Supplemental BART Analysis 

CALPUFF Protocol 

for 

Class I Federal Area 

Visibility Improvement Modeling Analysis 

DRAFT 

April 15, 2010 

(revised June 25, 2010 and August 19, 2010) 

Colorado Department of Public Health and Environment 

Air Pollution Control Division 

Technical Services Program 

4300 Cherry Creek Drive South 

Denver, Colorado 80246 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 1 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 

Table of Contents 

1. INTRODUCTION .................................................................................................................................................4

1.1. VISIBILITY CALCULATIONS.............................................................................................................................7

2. EMISSION ESTIMATES.....................................................................................................................................9

2.1. PRE-CONTROL EMISSION ESTIMATES .............................................................................................................9

2.2. POST-CONTROL SCENARIO/STRATEGY EMISSIONS .......................................................................................10

2.3. DOCUMENTATION AND SUPPORTING DATA ..................................................................................................10

2.4. TREATMENT OF DIRECT PARTICULATE MATTER EMISSIONS AND PARTICLE SIZE DISTRIBUTIONS ...............10

3. CALMET, CALPUFF, POSTUTIL, CALPOST MODELING METHODOLOGY AND POSTPROCESSOR DATA PROCESSING .........................................................................................................................11

3.1. CALMET/CALPUFF MODEL SELECTION ...................................................................................................11

3.1.1. CALMET .................................................................................................................................................12

3.1.1.1. CALMET Modeling Domain......................................................................................................................... 12

3.1.1.2. CALMET Performance Evaluation ............................................................................................................... 14

3.1.1.3. Geophysical Processing (Terrain, Landuse, Landcover)................................................................................ 14

3.1.1.4. CALMET Parameter Settings........................................................................................................................ 17

3.1.1.5. CALMET Surface Stations............................................................................................................................ 19

3.1.1.6. CALMET Upper Air...................................................................................................................................... 19

3.1.1.7. CALMET Precipitation Stations.................................................................................................................... 20

3.1.1.8. CALMET Parameter Summary ..................................................................................................................... 20

3.1.2. CALPUFF ...............................................................................................................................................21

3.1.2.1. Receptor Network and Class I Federal Areas ................................................................................................ 21

3.1.2.2. CALPUFF Meteorology ................................................................................................................................ 22

3.1.2.3. CALPUFF Modeling Domain........................................................................................................................ 22

3.1.2.4. CALPUFF Parameter Summary .................................................................................................................... 22

3.1.2.5. Chemical Mechanism .................................................................................................................................... 23

3.1.2.6. Chemical Mechanism – Ammonia Sensitivity Tests ..................................................................................... 26

3.1.2.7. Ammonia Assumptions - Discussion............................................................................................................. 31

3.1.2.8. Ammonia Assumptions.................................................................................................................................. 33

3.1.2.9. Ozone Assumptions....................................................................................................................................... 33

3.1.3. CALPOST Settings and Visibility Post-Processing.................................................................................34

3.1.3.1. Natural Conditions - Determining Hygroscopic And Non-Hygroscopic Values For the Best 20% Visibility 

Days 35

3.1.3.1.1. Natural Background - Objective .................................................................................................................... 35

3.1.3.1.2. Natural Background - Discussion .................................................................................................................. 36

3.1.3.1.3. Natural Background - Method ....................................................................................................................... 36

3.1.3.2. CALPOST and POSTUTIL Parameters......................................................................................................... 38

4. BART ANALYSIS MODELING PROCESS....................................................................................................42

5. REPORTING OF RESULTS FOR THE DEGREE OF VISIBILITY CHANGE.........................................43

5.1. 1ST-HIGH AND 98TH PERCENTILE METRICS.....................................................................................................44

5.2. METRICS FOR CHARACTERIZING THE CHANGE IN VISIBILITY IMPACTS ........................................................44

5.3. POSTPROCESSOR FOR GENERATING METRICS...............................................................................................44

6. REFERENCES ....................................................................................................................................................45

APPENDIX A – NATURAL BACKGROUND VALUES .........................................................................................46

APPENDIX B – MONTHLY F(RH) VALUES ..........................................................................................................54

APPENDIX C – SAMPLE CALMET FILE...............................................................................................................61

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

1. Introduction 

This protocol documents the Colorado Department of Public Health and Environment Air 

Pollution Control Division (Division) CALPUFF modeling analysis for estimating the degree of 

visibility improvement from potential Best Available Retrofit Technology (BART) control 

technology options. It describes dispersion modeling and analysis procedures and methods for 

quantifying the degree of visibility improvement from potential BART control scenarios/strategies. 

It does not explain how the visibility results are factored into the BART determination process 

(i.e., 5-step process) or discuss the specific BART scenarios that will analyzed. 

This protocol is based on the following two documents: 

1. “CALMET/CALPUFF BART Protocol for Class I Federal Area Individual Source 

Attribution Visibility Impairment Modeling Analysis.” Colorado Department of Public 

Health and Environment. October 24, 2005. 

http://www.colorado.gov/airquality/documents/Colorado-subject-to-BARTCALPUFFprotocol.pdf

2. “BART Control Technology Visibility Improvement Modeling Analysis Guidance.” 

Colorado Department of Public Health and Environment. April 12, 2006. 

http://www.colorado.gov/airquality/documents/Colorado-BART-Analysis-ModelingGuidance.pdf 

This protocol follows the procedures above with the following exceptions: 

1. General changes were made to reflect the fact that this modeling analysis will be performed 

by the Division and not by the source operators. 

2. CALMET settings are consistent with the August 31, 2009 EPA memo "Clarification on 

EPA-FLM Recommended Settings for CALMET" with the exception of three CALMET 

parameters (NZ, ZFACE, and ZIMAX). U.S. EPA Region 8 approved this deviation for 

CALMET modeling in Colorado via email on October 7, 2009. Details about these 

parameters and the technical justification are found elsewhere in this protocol. 

3. MM5 meteorological fields used in CALMET include the following three years: 2001, 

2002, and 2003. Specifically, 36 kilometer (km) resolution meteorological fields are from a 

national U.S. EPA MM5 modeling analysis for 2001. For 2002, 12km resolution Western 

Regional Air Partnership (WRAP) MM5 fields are used. For 2003, 4 km resolution 

kilometer fields from a CDPHE MM5 analysis, performed by Alpine Geophysics, are used. 

Language in the CALMET section of this protocol has been revised accordingly. 

4. Emissions estimation language from the subject-to-BART modeling protocol was replaced 

with BART analysis modeling language. 

5. The most recent regulatory model versions of CALMET, CALPUFF, and CALPOST are 

used. 

6. CALMET processing for all three years has been revised. As compared to the 2005 

Division BART modeling, this analysis uses higher resolution MM5 data for 2002 and 

2003. As compared to the Division’s 2005 modeling, this analysis uses a larger modeling 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

domain and a different projection. All of the geophysical processing and meteorological 

data preprocessing was revised. The CALMET modeling used in this analysis was 

performed by CH2M Hill for a recent PSD permit application in Colorado. Prior to use for 

this modeling effort, the CALMET analysis was reviewed and approved by the Division 

earlier in 2010. This protocol has been updated accordingly to reflect the way the 

CALMET fields were developed by the permit applicant. 

7. Degree of visibility improvement metrics and associated modeling procedures have been 

revised to streamline the reporting process, to improve the clarity of the procedures, and to 

remove the methods that relied on use of presumptive limits as a starting point. 

8. The June 25, 2010 revision to this protocol clarifies the modeling procedures. It includes 

language revisions to better describe model settings and the modeling process. In addition, 

during the modeling process, there were a few deviations from the April 15, 2010 protocol. 

A description of the deviations is presented below: 

a. Ozone Stations. The Division inadvertently included an old ozone station list in the 

April 15, 2010 draft protocol. The ozone station list in this protocol has been 

updated to match the stations used in this analysis. 

b. Upper Air Stations. The Division inadvertently retained language from the 2005 

protocol in the April 15, 2010 draft protocol that stated the CALMET 

meteorological modeling would include the Grand Junction upper air station. For 

this supplemental BART modeling, as indicated in #6, above, the Division used the 

CALMET.DAT files developed by a recent PSD permit applicant. The CALMET 

modeling performed by the applicant did not use the Grand Junction upper air 

station. The Division did not make any changes to the permit applicant’s CALMET 

modeling for this supplemental BART analysis.

c. Ammonia Background. The April 15 protocol indicated that an ammonia 

background of 44 ppb would be used for all sources in northeast Colorado. During 

the process of setting up modeling runs for CENC (near Golden) and CEMEX (near 

Lyons), file review showed that the Division’s technical staff had previously 

approved an ammonia background of 5 ppb for CENC and CEMEX in 2006 during 

the BART Analysis process. To maintain consistency with previous ammonia 

background decisions for these two BART-eligible sources, the ammonia 

background for CEMEX and CENC used in this analysis is 5 ppb, not 44 ppb. The 

ammonia section of this protocol has been updated accordingly. 

d. Degree of Visibility Improvement Metrics. Per U.S. EPA comments on the April 

15, 2010 protocol, a statement has been added to the protocol to reflect the U.S. 

EPA Region 8 comment that “To show the change in visibility impact between 

scenarios the most important metric to provide would be the delta-deciview 

between pre and post control 98th percentile impacts for each scenario in the three 

modeling years. Also provide the number of days exceeding .5 and 1 deciview.” 

e. Postprocessors. The April 15 protocol indicated that the Division might use its 98th 

percentile processor to streamline the modeling. In fact, the Division’s 98th

percentile processor was not used because the regulatory version of CALPOST 

adequately summarizes results. 

f. Domain maps. The protocol has been clarified to reflect the fact that the modeling 

domain for 2003 is slightly smaller than the 2001 and 2002 domains due to the 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

limited size of the CDPHE 2003 4km MM5 fields. Language describing the domain 

has been updated to reflect the domains used in this analysis. 

g. Section 2 (Emission Estimates) revisions. The opening paragraph of Section 2 and 

Section 2.2 were revised to clarify the emission estimation process for this analysis. 

9. The August 19, 2010 revision to this protocol are limited to Section 2.4. The revised 

language provides additional detail and clarification regarding the treatment of direct 

particulate matter. 

 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

1.1. Visibility Calculations 

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) 

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

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

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] 

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

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. The f(RH) term is the relative humidity adjustment 

factor. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

The total atmospheric extinction 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 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 BART guideline, monthly f(RH) values 

should be used. 

The CALPUFF modeling techniques in this analysis 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. 

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) 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

2. Emission Estimates 

The Division will perform the visibility change analysis based on 24-hour emission rates, 

described herein, that are developed for each unit evaluated in this supplemental BART analysis. 

2.1. Pre-Control Emission Estimates 

Pre-control emission rates are intended to reflect peak 24-hour average emissions that may 

occur in the future under the source’s current permit. There are several ways the emission rates 

may be determined. 

For each BART-eligible unit at the facility, determine the pre-control peak 24-hour average 

emission rate for SO2, NOx, and direct particulate matter (PM) emissions (e.g., filterable and 

condensable PM2.5 and PM10) for each fuel and operational scenario allowed under the 

source’s current permit. For simplicity and to reduce the number of modeling scenarios, the 

Division may determine the peak 24-hour emission rate for each pollutant from all 

fuel/operational scenarios and combine the peak emission rates to produce a single pre-control 

emissions scenario. For example, the NOx emission rate might be from a natural gas-fired 

scenario while the SO2 emission rate is from a coal-fired scenario. However, if the Division 

believes it is problematic to combine emissions from different fuel/operational scenarios, 

individual emission scenarios may be developed for each fuel/operational scenario allowed 

under the permit. 

Historic data (e.g., CEM data) may be used to determine peak 24-hour emission rates. If 

historic emissions/operational data are used, it should: 

1. Reflect operations from the most recent 3 to 5 year period unless a more recent period 

is more representative due to the recent installation of emission controls or due to other 

recent permit modifications. 

2. Account for “high capacity utilization” during normal operating conditions. 

3. Not include periods of start-up, shutdown, and malfunction, although these periods may 

be included for simplicity. 

4. Be a good indicator of anticipated future peak emissions allowed under the current 

permit. 

5. Account for fuel/material flexibility allowed under the source's permit. For example, if 

the unit is allowed to use more than one fuel, and the fuel resulting in the highest 

emission rates is not reflected in the historic data, conduct additional analysis to 

determine the peak 24-hour average emissions. Similarly, if a raw material has variable 

properties (e.g., variable sulfur content) and the raw material resulting in the highest 

emission rates was not used during the historic data period, conduct additional analysis. 

If historic data are not a good indicator of anticipated future peak emissions allowed under the 

current permit, use supplemental emission calculations to determine the peak 24-hour average 

emission rates. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Allowable short-term (≤24-hours) emission rates or federally enforceable short-term emission 

limits (≤24-hours) may be used instead of CEM data or other historic data. If 24-hour emission 

limits do not exist, use limits of a shorter averaging period. If limits do not exist, use maximum 

hourly emissions based on emission factors and design capacity. 

2.2. Post-Control Scenario/Strategy Emissions 

The Division will determine the post-control emissions based on (1) estimated percent 

reduction for a particular control scenario using the highest 30-day rolling average emission 

rate in lb/MMBtu over the 3-year baseline period, or (2) the generally accepted lb/MMBtu 

emission rate documented for similar sources; depending on the availability of information 

from the source that specifies the expected post-control emission rate. Refer to section 2.4 for 

a discussion on PM speciation. 

2.3. Documentation and Supporting Data 

The Division will document and support the emission rates. 

2.4. Treatment of Direct Particulate Matter Emissions and Particle 

Size Distributions 

Direct filterable particulate matter (PM) emissions will be modeled initially with the same 

method used in the Division's original subject-to-BART CALPUFF modeling. Specifically, all 

direct filterable PM is modeled in CALPUFF as a single species with a geometric mass mean 

diameter of 2.5 microns and a geometric standard deviation of five. In CALPOST, the 

extinction efficiency for direct PM is set equal to 1.0 1/Mm per μg/m3

. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

3. CALMET, CALPUFF, POSTUTIL, 

CALPOST Modeling Methodology and 

Post-Processor Data Processing 

This report includes sufficient technical documentation to support the application of 

CALPUFF at distances up to 300 kilometers. While CALPUFF may be used for source-toreceptor distances less than 50 kilometers at some receptors, depending on the sources 

modeled, there is a Class I area within the 50 to 300 km range from every BART source in 

Colorado. 

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

Report and Recommendations for Modeling Long Range Transport Impacts” (IWAQM Phase 

2 Report): 

In the context of the Phase 2 recommendation, the focus of the visibility analysis is on haze. 

These techniques are applicable in the range of thirty to fifty kilometers and beyond from a 

source. At source-receptor distances less than thirty to fifty kilometers, the techniques for 

analyzing visual plumes (sometimes referred to as ‘plume blight’) should be applied. 

For the few cases where BART source-to-receptors distances are less than 50 kilometers, both 

the topography and the meteorological fields are complex and the use of CALPUFF appears to 

be appropriate based on the possibility of recirculation, stagnation, and complex flows. If the 

CEMEX Lyons plant is modeled, for example, the shortest source-to-receptor distance 

modeled is about 25 kilometers, but it involves an elevation change of about 3000 ft. In 

addition, in each case where a source has a source-to-receptor distance of less than 50 

kilometers, such as the CEMEX, only a portion of the Class I area is less than 50 km from the 

source. 

3.1. CALMET/CALPUFF Model Selection 

The following model versions will be used: 

• CALPUFF version 5.8, level 070623

• CALMET version 5.8, level 070623 

• POSTUTIL version 1.56, level 070627 

• MAKEGEO version 2.29, level 070327 

• PMERGE version 5.32, level 070627 

• SMERGE version 5.57, level 070627 

• CALPOST version 5.6394, level 070622 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

3.1.1. CALMET 

The MM5/CALMET meteorological fields have been generated for 2001, 2002, and 2003. 

CALMET is based on the Diagnostic Wind Model (Douglas, S. and R. Kessler, 1988). The 

Diagnostic Wind Model has been significantly enhanced (Scire, 2000). For this particular 

study, the model uses a Lambert Conformal Projection coordinate system to account for the 

Earth's curvature. 

CALMET uses a two-step approach to calculate wind fields. In the first step, an initialguess wind field is adjusted for slope flows and terrain blocking effects, for example, to 

produce a Step 1 wind field. In the second step, an objective analysis is performed to 

introduce observational data into the Step 1 wind field. 

In this application, the initial guess wind fields are based on 36 km resolution MM51

meteorological fields for 2001, 12 km resolution MM5 fields for 2002, and 4 km resolution 

MM5 fields for 2003. CALMET setting IPROG=14 will be used. Alpine Geophysics 

performed the CALMM5 extractions to convert the data format from MM5 output into a 

CALMET MM5.DAT format. The 2001 MM5 data were generated by the U.S. EPA. The 

2002 MM5 data were generated by the Western Regional Air Partnership (WRAP). The 

2003 MM5 data were generated for CDPHE by Alpine Geophysics. 

The BART guideline does not specify the exact number of years of mesoscale 

meteorological data for use in CALPUFF, but according to 40 CFR 51 Appendix W, at 

least three years of meteorological data should be used. 

3.1.1.1. CALMET Modeling Domain 

The CALMET computational modeling domain is shown in Figure 1. It is based on a 

Lambert Conformal Conic (LCC) projection, as follows: 

Latitude and longitude (decimal degrees) of projection origin: 

RLAT0 = 38.4N 

RLON0 = 105.5W 

Matching parallels of latitude (decimal degrees) for project: 

 XLAT1 = 36.4N 

 XLAT2 = 40.5N 

Datum: 

 DATUM = NAR-C 

(North American 1983 GRS 80 Spheroid, mean for CONUS (NAD83) 

The domain includes all Class I areas in Colorado with the exception of Mesa Verde 

NP. Mesa Verde was excluded because it is more than 300 km from all of the BARTeligible sources in Colorado and because the BART-eligible sources in Colorado 

would have higher impacts at other Class I areas. In addition, preliminary BART 

modeling in 2005 indicated that impacts at Mesa Verde would be small enough that 

its inclusion would not alter decisions based on impacts at other Class I areas that are 

 

1

 Fifth-Generation NCAR/Penn State Mesoscale Model. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

closer to the BART sources. The domain does not include Class I areas in any nearby 

states because visibility impacts from Colorado’s BART sources are expected to be 

highest at Class I areas in Colorado. This assumption is based on source-to-receptor 

distances, professional judgment regarding prevailing air pollutant transport regimes, 

and recent modeling for a PSD permit in Pueblo. The CALMET domain includes 

almost the entire state of Colorado. For 2001 and 2002, it is 508 km x 688 km with 

4-kilometer CALMET grid cells. For 2003, it is 504 km x 616 km with 4-kilometer 

CALMET grid cells. The domain for 2003 is smaller due to limitations in the size of 

the CDPHE 4km MM5 domain for 2003. 

Figure 1. CALMET/CALPUFF modeling domain for 2001 and 2002. For 2003, the southern 

end of the domain is about 72 km north of the one shown above because of limitations with 

the CDPHE 2003 MM5 domain. Refer to Figure 2 to view the southern end of the 2003 

domain. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 13 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

3.1.1.2. CALMET Performance Evaluation 

The MM5 meteorological fields used in this analysis were evaluated historically as 

part of other projects. The CALMET meteorological fields used in this analysis were 

developed by CH2M Hill for a recent PSD permit in Colorado. CH2M Hill 

performed a CALMET performance evaluation and concluded that the 

meteorological fields performed satisfactorily for the PSD application. The Division 

also reviewed the performance evaluation and the meteorological fields and 

concluded that the fields were satisfactory for the PSD permit. After further review, 

the Division concluded that the CALMET fields, which are consistent with the 

August 2009 EPA CALMET memo, are satisfactory for this supplemental BART 

analysis modeling. 

3.1.1.3. Geophysical Processing (Terrain, Landuse, Landcover) 

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, shown in Figure 2. 

TERREL version 3.684, level 070327 was used. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Figure 2. CALMET terrain plus Class I Area receptors (blue) and BART sources. This 

example image is for the year 2003 configuration. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

The land use data are based on USGS NLCD 1992 data use categories were mapped 

into the CALMET land use categories, as shown in Figure 3, using CTGPROC 

version 2.682, level 070430 with internal coordinate transformations by COORDLIB 

version 1.98, level 060911. 

Figure 3. Land Use (example shown is for year 2002). 

MAKEGEO version 2.29, level 070327 was used to process the geophysical data to 

create the GEO.DAT file. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

3.1.1.4. CALMET Parameter Settings 

U.S. EPA issued a memo regarding CALMET settings dated August 31, 2009 titled 

"Clarification on EPA-FLM Recommended Settings for CALMET." As shown in the 

example CALMET file in Appendix C, the CALMET settings in the U.S. EPA memo 

will be used with the exception of three CALMET parameters (NZ, ZFACE, and 

ZIMAX). U.S. EPA Region 8 approved this deviation for CALMET modeling in 

Colorado via email on October 7, 2009. 

Parameter Descriptions: 

NZ = number of vertical layers 

ZFACE = cell face heights in arbitrary vertical grid (ZFACE (NZ+1)) (m) 

ZIMAX = maximum overland mixing height (m) 

EPA-FLM Recommended Setting: 

NZ = 10 

ZFACE = 0,20,40,80,160,320, 640, 1200, 2000, 3000, 4000 

ZIMAX = 3000 m 

CDPHE Setting: 

NZ = 11 

ZFACE = 0,20,40,80,160,320, 640, 1200, 2000, 3000, 4000, 5000 

ZIMAX = 4500 m 

Justification: 

A ZIMAX setting of 3000 m is too low for some summer days in Colorado. A value 

of 4500 m is recommended instead of 3000 m. A ZIMAX setting of 4500 meters is 

based on analyses of soundings for summer ozone events. The analysis suggests 

mixing heights in the Denver area are often well above the CALMET default and 

EPA-FLM 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. A sounding from the evening of July, 1 2002 (see Figure 4), which is a day 

the 8-hour ozone standard was exceeded at Rocky Mountain National Park, suggests 

the mixing height was likely around 6000 meters MSL. The mixing height estimate is 

based on the relative uniformity of the water vapor mixing ratio below 6000 meters, 

the temperature profile, the inverted "V" in the sounding, and data from a NOAA 

ozonesonde from Boulder that shows relatively constant ozone levels with height. 

Although low mixing heights can occur during the summer and other times of the 

year, maximum summertime daytime mixing heights in the Denver area often range 

from about 12,000 feet (3700 m) to 20,000 feet (6000 m) MSL. Since the CALMET 

ZIMAX setting is above ground level (AGL), not above mean sea level (MSL), the 

maximum summer daytime mixing height range over the plains would be about 

15000 feet (4500 m) AGL. Thus, a ZIMAX setting of 4500 m is appropriate. In order 

to implement a ZIMAZ of 4500 m, it would be appropriate to add one additional 

vertical layer with a cell face height at 5000 m. 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Figure 4. Example Denver summertime sounding. 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

3.1.1.5. CALMET Surface Stations 

Figure 5. Surface meteorological stations. 

3.1.1.6. CALMET Upper Air 

The Denver upper air station is included in CALMET. 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

3.1.1.7. CALMET Precipitation Stations 

Figure 6. Precipitation stations. 

3.1.1.8. CALMET Parameter Summary 

See Appendix C for a sample CALMET input file. 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

3.1.2. CALPUFF 

The use of CALPUFF is recommended in 40 CFR 51 Appendix Y (BART guideline). The 

primary niche for CALPUFF is as a long-range transport model. It is a multi-layer, nonsteady-state puff dispersion model that can simulate the effects of time- and space-varying 

meteorological conditions on pollutant transport, chemical transformations, vertical wind 

shear, and deposition (Scire, 2000). 

The default technical options in CALPUFF are used, unless specified otherwise in this 

report. 

3.1.2.1. Receptor Network and Class I Federal Areas 

The modeling domain will contain all Class I federal areas in Colorado within 300 

kilometers of the BART-eligible source. Eleven federal Class I areas are included: 

 Flat Tops Wilderness Area 

 Rawah Wilderness Area 

 Mt Zirkel Wilderness Area 

 Weminuche Wilderness Area 

 Rocky Mountain National Park 

 Maroon Bells-Snowmass Wilderness Area 

 La Garita Wilderness Area 

 Great Sand Dunes National Park 

 West Elk Wilderness Area 

 Eagles Nest Wilderness Area 

 Black Canyon of the Gunnison National Park 

The discrete receptors for the Class I federal areas were generated by the National 

Park Service (NPS) NPS Convert Class I Areas (NCC) computer program. Receptor 

elevations provided by the NPS conversion program are used. 

All receptors are included in a single CALPUFF simulation for each pre-control or 

post-control BART scenario. The appropriate receptors for each Class I area were 

extracted from the CALPUFF or POSTUTIL output files with the NCRECP 

parameter in CALPOST, which specifies the receptor range to be processed in 

CALPOST, as shown below. 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

3.1.2.2. CALPUFF Meteorology 

Refer to the CALMET section of the report for details. 

3.1.2.3. CALPUFF Modeling Domain 

In this case, the CALPUFF and CALMET modeling domains are identical. Based on 

prevailing transport and modeling analyses done to support the subject-to-BART 

process, the Division concluded that the modeling domain used during the BART 

process would be sufficient for BART analysis modeling. In this case, the Division is 

using a larger CALPUFF domain that the one used in the subject-to-BART 

modeling. The larger domain retains more mass in the modeling system. 

Nevertheless, for some of the BART sources closer to the edge of the modeling 

domain, mass may be lost during some transport regimes. While this is less than 

ideal, modeling suggests that the periods with highest impacts occur with relatively 

direct transport from the BART source to the affected Class I areas and this same 

approach resulted in the inclusion of these BART-eligible sources in the BART 

process (i.e., the sources like Craig and Hayden near the domain boundary were 

found to be subject-to-BART based on CALPUFF modeling with a similar domain). 

Therefore, this modeling domain is sufficient in size to capture impacts on the days 

likely to be associated with the highest degree of visibility impairment. The 

modeling configuration provides a reasonable measure of the degree of visibility 

improvement associated with various BART alternatives. 

3.1.2.4. CALPUFF Parameter Summary 

Figure 7 summarizes some of the key CALPUFF settings. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Figure 7. CALPUFF parameter summary. 

3.1.2.5. Chemical Mechanism 

The MESOPUFF II pseudo-first-order chemical reaction mechanism (MCHEM=1) is 

used for the conversion of SO2 to sulfate (SO4) and NOx to nitrate (NO3). Refer to 

the CALPUFF User’s Guide for a description of the mechanism (Scire, 2000). 

In the MESOPUFF II mechanism, the ammonia background concentration affects the 

equilibrium between nitric acid, ammonia, and ammonium nitrate. The equilibrium 

constant for the reaction is a non-linear function of temperature and relative humidity 

(Scire, 2000). Unlike sulfate, the calculated nitrate concentration is limited by the 

amount of available ammonia, which is preferentially scavenged by sulfate (Scire, 

2000). In particular, the amount of ammonia available for the nitric acid, ammonium 

nitrate, and ammonia reactions is determined by subtracting sulfate from total 

ammonia. 

While the chemical mechanism simulates both the gas phase and aqueous phase 

conversion of SO2 to sulfate, the aqueous phase method, which is important when the 

plume interacts with clouds and fog, can significantly underestimate sulfate 

formation. In this report, as recommended by the IWAQM Phase 2 report, the 

“nighttime SO2 loss rate (RNITE1)” is set to 0.2 percent per hour. The “nighttime 

NOx loss rate (RNITE2)” is set to 2.0 percent per hour and the “nighttime HNO3

formation rate (RNITE3)” is set to 2.0 percent per hour. 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

According to the 1996 “Mt. Zirkel Wilderness Area Reasonable Attribution Study of 

Visibility Impairment. Volume II: Results of Data Analysis and Modeling - Final 

Report,” 

The CALPUFF chemical module is formulated around linear transformation 

rates for SO2 to sulfate and NOX to total nitrate. There are two options for 

specifying these transformation rates: 

Option 1: An internal calculation of rates based on local values for several 

controlling variables (e.g., solar radiation, background ozone, relative 

humidity, and plume NOX) as used in MESOPUFF-II. The parametric 

transformation rate relationships employed were derived from box model 

calculations using the mechanism of Atkinson et al. (1982). 

Option 2: A user-specified input file of diurnally varying but spatially uniform 

conversion rates. 

Morris et al. (1987) reviewed the MESOPUFF-II mechanism as part of the 

U.S. EPA Rocky Mountain Acid Deposition Model Assessment study. They 

found that it provided physically plausible responses to many of the controlling 

environmental parameters. However, the mechanism had no temperature 

dependence, which is an important factor in the Rocky Mountain region where 

there are wide variations in temperature. Furthermore, the MESOPUFF-II 

transformation scheme was based on box model simulations for conditions 

more representative of the Eastern U.S. than of the Rocky Mountains. 

The largest deficiency in the MESOPUFF-II chemical transformation 

algorithm is the lack of explicit treatment for in-cloud (aqueous-phase) 

enhanced oxidation of SO2 to sulfate. The MESOPUFF-II chemical 

transformation algorithm includes a surrogate reaction rate to account for 

aqueous-phase oxidation of SO2 to sulfate as follows: 

 Kaq = 3 × 10-8 × RH4 (%/hr) (B.2-1) 

Thus, at 100% relative humidity (RH), the MESOPUFF-II aqueous-phase 

surrogate SO2 oxidation rate will be 3% per hour. Measurements in 

generating station plumes suggest spatially- and temporally-integrated SO2

oxidation rates due to oxidants in clouds to be 10 times this value. 

Another issue is the amount of ammonia available for nitrate chemistry. According to 

a paper by EarthTech (Escoffier-Czaja and Scire, 2002), 

“In the CALPUFF model, total nitrate (TNO3 = HNO3 + NO3) is 

partitioned into each species according to the equilibrium relationship 

between HNO3 and NO3. This equilibrium varies as a function of time and 

space, in response to both the ambient temperature and relative humidity. In 

addition, the formation of nitrate is subject to the availability of NH3 to 

form ammonium nitrate (NH4NO3), the assumed form of nitrate in the 

model. In CALPUFF, a continuous plume is simulated as a series of puffs, 

or discrete plume elements. The total concentration at any point in the 

model is the sum of the contribution of all nearby puffs from each source. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Because CALPUFF allows the full amount of the specified background 

concentration of ammonia to be available to each puff for forming nitrate, 

the same ammonia may be used multiple times in forming nitrate, resulting 

in an overestimate of nitrate formation. In order to properly account for 

ammonia consumption, a program called POSTUTIL was introduced into 

the CALPUFF modeling system in 1999. POSTUTIL allows total nitrate to 

be repartitioned in a post-processing step to account for the total amount of 

sulfate scavenging ammonia from all sources (both project and background 

sources) and the total amount of TNO3 competing for the remaining 

ammonia. In POSTUTIL, ammonia availability is computed based on 

receptor concentrations of total sulfate and TNO3, not on a puff-by-puff 

basis.” 

Ammonia-limiting methods are used for repartitioning nitric acid and nitrate on a 

receptor-by-receptor and hour-by-hour basis to account for over prediction due to 

overlapping puffs in CALPUFF. Specifically, the use of the MNIRATE=1 option in 

POSTUTIL is acceptable. At this time, other ammonia-limiting methods, including 

iterative techniques that use observational data to resolve backward the 

thermodynamic equilibrium equation between NO3/HNO3 for each hour to minimize 

available ammonia, are not acceptable. Generally, for regulatory CALPUFF 

modeling in Colorado, techniques that assume the atmosphere is always ammonia 

poor are not acceptable, particularly in eastern Colorado. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

3.1.2.6. Chemical Mechanism – Ammonia Sensitivity Tests 

In 2005, to better understand the response of the modeling system to background 

ammonia when a single point source with significant emissions of SO2 and NOx is 

modeled, the Division performed sensitivity tests for a source in northeast Colorado 

and a source in northwest Colorado using the 2002 MM5/CALMET meteorology. 

These tests have not been revised for this supplemental BART modeling, but they are 

provided here for informational purposes. In the test case, SO2, NOx, and filterable 

PM10 emissions were modeled. The ammonia background value was varied from 0 

to 100 ppb. In the northeast Colorado test case, the SO2 emission rate is about 3 

times higher than the NOx emission rate. In the northwest Colorado test case, the 

modeled NOx emission rate is about 4.4 times higher than the SO2 rate. 

In both cases, when the background ammonia concentration is zero, the model 

produces no nitrate, as expected; however, it produces sulfate. 

For the northeast Colorado sensitivity test (see Figure 8), where the modeled SO2

emission rate is significantly higher than the NOx emission rate, the change in 

visibility (delta-deciview) is not very sensitive to the background ammonia 

concentration across the range from 1.0 ppb to 100.0 ppb because of the high SO2

emission rates relative to NOx and the way sulfate is produced in the MESOPUFF II 

chemical mechanism. Visibility impacts drop significantly when the ammonia 

background is less than 1.0 ppb, but even at 0.0 ppb of ammonia, sulfate impacts 

remain relative high. 

Figure 8. Sensitivity of CALPUFF visibility impacts (delta-deciview) to 

ammonia backgrounds from 0 ppb to 100 ppb from a source with high SO2

emissions relative to NOx. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

For the northeast Colorado case, on days with the highest visibility impacts, the 

relative contribution of nitrate and sulfate vary (see Figure 9 and Figure 10), but most 

of the modeled visibility impairment is due to sulfate. When comparing these figures, 

be aware the relative rank for some days is different. For example, day 85 is the 2nd

worst day for the 0.1 ppb ammonia case, but it’s the 3rd worst day for the 100 ppb 

case. On the day with the highest impact (day 84), the contribution from sulfate is 

98.8% for the 0.1 ppb ammonia case and 72.7% for the 100 ppb ammonia case. For 

the 8th high delta-deciview value, the contribution from sulfate is 86.3% for the 0.1 

ppb case and 67.9% for the 100 ppb case. 

Figure 9. Contribution of sulfate and nitrate to the modeled change in 

deciviews, assuming a background ammonia of 0.1 ppb in CALPUFF. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Figure 10. Contribution of sulfate and nitrate to the modeled change in 

deciviews, assuming a background ammonia of 100 ppb. 

 

For the northwest Colorado sensitivity test (see Figure 11), where the modeled NOx 

emission rate is significantly higher than the SO2 emission rate, the change in 

visibility (delta-deciview) is not sensitive to the background ammonia concentration 

across the range from 10 ppb to 100 ppb. While there is a moderate drop in impacts 

when ammonia is dropped from 10 ppb to 1.0 ppb, the model is very sensitive to 

ammonia when the background ammonia level is less than 1.0 ppb. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Figure 11. Sensitivity of CALPUFF visibility impacts (delta-deciview) to 

ammonia backgrounds from 0 ppb to 100 ppb from a source with high NOx 

emissions relative to SO2. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

For the northwest Colorado test case, according to CALPUFF as implemented here, 

impairment is primarily due to nitrate (see Figure 12 and Figure 13), but the 

contribution due to nitrate varies significantly depending on the assumed ammonia 

background level. For the 100 ppb background case, the nitrate contribution is 

greater than 90% for the top 20 days. However, for the 0.1 ppb case, the nitrate 

contribution varies from 43% to 81% for the top 20 days. 

Figure 12. Contribution of sulfate and nitrate to the modeled change in 

deciviews, assuming a background ammonia of 0.1 ppb in CALPUFF. 

Figure 13. Contribution of sulfate and nitrate to the modeled change in 

deciviews, assuming a background ammonia of 100 ppb in CALPUFF. 

Caution should be used when extrapolating the results of these tests to other 

CALPUFF applications. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Since the MESOPUFF II chemical mechanism used in this analysis depends on 

several parameters, including ozone and ammonia background concentrations, the 

methods for determining the background ozone and ammonia concentration fields are 

discussed in more detail in the next two sections. 

3.1.2.7. Ammonia Assumptions - Discussion 

In CALPUFF, as used in this 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 domain-wide 

background is problematic. As discussed in the previous section, when modeling a 

single large source with high SO2 emission rates relative to NOx, the assumed 

background ammonia concentration is not a critical parameter for determining 

visibility impacts. 

According to the IWAQM Phase 2 Report, 

A further complication is that the formation of particulate nitrate is 

dependent on the ambient concentration of ammonia, which preferentially 

reacts with sulfate. The ambient ammonia concentration is an input to the 

model. Accurate specification of this parameter is critical to the accurate 

estimation of particulate nitrate concentrations. Based on a review of 

available data, Langford et al. (1992) suggest that 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. Langford et al. (1992) provide 

strong evidence that background levels of ammonia show strong 

dependence with ambient temperature (variations of a factor of 3 or 4) and 

a strong dependence on the soil pH. However, given all the uncertainties in 

ammonia data, IWAQM recommends use of the background levels provided 

above, unless specific data are available for the modeling domain that 

would discredit the values cited. It should be noted, however, that in areas 

where there are high ambient levels of sulfate, values such as 10 ppb might 

overestimate the formation of particulate nitrate from a given source, for 

these polluted conditions. Furthermore, areas in the vicinity of strong point 

sources of ammonia, such as feedlots or other agricultural areas, may 

experience locally high levels of background ammonia. 

The Northern Front Range is assumed to be ammonia rich. “Sulfate along the 

Northern Front Range is completely neutralized by available ammonium and is 

present in the form of ammonium sulfate.... The Northern Front Range is ammonia 

rich. There was sufficient ammonia, on most days during winter, to completely 

neutralize available nitric acid (NFRAQS, 1998).” 

For northeast Colorado, a background ammonia concentration of 30.4 μg/m3

 (about 

44 ppb) or less appears to be reasonable based on measurements for this modeling 

study. According to monitoring conducted for NFRAQS, 

• "With respect to gaseous measurements, only ammonia was acquired at all nine 

sites with the denuder difference method at the Brighton and Welby sites and 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

with the filter-pack method (i.e., impregnated cellulose-fiber filters behind 

Teflon-membrane filters) at the other sites. Average ammonia concentrations 

were 30.4 ± 53.4 μg/m3 at the core sites and 10.3 ±12.6 μg/m3 at the satellite 

sites. The large standard deviation is mainly due to elevated ammonia 

concentrations found at the Evans site. Maximum 24-hour ammonia 

concentrations were 187.0 ± 5.4 μg/m3 at the Evans core site on 01/17/97 and 

66.7 ± 3.5 μg/m3 at the Masters site on 01/20/97. Figure 6.3-5 shows that 

during the mid-January episode, 24-hour ammonia concentrations varied by 

orders of magnitude at the nine NFRAQS sites."

• "For the 6- and 12-hour samples, Figure 6.4-3[not included in this report]

ammonia concentrations were rather consistent throughout the day, with 

apparent site -to-site and season-to-season variation. Average ammonia 

concentrations at the Brighton site were double those at the Welby site during 

Winter 97. Summertime ammonia concentrations were ~1 to 2 μg/m3 higher 

than the wintertime at the Welby site. Since ammonia concentrations closely 

reflect the vicinity of the sampling area, site-to-site variations were more 

pronounced than seasonal or diurnal variations. This is evidenced by the graph 

in Figure 6.4-4[not included in this report], which shows ammonia 

concentrations were factors of 10 to 20 higher at the Evans site than at most of 

the other sites during Winter 97. Elevated concentrations exceeded 50 μg/m3 on 

20% of the days at the Evans site. Twenty-four hour ammonia concentrations at 

the Masters and Longmont sites were also factors of 5 to 10 higher than at the 

other sites." 

For other areas like northwest Colorado, an annual background ammonia concentration 

of about 1 ppb or less is probably more reasonable, based on ammonia measurements 

from the Mt. Zirkel Visibility Study. 

In the Aerosol Evolution Model (AEM) simulations done for the Mt Zirkel Study for 

a specific period, “base case background air concentrations for ammonia were assumed 

to be 0.5 μg/m3

 and 30 ppbv for ozone, consistent with measured values at the Hayden 

VOR site.” An ammonia concentration of 0.5μg/m3 is about 0.7 ppb. 

In the CALPUFF modeling section of the Mt Zirkel Study report, 

“The CALPUFF default value for background ammonia concentrations of 

10 ppb was also considered far too high as a representative area-average. 

Measurements from the Buffalo Pass and Gilpin Creek sites were used to 

adjust ammonia concentration to episode and site-mean values.” 

Based on a review of CALUFF files used for the Mt. Zirkel Study, for the August 

simulations, the assumed ammonia background (BCKNH3) was 1.6 ppb; for the 

October simulation, the assumed background was 0.5 ppb; and for the September 

simulation, the assumed background was 0.8 ppb. 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

3.1.2.8. Ammonia Assumptions 

To help provide consistency with the Division’s original BART modeling, the 

Division has not determined if more recent ammonia measurements would change the 

assumptions below. The assumptions below are assumed to be reasonable for 

purposes of comparing control technologies. 

Based on information in the previous section, for sources located in northeast 

Colorado (e.g., Pawnee) and along the South Platte River, a domain-wide ammonia 

background value of 44 ppb is used. For CENC near Golden and CEMEX near Lyons, 

a background of 5 ppb is used, as justified by the source operators and approved by 

the Division in 2006 during the original BART Analysis process. For sources located 

in northwest Colorado (e.g., Craig and Hayden), a background ammonia 

concentration of 1.0 ppb is used. For sources located in Colorado Springs (e.g., 

Drake), southeastern Colorado along the Arkansas River (e.g., Comanche), a 

background value of 10 ppb is used. 

3.1.2.9. Ozone Assumptions 

According to the IWAQM Phase 2 Report, 

CALPUFF provides two options for providing the ozone background data: 

(1) a single, typical background value appropriate for the modeling region, 

or (2) hourly ozone data from one or more ozone monitoring stations. The 

second and preferred option requires the creation of the OZONE.DAT file 

containing the necessary data. For the Demonstration Assessment, the 

domain was large (700 km by 1000 km) such that the second option was 

necessary. The IWAQM does not anticipate such large domains as being the 

typical application. Rather, it is anticipated that the more typical 

application will involve domains of order 400 km by 400 km or smaller. But 

even for smaller domains, the ability to provide at least monthly background 

values of ozone is deemed desirable. The problem in developing time (and 

perhaps spatial) varying background ozone values is having access to 

representative background ozone data. Ozone data are available from 

EPA’s Aerometric Information Retrieval System (AIRS); however, AIRS 

data must be used with caution. Many ozone sites are located in urban and 

suburban centers and are not representative of oxidant levels experienced 

by plumes undergoing long range transport.

In this study, the following ozone stations were used:

• Welby 

• Rocky Mountain National Park 

• Greeley 

• Highland 

• S. Boulder Creek

• Carriage

• Chatfield

• USAF Academy

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

• Arvada

• Welch

• Rocky Flats North

• NREL

• Ignacio (S. Ute)

• Hwy. 550 (S. Ute)

• Ft. Collins S. Mason-CSU

• Mesa Verde

• Bloomfield-Hyw. Dept. Yard

• USBR-Shiprock Substation (Farmington)

3.1.3. CALPOST Settings and Visibility Post-Processing 

To maintain consistency with previous BART modeling in Colorado, to expedite this 

analysis, and as approved by EPA Region 8, the old IMPROVE equation is used for this 

CALPUFF analysis. As of the date of this report, the regulatory version of CALPUFF 

relies on the old IMPROVE equation. 

The CALPUFF results are post-processed with the regulatory version of CALPOST and 

POSTUTIL. 

For the Division’s original subject-to-BART modeling analysis, all PM10 was assumed to 

have a extinction efficiency of 1.0 since the contribution of direct PM10 emissions was 

expected to be relatively small compared to visibility impairment caused by SO2 and NOx 

emissions. This same approach is used for this supplemental BART analysis modeling. 

However, if it is reasonable to believe that the inclusion of condensable and filterable 

PM10 emissions and speciation would change the outcome of a BART analysis decision, 

the Division may consider including these factors. If speciated PM emissions are modeled, 

the following species are considered: fine particulates (PMF), coarse particulates (PMC), 

elemental carbon (EC), organic carbon (SOA), and sulfate (SO4) along with appropriate 

particle size and deposition parameters for the source type and emission control 

technology. 

To calculate background light extinction, MVISBK = 6 is used. That is, monthly RH 

adjustment factors are applied directly to the background and modeled sulfate and nitrate 

concentrations, as recommended by the BART guideline. 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. 

EPA allows use of either the 20% best visibility days or annual average to calculate natural 

background for purposes of BART. In 2005, prior to the Utility Air Regulatory Group 

(UARG) settlement, the Division based natural background on the 20% best visibility 

days, as recommended by the BART guideline preamble: 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Finally, these BART guidelines use the natural visibility baseline for the 20 percent 

best visibility days for comparison to the "cause or contribute" applicability 

thresholds. We believe this estimated baseline is likely to be reasonably 

conservative and consistent with the goal of natural conditions (70 FR 39125). 

This assumption was revisited in 2006 after the UARG settlement. The Division decided to 

continue using 20% best days for BART natural background. For this supplemental 

modeling analysis, 20% best days for natural background is used. 

The method for estimating natural background is presented in section 3.1.3.1. Specifically, 

for hygroscopic components, BKSO4 in CALPOST is set to 0.0893 for all months. For 

non-hygroscopic components, BKSOIL should be set to 1.620 for all months. The BKSO4 

and BKSOIL values have been computed specifically for the Colorado Class I areas used in 

this analysis. 

The extinction due to Rayleigh scattering (i.e., the scattering of light by natural particles 

much smaller than the wavelength of the light) is set to 10 Mm-1 (BEXTRAY = 10.0). 

As part of the protocol development process, previous analyses performed by the Division 

were reviewed regarding comparison’s between the natural background assumptions used 

in this analysis (see next section) and newer methods such as those presented in the draft 

FLAG 2008 report. For Rocky Mountain National Park, the approach specified in this 

analysis uses a natural background that has a monthly background extinction of about 12 

Mm-1 whereas the FLAG 2008 “20% best days” value is about 14 Mm-1 and the FLAG 

2008 “annual average best days” value is about 10 Mm-1. A directionally similar trend 

exists for the other Class I areas in Colorado. That is, the Division’s “20% best days” 

natural background assumption is between the FLAG 2008 recommendations. 

Consequently, as mentioned earlier, to help maintain consistency with previous BART 

modeling and to streamline this supplemental BART analysis process, the Division retained 

its original approach, as described in the next section. 

 

3.1.3.1. Natural Conditions - Determining Hygroscopic And NonHygroscopic Values For the Best 20% Visibility Days 

3.1.3.1.1. Natural Background - Objective 

 The spreadsheet shown in Figure 14 was created to determine the hygroscopic 

(3[BKSO4]) and non-hygroscopic (equivalent to [BKSOIL]) portions of natural 

background for the best 20% visibility days (Best Days) at all Class I areas in 

Colorado's BART modeling. These concentrations, [BKSO4] and [BKSOIL], are 

used in CALPOST with monthly relative humidity adjustment factors (f(RH)) to 

determine monthly natural background visibility that would, on average, represent 

the average natural background visibility for the best 20% days in EPA's “Guidance 

for Estimating Natural Visibility Conditions Under the Regional Haze Program” 

(EPA, 2003). 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

3.1.3.1.2. Natural Background - Discussion 

“Guidance for Estimating Natural Visibility Conditions Under the Regional Haze 

Program” (EPA, 2003), section 2.4, describes the calculation of the annual average 

background extinction (in 1/Mm) for a Class I area using the area's annual f(RH) 

and average natural concentrations based on the area's geographic location (east 

versus west). Annual average background extinction values (in 1/Mm) are 

converted to annual average Haze Index (HI) values (in deciview or dv). Then, the 

average HI value for the 20% best visibility days (Best Days (dv)) is estimated from 

10th percentile of the annual average HI value for a Class I area assuming normal 

distribution. Thus, no average natural concentrations are provided for determining 

extinction for the 20% best visibility days. 

 

For background extinction computation methods 2, 3, and 6 in CALPOST, 

background extinction is calculated with user-supplied monthly concentrations of 

SO4, NO3, PM coarse, organic carbon, soil, and elemental carbon species. In 

practice, concentrations for only 2 species, SO4 ([BKSO4]) and soil ([BKSOIL]), 

are supplied in the CALPOST input file to represent hygroscopic and nonhygroscopic portions of background extinction, respectively. 

To determine background extinction for the BART analysis with CALPOST, 

average natural concentrations that represent average natural background visibility 

for the best 20% days need to be determined. 

3.1.3.1.3. Natural Background - Method 

Following EPA's approach of using regional average natural concentrations and the 

concept of using simplified inputs in CALPOST, the same hygroscopic (3[BKSO4]

best20) and non-hygroscopic ([BKSOIL]best20) values would be used in CALPOST for 

all Class I areas in Colorado's BART modeling. 

The spreadsheet calculates an average background (dv) based on monthly 

background extinction (1/Mm) for each Class I area in Colorado's BART modeling 

using the following equations: 

1. Monthly background extinction in 1/Mm (bextmonth) = 3[BKSO4]best20f(RH) 

+ [BKSOIL] best20 + Rayleigh 

2. Annual average background extinction in 1/Mm (bextannual_ave) = (bextJan + 

bextFeb + ... + bextDec)/12 

3. Calculated Best Days in dv = 10ln(bextannual_ave/10) 

EPA guidance provides f(RH) values based on the centroid of the Class I area (see 

Appendix B – Monthly f(RH) Values) and a Best Days (dv) value for each of the 

Class I areas (see Appendix A – Natural Background Values). 

The hygroscopic (3[BKSO4]) and non-hygroscopic ([BKSOIL]) values determined 

yielded the lowest sum of the absolute differences between the published Best Days 

(dv) and calculated Best Days (dv) for all Class I areas in the analysis: 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

∑ ( ) ( ) =

11

1n

n DaysBest calculated - DaysBest published n Minimize

 where: n = number of Class I areas in analysis 

The "hygro (3[BKSO4])” and "non-hygro ([BKSOIL])" values of 0.268 and 1.620 

were calculated in Microsoft Excel using the "solver add-in" tool for optimization 

and equation solving (Figure 14). As can be seen from the “difference” values in 

Figure 14, the annual 20% best visibility days background concentrations for each 

Class I area calculated with this method are within 0.01 deciviews or less of the 

annual 20% best visibility days background values recommended by EPA. For 

CALPOST, the hygroscopic component of extinction is divided by 3 (the extinction 

coefficient of sulfate and nitrate) and input as BKSO4 (i.e., BKSO4 = 0.268/3 = 

0.0893). The non-hygroscopic component is used directly (i.e., BKSOIL = 1.620). 

Figure 14. Spreadsheet showing the "hygro (3[BKSO4])" (0.268)and "nonhygro ([BKSOIL])" (1.620) values calculated in Microsoft Excel using the 

"solver add-in" tool for optimization and equation solving. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

3.1.3.2. CALPOST and POSTUTIL Parameters 

Two post-processing examples are provided. In example #1, fine particulate 

emissions are speciated into PMF, PMC, EC, SOA, and SO4 and explicitly included 

as species in CALPUFF. Emission rates for each species are included in CALPUFF. 

Figure 15 summarizes some of the key CALPOST settings. The monthly f(RH) 

values (RHFAC), which are different for each Class I area, are from Appendix B – 

Monthly f(RH) Values. 

Figure 15. CALPOST - key parameters (example #1 setup). 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

In example #1, POSTUTIL is used to compute the partition for the total 

concentration fields with MNITRATE=1 and the appropriate ammonia background 

concentration. The ammonia background concentration, BCKNH3, in POSTUTIL is 

the same as the background value presented in section 3.1.2.8. In POSTUIL, the 

input species include SO2, SO4, NOX, HNO3, NO3, SOA, PMF, PMC, and EC and 

the output species include SO4, HNO3, NO3, SOA, PMF, PMC, and EC. Key 

POSTUTIL parameters are shown in Figure 16. 

Figure 16. POSTUTIL - key parameters for cases with nitrate partitioning and 

speciated PM10 concentrations (example #1 setup). 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

In example #2, PM10 is included as a species in CALPUFF and ammonia limiting is 

performed with POSTUTIL. The example #2 CALPOST setup is the same as shown 

in example #1 (see Figure 15) except LVPMC=F, since there are is no coarse PM, 

and SPECPMF=SOIL because the PM10 emissions from CALPUFF are reallocated 

to the species SOIL and EC in the first of two POSTUTIL runs. The first POSTUTIL 

setup for example #2 (see Figure 17) is intended to provide a post-processing 

opportunity to divide the PM10 concentrations into SOIL and EC components; 

however, in the setup example shown in Figure 17, all of the PM10 is allocated to 

SOIL and none is allocated to EC. 

Figure 17. POSTUTIL setup for simulations where PM10 is divided into SOIL 

and EC species (example #2 setup). 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

In the second POSTUTIL setup for example #2, POSTUTIL is used to compute the 

partition for the total concentration fields with MNITRATE=1 and the appropriate 

ammonia background concentration. The ammonia background concentration, 

BCKNH3, in POSTUTIL is the same as the background value presented in section 

3.1.2.8. In this POSTUIL setup, the input species include SO4, NO3, HNO3, EC, 

SOIL, and SOA and the output species include SO4, NO3, HNO3, EC, SOIL, and 

SOA. Key POSTUTIL parameters are shown in Figure 16. 

Figure 18. POSTUTIL setup for simulations where ammonia limiting is 

performed using the output file generated from the POSTUTIL setup in Figure 

17 (example #2 setup). 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

4. BART Analysis Modeling Process 

The Division’s modeling approach models all pollutants (i.e., direct PM, SO2, and NOx) from 

all BART-eligible units at a source in each CALPUFF run. The Division is not modeling unitby-unit and pollutant-by-pollutant impacts because looking at results from individual units and 

pollutants can, in some cases, provide misleading results. 

Judicious selection of “pre-control” and “post-control” scenarios is used to isolate specific 

units or pollutants. 

For example: 

1. Consider a source with one unit where a decision has already been made on SO2 BART 

and only NOx BART controls are under evaluation. In this case, it would be 

appropriate to compare the following two scenarios: 

• Scenario #1 = Model pre-control emissions for NOx, pre-control emissions 

direct PM, and post-control (BART) emissions for SO2. 

• Scenario #2 = keep everything constant from Scenario #1 but model a NOx 

BART control scenario. 

Impacts from the two scenarios above would then be compared to provide “degree of 

visibility improvement” results for the specified NOx control. 

2. The situation becomes more complicated when a source has more than one unit. 

However, the same isolation method would be used. For example, consider a source 

with 3 units: 

• Scenario #1 

o Pre-control emissions for NOx and direct PM; SO2 BART post-control 

emissions on unit 1 

o Pre-control emissions for NOx and direct PM; SO2 BART post-control 

emissions on unit 2 

o Pre-control emissions for NOx, direct PM, and SO2 on unit 3 

• Scenario #2 = keep everything constant from Scenario #1 but add a NOx 

control for unit 2. 

Impacts from the two scenarios above would isolate the degree of visibility 

improvement from the addition of NOx controls to unit 2. 

A matrix of BART scenarios is established and the effects of BART controls are estimated for 

individual pollutants and individual units by using the isolation technique above. In addition, 

the cumulative impact for a given source from the total BART control strategy (e.g., SO2

controls and NOx controls), as compared to pre-control emissions, is evaluated as appropriate. 

The BART modeling process is summarized in the following steps: 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Step A. 

Model the pre-control emission rates for SO2, NOx, and direct PM emissions (e.g., filterable 

and condensable PM2.5 and PM10) from all BART-eligible units at the source. This scenario 

becomes the pre-control “base case.” 

Step B. 

Model as many pre- and post-control scenarios as necessary to isolate the desired units, 

pollutants, and BART scenarios. (Note: For each control scenario/strategy evaluated, model 

SO2, NOx, and direct PM emissions together from all BART-eligible units at the facility.) 

Step C. 

As appropriate to complete the BART analysis, compare the pre-control (step A) with postcontrol (step B) results and/or compare various permutations to isolate specific units and 

specific pollutants. 

There could be a large number of combinations if every unit, every pollutant, and every 

potential BART control is isolated with the steps above. Consequently, the Division may not 

conduct an exhaustive set of modeling analyses that examine every possible combination of 

potential BART controls if it is clear that the evaluation of certain combinations of controls are 

solely academic exercises. The Division will exercise reasonable professional judgment when 

deciding how many modeling analyses are necessary to characterize the degree of visibility 

improvement from the realistically viable BART scenarios. In addition, the actual number of 

modeling analyses depends on how the modeling results are factored into the BART 

determination process. In cases where the weight given to modeling is relatively low compared 

to the weight given to other factors, a limited number of modeling analyses may be adequate to 

satisfactorily complete the BART analysis process. 

5. Reporting of Results for the Degree of 

Visibility Change 

The metrics discussed in this section are intended to help provide a common framework for 

quantifying the degree of change from control scenarios/strategies. The BART analysis should 

discuss the recommended metrics in this section (plus others, as appropriate) and how the results 

have been factored into the BART determination process. 

For this analysis, the magnitude (e.g., 98th percentile delta-deciview impact) and frequency (e.g., 

days per year with impacts above 0.5 dv and 1.0 dv) for the pre-control and post-control scenario 

under evaluated are presented. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

5.1. 1st-High and 98th Percentile Metrics 

The BART guideline provided specific guidance on the use of 98th percentile values for the 

subject-to-BART modeling: 

...you should compare your “contribution” threshold against the 98th percentile of values. If 

the 98th percentile value from your modeling is less than your contribution threshold, then you 

may conclude that the source does not contribute to visibility impairment and is not subject to 

BART. (70 FR 39162) 

The BART guideline did not recommend the use of a specific set of metrics for determining 

the degree of visibility improvement from BART. 

As explained in more detail later, to determine the degree of visibility improvement from 

various BART scenarios, the Division will report the 98th percentile value, as well as the 

number of days over 0.5 dv and the number of days over 1.0 dv. 

For a 365-day simulation, the 98th percentile value is the 8th highest modeled delta-deciview 

value from the list of ranked delta-deciview values. That is, the top 7 days are ignored, even 

though the values being ignored may be at different receptors. 

The use of the 8th high value for a given year to represent the 98th percentile value, as 

recommended by U.S. EPA, is consistent with the values that would be generated from the 

equations in 40 CFR 50 Appendix N - “Interpretation of the National Ambient Air Quality 

Standards for PM2.5” – for determining 98th percentile values for PM2.5 monitoring. 

5.2. Metrics for Characterizing the Change in Visibility Impacts 

According to U.S. EPA Region 8, “to show the change in visibility impact between 

scenarios the most important metric to provide would be the delta-deciview between pre 

and post control 98th percentile impacts for each scenario in the three modeling years. Also 

provide the number of days exceeding .5 and 1 deciview.” 

In addition to the approach recommended by U.S. EPA, the Division may use other 

metrics, if appropriate, to describe the expected degree of visibility change from each 

BART scenario. 

5.3. Postprocessor for Generating Metrics 

The Division’s BART postprocessor from 2005 and 2006, which was described in the April 

15, 2010 draft protocol, was not used because the newer versions of CALPOST provide 

results in a more convenient format than older versions of the postprocessor. 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

6. References 

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. 

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

Systems Applications, Inc., San Rafael, CA. 

“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. 

“Guidance for Estimating Natural Visibility Conditions Under the Regional Haze Rule.” EPA454/B-03-005. September 2003. 

“Guidance for Tracking Progress Under the Regional Haze Rule.” U.S. EPA, EPA-454/B-03-

004. September 2003. 

“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. 

“Mt. Zirkel Wilderness Area Reasonable Attribution Study of Visibility Impairment. Volume 

II: Results of Data Analysis and Modeling - Final Report.” Prepared by John G. Watson, et al, 

Prepared for Colorado Department of Public Health and Environment, 1996. 

“Northern Front Range Air Quality Study Final Report.” Prepared for Colorado State 

University, Prepared by John G. Watson, Eric Fujita, Judith C. Chow Barbara Zielinska 

(Desert Research Institute), L. Willard Richards (Sonoma Technology, Inc.), William Neff 

(NOAA), David Dietrich (Air Resource Specialists, Inc.), 1998.

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

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

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Appendix A – Natural Background Values 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Appendix B – Monthly f(RH) Values 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

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Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Appendix C – Sample CALMET File 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

Sample CALMET file 

---------------- Run title (3 lines) ------------------------------------------ 

 CALMET MODEL CONTROL FILE 

 -------------------------- 

------------------------------------------------------------------------------- 

INPUT GROUP: 0 -- Input and Output File Names 

Subgroup (a) 

------------ 

Default Name Type File Name 

------------ ---- --------- 

GEO.DAT input ! GEODAT= geo4km.DAT ! 

SURF.DAT input ! SRFDAT= surf01.DAT ! 

CLOUD.DAT input * CLDDAT= * 

PRECIP.DAT input ! PRCDAT= PRECIP01.DAT ! 

WT.DAT input * WTDAT= * 

CALMET.LST output ! METLST= APR01.LST ! 

CALMET.DAT output ! METDAT= APR01.DAT ! 

PACOUT.DAT output * PACDAT= * 

All file names will be converted to lower case if LCFILES = T 

Otherwise, if LCFILES = F, file names will be converted to UPPER CASE 

 T = lower case ! LCFILES = T ! 

 F = UPPER CASE 

NUMBER OF UPPER AIR & OVERWATER STATIONS: 

 Number of upper air stations (NUSTA) No default ! NUSTA = 1 ! 

 Number of overwater met stations 

 (NOWSTA) No default ! NOWSTA = 0 ! 

NUMBER OF PROGNOSTIC and IGF-CALMET FILEs: 

 Number of MM4/MM5/3D.DAT files 

 (NM3D) No default ! NM3D = 1 ! 

 Number of IGF-CALMET.DAT files 

 (NIGF) No default ! NIGF = 0 ! 

 !END! 

-------------------------------------------------------------------------------

- 

Subgroup (b) 

--------------------------------- 

Upper air files (one per station) 

--------------------------------- 

Default Name Type File Name 

------------ ---- --------- 

UP1.DAT input 1 ! UPDAT= UPden01.DAT! !END! 

-------------------------------------------------------------------------------

- 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Subgroup (c) 

----------------------------------------- 

Overwater station files (one per station) 

----------------------------------------- 

Default Name Type File Name 

------------ ---- --------- 

-------------------------------------------------------------------------------

- 

Subgroup (d) 

------------------------------------------------ 

MM4/MM5/3D.DAT files (consecutive or overlapping) 

------------------------------------------------ 

Default Name Type File Name 

------------ ---- --------- 

MM51.DAT input 1 ! M3DDAT= APR01.MM5 ! !END! 

-------------------------------------------------------------------------------

- 

Subgroup (e) 

------------------------------------------------- 

IGF-CALMET.DAT files (consecutive or overlapping) 

------------------------------------------------- 

Default Name Type File Name 

------------ ---- --------- 

IGFn.DAT input 1 * IGFDAT=CALMET0.DAT * *END* 

-------------------------------------------------------------------------------

- 

Subgroup (f) 

---------------- 

Other file names 

---------------- 

Default Name Type File Name 

------------ ---- --------- 

DIAG.DAT input * DIADAT= * 

PROG.DAT input * PRGDAT= * 

TEST.PRT output * TSTPRT= * 

TEST.OUT output * TSTOUT= * 

TEST.KIN output * TSTKIN= * 

TEST.FRD output * TSTFRD= * 

TEST.SLP output * TSTSLP= * 

DCST.GRD output * DCSTGD= * 

-------------------------------------------------------------------------------

- 

NOTES: (1) File/path names can be up to 70 characters in length 

 (2) Subgroups (a) and (f) must have ONE 'END' (surrounded by 

 delimiters) at the end of the group 

 (3) Subgroups (b) through (e) are included ONLY if the corresponding 

 number of files (NUSTA, NOWSTA, NM3D, NIGF) is not 0, and each must 

have 

 an 'END' (surround by delimiters) at the end of EACH LINE 

 !END! 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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------------------------------------------------------------------------------- 

INPUT GROUP: 1 -- General run control parameters 

-------------- 

 Starting date: Year (IBYR) -- No default ! IBYR= 2001 ! 

 Month (IBMO) -- No default ! IBMO= 4 ! 

 Day (IBDY) -- No default ! IBDY= 1 ! 

 Hour (IBHR) -- No default ! IBHR= 0 ! 

 Note: IBHR is the time at the END of the first hour of the simulation 

 (IBHR=1, the first hour of a day, runs from 00:00 to 01:00) 

 Base time zone (IBTZ) -- No default ! IBTZ= 7 ! 

 PST = 08, MST = 07 

 CST = 06, EST = 05 

 Length of run (hours) (IRLG) -- No default ! IRLG= 720 ! 

 Run type (IRTYPE) -- Default: 1 ! IRTYPE= 1 ! 

 0 = Computes wind fields only 

 1 = Computes wind fields and micrometeorological variables 

 (u*, w*, L, zi, etc.) 

 (IRTYPE must be 1 to run CALPUFF or CALGRID) 

 Compute special data fields required 

 by CALGRID (i.e., 3-D fields of W wind 

 components and temperature) 

 in additional to regular Default: T ! LCALGRD = T ! 

 fields ? (LCALGRD) 

 (LCALGRD must be T to run CALGRID) 

 Flag to stop run after 

 SETUP phase (ITEST) Default: 2 ! ITEST= 2 ! 

 (Used to allow checking 

 of the model inputs, files, etc.) 

 ITEST = 1 - STOPS program after SETUP phase 

 ITEST = 2 - Continues with execution of 

 COMPUTATIONAL phase after SETUP 

 Test options specified to see if 

 they conform to regulatory 

 values? (MREG) No Default ! MREG = 1 ! 

 0 = NO checks are made 

 1 = Technical options must conform to USEPA guidance 

 IMIXH -1 Maul-Carson convective mixing height 

 over land; OCD mixing height overwater 

 ICOARE 0 OCD deltaT method for overwater fluxes 

 THRESHL 0.0 Threshold buoyancy flux over land needed 

 to sustain convective mixing height growth 

!END! 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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------------------------------------------------------------------------------- 

INPUT GROUP: 2 -- Map Projection and Grid control parameters 

-------------- 

 Projection for all (X,Y): 

 ------------------------- 

 Map projection 

 (PMAP) Default: UTM ! PMAP = LCC ! 

 UTM : Universal Transverse Mercator 

 TTM : Tangential Transverse Mercator 

 LCC : Lambert Conformal Conic 

 PS : Polar Stereographic 

 EM : Equatorial Mercator 

 LAZA : Lambert Azimuthal Equal Area 

 False Easting and Northing (km) at the projection origin 

 (Used only if PMAP= TTM, LCC, or LAZA) 

 (FEAST) Default=0.0 ! FEAST = 0.000 ! 

 (FNORTH) Default=0.0 ! FNORTH = 0.000 ! 

 UTM zone (1 to 60) 

 (Used only if PMAP=UTM) 

 (IUTMZN) No Default ! IUTMZN = -999 ! 

 Hemisphere for UTM projection? 

 (Used only if PMAP=UTM) 

 (UTMHEM) Default: N ! UTMHEM = N ! 

 N : Northern hemisphere projection 

 S : Southern hemisphere projection 

 Latitude and Longitude (decimal degrees) of projection origin 

 (Used only if PMAP= TTM, LCC, PS, EM, or LAZA) 

 (RLAT0) No Default ! RLAT0 = 38.4N ! 

 (RLON0) No Default ! RLON0 = 105.5W ! 

 TTM : RLON0 identifies central (true N/S) meridian of projection 

 RLAT0 selected for convenience 

 LCC : RLON0 identifies central (true N/S) meridian of projection 

 RLAT0 selected for convenience 

 PS : RLON0 identifies central (grid N/S) meridian of projection 

 RLAT0 selected for convenience 

 EM : RLON0 identifies central meridian of projection 

 RLAT0 is REPLACED by 0.0N (Equator) 

 LAZA: RLON0 identifies longitude of tangent-point of mapping plane 

 RLAT0 identifies latitude of tangent-point of mapping plane 

 Matching parallel(s) of latitude (decimal degrees) for projection 

 (Used only if PMAP= LCC or PS) 

 (XLAT1) No Default ! XLAT1 = 36.4N ! 

 (XLAT2) No Default ! XLAT2 = 40.5N ! 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 LCC : Projection cone slices through Earth's surface at XLAT1 and 

XLAT2 

 PS : Projection plane slices through Earth at XLAT1 

 (XLAT2 is not used) 

 ---------- 

 Note: Latitudes and longitudes should be positive, and include a 

 letter N,S,E, or W indicating north or south latitude, and 

 east or west longitude. For example, 

 35.9 N Latitude = 35.9N 

 118.7 E Longitude = 118.7E 

 Datum-region 

 ------------ 

 The Datum-Region for the coordinates is identified by a character 

 string. Many mapping products currently available use the model of the 

 Earth known as the World Geodetic System 1984 (WGS-84). Other local 

 models may be in use, and their selection in CALMET will make its output 

 consistent with local mapping products. The list of Datum-Regions with 

 official transformation parameters is provided by the National Imagery and 

 Mapping Agency (NIMA). 

 NIMA Datum - Regions(Examples) 

 --------------------------------------------------------------------------

---- 

 WGS-84 WGS-84 Reference Ellipsoid and Geoid, Global coverage (WGS84) 

 NAS-C NORTH AMERICAN 1927 Clarke 1866 Spheroid, MEAN FOR CONUS (NAD27) 

 NAR-C NORTH AMERICAN 1983 GRS 80 Spheroid, MEAN FOR CONUS (NAD83) 

 NWS-84 NWS 6370KM Radius, Sphere 

 ESR-S ESRI REFERENCE 6371KM Radius, Sphere 

 Datum-region for output coordinates 

 (DATUM) Default: WGS-84 ! DATUM = NAR-C ! 

 Horizontal grid definition: 

 --------------------------- 

 Rectangular grid defined for projection PMAP, 

 with X the Easting and Y the Northing coordinate 

 No. X grid cells (NX) No default ! NX = 127 ! 

 No. Y grid cells (NY) No default ! NY = 172 ! 

 Grid spacing (DGRIDKM) No default ! DGRIDKM = 4. ! 

 Units: km 

 Reference grid coordinate of 

 SOUTHWEST corner of grid cell (1,1) 

 X coordinate (XORIGKM) No default ! XORIGKM = -253.0 ! 

 Y coordinate (YORIGKM) No default ! YORIGKM = -348.0 ! 

 Units: km 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

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 66 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 Vertical grid definition: 

 ------------------------- 

 No. of vertical layers (NZ) No default ! NZ = 11 ! 

 Cell face heights in arbitrary 

 vertical grid (ZFACE(NZ+1)) No defaults 

 Units: m 

 ! ZFACE = 0.,20.,40.,80.,160.,320.,640.,1200.,2000.,3000.,4000.,5000. ! 

!END! 

------------------------------------------------------------------------------- 

INPUT GROUP: 3 -- Output Options 

-------------- 

 DISK OUTPUT OPTION 

 Save met. fields in an unformatted 

 output file ? (LSAVE) Default: T ! LSAVE = T ! 

 (F = Do not save, T = Save) 

 Type of unformatted output file: 

 (IFORMO) Default: 1 ! IFORMO = 1 ! 

 1 = CALPUFF/CALGRID type file (CALMET.DAT) 

 2 = MESOPUFF-II type file (PACOUT.DAT) 

 LINE PRINTER OUTPUT OPTIONS: 

 Print met. fields ? (LPRINT) Default: F ! LPRINT = F ! 

 (F = Do not print, T = Print) 

 (NOTE: parameters below control which 

 met. variables are printed) 

 Print interval 

 (IPRINF) in hours Default: 1 ! IPRINF = 1 ! 

 (Meteorological fields are printed 

 every 1 hours) 

 Specify which layers of U, V wind component 

 to print (IUVOUT(NZ)) -- NOTE: NZ values must be entered 

 (0=Do not print, 1=Print) 

 (used only if LPRINT=T) Defaults: NZ*0 

 ! IUVOUT = 11*0 ! 

 ----------------------- 

 Specify which levels of the W wind component to print 

 (NOTE: W defined at TOP cell face -- 10 values) 

 (IWOUT(NZ)) -- NOTE: NZ values must be entered 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 67 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 (0=Do not print, 1=Print) 

 (used only if LPRINT=T & LCALGRD=T) 

 ----------------------------------- 

 Defaults: NZ*0 

 ! IWOUT = 11*0 ! 

 Specify which levels of the 3-D temperature field to print 

 (ITOUT(NZ)) -- NOTE: NZ values must be entered 

 (0=Do not print, 1=Print) 

 (used only if LPRINT=T & LCALGRD=T) 

 ----------------------------------- 

 Defaults: NZ*0 

 ! ITOUT = 11*0 ! 

 Specify which meteorological fields 

 to print 

 (used only if LPRINT=T) Defaults: 0 (all variables) 

 ----------------------- 

 Variable Print ? 

 (0 = do not print, 

 1 = print) 

 -------- ------------------ 

 ! STABILITY = 0 ! - PGT stability class 

 ! USTAR = 0 ! - Friction velocity 

 ! MONIN = 0 ! - Monin-Obukhov length 

 ! MIXHT = 0 ! - Mixing height 

 ! WSTAR = 0 ! - Convective velocity scale 

 ! PRECIP = 0 ! - Precipitation rate 

 ! SENSHEAT = 0 ! - Sensible heat flux 

 ! CONVZI = 0 ! - Convective mixing ht. 

 Testing and debug print options for micrometeorological module 

 Print input meteorological data and 

 internal variables (LDB) Default: F ! LDB = F ! 

 (F = Do not print, T = print) 

 (NOTE: this option produces large amounts of output) 

 First time step for which debug data 

 are printed (NN1) Default: 1 ! NN1 = 1 ! 

 Last time step for which debug data 

 are printed (NN2) Default: 1 ! NN2 = 1 ! 

 Print distance to land 

 internal variables (LDBCST) Default: F ! LDBCST = F ! 

 (F = Do not print, T = print) 

 (Output in .GRD file DCST.GRD, defined in input group 0) 

 Testing and debug print options for wind field module 

 (all of the following print options control output to 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 68 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 wind field module's output files: TEST.PRT, TEST.OUT, 

 TEST.KIN, TEST.FRD, and TEST.SLP) 

 Control variable for writing the test/debug 

 wind fields to disk files (IOUTD) 

 (0=Do not write, 1=write) Default: 0 ! IOUTD = 0 ! 

 Number of levels, starting at the surface, 

 to print (NZPRN2) Default: 1 ! NZPRN2 = 0 ! 

 Print the INTERPOLATED wind components ? 

 (IPR0) (0=no, 1=yes) Default: 0 ! IPR0 = 0 ! 

 Print the TERRAIN ADJUSTED surface wind 

 components ? 

 (IPR1) (0=no, 1=yes) Default: 0 ! IPR1 = 0 ! 

 Print the SMOOTHED wind components and 

 the INITIAL DIVERGENCE fields ? 

 (IPR2) (0=no, 1=yes) Default: 0 ! IPR2 = 0 ! 

 Print the FINAL wind speed and direction 

 fields ? 

 (IPR3) (0=no, 1=yes) Default: 0 ! IPR3 = 0 ! 

 Print the FINAL DIVERGENCE fields ? 

 (IPR4) (0=no, 1=yes) Default: 0 ! IPR4 = 0 ! 

 Print the winds after KINEMATIC effects 

 are added ? 

 (IPR5) (0=no, 1=yes) Default: 0 ! IPR5 = 0 ! 

 Print the winds after the FROUDE NUMBER 

 adjustment is made ? 

 (IPR6) (0=no, 1=yes) Default: 0 ! IPR6 = 0 ! 

 Print the winds after SLOPE FLOWS 

 are added ? 

 (IPR7) (0=no, 1=yes) Default: 0 ! IPR7 = 0 ! 

 Print the FINAL wind field components ? 

 (IPR8) (0=no, 1=yes) Default: 0 ! IPR8 = 0 ! 

!END! 

------------------------------------------------------------------------------- 

INPUT GROUP: 4 -- Meteorological data options 

-------------- 

 NO OBSERVATION MODE (NOOBS) Default: 0 ! NOOBS = 0 ! 

 0 = Use surface, overwater, and upper air stations 

 1 = Use surface and overwater stations (no upper air observations) 

 Use MM4/MM5/3D for upper air data 

 2 = No surface, overwater, or upper air observations 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 69 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 Use MM4/MM5/3D for surface, overwater, and upper air data 

 NUMBER OF SURFACE & PRECIP. METEOROLOGICAL STATIONS 

 Number of surface stations (NSSTA) No default ! NSSTA = 25 ! 

 Number of precipitation stations 

 (NPSTA=-1: flag for use of MM5/3D precip data) 

 (NPSTA) No default ! NPSTA = 91 ! 

 CLOUD DATA OPTIONS 

 Gridded cloud fields: 

 (ICLOUD) Default: 0 ! ICLOUD = 0 ! 

 ICLOUD = 0 - Gridded clouds not used 

 ICLOUD = 1 - Gridded CLOUD.DAT generated as OUTPUT 

 ICLOUD = 2 - Gridded CLOUD.DAT read as INPUT 

 ICLOUD = 3 - Gridded cloud cover computed from prognostic fields 

 FILE FORMATS 

 Surface meteorological data file format 

 (IFORMS) Default: 2 ! IFORMS = 2 ! 

 (1 = unformatted (e.g., SMERGE output)) 

 (2 = formatted (free-formatted user input)) 

 Precipitation data file format 

 (IFORMP) Default: 2 ! IFORMP = 2 ! 

 (1 = unformatted (e.g., PMERGE output)) 

 (2 = formatted (free-formatted user input)) 

 Cloud data file format 

 (IFORMC) Default: 2 ! IFORMC = 2 ! 

 (1 = unformatted - CALMET unformatted output) 

 (2 = formatted - free-formatted CALMET output or user input) 

!END! 

------------------------------------------------------------------------------- 

INPUT GROUP: 5 -- Wind Field Options and Parameters 

-------------- 

 WIND FIELD MODEL OPTIONS 

 Model selection variable (IWFCOD) Default: 1 ! IWFCOD = 1 ! 

 0 = Objective analysis only 

 1 = Diagnostic wind module 

 Compute Froude number adjustment 

 effects ? (IFRADJ) Default: 1 ! IFRADJ = 1 ! 

 (0 = NO, 1 = YES) 

 Compute kinematic effects ? (IKINE) Default: 0 ! IKINE = 0 ! 

 (0 = NO, 1 = YES) 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 70 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 Use O'Brien procedure for adjustment 

 of the vertical velocity ? (IOBR) Default: 0 ! IOBR = 0 ! 

 (0 = NO, 1 = YES) 

 Compute slope flow effects ? (ISLOPE) Default: 1 ! ISLOPE = 1 ! 

 (0 = NO, 1 = YES) 

 Extrapolate surface wind observations 

 to upper layers ? (IEXTRP) Default: -4 ! IEXTRP = -4 ! 

 (1 = no extrapolation is done, 

 2 = power law extrapolation used, 

 3 = user input multiplicative factors 

 for layers 2 - NZ used (see FEXTRP array) 

 4 = similarity theory used 

 -1, -2, -3, -4 = same as above except layer 1 data 

 at upper air stations are ignored 

 Extrapolate surface winds even 

 if calm? (ICALM) Default: 0 ! ICALM = 0 ! 

 (0 = NO, 1 = YES) 

 Layer-dependent biases modifying the weights of 

 surface and upper air stations (BIAS(NZ)) 

 -1<=BIAS<=1 

 Negative BIAS reduces the weight of upper air stations 

 (e.g. BIAS=-0.1 reduces the weight of upper air stations 

 by 10%; BIAS= -1, reduces their weight by 100 %) 

 Positive BIAS reduces the weight of surface stations 

 (e.g. BIAS= 0.2 reduces the weight of surface stations 

 by 20%; BIAS=1 reduces their weight by 100%) 

 Zero BIAS leaves weights unchanged (1/R**2 interpolation) 

 Default: NZ*0 

 ! BIAS = 11*0 ! 

 Minimum distance from nearest upper air station 

 to surface station for which extrapolation 

 of surface winds at surface station will be allowed 

 (RMIN2: Set to -1 for IEXTRP = 4 or other situations 

 where all surface stations should be extrapolated) 

 Default: 4. ! RMIN2 = -1 ! 

 Use gridded prognostic wind field model 

 output fields as input to the diagnostic 

 wind field model (IPROG) Default: 0 ! IPROG = 14 ! 

 (0 = No, [IWFCOD = 0 or 1] 

 1 = Yes, use CSUMM prog. winds as Step 1 field, [IWFCOD = 0] 

 2 = Yes, use CSUMM prog. winds as initial guess field [IWFCOD = 1] 

 3 = Yes, use winds from MM4.DAT file as Step 1 field [IWFCOD = 0] 

 4 = Yes, use winds from MM4.DAT file as initial guess field [IWFCOD = 

1] 

 5 = Yes, use winds from MM4.DAT file as observations [IWFCOD = 1] 

 13 = Yes, use winds from MM5/3D.DAT file as Step 1 field [IWFCOD = 0] 

 14 = Yes, use winds from MM5/3D.DAT file as initial guess field [IWFCOD 

= 1] 

 15 = Yes, use winds from MM5/3D.DAT file as observations [IWFCOD = 1] 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 71 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 Timestep (hours) of the prognostic 

 model input data (ISTEPPG) Default: 1 ! ISTEPPG = 1 ! 

 Use coarse CALMET fields as initial guess fields (IGFMET) 

 (overwrites IGF based on prognostic wind fields if any) 

 Default: 0 ! IGFMET = 0 ! 

 RADIUS OF INFLUENCE PARAMETERS 

 Use varying radius of influence Default: F ! LVARY = F! 

 (if no stations are found within RMAX1,RMAX2, 

 or RMAX3, then the closest station will be used) 

 Maximum radius of influence over land 

 in the surface layer (RMAX1) No default ! RMAX1 = 100. ! 

 Units: km 

 Maximum radius of influence over land 

 aloft (RMAX2) No default ! RMAX2 = 200. ! 

 Units: km 

 Maximum radius of influence over water 

 (RMAX3) No default ! RMAX3 = 200. ! 

 Units: km 

 OTHER WIND FIELD INPUT PARAMETERS 

 Minimum radius of influence used in 

 the wind field interpolation (RMIN) Default: 0.1 ! RMIN = 0.1 ! 

 Units: km 

 Radius of influence of terrain 

 features (TERRAD) No default ! TERRAD = 15. ! 

 Units: km 

 Relative weighting of the first 

 guess field and observations in the 

 SURFACE layer (R1) No default ! R1 = 50. ! 

 (R1 is the distance from an Units: km 

 observational station at which the 

 observation and first guess field are 

 equally weighted) 

 Relative weighting of the first 

 guess field and observations in the 

 layers ALOFT (R2) No default ! R2 = 100. ! 

 (R2 is applied in the upper layers Units: km 

 in the same manner as R1 is used in 

 the surface layer). 

 Relative weighting parameter of the 

 prognostic wind field data (RPROG) No default ! RPROG = 0. ! 

 (Used only if IPROG = 1) Units: km 

 ------------------------ 

 Maximum acceptable divergence in the 

 divergence minimization procedure 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 72 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 (DIVLIM) Default: 5.E-6 ! DIVLIM= 5.0E-06 

! 

 Maximum number of iterations in the 

 divergence min. procedure (NITER) Default: 50 ! NITER = 50 ! 

 Number of passes in the smoothing 

 procedure (NSMTH(NZ)) 

 NOTE: NZ values must be entered 

 Default: 2,(mxnz-1)*4 ! NSMTH = 2, 10*4 ! 

 Maximum number of stations used in 

 each layer for the interpolation of 

 data to a grid point (NINTR2(NZ)) 

 NOTE: NZ values must be entered Default: 99. ! NINTR2 = 11*99 

! 

 Critical Froude number (CRITFN) Default: 1.0 ! CRITFN = 1. ! 

 Empirical factor controlling the 

 influence of kinematic effects 

 (ALPHA) Default: 0.1 ! ALPHA = 0.1 ! 

 Multiplicative scaling factor for 

 extrapolation of surface observations 

 to upper layers (FEXTR2(NZ)) Default: NZ*0.0 

 ! FEXTR2 = 11*0. ! 

 (Used only if IEXTRP = 3 or -3) 

 BARRIER INFORMATION 

 Number of barriers to interpolation 

 of the wind fields (NBAR) Default: 0 ! NBAR = 0 ! 

 Level (1 to NZ) up to which barriers 

 apply (KBAR) Default: NZ ! KBAR = 11 ! 

 THE FOLLOWING 4 VARIABLES ARE INCLUDED 

 ONLY IF NBAR > 0 

 NOTE: NBAR values must be entered No defaults 

 for each variable Units: km 

 X coordinate of BEGINNING 

 of each barrier (XBBAR(NBAR)) ! XBBAR = 0. ! 

 Y coordinate of BEGINNING 

 of each barrier (YBBAR(NBAR)) ! YBBAR = 0. ! 

 X coordinate of ENDING 

 of each barrier (XEBAR(NBAR)) ! XEBAR = 0. ! 

 Y coordinate of ENDING 

 of each barrier (YEBAR(NBAR)) ! YEBAR = 0. ! 

 DIAGNOSTIC MODULE DATA INPUT OPTIONS 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 73 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 Surface temperature (IDIOPT1) Default: 0 ! IDIOPT1 = 0 ! 

 0 = Compute internally from 

 hourly surface observations 

 1 = Read preprocessed values from 

 a data file (DIAG.DAT) 

 Surface met. station to use for 

 the surface temperature (ISURFT) No default ! ISURFT = 9 ! 

*DEN* 

 (Must be a value from 1 to NSSTA) 

 (Used only if IDIOPT1 = 0) 

 -------------------------- 

 Domain-averaged temperature lapse 

 rate (IDIOPT2) Default: 0 ! IDIOPT2 = 0 ! 

 0 = Compute internally from 

 twice-daily upper air observations 

 1 = Read hourly preprocessed values 

 from a data file (DIAG.DAT) 

 Upper air station to use for 

 the domain-scale lapse rate (IUPT) No default ! IUPT = 1 ! 

 (Must be a value from 1 to NUSTA) 

 (Used only if IDIOPT2 = 0) 

 -------------------------- 

 Depth through which the domain-scale 

 lapse rate is computed (ZUPT) Default: 200. ! ZUPT = 200. ! 

 (Used only if IDIOPT2 = 0) Units: meters 

 -------------------------- 

 Domain-averaged wind components 

 (IDIOPT3) Default: 0 ! IDIOPT3 = 0 ! 

 0 = Compute internally from 

 twice-daily upper air observations 

 1 = Read hourly preprocessed values 

 a data file (DIAG.DAT) 

 Upper air station to use for 

 the domain-scale winds (IUPWND) Default: -1 ! IUPWND = -1 ! 

 (Must be a value from -1 to NUSTA) 

 (Used only if IDIOPT3 = 0) 

 -------------------------- 

 Bottom and top of layer through 

 which the domain-scale winds 

 are computed 

 (ZUPWND(1), ZUPWND(2)) Defaults: 1., 1000. ! ZUPWND= 1., 1000. 

! 

 (Used only if IDIOPT3 = 0) Units: meters 

 -------------------------- 

 Observed surface wind components 

 for wind field module (IDIOPT4) Default: 0 ! IDIOPT4 = 0 ! 

 0 = Read WS, WD from a surface 

 data file (SURF.DAT) 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 74 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 1 = Read hourly preprocessed U, V from 

 a data file (DIAG.DAT) 

 Observed upper air wind components 

 for wind field module (IDIOPT5) Default: 0 ! IDIOPT5 = 0 ! 

 0 = Read WS, WD from an upper 

 air data file (UP1.DAT, UP2.DAT, etc.) 

 1 = Read hourly preprocessed U, V from 

 a data file (DIAG.DAT) 

 LAKE BREEZE INFORMATION 

 Use Lake Breeze Module (LLBREZE) 

 Default: F ! LLBREZE = F ! 

 Number of lake breeze regions (NBOX) ! NBOX = 0 ! 

 X Grid line 1 defining the region of interest 

 ! XG1 = 0. ! 

 X Grid line 2 defining the region of interest 

 ! XG2 = 0. ! 

 Y Grid line 1 defining the region of interest 

 ! YG1 = 0. ! 

 Y Grid line 2 defining the region of interest 

 ! YG2 = 0. ! 

 X Point defining the coastline (Straight line) 

 (XBCST) (KM) Default: none ! XBCST = 0. ! 

 Y Point defining the coastline (Straight line) 

 (YBCST) (KM) Default: none ! YBCST = 0. ! 

 X Point defining the coastline (Straight line) 

 (XECST) (KM) Default: none ! XECST = 0. ! 

 Y Point defining the coastline (Straight line) 

 (YECST) (KM) Default: none ! YECST = 0. ! 

 Number of stations in the region Default: none ! NLB = 0 ! 

 (Surface stations + upper air stations) 

 Station ID's in the region (METBXID(NLB)) 

 (Surface stations first, then upper air stations) 

 ! METBXID = 0 ! 

!END! 

------------------------------------------------------------------------------- 

INPUT GROUP: 6 -- Mixing Height, Temperature and Precipitation Parameters 

-------------- 

 EMPIRICAL MIXING HEIGHT CONSTANTS 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 75 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 Neutral, mechanical equation 

 (CONSTB) Default: 1.41 ! CONSTB = 1.41 ! 

 Convective mixing ht. equation 

 (CONSTE) Default: 0.15 ! CONSTE = 0.15 ! 

 Stable mixing ht. equation 

 (CONSTN) Default: 2400. ! CONSTN = 2400.! 

 Overwater mixing ht. equation 

 (CONSTW) Default: 0.16 ! CONSTW = 0.16 ! 

 Absolute value of Coriolis 

 parameter (FCORIOL) Default: 1.E-4 ! FCORIOL = 1.0E04! 

 Units: (1/s) 

 SPATIAL AVERAGING OF MIXING HEIGHTS 

 Conduct spatial averaging 

 (IAVEZI) (0=no, 1=yes) Default: 1 ! IAVEZI = 1 ! 

 Max. search radius in averaging 

 process (MNMDAV) Default: 1 ! MNMDAV = 1 ! 

 Units: Grid 

 cells 

 Half-angle of upwind looking cone 

 for averaging (HAFANG) Default: 30. ! HAFANG = 30. ! 

 Units: deg. 

 Layer of winds used in upwind 

 averaging (ILEVZI) Default: 1 ! ILEVZI = 1 ! 

 (must be between 1 and NZ) 

 CONVECTIVE MIXING HEIGHT OPTIONS: 

 Method to compute the convective 

 mixing height(IMIHXH) Default: 1 ! IMIXH = -1 ! 

 1: Maul-Carson for land and water cells 

 -1: Maul-Carson for land cells only - 

 OCD mixing height overwater 

 2: Batchvarova and Gryning for land and water cells 

 -2: Batchvarova and Gryning for land cells only 

 OCD mixing height overwater 

 Threshold buoyancy flux required to 

 sustain convective mixing height growth 

 overland (THRESHL) Default: 0.05 ! THRESHL = 0. ! 

 (expressed as a heat flux units: W/m3 

 per meter of boundary layer) 

 Threshold buoyancy flux required to 

 sustain convective mixing height growth 

 overwater (THRESHW) Default: 0.05 ! THRESHW = 0.05 ! 

 (expressed as a heat flux units: W/m3 

 per meter of boundary layer) 

 Option for overwater lapse rates used 

 in convective mixing height growth 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 76 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 (ITWPROG) Default: 0 ! ITWPROG = 0 ! 

 0 : use SEA.DAT lapse rates and deltaT (or assume neutral 

 conditions if missing) 

 1 : use prognostic lapse rates (only if IPROG>2) 

 and SEA.DAT deltaT (or neutral if missing) 

 2 : use prognostic lapse rates and prognostic delta T 

 (only if iprog>12 and 3D.DAT version# 2.0 or higher) 

 Land Use category ocean in 3D.DAT datasets 

 (ILUOC3D) Default: 16 ! ILUOC3D = 16 ! 

 Note: if 3D.DAT from MM5 version 3.0, iluoc3d = 16 

 if MM4.DAT, typically iluoc3d = 7 

 OTHER MIXING HEIGHT VARIABLES 

 Minimum potential temperature lapse 

 rate in the stable layer above the 

 current convective mixing ht. Default: 0.001 ! DPTMIN = 0.001 ! 

 (DPTMIN) Units: deg. K/m 

 Depth of layer above current conv. 

 mixing height through which lapse Default: 200. ! DZZI = 200. ! 

 rate is computed (DZZI) Units: meters 

 Minimum overland mixing height Default: 50. ! ZIMIN = 50. ! 

 (ZIMIN) Units: meters 

 Maximum overland mixing height Default: 3000. ! ZIMAX = 4500. ! 

 (ZIMAX) Units: meters 

 Minimum overwater mixing height Default: 50. ! ZIMINW = 50. ! 

 (ZIMINW) -- (Not used if observed Units: meters 

 overwater mixing hts. are used) 

 Maximum overwater mixing height Default: 3000. ! ZIMAXW = 4500. ! 

 (ZIMAXW) -- (Not used if observed Units: meters 

 overwater mixing hts. are used) 

 OVERWATER SURFACE FLUXES METHOD and PARAMETERS 

 (ICOARE) Default: 10 ! ICOARE = 0 ! 

 0: original deltaT method (OCD) 

 10: COARE with no wave parameterization (jwave=0, Charnock) 

 11: COARE with wave option jwave=1 (Oost et al.) 

 and default wave properties 

 -11: COARE with wave option jwave=1 (Oost et al.) 

 and observed wave properties (must be in SEA.DAT files) 

 12: COARE with wave option 2 (Taylor and Yelland) 

 and default wave properties 

 -12: COARE with wave option 2 (Taylor and Yelland) 

 and observed wave properties (must be in SEA.DAT files) 

 Coastal/Shallow water length scale (DSHELF) 

 (for modified z0 in shallow water) 

 ( COARE fluxes only) 

 Default : 0. ! DSHELF = 0. ! 

 units: km 

 COARE warm layer computation (IWARM) ! IWARM = 0 ! 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 77 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 1: on - 0: off (must be off if SST measured with 

 IR radiometer) Default: 0 

 COARE cool skin layer computation (ICOOL) ! ICOOL = 0 ! 

 1: on - 0: off (must be off if SST measured with 

 IR radiometer) Default: 0 

 TEMPERATURE PARAMETERS 

 3D temperature from observations or 

 from prognostic data? (ITPROG) Default:0 ! ITPROG = 0 ! 

 0 = Use Surface and upper air stations 

 (only if NOOBS = 0) 

 1 = Use Surface stations (no upper air observations) 

 Use MM5/3D for upper air data 

 (only if NOOBS = 0,1) 

 2 = No surface or upper air observations 

 Use MM5/3D for surface and upper air data 

 (only if NOOBS = 0,1,2) 

 Interpolation type 

 (1 = 1/R ; 2 = 1/R**2) Default:1 ! IRAD = 1 ! 

 Radius of influence for temperature 

 interpolation (TRADKM) Default: 500. ! TRADKM = 500. 

! 

 Units: km 

 Maximum Number of stations to include 

 in temperature interpolation (NUMTS) Default: 5 ! NUMTS = 5 ! 

 Conduct spatial averaging of temp- 

 eratures (IAVET) (0=no, 1=yes) Default: 1 ! IAVET = 1 ! 

 (will use mixing ht MNMDAV,HAFANG 

 so make sure they are correct) 

 Default temperature gradient Default: -.0098 ! TGDEFB = -

0.0098 ! 

 below the mixing height over Units: K/m 

 water (TGDEFB) 

 Default temperature gradient Default: -.0045 ! TGDEFA = -

0.0045 ! 

 above the mixing height over Units: K/m 

 water (TGDEFA) 

 Beginning (JWAT1) and ending (JWAT2) 

 land use categories for temperature ! JWAT1 = 55 ! 

 interpolation over water -- Make ! JWAT2 = 55 ! 

 bigger than largest land use to disable 

 PRECIP INTERPOLATION PARAMETERS 

 Method of interpolation (NFLAGP) Default: 2 ! NFLAGP = 2 ! 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 78 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

 (1=1/R,2=1/R**2,3=EXP/R**2) 

 Radius of Influence (SIGMAP) Default: 100.0 ! SIGMAP = 100. ! 

 (0.0 => use half dist. btwn Units: km 

 nearest stns w & w/out 

 precip when NFLAGP = 3) 

 Minimum Precip. Rate Cutoff (CUTP) Default: 0.01 ! CUTP = 0.01 ! 

 (values < CUTP = 0.0 mm/hr) Units: mm/hr 

!END! 

------------------------------------------------------------------------------- 

INPUT GROUP: 7 -- Surface meteorological station parameters 

-------------- 

 SURFACE STATION VARIABLES 

 (One record per station -- 25 records in all) 

 1 2 

 Name ID X coord. Y coord. Time Anem. 

 (km) (km) zone Ht.(m) 

 ---------------------------------------------------------- 

! SS1 ='AKO ' 24698 193.159 198.973 7 10 ! 

! SS2 ='ALS ' 24620 -32.336 -106.860 7 10 ! 

! SS3 ='APA ' 24666 55.922 130.041 7 10 ! 

! SS4 ='ASE ' 24676 -118.091 92.190 7 10 ! 

! SS5 ='CAG ' 25700 -171.322 234.404 7 10 ! 

! SS6 ='CAO ' 23600 210.283 -214.114 7 10 ! 

! SS7 ='COS ' 24660 68.475 45.993 7 10 ! 

! SS8 ='CYS ' 25640 58.198 306.332 7 10 ! 

! SS9 ='DEN ' 25650 72.093 159.306 7 10 ! 

! SS10 ='DHT ' 22636 266.176 -259.412 7 10 ! 

! SS11 ='DRO ' 24625 -200.668 -136.973 7 10 ! 

! SS12 ='EOO ' 24674 -203.468 185.599 7 10 ! 

! SS13 ='FMN ' 23658 -243.657 -180.141 7 10 ! 

! SS14 ='LAA ' 24636 246.555 -32.844 7 10 ! 

! SS15 ='LAR ' 25645 -14.616 323.319 7 10 ! 

! SS16 ='LHX ' 24635 173.058 -36.818 7 10 ! 

! SS17 ='LIC ' 24665 154.047 89.075 7 10 ! 

! SS18 ='LVS ' 23677 32.391 -304.593 7 10 ! 

! SS19 ='LXV ' 24673 -70.429 92.179 7 10 ! 

! SS20 ='MTJ ' 24765 -208.969 14.367 7 10 ! 

! SS21 ='PUB ' 24640 87.574 -11.726 7 10 ! 

! SS22 ='RIL ' 25717 -191.319 127.284 7 10 ! 

! SS23 ='SAF ' 23656 -53.382 -308.617 7 10 ! 

! SS24 ='SNY ' 25610 211.364 302.733 7 10 ! 

! SS25 ='TAD ' 24645 102.806 -125.906 7 10 ! 

------------------- 

 1 

 Four character string for station name 

 (MUST START IN COLUMN 9) 

 2 

 Six digit integer for station ID 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 79 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

!END! 

------------------------------------------------------------------------------- 

INPUT GROUP: 8 -- Upper air meteorological station parameters 

-------------- 

 UPPER AIR STATION VARIABLES 

 (One record per station -- 1 records in all) 

 1 2 

 Name ID X coord. Y coord. Time zone 

 (km) (km) 

 ----------------------------------------------- 

! US1 ='DEN ' 23062 59.101 152.186 7 ! 

------------------- 

 1 

 Four character string for station name 

 (MUST START IN COLUMN 9) 

 2 

 Five digit integer for station ID 

!END! 

------------------------------------------------------------------------------- 

INPUT GROUP: 9 -- Precipitation station parameters 

-------------- 

 PRECIPITATION STATION VARIABLES 

 (One record per station -- 91 records in all) 

 (NOT INCLUDED IF NPSTA = 0) 

 1 2 

 Name Station X coord. Y coord. 

 Code (km) (km) 

 ------------------------------------ 

! PS1 ='WY01' 481675 85.74 299.06 ! 

! PS2 ='WY02' 483050 -81.49 303.46 ! 

! PS3 ='WY03' 484930 -42.89 294.26 ! 

! PS4 ='WY04' 485420 10.07 308.59 ! 

! PS5 ='WY05' 487200 100.45 331.46 ! 

! PS6 ='WY06' 487240 118.50 300.60 ! 

! PS7 ='WY07' 487995 -81.29 322.34 ! 

! PS8 ='NM01' 290041 -68.41 -250.45 ! 

! PS9 ='NM02' 290407 27.86 -236.26 ! 

! PS10 ='NM03' 291887 216.54 -233.47 ! 

! PS11 ='NM04' 291982 -63.65 -334.85 ! 

! PS12 ='NM05' 292030 126.63 -349.69 ! 

! PS13 ='NM06' 292241 -97.39 -264.59 ! 

! PS14 ='NM07' 292700 30.57 -240.69 ! 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 80 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

! PS15 ='NM08' 292837 -84.37 -225.89 ! 

! PS16 ='NM09' 293142 -237.62 -216.24 ! 

! PS17 ='NM10' 294862 34.58 -341.69 ! 

! PS18 ='NM11' 296275 41.42 -252.85 ! 

! PS19 ='NM12' 297279 111.01 -204.49 ! 

! PS20 ='NM13' 297638 125.17 -313.06 ! 

! PS21 ='NM14' 298085 -8.19 -336.20 ! 

! PS22 ='NM15' 298501 102.51 -241.22 ! 

! PS23 ='NM16' 299031 -146.20 -322.71 ! 

! PS24 ='NE01' 257827 245.44 301.36 ! 

! PS25 ='CO01' 050109 205.46 190.22 ! 

! PS26 ='CO02' 050130 -1.77 -126.46 ! 

! PS27 ='CO03' 050183 15.34 191.98 ! 

! PS28 ='CO04' 050263 -3.46 66.56 ! 

! PS29 ='CO05' 050372 -86.44 79.24 ! 

! PS30 ='CO06' 050843 28.16 179.81 ! 

! PS31 ='CO07' 051179 122.18 116.33 ! 

! PS32 ='CO08' 051401 86.31 91.44 ! 

! PS33 ='CO09' 051443 -177.73 17.50 ! 

! PS34 ='CO10' 051539 192.94 -35.41 ! 

! PS35 ='CO11' 051547 86.12 109.20 ! 

! PS36 ='CO12' 051713 -83.95 -13.98 ! 

! PS37 ='CO13' 051778 93.29 10.53 ! 

! PS38 ='CO14' 051959 -94.98 14.98 ! 

! PS39 ='CO15' 052162 126.59 109.74 ! 

! PS40 ='CO16' 052211 84.30 118.05 ! 

! PS41 ='CO17' 052220 84.30 118.05 ! 

! PS42 ='CO18' 052354 25.52 206.44 ! 

! PS43 ='CO19' 052790 26.70 108.77 ! 

! PS44 ='CO20' 052965 28.75 16.69 ! 

! PS45 ='CO21' 053005 38.23 216.49 ! 

! PS46 ='CO22' 053007 31.41 222.01 ! 

! PS47 ='CO23' 053386 30.98 113.23 ! 

! PS48 ='CO24' 053500 -1.70 189.75 ! 

! PS49 ='CO25' 053553 91.89 204.72 ! 

! PS50 ='CO26' 053579 91.69 73.75 ! 

! PS51 ='CO27' 053584 91.60 81.51 ! 

! PS52 ='CO28' 053662 -94.38 -8.32 ! 

! PS53 ='CO29' 054155 123.78 178.51 ! 

! PS54 ='CO30' 054172 191.07 78.84 ! 

! PS55 ='CO31' 054293 31.88 104.35 ! 

! PS56 ='CO32' 054388 257.89 -35.82 ! 

! PS57 ='CO33' 054538 204.78 -122.78 ! 

! PS58 ='CO34' 054720 191.26 -38.78 ! 

! PS59 ='CO35' 054742 19.17 15.55 ! 

! PS60 ='CO36' 054877 11.18 117.61 ! 

! PS61 ='CO37' 055121 34.93 194.27 ! 

! PS62 ='CO38' 055352 81.93 12.62 ! 

! PS63 ='CO39' 055484 -177.53 180.65 ! 

! PS64 ='CO40' 055706 -54.91 -116.29 ! 

! PS65 ='CO41' 055765 32.72 109.91 ! 

! PS66 ='CO42' 055881 14.51 179.77 ! 

! PS67 ='CO43' 055922 169.01 219.33 ! 

! PS68 ='CO44' 055982 -59.29 239.94 ! 

! PS69 ='CO45' 056023 87.41 224.66 ! 

! PS70 ='CO46' 056136 181.79 -7.93 ! 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 81 
Supplemental BART Analysis CALPUFF Protocol for Class I Federal Area Visibility Improvement Modeling (DRAFT) 

! PS71 ='CO47' 056203 -166.75 -41.54 ! 

! PS72 ='CO48' 056740 105.09 -24.83 ! 

! PS73 ='CO49' 057031 -170.64 103.90 ! 

! PS74 ='CO50' 057296 5.94 224.17 ! 

! PS75 ='CO51' 057320 83.01 -92.76 ! 

! PS76 ='CO52' 057337 -50.88 -38.67 ! 

! PS77 ='CO53' 057428 23.10 -143.07 ! 

! PS78 ='CO54' 057519 257.30 90.70 ! 

! PS79 ='CO55' 057560 199.88 106.81 ! 

! PS80 ='CO56' 057572 31.85 -107.54 ! 

! PS81 ='CO57' 057664 125.39 76.43 ! 

! PS82 ='CO58' 058064 -62.20 83.45 ! 

! PS83 ='CO59' 058204 -178.35 -90.12 ! 

! PS84 ='CO60' 058220 41.80 -150.76 ! 

! PS85 ='CO61' 058429 107.51 -142.40 ! 

! PS86 ='CO62' 058436 103.98 -144.66 ! 

! PS87 ='CO63' 058781 92.05 -111.52 ! 

! PS88 ='CO64' 058997 126.35 -96.64 ! 

! PS89 ='CO65' 059096 -52.91 179.94 ! 

! PS90 ='CO66' 059210 37.21 71.09 ! 

! PS91 ='CO67' 059285 117.67 13.06 ! 

------------------- 

 1 

 Four character string for station name 

 (MUST START IN COLUMN 9) 

 2 

 Six digit station code composed of state 

 code (first 2 digits) and station ID (last 

 4 digits) 

!END! 

Colorado Department of Public Health & Environment / Air Pollution Control Division / Technical Services Program 

April 15, 2010 (revised June 25, 2010 and August 19, 2010) 

 82