Correction of WRAP region Plan02d CMAQ visibility modeling results on TSS

for Regional Haze Planning – Final Memorandum

June 30, 2011

Contact: Tom Moore, WRAP Air Quality Program Manager, 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
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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 used to assess Regional Haze. 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 
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planning period to the projection year. 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 i or j on the 36km modeling grid) 

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 the 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

WRAP “Plan02d” i, j, 

regional planning scenario 

extraction cell coordinates

WRAP “Plan02d_rev” i, j, 

regional planning scenario 

extraction cell coordinates

BADL1 Badlands National Park South Dakota 66,70 65,70

CRLA1

Crater Lake National Park 

Diamond Peak Wilderness

Gearhart Mountain Wilderness

Mountain Lakes Wilderness

Oregon 21,75 20,75

DOME1 Domelands Wilderness California 24,51 24,52

GICL1 Gila Wilderness New Mexico 48,39 47,39

HECA1 Hells Canyon Wilderness Oregon 34,79 33,79

JARB1 Jarbidge Wilderness Nevada 35,69 34,69

MONT1

Bob Marshall Wilderness

Scapegoat Wilderness

Mission Mountains Wilderness

Montana 43,83 42,83

NOCA1 North Cascades National Park

Glacier Peak Wilderness Washington 28,92 27,92

PASA1 Pasayten Wilderness Washington 30,90 29,90

The correctly extracted data has been added to TSS tools as results from another regional 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 has met by phone in May 2011 with affected States, EPA regional offices, and Federal Land Managers to 

review these changes and address concerns and questions. A draft of this memo was then circulated for review and 

comment. This 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 that are modified to add “Plan02d_rev” results.
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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

Plan02d_rev
7

Plan02d

Plan02d_rev
8

Plan02d

Plan02d_rev
9

Plan02d

Plan02d_rev
10

Plan02d

Plan02d_rev
11

Plan02d

Plan02d_rev
12

Plan02d

Plan02d_rev
13

Plan02d

Plan02d_rev
14

Plan02d

Plan02d_rev