Correction of WRAP region Plan02d CMAQ visibility modeling results on TSS 

for Regional Haze Planning 

April 27, 2011 

Contact: Tom Moore, WRAP Air Quality Program Manger, 970.491.8837 or mooret@cira.colostate.edu 

2018 Visibility Projections from the Plan02d and PRP18b regional modeling scenarios for the USFS Gila Wilderness 

Class I area (GICL1) in the NM Regional Haze Plan were not demonstrating reasonable progress on the Worst Visibility 

Days, as the visibility is worsening from 2002 to 2018, see Figure 1. 

 

Figure 1. Original GICL1 Visibility monitoring data, Glide Paths, and Visibility Projections for NM Regional Haze Plan 

After discussion with the State of NM and EPA Region 6, and in reviewing the 5 principle WRAP region visibility 

regional modeling scenarios for GICL1 shown in Figure 2, very different CMAQ results for Plan02d relative to Plan02c, 

Base18b, PRP18a, and PRP18b are shown for modeled Particulate Organic Mass on the 20% Worst Visibility Days for 

GICL1. This result would lead to questions about results at other WRAP region Class I areas. The difference in POM 

results for Plan02d to PRP18b is unexpected, because the dominant source category of Primary Organic Aerosol 

emissions are the Wildfire (natural) and Prescribed/Agricultural Fire (anthropogenic) types, relative to other sources of 

Primary Organic Aerosol emissions, see Figure 3. 

Figure 2. CMAQ-modeled Organic Mass from WRAP RMC Regional Haze Planning Scenarios
Figure 3. Comparison of Primary Organic Aerosol emissions source categories by WRAP region state for the Plan02d 

and PRP18b scenarios 

POA emissions for the Plan02d and PRP18b scenarios used by NM and other WRAP region states for their regional haze 

plans were to be held constant for Wildfires and decline for Prescribed and Agricultural Fire. The decline in 

anthropogenic fire emissions results from Emissions Reductions Techniques applied by burners as required by the NM 

and other states’ Smoke Management Programs, as shown in Figure 4. 

Figure 4. Comparison of Natural and Anthropogenic Fire Sources of Primary Organic Aerosol emissions by WRAP 

region state for the Plan02d and PRP18b scenarios 

With emissions sources’ inputs to Plan02d verified to be as specified, WRAP Regional Modeling Center staff then 

reviewed the scripts used to extract gridded CMAQ air quality modeling results to be displayed on TSS at IMPROVE site 

locations. We have identified that a different spheroid type of geographic projection was applied when the Plan02d 

regional planning scenario’s air quality modeling results were extracted in Fall 2007, relative to the projection used to 

extract the air quality results for the other 4 regional planning scenarios (Plan02c, Base18b, PRP18a, and PRP18b), which 

all used the same extraction scripts and spheroid type. The Plan02d CMAQ extraction results for all species would be 

affected (Sulfate, Nitrate, POM, Elemental Carbon, Soil, Coarse Mass, and Sea Salt), not just POM. We examined POM 

because it is dominated by a large and relatively unchanging source type from the planning period to the projection year. 

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Sulfate, Nitrate, and other species have a more-mixed variety of source types and have reduced emissions by 2018 from 

state and federal rules and permits. 

We determined that Plan02d CMAQ extraction results were off by one grid cell (either x or y) for 9 IMPROVE site 

locations in the WRAP region, affecting a total of 15 different Class I areas in 8 states represented by those IMPROVE 

sites. The Plan02d CMAQ results for the Worst and Best Visibility Days used for Regional Haze Planning, currently 

displayed on the TSS are from the wrong (next-door) grid cells for 9 sites in the Plan02d scenario, and thus cause the 2018 

visibility projections to either the PRP18a or PRP18b scenarios used by the 8 states for haze planning to also be incorrect 

for these 9 IMPROVE site locations in the WRAP region. 

We first compared the scripts, and then the CMAQ-extracted results between Plan02d and Plan02c cases, to isolate the 

locations of the extracted grid cells’ results where they are off by one grid cell. We then re-ran the extraction for Plan02d 

with the same version of executable as Plan02c and verified the locations of the grid cells between Plan02d and Plan02c 

to now be the same. We have determined that all other Class I area sites used for regional haze planning in the WRAP 

region, other than these 9 sites, are not affected. Four (4) sites outside the WRAP region and 1 WRAP region non-Class I 

area site (COGO1) were similarly affected – visibility projections are not made for those sites on the TSS. 

The following sites, Class I areas, and state regional haze plans are affected by this error. 

IMPROVE Site Code Class I area(s) represented State 

BADL1 Badlands National Park South Dakota 

CRLA1 

Crater Lake National Park 

Diamond Peak Wilderness 

Gearhart Mountain Wilderness 

Mountain Lakes Wilderness 

Oregon 

DOME1 Domelands Wilderness California 

GICL1 Gila Wilderness New Mexico 

HECA1 Hells Canyon Wilderness Idaho 

JARB1 Jarbidge Wilderness Nevada 

MONT1 

Bob Marshall Wilderness 

Scapegoat Wilderness 

Mission Mountains Wilderness 

Montana 

NOCA1 North Cascades National Park 

Glacier Peak Wilderness Washington 

PASA1 Pasayten Wilderness Washington 

The correctly extracted data has been added to TSS tools as another scenario, called “Plan02d_rev” and paired with 

appropriate 2018 projection scenarios. TSS users are able to compare “Plan02d” to “Plan02d_rev”, as well as to compare 

Visibility Projections from various combinations of planning scenarios (Plan02d, Plan02d_rev) to projection year results 

(PRP18a, PRP18b, and PRP18cmv). 

Results comparing Worst Visibility Days’ for PRP18b Projected Visibility from Plan02d versus Plan02d_rev are 

presented for the affected sites and Class I areas in Appendix A of this memo. 

WRAP staff have met by phone with affected States, EPA regional offices, and Federal Land Managers to review these 

changes and address concerns and questions. This memo was circulated for review and comment. The final version of 

the memo will be posted on the WRAP TSS website and the affected TSS tools footnoted. Figure 5 show the TSS tools 

modified to add “Plan02d_rev” results. 
Figures 5a, b, and c. Modified TSS tools adding “Plan02d_rev” results at: 

http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx

5a. Class I area Summary Table selection for data and results on Worst and Best Visibility Days

5b. Visibility Modeling Results selection under “Modeling button” comparing air quality modeling results in mass 

concentration units (μg/m3) from WRAP regional modeling scenarios.

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5c. 2018 Visibility Projections selection under “Modeling button” – WRAP regional visibility modeling results in 

Deciview and Species Light Extinction scaled by Relative Response Factors and projected to 2018, following 

EPA guidance.

 

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Appendix A 

Comparison of Changes to Worst Days’ PRP18b Projected Visibility from Plan02d versus Plan02d_rev 

Plan02d 

Plan02_rev 

6
Plan02d 

Plan02_rev 

 

7
Plan02d 

Plan02_rev 

 

8
Plan02d 

Plan02_rev 

 

9
Plan02d 

Plan02_rev 

   

10
Plan02d 

Plan02_rev 

 

11
Plan02d 

Plan02_rev 

 

12
Plan02d 

Plan02_rev 

 

13
Plan02d 

Plan02_rev 

14