Draft Final Modeling Protocol 

CALMET/CALPUFF Protocol for 

BART Exemption Screening 

Analysis for Class I Areas in the 

Western United States 

Prepared for: 

Western Regional Air Partnership 

Air Quality Modeling Forum 

c/o Tom Moore 

Western Governors’ Association 

Prepared by: 

Western Regional Air Partnership 

Air Quality Modeling Forum 

Regional Modeling Center 

Gail Tonnesen and Zion Wang 

University of California at Riverside 

Ralph Morris, Abby Hoats and Yiqin Jia 

ENVIRON International Corporation 

August 15, 2006 

ENVIRON, 101 Rowland Way, Suite 220, Novato, CA 94945 415.899.0700
 

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Table of Contents 

FOREWORD................................................................................................................................ iv 

1. INTRODUCTION................................................................................................................ 1-1 

1.1 Emissions Used.......................................................................................................... 1-2 

 1.2 Visibility Calculations ............................................................................................... 1-3

2. EXTRACTION OF MM5 DATA FOR CALMET/CALPUFF MODELING................ 2-1 

3. CALMET/CALPUFF MODELING METHODOLOGY ................................................ 3-1

3.1 CALMET/CALPUFF Model Selection ..................................................................... 3-2 

 3.1.1 CALMET ............................................................................................................. 3-2 

 3.1.1.1 CALMET Modeling Domain........................................................................ 3-3 

 3.1.1.2 CALMET Performance Evaluation ............................................................ 3-13 

3.1.1.3 Terrain......................................................................................................... 3-13 

3.1.1.4 Land Use ..................................................................................................... 3-13 

3.1.1.5 CALMET ZFACE and ZIMAX Settings.................................................... 3-14 

3.1.1.6 CALMET Options and Comparison with 

 Regulatory Default Settings........................................................................ 3-14 

 3.1.2 CALPUFF.......................................................................................................... 3-18 

 3.1.2.1 Receptor Network and Class I Federal Areas............................................. 3-18 

 3.1.2.2 CALPUFF Meteorology ............................................................................. 3-18 

 3.1.2.3 CALPUFF Modeling Domains................................................................... 3-18 

3.1.2.4 CALPUFF Parameter Summary and Comparison 

 with Regulatory Defaults ............................................................................ 3-19 

 3.1.2.5 Chemical Mechanism.................................................................................. 3-22 

 3.1.2.6 Ammonia Assumptions............................................................................... 3-22 

 3.1.2.7 Ozone Assumptions .................................................................................... 3-23 

 3.1.3 CALPOST Settings and Visibility Post-Processing .......................................... 3-23 

4. ALASKA CALPUFF BART MODELING ....................................................................... 4-1

4.1 CALMET Modeling................................................................................................... 4-2 

4.2 CALPUFF Modeling ................................................................................................. 4-3 

5. RESULTS ............................................................................................................................. 5-1 

6. REFERENCES..................................................................................................................... 6-1 
 

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TABLES 

Table 2-1. MM5 model options for the MM5 simulations to be used 

 in the WRAP BART screening modeling............................................................ 2-2 

Table 3-1. Definition of State CALMET/CALPUFF modeling 

 domains using the RPO LCC projections based on an origin at 

 (-97°, 40°) and true latitudes at 33° and 45°........................................................ 3-4 

Table 3-2. CALMET options and comparison of proposed values with 

 EPA regulatory default settings as given by Atkinson and 

 Fox (2006), deviations from EPA recommended defaults 

 are indicated by bold text.................................................................................. 3-15 

Table 3-3. CALPUFF options and comparison of EPA regulatory modeling 

 default values with proposed values for the RMC BART screening analysis... 3-19 

Table 4-1. Definition of the CALMET/CALPUFF Alaska BART modeling 

 domain using a Lambert Conformal Conic (LCC) map projection. .................... 4-2 

Table 4−2. Locations of the 5 surface meteorological sites used in the 

 Alaska BART CALMET/CALPUFF modeling.................................................. 4−2 

FIGURES 

Figure 2-1. Relationship of four MM5 extraction window domains 

 for State CALPUFF modeling (AZ, MT, NM, NV, SD and UT) 

 and Class I areas................................................................................................... 2-4 

Figure 3-1a. Proposed CALMET/CALPUFF modeling domain, 

 Class I area receptors (green) and observed surface 

 meteorological sites for Arizona.......................................................................... 3-5 

Figure 3-1b. Proposed CALMET/CALPUFF modeling domain, 

 Class I area receptors (green) and observed surface 

 monitoring sites (purple triangles) for Montana (RMC currently 

 does not have any plans for modeling Montana BART sources). ....................... 3-6 

Figure 3-1c. Proposed CALMET/CALPUFF modeling domain, 

 Class I area receptors (green), observed surface 

 meteorological sites (purple triangles) and potential 

 BART-eligible source locations (red circles) for New Mexico........................... 3-7 

Figure 3-1d-1. Proposed CALMET/CALPUFF modeling domain and Class I 

 area receptors (green) and observed surface meteorological 

 sites (purple triangles) for Nevada....................................................................... 3-8 

Figure 3-1d-2. Proposed CALPUFF modeling domain for Northern potential 

 BART-eligible sources near Reno and Class I area receptors (green)................. 3-9 

Figure 3-1d-3. Proposed CALPUFF modeling domain for Southern potential 

 BART-eligible sources near Las Vegas and Class I area receptors (green) ...... 3-10 

Figure 3-1e. Proposed CALMET/CALPUFF modeling domain and Class I 

 area receptors (green), observed surface meteorological 

 sites (purple triangles) and potential BART-eligible source 

 locations (red circles) for South Dakota ............................................................ 3-11 

Figure 3-1f. Proposed CALMET/CALPUFF modeling domain and 

 Class I area receptors (green) and observed surface meteorological 

 sites (purple triangles) for Utah ......................................................................... 3-12 
 

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Figure 3-2. Land use categories table from CALMET User's Guide ................................... 3-13 

Figure 4-1. Locations of potential BART-eligible sources (red dots) 

 and Class I areas (green regions) in Alaska......................................................... 4-1 

Figure 4-2. Alaska BART CALMET/CALPUFF modeling domain 

 showing the potential BART-eligible sources (red dots) and 

 Denali and Tuxedni Class I area receptors .......................................................... 4-3 
 

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FOREWORD 

This document is a draft final Modeling Protocol that discusses the procedures to be used by the 

Western Regional Air Partnership (WRAP) Regional Modeling Center (RMC) for developing 

MM5 databases to support CALMET/CALPUFF modeling and for conducting BART screening 

exemption modeling using the CALMET/CALPUFF modeling system for six WRAP region 

States: Alaska; Arizona; New Mexico; Nevada; Utah; and South Dakota. Processed MM5 data 

will also be provided to Montana who will conduct their own CALMET/CALPUFF BART 

modeling. 

This Modeling Protocol is based on the BART CALPUFF Modeling Protocol prepared by the 

Colorado Department of Public Health and Environment (CDPHE) Air Pollution Control 

Division (APCD) (CDPHE, 2005). We would like to thank Chuck Machovec and others at the 

CDPHE/APCD for allowing us to use their Modeling Protocol as a starting point for the WRAP 

RMC Modeling Protocol. 

In addition to addressing different States, potential BART-eligible sources and Class I areas, 

there are several other differences between the proposed CALMET/CALPUFF modeling 

approach in this Modeling Protocol versus those proposed by the CDPHE (CDPHE, 2005) and 

other WRAP States (e.g., NDDOH, 2005). For example, we are proposing to use the three years 

of 2001, 2002 and 2003 for which 36 km MM5 data are available, whereas the CDPHE used the 

three years of 1996, 2001 and 2002. One major change in this revised draft Modeling Protocol 

compared to previous draft Modeling Protocols prepared by the WRAP RMC is we are now 

using meteorological observations along with the MM5 data as input to the 

CALMET/CALPUFF modeling system. In previous draft Modeling Protocols we proposed to 

operate CALMET using just the MM5 data without observed meteorological observations (i.e., 

the NOOBS mode). Comments received from EPA and Federal Land Managers (FLMs) noted 

that running CALMET/CALPUFF with meteorological observations was preferred and more 

conservative. Thus, meteorological observations were acquired and processed for input into 

CALMET for the WRAP RMC BART screening exemption modeling. 

The resultant CALMET/CALPUFF modeling databases developed under this work effort will be 

made available to the affected States. If the States or others wish to use or enhance the databases 

(e.g., high grid resolution, addition of more meteorological observations, etc.), they may obtain 

the databases from the States. 
 

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1. Introduction 

Federal law requires Best Available Retrofit Technology (BART) for any BART-eligible source 

that ‘‘emits any air pollutant which may reasonably be anticipated to cause or contribute to any 

impairment of visibility” in any mandatory Class I federal area. Pursuant to federal regulations, 

states have the option of exempting a BART-eligible source from the BART requirements based 

on dispersion modeling demonstrating that the source cannot reasonably be anticipated to cause 

or contribute to visibility impairment in a Class I area. 

According to 40 CFR Part 51, Appendix Y (EPA BART Guidelines; EPA, 2005), a BARTeligible source is considered to “contribute” to visibility impairment in a Class I area if the 

modeled 98th percentile change in deciviews is equal to or greater than the “contribution 

threshold.” Any BART-eligible source determined to cause or contribute to visibility impairment 

in any Class I area is subject to BART. The EPA BART Guidelines suggest a contribution 

threshold of 0.5 change in deciview be used. 

The WRAP RMC is processing 36 km MM5 data for the three years of 2001, 2002 and 2003 to 

support CALMET/CALPUFF modeling for six WRAP region States in the contiguous United 

States: Arizona; Montana; New Mexico; Nevada; Utah; and South Dakota. The processing of 

MM5 data to support CALMET/CALPUFF modeling for these six WRAP region States is 

discussed in Section 2. The WRAP RMC will conduct BART screening modeling for five of 

these States using the CALMET/CALPUFF modeling system and the 2001, 2002 and 2003 

MM5 using procedures discussed in Section 3. The RMC will also conduct 

CALMET/CALPUFF BART screening modeling for sources in Alaska using a 2002 MM5 and 

CALMET/CALPUFF databases that is discussed in Section 4. 

The WRAP RMC will apply CALPUFF with three years of meteorological data (one year for 

Alaska) and report on the 24-hour change in visibility (delta-deciview, Δdv) from potential 

BART-eligible sources at mandatory Federal Class I areas in and near each of the States 

modeled. The maximum and 98th percentile estimated 24-hour change in visibility (Δdv) will be 

summarized for each potential BART-eligible source and each Class I area under study. 

Spreadsheets of 24-hout average change in deciview from each potential BART-eligible source 

and each Class I area will be provided to the States in question who will determine which 

potential BART-eligible sources in their States are subject to BART. 

The WRAP RMC will use this protocol for the initial subject-to-BART modeling for the States 

indicated above. However, it is up to the States themselves to make the subject to BART 

determination. Additional modeling performed by the States or source operators may supersede 

the screening results from the WRAP RMC. Subsequent modeling should use modeling 

techniques consistent with the EPA BART Guidelines (EPA, 2005). The CALMET/CALPUFF 

modeling databases developed by the WRAP RMC will be provided to the affected States if 

desired. 
 

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1.1. Emissions Used 

According to the EPA BART Guidelines: “The emissions estimates used in the models are 

intended to reflect steady-state operating conditions during periods of high capacity utilization. 

We do not generally recommend that emissions reflecting periods of start-up, shutdown, and 

malfunction be used, as such emission rates could produce higher than normal effects than 

would be typical of most facilities. We recommend that States use the 24 hour average actual 

emission rate from the highest emitting day of the meteorological period modeled, unless this 

rate reflects periods start-up, shutdown, or malfunction.” (EPA, 2005) 

Short-term emission rates (≤24-hours) should be modeled since visibility impacts are calculated 

for a 24-hour averaging period. SO2, NOx, and PM10 (including condensible and filterable direct 

PM10) should be modeled from all BART-eligible units at the facility. States will provide the 

WRAP RMC with the source characteristics and emission rates to be used in the BART 

screening analysis. Source characteristics that must be included are: 

• Stack Location (e.g., latitude/longitude, UTM, etc.) 

• Stack Height (e.g., m or ft) 

• Stack Diameter (e.g. m or ft) 

• Exit Velocity (e.g., m/s or ft/s) or Flow Rate (e.g., m3/s or ft3/s) 

Emission rates that must be included include the following (e.g., gm/s, tons/day. tons/year): 

• SO2 

• NOx (as NO2) 

• Primary PM10 

In addition, the PM10 emissions should be broken down by PM species as follows: 

• SO4 (Sulfate, included primary H2SO4) 

• NO3 (Nitrate) 

• EC (Elemental Carbon) 

• OC (Organic Carbon) 

• PMF (Other PM2.5 or Soil) 

• PMC (Coarse PM, PM2.5-10) 

However, in reality most States provided PM emission estimates for their potential BARTeligible sources as total PM10 without speciation. In this case we will model the PM10 as PM2.5

and summarize the PM contribution to light extinction for the highest visibility impairment days 

and it will be up to the States to justify performing the BART exemption screening analysis 

without speciating the PM emissions (see Section 1.2 for extinction characteristics of the 

different components of PM). 

Maximum actual 24-hour emission rates may not be generally available for all sources. It is up 

to the States to provide the WRAP RMC with the emission rates they wish the RMC to use. The 

CDPHE provided the following guidance in their BART Modeling Protocol on what emission 

rates the CDPHE felt was acceptable for CALPUFF BART exemption modeling (CDPHE, 

2005): 

• Short-term (≤24-hours) allowable emission rates (e.g., emission rates calculated using 

the maximum rated capacity of the source). 

• Federally enforceable short-term limits (≤24-hours). 

• Peak 24-hour actual emission rates (or calculated emission rates) from the most recent 

3 to 5 years of operation that account for “high capacity utilization” during normal 
 

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operating conditions and fuel/material flexibility allowed under the source's permit. In 

situations where a unit is allowed to use more than one fuel, the fuel resulting in the 

highest emission rates should be used for the modeling, even if that fuel has not been 

used in the last 3 to 5 years. 

If short-term rates are not available, emissions rates based on averaging periods longer than 24-

hours are acceptable only in cases where the modeling shows that the source has impacts equal to 

or greater than the contribution threshold (CDPHE, 2005). 

The WRAP region States reviewing the visibility impacts will make their own opinion on the 

interpretation of the visibility modeling results in the case emission rates with longer averaging 

times than 24-hours are used. As noted above, if the visibility impact at a Class I area exceeds 

the 0.5 dv using longer averaging time emissions, then the 0.5 dv threshold would also be 

exceeded using the maximum 24-hour average emissions. If on the other hand, the visibility 

impacts due to the source at all Class I areas and all days are substantially below the 0.5 dv 

threshold, the State may be able to justify the determination that the source does not contribute 

significantly to visibility impairment at any Class I area. 

1.2. Visibility Calculations 

The CALPUFF modeling of the potential BART-eligible sources at Class I areas will potentially 

produce estimated 24-hour concentrations of SO4, NO3, EC, OC, PMF and PMC concentrations 

at a set of receptors that cover the Class I area. These concentration estimates need to be 

converted to light extinction. The general theory for performing visibility calculations with the 

CALPUFF modeling system is described in several documents, including: 

 “Interagency Workgroup on Air Quality Modeling (IWAQM) Phase 2 Summary 

Report and Recommendations for Modeling Long Range Transport Impacts” 

(IWAQM, 1998) 

 “Federal Land Manager’s Air Quality Related Values Workgroup (FLAG): Phase I 

Report” (FLAG, 2000) 

 “A User's Guide for the CALPUFF Dispersion Model” (Scire, 2000) 

 IMPROVE documents such as “Spatial and Seasonal Patterns and Temporal 

Variability of Haze and its constituents in the United State” (Malm et al., 2000) 

In general, visibility is characterized either by visual range (the greatest distance that a large 

object can be seen) or by the light extinction coefficient, which is a measure of the light 

attenuation per unit distance due to scattering and absorption by gases and particles. 

Visibility is impaired when light is scattered in and out of the line of sight and by light absorbed 

along the line of sight. The light extinction coefficient (bext) considers light extinction by 

scattering (bscat) and light extinction by absorption (babs): 

bext = bscat + babs

The scattering components of extinction can be represented by these components: 

 light scattering due to air molecules = Rayleigh scattering = brayleigh

 light scattering due to particles = bsp
 

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The absorption components of extinction can be represented by these components: 

 light absorption due to gaseous absorption = bag

 light absorption due to particle absorption = bap

Modeled concentrations are converted to light extinction using the IMPROVE reconstructed 

mass extinction equation. This equation accounts for both light scattering and light absorption 

due to particles. The current IMPROVE reconstructed mass extinction equation does not 

account for light absorption due to gases. The IMPROVE Steering Committee has recently 

endorsed a new IMPROVE equation that includes light absorption due to gases, but EPA BART 

Guidelines and this Modeling Protocol will use the current IMPROVE equation. 

Particle scattering, bsp, can be expressed by its components: 

bsp = bSO4 + bNO3 + bOC + bSOIL+ bCoarse

where: 

 bSO4 = scattering coefficient due to sulfates = 3[(NH4)2SO4]f(RH) 

 bNO3 = scattering coefficient due to nitrates = 3[NH4NO3]f(RH) 

 bOC = scattering coefficient due to organic aerosols = 4[OC] 

 bSOIL= scattering coefficient due to fine particles = 1[Soil] = 1[PMF] 

 bCoarse= scattering coefficient due to coarse particles = 0.6[Coarse Mass] = 

0.6[PMC] 

Particle absorption from soot is defined as: 

 bap = absorption due to elemental carbon (soot) = 10[EC] 

The concentration values (in brackets) are expressed in micrograms per cubic meter. The 

numeric coefficient at the beginning of each equation is the dry scattering or absorption 

efficiency in meters-squared per gram (also called the extinction coefficient). Sulfate (SO4) and 

nitrate (NO3) are assumed to be completely neutralized by ammonium (NH4). Both SO4 and 

NO3 are assumed to by hygroscopic and take up water under conditions of higher moisture, 

which affects their scattering properties. This is accounted for by the f(RH) term that is the 

relative humidity adjustment factor. 

The total atmospheric extinction (bext) can be expressed as: 

bext = bSO4 + bNO3 + bOC + bSOIL+ bCoarse+ bap+ brayleigh

In this equation, the sulfate (SO4) and nitrate (NO3) components are referred to as hygroscopic 

components because the extinction coefficient depends upon relative humidity. The other 

components are assumed to be non-hygroscopic. 

The variation of the effect of relative humidity on the extinction coefficients for SO4 and NO3 

can be determined in several ways. According to the EPA BART Guidelines, monthly f(RH) 

values should be used (EPA, 2003a,b). 

The CALPUFF modeling techniques in this protocol will provide ground level concentrations of 

visibility impairing pollutants. The concentration estimates from CALPUFF are used with the 

previously shown equations to calculate the extinction coefficient. 
 

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As described in the IWAQM Phase 2 Report, the change in visibility is compared against 

background conditions. The delta-deciview, Δdv, value is calculated from the source’s 

contribution to extinction, bsource, and background extinction, bbackground, as follows:

Δdv = 10 ln((bbackground+ bsource)/ bbackground) 

Here the background extinction (bbackground) is supposed to represent Natural Conditions (i.e., no 

man made impairment). The EPA BART Guidelines references that Natural Conditions be based 

on EPA’s “Guidance for Estimating Natural Conditions under the Regional Haze Rule” (EPA, 

2003a). This guidelines lists three sets of Natural Conditions corresponding to Annual Average, 

Best 20% Days and Worst 20% Days. EPA initially stated that the Natural Visibility Conditions 

corresponding to the Best 20% Days should be used for BART modeling (EPA, 2005). 

However, the use of the B20% Natural Conditions was challenged by the Utility Air Regulatory 

Group (UARG) and now EPA will allow States to use the Annual Average Natural Conditions in 

their subject to BART assessment (Paise, 2006a,b). For the WRAP RMC CALPUFF BART 

exemption screening modeling, changes in visibility at Class I area will be calculated using all 

three types of EPA default Natural Conditions (B20%, Annual Average and W20%) so that the 

States can understand the sensitivity of the results to this assumption and it is up to the States to 

select what Natural Conditions they believe are appropriate for their subject to BART 

determinations. 
 

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2. Extraction of MM5 Data For 

CALMET/CALPUFF Modeling 

Three years of 36 km MM5 data from 2001, 2002 and 2003 will be processed for the 

CALMET/CALPUFF modeling system and six States in the western U.S.: Arizona; Montana; 

New Mexico; Nevada; Utah; and South Dakota. The MM5 data were carried out by different 

groups as follows: 

2001 36 km MM5 data developed by Alpine Geophysics, LLC for the EPA and was used 

in the CAIR and CAMR modeling (McNalley, 2003); 

2002 36 km MM5 data developed by the WRAP RMC for the WRAP regional modeling 

(Kemball-Cook et al., 2004); and 

2003 36 km MM5 data developed by the Midwest RPO (MRPO/LADCO) for their 

regional modeling (Baker, 2004a,b). 

The 2002 36km MM5 data have been more extensively analyzed and tested for optimal 

configuration by the RMC for performance in the WRAP region. The 2001 and 2003 MM5 

datasets have not been similarly evaluated in as detailed fashion for their accuracy and 

performance in the WRAP region. 

In addition, a separate 2002 MM5 database developed by the WRAP RMC will be used for the 

Alaska BART CALPUFF modeling analysis (see Section 4). 

Table 2-1 summarizes the model options used in the MM5 simulations that are being used in the 

CALMET/CALPUFF BART screening modeling. For the 2001, 2002 and 2003 continental US 

MM5 simulations the same 36 km Lambert Conformal Projection grid was used. Whereas, due 

to the much higher latitudes, the Alaska simulations used a Polar Stereographic grid projection. 

The Pleim-Xiu LSM module was used for the continental U.S. simulations, where for the 2002 

and 2003 runs the MM5 simulations were conducted in 51⁄2 day segments with a cold start and 12 

hours of spin up time, but for the 2001 run each MM5 run segment soil moisture was initialized 

off of the previous run segment (but not soil temperature which was found to lead to a cold bias 

in the runs). During the summer the Alaska MM5 simulations used the OSU/Noah LSM 

module. However the winter Alaska MM5 simulations was run with the “sea ice” turned on 

which does not support the OSU LSM so the simpler 5-layer LSM was used. 
 

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Table 2-1. MM5 model options for the MM5 simulations to be used in the WRAP BART 

screening modeling. 

Continental US Alaska 2002 

Model Option 2001 2002 2003 Summer Winter 

Source 

Coordinate System Lambert Lambert Lambert Polar Polar 

Grid Resolution 36 km 36 km 36 km 15 km 15 km 

Land Surface Module Pleim-Xiu1 Pleim-Xiu Pleim-Xiu OSU/Noah 5-Layer 

Planetary Boundary Layer ACM ACM ACM ETA ETA 

Radiation RRTM RRTM RRTM RRTM RRTM 

Moist Physics Reisner II Reisner I Reisner I Reisner II Reisner II 

Cumulus KF 1 BM KF 1 Grell Grell 

Shallow Convection None None None None None 

Sea Ice No No No No Yes 

Analysis Nudging 

 Surface None U/V None None None 

 Aloft U/V/T/Q U/V/T/Q U/V/T/Q U/V/T/Q U/V/T/Q 

Observation Nudging 

 Surface None U/V None U/V U/V 

1

 The 2001 Pleim-Xiu LSM simulation used continuous moisture, whereas 2002 and 2003 used cold starts with 12 

hours initialization.

The processed MM5 data for CALPUFF modeling produce quite large files. Thus, we wish to 

define smaller domains for each of the States that need the data in order for the file sizes and data 

transfers to be more manageable. The MM5 data must completely cover the 

CALMET/CALPUFF modeling domains. They need to include the State of interest, plus Class I 

areas in nearby States with sufficient buffer between the Class I areas and the boundaries (e.g., 

50 km) to assure that CALPUFF puffs are not eliminated due to the centerline leaving the 

domain while the puff is still having a significant visibility impacts at a Class I area. Based on 

the States that require MM5 processing assistance, we have identified the following four MM5 

extraction domains: 

Arizona-New Mexico 

Nevada-Utah 

Montana 

South Dakota

MM5 Windowed Domains

Figure 2-1 displays the four windowed domains where MM5 data will be processed for 

CALMET/CALPUFF modeling. Also displayed in Figure 2-1 are the locations of the States 

(source regions) and Class I area (receptor regions) in the western U.S. 
 

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Arizona-New Mexico 

The Arizona-New Mexico MM5 window domain is centered on the two States (Figure 2-1). It 

extends west to include the Sequoia and Kings Canyon National Parks and Dome Land 

Wilderness in the north as well as several Southern California Class I areas. The northern 

boundary of the Arizona-New Mexico MM5 window domain is sufficiently north to include 

Class I areas in southern Utah and Colorado with a 50 km buffer. The eastern boundary was 

extended to include all of New Mexico; originally it was extended as far east to include the 

Wichita Mountains Class I area in Oklahoma but comments received from the FLMs were that 

this was unnecessary. We also considered pushing the southern boundary sufficiently far to 

include Big Bend National Park, however any BART source impact at Big Bend would likely 

have much higher impacts at the closer southern New Mexico and Arizona Class I areas (e.g., 

Guadalupe and Carlsbad Caverns). Consequently, the southern boundary was terminated north 

of Big Bend National Park. 

Nevada-Utah

The Nevada-Utah MM5 window domain includes the two States and extends to the: (1) 

southwest to include the Southern California Class I areas; (2) northwest to include the 

northeastern California and some south-central Oregon Class I areas; (3) north to include the 

Sawtooth Wilderness Area; (4) northeast to include Wind River and Eton Class I areas in 

Wyoming; and (5) to the east and southeast to include Class I areas in the Colorado Rocky 

Mountains and San Pedro Parks Class I area in New Mexico. 

Montana

The Montana MM5 window domain includes all of Montana and all Class I areas in Idaho and 

some in eastern Washington and Oregon. The Southern boundary is sufficient south to include 

all of the Wyoming Class I areas. The eastern boundary was placed so that the Theodore 

Roosevelt, North Dakota and Wind Cave and Badlands, South Dakota Class I areas could be 

included. The State of Montana also provided the definitions of their CALPUFF modeling 

domain that stretched west-east from longitude –177 to –103 degrees and south-north from 

latitude 44 to 49.5 degrees. The Montana MM5 window domain was made sufficient large to 

encompass these dimensions. 

South Dakota

The South Dakota MM5 window domain had to be made fairly large due to distance between the 

State and Class I areas in nearby States. The western boundary was sufficiently west to include 

eastern Montana and western Wyoming Class I areas. Southern Boundary stretched down to 

include the Mount Zirkel Colorado Class I area. And the northern and eastern boundaries were 

defined so that the Voyageurs and Boundary Waters, Minnesota Class I areas could be included. 
 

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Figure 2-1. Relationship of four MM5 extraction window domains for State CALPUFF modeling 

(AZ, MT, NM, NV, SD and UT) and Class I areas. 
 

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3. CALMET/CALPUFF Modeling 

Methodology 

For the WRAP RMC BART exemption screening modeling, we will follow the EPA BART 

Guidelines (EPA, 2005) and the applicable CALMET/CALPUFF modeling guidance (e.g., 

IWAQM, 1998; FLAG, 2000; EPA, 2003c) including EPA’s recent March 16, 2006 

memorandum: “Dispersion Coefficients for Regulatory Air Quality Modeling in CALPUFF” 

(Atkinson and Fox, 2006). This memorandum was written by the EPA Office of Air Quality and 

Planning Standards (OAQPS) Model Clearing House Director in response to questions from 

EPA Region 4 on what constitutes the regulatory version of CALPUFF and recommended 

CALPUFF options for BART modeling in their region. Consequently, the CALMET/CALPUFF 

modeling recommendations in the EPA memorandum (Atkinson and Fox, 2006) are followed in 

this Modeling Protocol, with the following exceptions (more details on these exceptions are 

provided in Sections 3.1.1.6 and 3.1.2.4): 

• We propose to use the latest version of CALPUFF (Version 6 dated April 2006) rather 

than the “EPA Approved Version”; 

• A maximum mixing height of 4,500 m AGL will be specified rather than the EPA 

recommended default maximum mixing height value of 3,000 m AGL; 

• The modeling domains will be based on a Lambert Conformal Conic (LCC) projection 

consistent with the RPO modeling rather than the EPA default; 

• Compatible values for the CALMET IEXTRP and RMIN2 parameters will be used; 

• The number of emitted and modeled species will depend on the level of detail on 

emissions provided by the States rather than the EPA default 3 and 5 species, 

respectively; and 

• A background ammonia value of 1 ppb will be used in the CALPUFF modeling (0−1 ppb 

for Alaska) rather then the 10 ppb EPA default. 

• Water land use will be specified and no spatial averaging of temperatures will be 

performed (IAVET=0). 

The WRAP RMC will perform an initial subject-to-BART screening analysis modeling using the 

procedures in this Modeling Protocol and provide the results to the affected States. However, the 

WRAP RMC initial modeling may be superseded by additional modeling performed by the 

States or source operators. 

Relevant guidance suggests that the CALPUFF model is generally applicable at distances from 

50 km to 300 km downwind and may be used for distance less than 50 km when complex flows 

exist on a case by case basis (IWAQM, 1998; FLAG 2000; EPA, 2003c). Class I areas in the 

west generally are located in complex terrain resulting in complex flows. Consequently, the 

BART screening modeling conducted by the RMC will include results for potential BARTeligible sources that reside within 50 km of a Class I area. The WRAP RMC BART screening 

modeling may also apply CALPUFF to downwind distances greater than 300 km. When 

providing results to the States, the downwind distance between the BART source and the Class I 

area will be included, and a recommendation from the RMC as to the utility of applying the 

results for Class I areas less than 50 km and greater than 300 km from the source. The individual 

States will need to make their own regulatory assessment of the applicability of the model results 

at those distances less than 50 km and greater than 300 km.
 

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3.1. CALMET/CALPUFF Model Selection 

The March 16, 2006 memorandum from the EPA/OAQPS Model Clearing House is very clear 

on which is the regulatory version of the model: “The regulatory version of CALPUFF, along 

with specific regulatory options, resides on the Earth Tech website, described as the ‘EPAApproved Version’.” (Atkinson and Fox, 2006). This version was originally proposed for the 

BART screening analysis. However, discussions with the FLMs and others revealed that this 

version of the model contained errors and that a newer version should be used. Consequently, 

we propose to use the latest (as of April, 2006) version of the CALPUFF modeling system 

(available at www.src.com): 

• CALMET Version 6.211 Level 060414

• CALPUFF Version 6.112 Level 060412

3.1.1. CALMET 

CALMET will be applied for separate State domains using a 4 km grid and 11 vertical layers 

(see Figure 3-1). A Lambert Conformal Conic (LCC) map projection will be used that is the 

same as used in the WRAP MM5 and CMAQ/CAMx modeling. Terrain and land use data will 

be provided at 4 km grid resolution, whereas the MM5 data will be provided at a 36 km grid 

resolution. 

The 36 km MM5 meteorological fields for 2001, 2002 and 2003 have been processed into the 

format used by CALMET. CALMET is based on the Diagnostic Wind Model (Douglas and 

Kessler, 1988) that was originally developed as part of the EPA Rocky Mountain Acid 

Deposition Model Assessment Project (Morris et al., 1987) and later adapted for the UAM 

Modeling System (Morris and Myers, 1990). 

CALMET/DWM uses a two-step approach to calculate wind fields. In the first step, an initialguess wind field is adjusted for diagnostic wind effects of terrain, such as channeling, blocking 

and deflection and slope flows, to produce a Step 1 wind field. In Step 2, an objective analysis is 

performed to introduce observational data into the Step 1 wind field. For the WRAP RMC 

BART screening modeling, CALMET is being operated using hourly three-dimensional 36 km 

MM5 meteorological and observed surface meteorological and precipitation data. In earlier 

versions of this Modeling Protocol we have proposed to run CALMET using the no observations 

(NOOBS) mode. However, EPA/FLMs have noted that running CALMET/CALPUFF in the 

NOBS mode is less conservative that when meteorological observations are also used. The 

reasons why CALMET/CALPUFF run in the NOOBS model produces less conservative 

concentrations (i.e., lower) estimates than when observations are specified has been traced to the 

calculation of PGT stability Class. When surface meteorological observations are specified, 

PGT Stability Class is calculated using sky cover, solar intensity and wind speed, whereas in the 

NOOBS mode an alternative algorithms is used that estimates a more unstable atmosphere and 

therefore enhanced dispersion and lower concentration estimates. Using the NOOBS mode to 

operate CALMET/CALPUFF does not necessarily mean it is less accurate than when surface 

meteorological observations are used, just that it produces lower concentration estimates and is 

therefore less conservative. In fact, the IWAQM (1998) testing of the CALMET/CALPUFF 

modeling system against real-world observed atmospheric tracer measurements found it 
 

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overestimated downwind measured concentrations beyond 200-300 km by a factor of 3-4 due to 

inadequate spread (dispersion) of the plume, suggesting that enhanced dispersion may be more 

accurate. 

For the BART screening analysis, initial guess wind fields based on hourly 36-kilometer MM5 

meteorological fields for 2001, 2002 and 2003 (i.e., IPROG=14) will be used. These initial 

guess wind fields are adjusted to account for the effects of 4 km terrain and land use data on the 

wind fields in Step 1 of CALMET/DWM. Note that although surface meteorological and 

precipitation observations are specified as input to CALMET, no observed upper-air 

meteorological observations will be used as they are redundant to the MM5 data and may 

introduce spurious artifacts in the wind fields. In the application of the MM5, the twice daily 

upper-air meteorological observations are used as input with the MM5 model estimates nudged 

to the observations as part of the Four Dimensional Data Assimilation (FDDA). This results in 

higher temporal (hourly vs. 12-hour) and spatial (36 km vs. ~300 km) resolution upper-air 

meteorology in the MM5 field that is dynamically balanced than contained in the upper-air 

observations. Therefore the use of the upper-air observations with CALMET is not needed and 

in fact will upset the dynamic balance of the meteorological fields potentially producing spurious 

vertical velocities. 

The EPA BART Guidelines do not state the exact number of years of mesoscale meteorological 

data for use in CALPUFF, but according to EPA air quality modeling guidelines (EPA, 2003c, 

40 CFR 51 Appendix W) and discussed by FLAG (2000), at least three years of meteorological 

data should be used. Five years of meteorological data is preferable, but when mesoscale 

meteorological data are used (i.e., MM5) three years of modeling is acceptable. 

3.1.1.1. CALMET Modeling Domains 

The WRAP RMC has developed seven CALMET/CALPUFF modeling domains in the 

contiguous U.S. that focus on the following States and nearby Class I areas: Arizona, Montana, 

New Mexico, Nevada, South Dakota and Utah (Figure 3-1). In addition, there is an Alaska 

CALMET/CALPUFF modeling that is discussed in Section 4. At this time the RMC does not 

plan on performing CALMET/CALPUFF modeling for Montana. Montana has requested the 

2001, 2002 and 2003 processed MM5 data and will conduct their own CALPUFF modeling. 

All of the CALMET/CALPUFF modeling domains are based on the same Lambert Conformal 

Conic (LCC) map projection as used in the RPO’s MM5 and CMAQ modeling: 

• X-Center = 97° Longitude 

• Y-Center = 40° Latitude 

• Alpha = 33° Latitude 

• Beta = 45° Latitude 

Using the RPO LCC map projection, each of the CALMET/CALPUFF modeling domains shown 

in Figure 3-1 are defined using the parameters in Table 3-1. Shown in these figures are the Class 

I areas, potential BART-eligible sources (when available) and the locations of the surface 

meteorological observation sites. 
 

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Table 3-1. Definition of State CALMET/CALPUFF modeling domains using the RPO LCC 

projections based on an origin at (-97°, 40°) and true latitudes at 33° and 45°. 

SW and NE Corners (m LCP) Number of 4 km Grids 

State Southwest Northeast x-direction y-direction

No. Class I 

Receptors 

Arizona (-1944, -900) (-792, 0) 288 225 12,156 

Montana (-1656, 360) (-360, 1296) 324 234 10,575 

New Mexico (-1368, -900) (-504, -36) 216 216 4,471 

Nevada CALMET (-2088, -576) (-1296, 648) 198 306 10,254 

NV CALPUFF N (-2088, -200) (-1460, 500) 157 175 4900 

NV CALPUFF S (-2000, -576) (-1300, 420) 175 249 8183 

S. Dakota (-1080, 216) (468, 1044) 387 207 5,786 

Utah (-1620, -540) (-792, 648) 207 297 11,365 

These domains are quite large and many of the source-receptor distances will exceed 300 km. 

Thus, when the RMC provides the modeling results to the States, the distance between the 

potential BART-eligible source and the Class I area should be considered in their interpretation 

of whether a visibility impact is significant. Also, the proposed modeling domains contain many 

receptors in the Class I areas (roughly 4,000-12,000). This may result in CALPUFF simulations 

with excessive computational requirements. Consequently, we will discuss the following issues 

with each State that would reduce the computational requirements of the CALPUFF simulations: 

• Reductions in the size of the CALPUFF computational domains displayed in Figure 3-1. 

• Reduction in the number of receptors covering the Class I areas (e.g., reduction in the 

density or elimination of receptors over 300 km from the sources of interest). 

For the Nevada CALMET/CALPUFF modeling, CALMET modeling for 2001, 2002 and 2003 

will be conducted for the entire 198 x 306 4 km domain depicted in Figure 3-1d-1. The Nevada 

BART sources are clustered either near Reno in the northern or Las Vegas in the southern parts 

of the State. Consequently, we will run two separate CALPUFF modeling domains, a northern 

and southern domain that are shown in Figure 3-1d-2 and Figure 3-1d-3, respectively. 
 

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-2000 -1800 -1600 -1400 -1200 -1000 -800

-800

-600

-400

-200

0

Figure 3-1a. Proposed CALMET/CALPUFF modeling domain, Class I area receptors (green) and 

observed surface meteorological sites for Arizona. 
 

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-1600 -1400 -1200 -1000 -800 -600 -400

400

600

800

1000

1200

Figure 3-1b. Proposed CALMET/CALPUFF modeling domain, Class I area receptors (green) and 

observed surface monitoring sites (purple triangles) for Montana (RMC currently does not have any 

plans for modeling Montana BART sources). 
 

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-1400 -1300 -1200 -1100 -1000 -900 -800 -700 -600 -500

-900

-800

-700

-600

-500

-400

-300

-200

-100

0

Figure 3-1c. Proposed CALMET/CALPUFF modeling domain, Class I area receptors (green), 

observed surface meteorological sites (purple triangles) and potential BART-eligible source locations 

(red circles) for New Mexico. 
 

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Figure 3-1d-1. Proposed CALMET/CALPUFF modeling domain and Class I area receptors (green) 

and observed surface meteorological sites (purple triangles) for Nevada. 
 

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Figure 3-1d-2. Proposed CALPUFF modeling domain for northern potential BART-eligible 

sources (red circles) near Reno and Class I area receptors (green).
 

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Figure 3-1d-3. Proposed CALPUFF modeling domain for southern potential BART-eligible 

sources (red circles) near Las Vegas and Class I area receptors (green).
 

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-1000 -800 -600 -400 -200 0 200 400

200

400

600

800

1000

Figure 3-1e. Proposed CALMET/CALPUFF modeling domain and Class I area receptors (green), 

observed surface meteorological sites (purple triangles) and potential BART-eligible source locations 

(red circles) for South Dakota. 
 

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-1600 -1400 -1200 -1000 -800

-600

-400

-200

0

200

400

600

Figure 3-1f. Proposed CALMET/CALPUFF modeling domain and Class I area receptors (green) and 

observed surface meteorological sites (purple triangles) for Utah. 
 

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3.1.1.2. CALMET Performance Evaluation 

The CALMET meteorological fields will be spot checked for reasonableness using visualization 

and animation tools, but no comprehensive evaluation will be undertaken. The main inputs to 

CALMET are the hourly 36 km MM5 data, surface meteorological and precipitation 

measurements, terrain data and land use data. The 36 km MM5 fields have been evaluated 

previously (McNally, 2003; Kemball-Cook et al., 2005; Baker, 2004a,b) and the terrain and land 

use inputs will be evaluated by comparison spatial plots of the inputs against topographic and 

land use maps. 

3.1.1.3. Terrain 

Gridded terrain elevations for the modeling domain are derived from 3 arc-second digital 

elevation models (DEMs) produced by the United States Geological Survey (USGS). The files 

cover 1-degree by 1-degree blocks of latitude and longitude. USGS 1:250,000 scale DEMs were 

used. The elevations are in meters relative to mean sea level and have a resolution of about 90 

meters. These data will be processed to generate 4 km average terrain heights that will be input 

into CALMET. Additional terrain databases will be used to define terrain heights in the Canada 

and Mexico portions of the modeling domains as needed. 

3.1.1.4. Land Use 

The land use data is based on the Composite Theme Grid format (CTG) using Level I USGS 

land use categories were “mapped into the 14 primary CALMET land use categories described in 

Figure 3-2. 

Figure 3-2. Land use categories table from CALMET User's Guide.
 

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3.1.1.5. CALMET ZFACE and ZIMAX Settings 

Eleven vertical layers will be used with vertical cell face (ZFACE) heights at: 0, 20, 100, 200, 

350, 500, 750, 1000, 2000, 3000, 4000, and 5000 meters. 

ZIMAX was set to 4500 meters based on the CDPHE analyses of soundings for summer ozone 

events in the Denver area (CDPHE, 2005). The CDPHE analysis suggests mixing heights in the 

Denver area are often well above the CALMET default value of 3000 meters during the summer. 

For example, on some summer days, ozone levels are elevated all the way to 6000 meters MSL 

or beyond during some meteorological regimes, including some regimes associated with high 

ozone episodes. We suspect that, like in Denver, mixing heights in excess of the 3,000 m AGL 

CALMET default maximum would occur in the western States. Note that this is one area where 

we are deviating from EPA’s March 16, 2006 memorandum on CALMET/CALPUFF regulatory 

settings. 

3.1.1.6. CALMET Options and Comparison with Regulatory Default Settings 

Table 3-2 compares the proposed CALMET options and settings with those recommended by 

EPA for the regulatory application of the CALMET model (Atkinson and Fox, 2006). The RMC 

BART screening analysis CALMET parameters conforms with all of EPA’s recommendations 

for regulatory application of the CALPUFF modeling system, with the following exceptions: 

• The WRAP CALMET/CALPUFF modeling domains will be based on the same InterRPO Lambert Conformal Conic (LCC) projection as used in the WRAP MM5 and 

CMAQ modeling rather than the EPA default LCC projection. 

• Proposed maximum mixing height (Z1MAX) of 4,500 m AGL versus EPA regulatory 

default of 3,000 m AGL. A 3,000 m AGL maximum mixing height might be appropriate 

in the eastern U.S., however in the western U.S. in the summer mixing heights may 

exceed this value. In their BART Modeling Protocol, the CDPHE presents compelling 

evidence that mixing heights exceed 3,000 m AGL in Denver during the summer. We 

would expect other areas in the west to also have higher mixing heights so we have 

adopted the 4,500 m AGL values as used by CDPHE (CDPHE, 2005); 

• The EPA default assumes no MM5 data will be used (IPROG=0). In the RMC BART 

screening analysis MM5 data will be used as an initial guess field (IPROG=14). 

• The EPA default assumes values for IEXTRP (-4) and RMIN2 (4) that are incompatible 

with each other, thus we will use values that are consistent with each other (1 and 4, 

respectively). Because we are using hourly 36 km MM5 data to define the upper−level 

winds, the extrapolation of the surface wind data aloft as recommended by EPA 

(IEXTRP= −4) is not needed and in fact would upset the dynamic balance of the aloft 

winds producing spurious vertical velocities. 

• We are setting IAVET to 0 to turn off spatially averaging of the temperature interpolation 

since the MM5 temperatures with already be fairly smooth. 

• We are setting the beginning and ending water land use categories to 51 and 55, 

respectively (see Figure 3−2), rather than EPA default (999) that assumes no water 

landuse categories. 
 

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Table 3-2. CALMET options and comparison of proposed values with EPA regulatory default 

settings as given by Atkinson and Fox (2006), deviations from EPA recommended defaults are 

indicated by bold text. 

Variable Description EPA Default Our Values 

GEO.DAT Name of Geophysical data file GEO.DAT GEO.DAT 

SURF.DAT Name of Surface data file SURF.DAT SURF.DAT 

PRECIP.DAT Name of Precipitation data file PRECIP.DAT PRECIP.DAT 

NUSTA Number of upper air data sites User Defined 0 

UPN.DAT Names of NUSTA upper air data 

files 

UPN.DAT NA 

IBYR Beginning year User Defines User Defines 

IBMO Beginning month User Defines User Defines 

IBDY Beginning day User Defines User Defines 

IBHR Beginning hour User Defines User Defines 

IBTZ Base time zone User Defines User Defines 

IRLG Number of hours to simulate User Defines User Defines 

IRTYPE Output file type to create (must be 

1 for CALPUFF) 

1 1 

LCALGRD Are w-components and 

temperature needed? 

T T 

NX Number of east-west grid cells User Defines Table 3-1 

NY Number of north-south grid cells User Defines Table 3-1

DGRIDKM Grid spacing User Defines Table 3-1

XORIGKM Southwest grid cell X coordinate User Defines Table 3-1

YORIGKM Southwest grid cell Y coordinate User Defines Table 3-1

XLATO Southwest grid cell latitude User Defines Table 3-1

YLONO Southwest grid cell longitude User Defines Table 3-1

IUTMZN UTM Zone User Defines NA 

LLCONF When using Lambert Conformal 

map coordinates, rotate winds 

from true north to map north? 

F F 

XLAT1 Latitude of 1st standard parallel 30 33 

XLAT2 Latitude of 2nd standard parallel 60 45 

RLON0 Longitude used if LLCONF = T 90 97 

RLAT0 Latitude used if LLCONF = T 40 40 

NZ Number of vertical Layers User Defines 11 

ZFACE Vertical cell face heights (NZ+1 

values) 

User Defines 0,20,100,200,350,500,750,1

000,2000,3000,4000, and 

5000 

LSAVE Save met. Data fields in an 

unformatted file? 

T T 

IFORMO Format of unformatted file (1 for 

CALPUFF) 

1 1 

NSSTA Number of stations in SURF.DAT 

file 

User Defines Domain dependent, see 

Figure 3-1 for locations

NPSTA Number of stations in 

PRECIP.DAT 

User Defines Domain dependent, see 

Figure 3-1 for locations

ICLOUD Is cloud data to be input as 

gridded fields? 0=No) 

0 0 

IFORMS Format of surface data (2 = 

formatted) 

2 2 

IFORMP Format of precipitation data (2= 

formatted) 

2 2 

IFORMC Format of cloud data (2= 

formatted) 

2 2 
 

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Variable Description EPA Default Our Values 

IWFCOD Generate winds by diagnostic 

wind module? (1 = Yes) 

1 1 

IFRADJ Adjust winds using Froude 

number effects? (1= Yes) 

1 1 

IKINE Adjust winds using Kinematic 

effects? (1 = Yes) 

0 0 

IOBR Use O’Brien procedure for vertical 

winds? (0 = No) 

0 0 

ISLOPE Compute slope flows? (1 = Yes) 1 1 

IEXTRP Extrapolate surface winds to 

upper layers? (-4 = use similarity 

theory and ignore layer 1 of upper 

air station data) 

-4 1 

ICALM Extrapolate surface calms to 

upper layers? (0 = No) 

0 0 

BIAS Surface/upper-air weighting 

factors (NZ values) 

NZ*0 NZ*0 

IPROG Using prognostic or MM-FDDA 

data? (0 = No) 

0 14 

LVARY Use varying radius to develop 

surface winds? 

F F 

RMAX1 Max surface over-land 

extrapolation radius (km) 

User Defines 50. 

RMAX2 Max aloft over-land extrapolations 

radius (km) 

User Defines 100. 

RMAX3 Maximum over-water 

extrapolation radius (km) 

User Defines 100. 

RMIN Minimum extrapolation radius 

(km) 

0.1 0.1 

RMIN2 Distance (km) around an upper 

air site where vertical 

extrapolation is excluded (Set to –

1 if IEXTRP = ±4) 

4 4 

TERRAD Radius of influence of terrain 

features (km) 

User Defines 10. 

R1 Relative weight at surface of Step 

1 field and obs 

User Defines 100. 

R2 Relative weight aloft of Step 1 

field and obs 

User Defines 200. 

DIVLIM Maximum acceptable divergence 5.E-6 5.E-6 

NITER Max number of passes in 

divergence minimization 

50 50 

NSMTH Number of passes in smoothing 

(NZ values) 

2,4*(NZ-1) 2,4*(NZ-1) 

NINTR2 Max number of stations for 

interpolations (NA values) 

99 99 

CRITFN Critical Froude number 1 1 

ALPHA Empirical factor triggering 

kinematic effects 

0.1 0.1 

IDIOPT1 Compute temperatures from 

observations (0 = True) 

0 0 

ISURFT Surface station to use for surface 

temperature (between 1 and 

NSSTA) 

User Defines 1 

IDIOPT2 Compute domain-average lapse 

rates? (0 = True) 

0 0 
 

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Variable Description EPA Default Our Values 

IUPT Station for lapse rates (between 1 

and NUSTA) 

User Defines 1 

ZUPT Depth of domain-average lapse 

rate (m) 

200 200 

IDIOPT3 Compute internally initial guess 

winds? (0 = True) 

0 0 

IUPWND Upper air station for domain 

winds (-1 = 1/r**2 interpolation of 

all stations) 

-1 -1 

ZUPWND Bottom and top of layer for 1st

guess winds (m) 

1,1000 1,1000 

IDIOPT4 Read surface winds from 

SURF.DAT? ( 0 = True) 

0 0 

IDIOPT5 Read aloft winds from UPn.DAT? 

( 0 = True) 

0 0 

CONSTB Neutral mixing height B constant 1.41 1.41 

CONSTE Convective mixing height E 

constant 

0.15 0.15 

CONSTN Stable mixing height N constant 2400 2400 

CONSTW Over-water mixing height W 

constant 

0.16 0.16 

FCORIOL Absolute value of Carioles 

parameter 

1.E-4 1.E-4 

IAVEZI Spatial averaging of mixing 

heights? ( 1 = True) 

1 1 

MNMDAV Max averaging radius (number of 

grid cells) 

1 1 

HAFANG Half-angle for looking upwind 

(degrees) 

30 30 

ILEVZI Layer to use in upwind averaging 

(between 1 and NZ) 

1 1 

DPTMIN Minimum capping potential 

temperature lapse rate 

0.001 0.001 

DZZI Depth for computing capping 

lapse rate (m) 

200 200 

ZIMIN Minimum over-land mixing height 

(m) 

50 50 

ZIMAX Maximum over-land mixing height 

(m) 

3000 4500 

ZIMINW Minimum over-water mixing 

height (m) 

50 50 

ZIMAXW Maximum over-water mixing 

height (m) 

3000 4500 

IRAD Form of temperature interpolation 

(1 = 1/r) 

1 1 

TRADKM Radius of temperature 

interpolation (km) 

500 500 

NUMTS Max number of stations in 

temperature interpolations 

5 5 

IAVET Conduct spatial averaging of 

temperature? (1 = True) 

1 0 

TGDEFB Default over-water mixed layer 

lapse rate (K/m) 

-0.0098 -0.0098 

TGDEFA Default over-water capping lapse 

rate (K/m) 

-0.0045 -0.0045 

JWAT1 Beginning landuse type defining 999 51 
 

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Variable Description EPA Default Our Values 

water 

JWAT2 Ending landuse type defining 

water 

999 55 

NFLAGP Method for precipitation 

interpolation (2= 1/r**2) 

2 2 

SIGMAP Precip radius for interpolations 

(km) 

100 100 

CUTP Minimum cut off precip rate 

(mm/hr) 

0.01 0.01 

SSn NSSTA input records for surface 

stations 

User Defines Figure 3-1 

Usn NUSTA input records for upperair stations User Defines NA 

PSn NPSTA input records for 

precipitations stations 

User Defines Figure 3-1 

3.1.2. CALPUFF

The CALPUFF model will be applied following EPA guidance and recommendations (EPA, 

2003c; Atkinson and Fox, 2006) and other recommendations (IWAQM, 1998; FLAG, 2000). 

3.1.2.1. Receptor Network and Class I Federal Areas 

 

The NPS recommended receptor networks for Class I areas will be used in the analysis. The 

locations of these receptors for each of the CALMET/CALPUFF modeling domains are shown 

in Figure 3-1. Because of the large size of the CALPUFF modeling domains, the high density of 

the NPS receptors in the Class I areas and the many Class I areas in the west, there may be a 

need to reduce the number of receptors to a more manageable number. For example, the 

proposed Utah CALPUFF modeling domain (Figure 3-1f) includes 11,365 receptors. As the 

CALPUFF run times depend on the number of sources and receptors, then specifying too many 

receptors results in excessive run times. For PSD/NSR modeling Class I area receptors are 

typically limited to within 300 km of the source. The RMC will work with the WRAP Modeling 

Forum and affected States to determine ways to reduce the total number of receptors without 

sacrificing the identification of the maximum visibility impacts from potential BART eligible 

sources at Class I areas. 

3.1.2.2. CALPUFF Meteorology 

The CALPUFF meteorology will be based on CALMET as described in Section 3.1.1. 

3.1.2.3. CALPUFF Modeling Domain 

The CALPUFF modeling domains are mostly assumed to be identical to the CALMET modeling 

domains and are shown in Figure 3-1. Although if run times are excessive the relevant States 

will be consulted about potential reductions in the size of the CALPUFF computational domain. 

The State of Nevada requested that two separate CALPUFF computational grids be used, one 
 

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associated with northern (Figure 3-1d-2) and one associated with southern Nevada sources 

(Figure 3-1d-3). 

3.1.2.4. CALPUFF Parameter Summary and Comparison with Regulatory 

Defaults 

The CALPUFF options were selected to follow EPA’s recommended settings for regulatory 

modeling (Atkinson and Fox, 2006) as shown in Table 3-3. Differences from these 

recommendations are as follows: 

• The number of species modeled and emitted will depend on the emissions data 

provided by the States for the BART sources. If just SO2 and NOx emissions are 

provided, 5 species will be modeled (SO2, SO4, NOx, NHNO3 and NO3) as 

recommended by EPA. For States that also provide total PM10 emissions 6 species 

will be modeled. Potentially States could provide PM emissions split into SO4, NO3, 

EC, OC, PMF and PMC in which case 9 species will be modeled. 

• MRESTART will be 2 for first run segment of the year and 3 for subsequent run 

segments. 

• The background ammonia for the CALPUFF runs will be 1 ppb that is believed to be a 

more representative value for the western U.S. than the 10 ppb EPA default. Note that 

we are still reviewing what background ammonia value should be used when postprocessing the results to calculate ammonia limiting where site and monthly specific 

values are being considered. 

Table 3-3. CALPUFF options and comparison of EPA regulatory modeling default values with 

proposed values for the RMC BART screening analysis, bold text indicates deviations from EPA 

recommendations. 

Variable Description EPA Default Our Values 

METDAT CALMET input data filename CALMET.DAT CALMET.DAT 

PUFLST Filename for general output from 

CALPUFF 

CALPUFF.LST CALPUFF.LST 

CONDAT Filename for output concentration data CONC.DAT CONC.DAT 

DFDAT Filename for output dry deposition fluxes DFLX.DAT DFLX.DAT 

WFDAT Filename for output wet deposition fluxes WFLX.DAT WFLX.DAT 

VISDAT Filename for output relative humidities (for 

visibility) 

VISB.DAT VISB.DAT 

METRUN Do we run all periods (1) or a subset (0)? 0 0 

IBYR Beginning year User Defined User Defined 

IBMO Beginning month User Defined User Defined 

IBDY Beginning day User Defined User Defined 

IBHR Beginning hour User Defined User Defined 

IRLG Length of runs (hours) User Defined User Defined 

NSPEC Number of species modeled (for 

MESOPUFF II chemistry) 

5 5-9 

NSE Number of species emitted 3 2-9 

MRESTART Restart options (0 = no restart), allows 

splitting runs into smaller segments 

0 2 or 3 

METFM Format of input meteorology (1 = 

CALMET) 

1 1 

AVET Averaging time lateral dispersion 

parameters (minutes) 

60 60 

MGAUSS Near-field vertical distribution (1 = 1 1 
 

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Variable Description EPA Default Our Values 

Gaussian) 

MCTADJ Terrain adjustments to plume path (3 = 

Plume path) 

3 3 

MCTSG Do we have subgrid hills? (0 = No), allows 

CTDM-like treatment for subgrid scale 

hills 

0 0 

MSLUG Near-field puff treatment (0 = No slugs) 0 0 

MTRANS Model transitional plume rise? (1 = Yes) 1 1 

MTIP Treat stack tip downwash? (1 = Yes) 1 1 

MSHEAR Treat vertical wind shear? (0 = No) 0 0 

MSPLIT Allow puffs to split? (0 = No) 0 0 

MCHEM MESOPUFF-II Chemistry? (1 = Yes) 1 1 

MWET Model wet deposition? (1 = Yes) 1 1 

MDRY Model dry deposition? (1 = Yes) 1 1 

MDISP Method for dispersion coefficients (3 = PG 

& MP) 

3 3 

MTURBVW Turbulence characterization? (Only if 

MDISP = 1 or 5) 

3 3 

MDISP2 Backup coefficients (Only if MDISP = 1 or 

5) 

3 3 

MROUGH Adjust PG for surface roughness? (0 = 

No) 

0 0 

MPARTL Model partial plume penetration? (0 = No) 1 1 

MTINV Elevated inversion strength (0 = compute 

from data) 

0 0 

MPDF Use PDF for convective dispersion? (0 = 

No) 

0 0 

MSGTIBL Use TIBL module? (0 = No) allows 

treatment of subgrid scale coastal areas 

0 0 

MREG Regulatory default checks? (1 = Yes) 1 1 

CSPECn Names of species modeled (for 

MESOPUFF II, must be SO2, SO4, NOx, 

HN03, NO3) 

User Defined 5 

Specie 

Names 

Manner species will be modeled User Defined SO2, SO4, NOX, 

NO3, HNO3, PM25 

(depends on 

emissions data 

provide by States) 

Specie 

Groups 

Grouping of species, if any. User Defined 

NX Number of east-west grids of input 

meteorology 

User Defined Table 3-1 

NY Number of north-south grids of input 

meteorology 

User Defined Table 3-1 

NZ Number of vertical layers of input 

meteorology 

User Defined 11 

DGRIDKM Meteorology grid spacing (km) User Defined 4 

ZFACE Vertical cell face heights of input 

meteorology 

User Defined Table 3-2 

XORIGKM Southwest corner (east-west) of input 

meteorology 

User Defined Table 3-1 

YORIGIM Southwest corner (north-south) of input 

meteorology 

User Defined Table 3-1 

IUTMZN UTM zone User Defined NA 

XLAT Latitude of center of meteorology domain User Defined Table 3-1 

XLONG Longitude of center of meteorology User Defined Table 3-1 
 

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Variable Description EPA Default Our Values 

domain 

XBTZ Base time zone of input meteorology User Defined MST 

IBCOMP Southwest of Xindex of computational 

domain 

User Defined Table 3-1 

JBCOMP Southwest of Y-index of computational 

domain 

User Defined Table 3-1 

IECOMP Northeast of Xindex of computational 

domain 

User Defined Table 3-1 

JECOMP Northeast of Y- index of computational 

domain 

User Defined Table 3-1 

LSAMP Use gridded receptors (T -= Yes) F F 

IBSAMP Southwest of Xindex of receptor grid User Defined NA 

JBSAMP Southwest of Y-index of receptor grid User Defined NA 

IESAMP Northeast of Xindex of receptor grid User Defined NA 

JESAMP Northeast of Y-index of receptor grid User Defined NA 

MESHDN Gridded receptor spacing = 

DGRIDKM/MESHDN 

1 NA 

ICON Output concentrations? (1 = Yes) 1 1 

IDRY Output dry deposition flux? (1 = Yes) 1 1 

IWET Output wet deposition flux? (1 = Yes) 1 1 

IVIS Output RH for visibility calculations (1 = 

Yes) 

1 1 

LCOMPRS Use compression option in output? (T = 

Yes) 

T T 

ICPRT Print concentrations? (0 = No) 0 0 

IDPRT Print dry deposition fluxes (0 = No) 0 0 

IWPRT Print wet deposition fluxes (0 = No) 0 0 

ICFRQ Concentration print interval (1 = hourly) 1 1 

IDFRQ Dry deposition flux print interval (1 = 

hourly) 

1 1 

IWFRQ Wet deposition flux print interval (1 = 

hourly) 

1 1 

IPRTU Print output units (1 = g/m**3; g/m**2/s) 1 1 

IMESG Status messages to screen? (1 = Yes) 1 1 

Output 

Species 

Where to output various species User Defined Default 

LDEBUG Turn on debug tracking? (F = No) F F 

Dry Gas Dep Chemical parameters of gaseous 

deposition species 

User Defined Default 

Dry Part. Dep Chemical parameters of particulate 

deposition species 

User Defined Default 

RCUTR Reference cuticle resistance (s/cm) 30. 30. 

RGR Reference ground resistance (s/cm) 10. 10. 

REACTR Reference reactivity 8 8 

NINT Number of particle-size intervals 9 9 

IVEG Vegetative state (1 = active and 

unstressed) 

1 1 

Wet Dep Wet deposition parameters User Defined TBD 

MOZ Ozone background? (1 = read from 

ozone.dat) 

1 1 

BCKO3 Ozone default (ppb) (Use only for missing 

data) 

80 80 

BCKNH3 Ammonia background (ppb) 10 1 

RNITE1 Nighttime SO2 loss rate (%/hr) 0.2 0.2 

RNITE2 Nighttime NOx loss rate (%/hr) 2 2 

RNITE3 Nighttime HNO3 loss rate (%/hr) 2 2 
 

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Variable Description EPA Default Our Values 

SYTDEP Horizontal size (m) to switch to time 

dependence 

550. 550. 

MHFTSZ Use Heffter for vertical dispersion? (0 = 

No) 

0 0 

JSUP PG Stability class above mixed layer 5 5 

CONK1 Stable dispersion constant (Eq. 2.7-3) 0.01 0.01 

CONK2 Neutral dispersion constant (Eq. 2.7-4) 0.1 0.1 

TBD Transition for downwash algorithms (0.5 = 

ISC) 

0.5 0.5 

IURB1 Beginning urban landuse type 10 10 

IURB2 Ending urban landuse type 19 19 

3.1.2.5. Chemical Mechanism 

The MESOPUFF II pseudo-first-order chemical reaction mechanism (MCHEM=1) will be used 

for the conversion of SO2 to sulfate (SO4) and NOx to nitrate (NO3) as recommended by EPA 

(Atkinson and Fox, 2006). 

3.1.2.6. Ammonia Assumptions 

Ammonia is not simulated by CALPUFF, but rather a background value is specified. Ammonia 

is important because the level of particulate nitrate (NO3) can depend on the amount of ammonia 

present. The partitioning of total nitrate between gaseous HNO3 and particulate NO3 depends 

on the amount of ammonia present and other parameters (e.g., SO4, temperature and RH). In the 

CALPUFF simulation, one value for background ammonia is assumed across the region and each 

puff uses the full background value in its equilibrium calculation even though puffs may be 

overlapping thereby “double counting” the background ammonia value. However, in postprocessing the results, you may specific hourly values at receptors and recalculate the 

HNO3/NO3 equilibrium partitioning on the total concentration due to all overlapping puffs at a 

receptor. 

 

The IWAQM Phase II report contains the following recommendations for background ammonia 

“typical (within a factor of 2) background values of ammonia are: 10 ppb for grasslands, 0.5 ppb 

for forest, and 1 ppb for arid lands at 20 C” (IWAQM, 1998). The CDPHE performed analysis 

for Colorado and concluded that for sources located in northeast Colorado and along the South 

Platte River, a domain-wide ammonia background value of 44 ppb is used. For sources located in 

northwest Colorado, a background ammonia concentration of 1.0 ppb is used. For sources 

located in southeastern Colorado and for sources located along the Arkansas River, a background 

value of 10 ppb is used. 

In a CALPUFF application, the background ammonia concentration is temporally and spatially 

uniform. It is likely that some portions of the modeling domain are ammonia poor and some are 

ammonia rich. Thus, setting a single domain-wide background is problematic. There is no one 

value that is likely valid across the modeling domains in Figure 3-1 or even across the different 

seasons at one particulate location. Although the domain-wide background ammonia value 

specified in the CALPUFF run is important because it determines how much of the total nitrate is 

gaseous (HNO3) versus particles (NO3) and therefore affects the dry and wet deposition rates, 
 

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the specification of the background ammonia in the post-processing step to partition the total 

nitrate from overlapping puffs at the Class I areas into HNO3 and NO3 is even more important. 

Thus, based on the fact that western Class I areas tend to be either more arid or forest land than 

grassland we proposed to initially use a 1 ppb background ammonia value for the CALPUFF 

runs. We will then revisit the background ammonia values for the Class I areas for the postprocessing step and provide the CALPUFF output to the States so they can investigate alternative 

background ammonia values if desired. 

3.1.2.7. Ozone Assumptions 

Hourly ozone concentrations from the EPA AIRS and CASTNet networks will be processed and 

provided as input to the CALPUFF modeling for the three years of modeling. 

3.1.3. CALPOST Settings and Visibility Post-Processing 

The CALPUFF results will be post-processed using the CALPOST and POSTUTIL or their 

functional equivalents. The CDPHE had to modify these programs to output the correct values 

needed for BART analysis. The WRAP RMC may also need to make modifications or perform 

the post-processing using different tools to obtain the metrics needed for a BART analysis. 

To calculate background light extinction, MVISBK should be set to 6. That is, monthly RH 

adjustment factors (EPA, 2003b) are applied directly to the background and modeled sulfate and 

nitrate concentrations, as recommended by the EPA BART Guidelines (EPA, 2005). The 

RHMAX parameter, which is the maximum relative humidity factor used in the particle growth 

equation for visibility processing, is not used when method 6 is selected. Similarly, the relative 

humidity adjustment factor (f(RH)) curves in CALPOST (e.g., IWAQM growth curve and the 

1996 IMPROVE curve) are not used when MVISBK is equal to 6. The monthly f(RH) values 

recommended by EPA would be used (EPA, 2003a,b).

EPA lists three types of Natural Conditions (natural background) in their guidance document, 

Annual Average, Best 20% (B20%) Days and Worst 20% (W20%) Days (EPA, 2003a). The 

EPA BART Guidance recommends that the Natural Conditions corresponding to the Best 20% 

Days be used (EPA, 2005). However, UARG challenged this assumption and EPA has 

determined that Annual Average Natural Conditions can be used for BART determinations 

(Paise, 2006a,b). In this analysis, the visibility impacts will be calculated using all three sets of 

Natural Conditions (Annual Average, B20% and W20%) and provided to the States. 
 

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4. ALASKA CALPUFF BART Modeling 

The Alaska CALPUFF modeling will follow the general procedures outlined for the other 

WRAP States described in Section 3, only it will be based on Alaska MM5 modeling conducted 

by WRAP for the 2002 calendar year (Kemball-Cook et al., 2005). The WRAP RMC performed 

MM5 meteorological modeling of Alaska for 2002 on a 45/15 km nested grid. Numerous 

sensitivity tests were conducted to determine the best physics options and other parameters (e.g., 

time of year when sea ice forms and melts) to optimized model performance. The Alaska MM5 

modeling is described in the report “Alaska MM5 Modeling for the 2002 Annual Period to 

Support Visibility Modeling” by Kemball-Cook and co-workers (2005) and can be found at: 

 http://pah.cert.ucr.edu/aqm/308/docs/alaska/Alaska_MM5_DraftReport_Sept05.pdf

Figure 4-1 displays the locations of the potential BART-eligible sources in Alaska along with the 

Denali (central Alaska), Tuxedni (Cook Inlet), Simenof (Aleutian Islands) and Bearing Sea (far 

west) Class I areas. Both the Simenof (> 700 km) and Bearing Sea (> 1000 km) lie far away 

from the potential BART-eligible sources in Alaska, so will not be considered in the analysis. 

-1000 -800 -600 -400 -200 0 200 400

-400

-200

0

200

400

600

800

Figure 4-1. Locations of potential BART-eligible sources (red dots) and Class I areas (green 

regions) in Alaska. 
 

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The early versions of the WRAP draft modeling protocol for BART modeling in Alaska 

proposed to model most of Alaska using a 5 km grid and no observations (NOOBS mode). 

However, when the Alaska Department of Environmental Protection (ADEQ) provided their list 

of potential BART-eligible sources it was noted that most of them are located in the AnchorageValdez area in southern Alaska, with one located just northeast of Denali National Park (Figure 

4-1). Concerns were raised that operating CALMET using 5 km resolution with the 15 km MM5 

data in the NOOBS mode would not adequately capture the airflows around the Cook Inlet that 

would be important in simulating the potential visibility impacts at Tuxedni Wildlife Refuge 

from BART sources located in southern Alaska. Consequently, the ADEQ sponsored the 

acquisition and reformatting of surface meteorological observations for input into CALMET and 

the year 2002 and the Alaska BART modeling domain was redefined with a 2 km resolution 

grid. 

4.1. CALMET Modeling 

Although the MM5 modeling was performed on a polar stereographic domain at 45/15 km 

resolution, since the CALMET/CALPUFF domain did not go as far north we were able to use a 

Lambert Conformal Conic (LCC) projection at 2 km resolution using the domain definition 

provided in Table 4-1. 

Table 4-1. Definition of the CALMET/CALPUFF Alaska BART modeling domain using a 

Lambert Conformal Conic (LCC) map projection.

Longitude Origin -151 degrees 

Latitude Origin 59 degrees 

1st Standard Parallel 30 degrees 

2nd Standard Parallel 60 degrees 

X-Origin Offset -200 km 

Y-Origin Offset 0 km 

Horizontal Grid Resolution 2 km 

Number of Grids 275 x 325 

Domain Extent 550 km x 650 km 

CALMET will be run using the 15 km resolution 2002 MM5 data (Kemball-Cook et al., 2005), 

surface meteorological observations from five sites and terrain and landuse data. The locations 

of the five surface meteorological sites are shown in Table 4-2. Precipitation data will be based 

on the MM5 15 km resolution output. Similar CALMET options will be used for the Alaska 

CALMET modeling as discussed in Chapter 3 (i.e., Table 3-2), only using the MM5 precipitation 

instead of observed precipitation. 

Table 4-2. Locations of the 5 surface meteorological sites used in the Alaska BART 

CALMET/CALPUFF modeling. 

Site ID LCC-X (km) LCC-Y(km) 

EDF 26401 64.614 250.825 

PANC 26451 53.916 245.081 

VWS 26442 251.006 244.575 

ENA 26523 -12.782 175.868 

HOM 25507 -27.103 72.100 
 

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-200 -100 0 100 200 300

0

100

200

300

400

500

600

Figure 4-2. Alaska BART CALMET/CALPUFF modeling domain showing the potential 

BART-eligible sources (red dots) and Denali and Tuxedni Class I area receptors. 

4.2 . CALPUFF Modeling 

The Alaska BART CALPUFF model will be operated with similar regulatory default settings as 

discussed in Section 3 (Table 3-3). One major difference is the background ammonia value. The 

IWAQM (1998) recommendations for background ammonia are representative for the lower 48 

states and may not be appropriate for Alaska where lower values are expected to occur. Also, 

the regulatory default background ozone value when no measurements are available (80 ppb) is 

also too high for Alaska. Thus, initial background ammonia and ozone values of 0.1 ppb and 40 

ppb will be used for the Alaska BART CALPUFF modeling. The specifications of the 

background ammonia and default background ozone values are undergoing review. 
 

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5. Results 

For each modeling day, the CALPUFF modeling results would be processed to extract maximum 

24-hour visibility impact at any receptor in a Class I area due to a potential BART-eligible 

source. These maximum 24-hour visibility impacts would be expressed as changes in deciview 

using three levels of Natural Conditions (Annual Average and Best 20% and Worst 20% Days). 

For each potential BART-eligible source, Class I area and modeling day (2001, 2002 and 2003), 

the maximum 24-hour visibility impact would be provided to the States who would make the 

subject to BART determination. Spread sheets of daily change in deciview impacts would be 

provided to each State for each of the State’s potential BART-eligible source. The maximum 

and 98th percentile change in deciview would also be provided in summary form to the States. 

The CALMET and CALPUFF modeling databases will also be provided to the States if desired. 

Information on the status of the WRAP BART CALMET/CALPUFF modeling will be posted on 

the WRAP RMC Website: 

http://pah.cert.ucr.edu/aqm/308/bart.shtml

The CALMET MM5 inputs are quite large (several hundred Gb of data) and will be provided on 

IDE disks that will be distributed to the States as desired for copy. The rest of the 

CALMET/CALPUFF modeling inputs will be provided on the WRAP RMC Website at the link 

provided above. CALMET output will not be distributed; rather all CALMET inputs and scripts 

will be made available so that the CALMET output can be recreated. CALPOST (or similar 

post-processing program) output will be available on the WRAP RMC Website and depending 

on their size CALPUFF modeling output will be either available through the Website, ftp 

transfer or IDE disk transfer. 

Note that the WRAP RMC will conduct the BART screening CALPUFF/CALMET modeling on 

Linux computing platforms. If states wish to use a windows platform then they will have to 

make the conversion. 
 

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6. References 

Atkinson, D. and T. Fox. 2006. Dispersion Coefficients for Regulatory Air Quality Modeling in 

CLAPUFF. Memorandum from U.S. EPA/OAQPS to Kay T. Prince, EPA Region 4. 

March 16. 

Baker, K. 2004a. Summer MM5 Performance. Midwest Regional Planning Organization. 

(http://www.ladco.org/tech/photo/present/MPE_MM5_summer.pdf). November. 

Baker, K. 2004b. Monthly Rainfall Evaluation. Midwest regional Planning Organization. 

(http://www.ladco.org/tech/photo/present/rainfall_eval.pdf). November. 

CDPHE. 2005. CALMET/CALPUFF BART Protocol for Class I federal Area Individual 

Source Attribution Visibility Impairment Modeling Analysis. Colorado Department of 

Public Health and Environment, Air Pollution Control Division, Denver, Colorado. 

October 24. 

Douglas, S. and R. Kessler. 1988. User's Guide to the Diagnostic Wind Model (Version 1.0). 

Systems Applications, Inc., San Rafael, CA. 

Escoffier-Czaja, Christelle and J. Scire. 2002. “The Effects of Ammonia Limitation on Nitrate 

Aerosol Formation and Visibility Impacts in Class I Areas.” Earth Tech, Inc., Extended 

abstract. 12th Joint Conference on the Applications of Air Pollution Meteorology with the 

Air and Waste Management Association, Norfolk, VA, Amer. Meteor. Soc, J5.13. 

EPA. 2003a. “Guidance for Estimating Natural Visibility Conditions under the Regional Haze 

Rule.” EPA-454/B-03-005. September 2003. 

EPA. 2003b. “Guidance for Tracking Progress under the Regional Haze Rule.” U.S. EPA, EPA454/B-03-004. September 2003. 

EPA. 2003c. “Revisions to the Guideline on Air Quality Models: Adoption of a Preferred Long 

Range Transport Model and Other Resources”; Final Rule. Fed. Reg./Vol. 68, No. 

72/Tuesday April 15, 2003/Rules and Regulations. 40 CFR51. 

EPA. 2005. “Regional Haze Regulations and Guidelines for Best Available Technology 

(BART) Determinations”. Fed. Reg./Vol. 70, No. 128/Wed. July 6, 2005, Rules and 

Regulations, pp. 39104-39172. 40 CFR Part 51, FRL-7925-9, RIN AJ31. 

FLAG. 2000. “Federal Land Manager’s Air Quality Related Values Workgroup (FLAG): Phase 

I Report,” U.S. Forest Service, National Park Service, U.S. Fish and Wildlife Service, 

December 2000. 

IWAQM. 1998. “Interagency Workgroup on Air Quality Modeling (IWAQM) Phase 2 

Summary Report and Recommendations for Modeling Long Range Transport Impacts.” 

EPA-454/R-98-019, December 1998. 
 

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Kemball-Cook, S., Y. Jia, C. Emery, R. Morris, Z. Wang and G. Tonnesen. 2004. 2002 Annual 

MM5 Simulation to Support WRAP CMAQ Visibility Modeling for the Section 308 

SIP/TIP – MM5 Sensitivity Simulations to Identify a More Optimal MM5 Configuration 

for Simulating Meteorology in the Western United States. Western Regional Air 

Partnership, Regional Modeling Center. December 10. 

(http://pah.cert.ucr.edu/aqm/308/reports/mm5/MM5SensitivityRevRep_Dec_10_2004.pd

f) 

Kemball-Cook, S., Y. Jia, C. Emery and R. Morris. 2005. Alaska MM5 Modeling for the 2002 

Annual Period to Support Visibility Modeling. Western Regional Air Partnership, 

Regional Modeling Center. September. 

(http://pah.cert.ucr.edu/aqm/308/docs/alaska/Alaska_MM5_DraftReport_Sept05.pdf) 

Malm, W., M. Pitchford, M. Scruggs, J. Sisler, R. Ames, S. Copeland, K. Gebhart and D. Day. 

2000. Spatial and Seasonal Patterns and Temporal Variability of Haze and its 

Constituents in the United States. Cooperative Institute for Research in the Atmosphere, 

Colorado State University, Fort Collins, CO. May. 

McNally, D.E. 2003. Annual Application of MM5 for Calendar Year 2001. Prepared for U.S. 

EPA, Office of Air Quality and Planning Standards. Prepared by Alpine Geophysics, 

Arvada, CO. 

Morris, R.E., R.C. Kessler, S.G. Douglas and K.R. Styles. 1987. The Rocky Mountain Acid 

Deposition Model Assessment Project – Evaluation of Mesoscale Acid Deposition 

Models for use in Complex Terrain. Prepared for U.S. Environmental Protection 

Agency, Research Triangle Park, NC. 

Morris, R.E. and T.C. Myers. 1990. User’s Guide for the Urban Airshed Model. Prepared for 

U.S. Environmental Protection Agency (EPA-450/4-90-007a). 

NDDH. 2005. Protocol for BART-Related Visibility Impairment Modeling Analysis in North 

Dakota (Draft). North Dakota Department of Health, Division of Air Quality, Bismarck, 

North Dakota. October 26. 

Paise, J.W. 2006a. Regional Haze Regulations and Guidelines for Best Available Retrofit 

Technology (BART) Determinations. Memorandum to Kay Prince, Branch Chief EPA 

Region 4. Attachment A to April 20, 2006 DC Circuit Court document UARG vs. EPA, 

No. 06-1056. 

Paise, J.W. 2006b. Letter to Mel S. Schulze, Esq., Hunton and Williams representing the Utility 

Air Regulatory Group (UARG). Attachment B to April 20, 2006 DC Circuit Court 

document UARG vs. EPA, No. 06-1056. 

Scire, J.S., D.G. Strimaitis, R.J. Yamartino. 2000a. “A User's Guide for the CALPUFF 

Dispersion Model.” Earth Tech, Concord, MA, January 2000. 

Scire, J.S., F. Robe, F.E. Fernau, R.J. Yamartino. 2000b. “A User's Guide for the CALMET 

Meteorological Model.” Earth Tech, Concord, MA, January 2000.