

.

TSS = Technical Support System

.

URP = Uniform Rate of Progress.

VIEW = Visibility Intensive Experiment in the West

- A project of the US EPA, with cooperation of the National Park Service, to measure visibility at many stations throughout the western United States to document current visibility and examine trends.

VIEWS = Visibility Information Exchange W eb System

- A n online exchange of air quality data, research, and ideas designed to understand the effects of air pollution on visibility and to support the Regional Haze Rule enacted by the U.S. Environmental Protection Agency (EPA) to reduce regional haz e and improve visibility in national parks and wilderness areas. ( http://vista.cira.colostate.edu/views/ )

VISTAS = Visibility Improvement States and Tribal Association of the Southeast

- One of the five RPOs. Includes the states and tribal areas encompas sed by Alabama, Tennessee, Virginia, West Virginia, Georgia, Kentucky, Florida, Mississippi, North Carolina, and South

Carolina. Affiliated with SESARM.

VOC = Volatile organic carbons

.

VR = Visual range

.

WEP = Weighted Emissions Potential

- Specific to the Weighted Emissions Potential (WEP) analysis on the TSS. Gridded emissions were weighted by gridded residence times and distance from a Class I area, and normalized. The results of this analysis are interpreted as the potential for sources within spe cific grid cells to impact visibility at a Class I area, and thus provide a screening tool for planners. The results are not scientifically rigorous as it contains no method for accounting for chemistry and deposition.

WESTAR = Western States Air Resourc es Council . Represents the states of Alaska, California, Oregon, Washington, Hawaii, Arizona, New Mexico, Montana, Nevada, Colorado, Idaho, North Dakota, Oregon, South Dakota, Utah, and Wyoming.

Wildfire

- Any wildland fire that requires a suppression re sponse. A controlled burn may be declared a wildfire if part of it escapes from the control line or if weather conditions deteriorate and become unacceptable, as described in the burning plan.

Windblown Dust

- Emissions associated with aeolian re

- entrainment affecting the release of dust and organic carbon from disturbed or undisturbed lands by land use type. These sources are computed by applying meteorological data by land use type over a spatia l extent (an emissions model grid cell, cross

- referenced to a county or air district).7

WRAP = Western Regional Air Partnership . One of five RPOs. Includes the states and tribal areas encompassed by Arizona, California, Colorado, Idaho, Montana, New Mexico, North Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming. Affiliated with WESTAR.

2000

- 04 Baseline

- Refers to a WRAP emissions or mo deling scenario based on the designated planning emissions inventories, including a 5

- year average of fire emissions. Also referred to as Plan02 analysis series.

2002 Base Case

- Refers to a WRAP emissions or modeling scenario based on 2002 emissions

inv entories, including actual fire emissions for 2002. Also referred to as Base02 analysis series.

2018 Base Case

- Refers to a WRAP emissions or modeling scenario based on 2018 emissions inventories estimated by applying rules on the books in late 2004, ge nerated in early 2006. Also referred to as Base18 analysis series.

2018 Preliminary Reasonable Progress

- Refers to a WRAP emissions or modeling scenario based on the preliminary reasonable progress emissions inventories, generated in early 2007.

Includ es corrections, refinements and additions to the 2018 Base Case, as well as estimates of controlling SO 2 and some NOx from special coal

- fired power plants, called BART sources. Also referred to as PRP18 analysis series.

Partners

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ARS = Air Resource Specialists , Inc. provides professional consulting and support services in air quality monitoring, modeling, and permitting. Formed in 1981, ARS has successfully conducted a variety of contracts for federal, state, and local agencies, Indian nations, and

industrial clients. ARS maintains close, cooperative, and professional working relationships with its clients to ensure dedicated, comprehensive scientific services at competitive rates. ( http://www.air

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CIRA = Cooperative Institute for Research in the Atmosphere

. The Institute’s research is concentrated in several theme areas that include global and regional climate, local and mesoscale weather forecasting and evaluation, applied cloud physic s, applications of satellite observations, air quality and visibility, and societal and economic impacts, along with cross

- cutting research areas of numerical modeling and education, training and outreach. In addition to CIRA’s relationship with NOAA, the National Park Service also has an ongoing cooperation in air quality and visibility research that involves scientists from numerous disciplines, and the Center8

for Geosciences/Atmospheric Research based at CIRA is a long

- term program sponsored by the Depa rtment of Defense. ( http://www.cira.colostate.edu/ )

ENVIRON

- An international environmental and health sciences consultancy, ENVIRON partners with clients to assess and manage the potential environmental, energy, and health issues associated with their activities and products. ( http://www.environcorp.com/ )

Note: Other terms not defined in this glossary may be found in the WRAP TSS glossary at: http://vista.cira.colostate.edu/TSS/Help/Glossary.aspx

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