WRAP/WAQS Regional Haze Modeling Scenarios' Specification Sheets

Note: Scenarios are based on modifications to the WRAP/WAQS 2014v2 scenario data, with associated future projections.

August 4, 2021 update: Listed below are current technical descriptions of Regional Haze modeling. These Modeling Scenario Specification Sheets define modeling simulations conducted using the Western Regional Air Partnership (WRAP)/Western Air Quality Study (WAQS) Regional Haze photochemical grid modeling platform:

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Modeling Scenarios for Estimating Reasonable Progress Goals

• Representative Baseline v2 and 2028OTBa2: Representative Baseline emissions scenario version 2 represents emissions from the 2014-2018 period as updated in Sept. 2020 using corrected point source data from the WESTAR-WRAP states and described in the linked memo. RepBase2 was then modeled, and includes representative fire emissions developed by the Fire and Smoke Work Group (FSWG). Two 2028 On-the-Books emissions scenarios were also developed and modeled. Scenario 2028OTBa2 was updated in Sept. 2020 and modeled using corrected point source data from the WESTAR-WRAP states and also applied the FSWG representative baseline fire emissions. Scenario 2028OTBb uses the 2014 actual fire emissions, is not discussed in the linked memo, and there are no plans to re-model the scenario as of September 2020. The purpose of RepBase2 and 2028OTBa2 are the source of data results to provide visibility projection estimates of Reasonable Progress Goals for use in Regional Haze planning in the WESTAR-WRAP region. Those results appear on the TSS Modeling Tools.
• Dynamic Evaluation 2002 Simulation: The 2014v2 U.S. anthropogenic emissions are being backcast to 2002 and a CAMx 2002 simulation conducted in order to compare modeled and observed changes in visibility between the 2000-2004 Baseline and the 2014-2018 5-year planning periods.

Source Apportionment and Sector Contribution Modeling

• High-Level and Low-Level Source Apportionment using the RepBase2 and 2028OTBa2 Emissions Scenarios
• Natural (NAT) and No International Anthropogenic Emissions (ZROW): Paired 2014 GEOS-Chem global and CAMx Representative Baseline emissions (version 1) regional photochemical model simulations (Geos-Chem provides Boundary Conditions to CAMx) are being carried out that zero-out portions of the anthropogenic emissions inventory: (a) NAT eliminates all anthropogenic emissions world-wide in the GEOS-Chem and CAMx simulations; and (b) ZROW eliminates all non-U.S. (International) anthropogenic emissions (Zero-out Rest of World, ZROW).
• Future Fire Scenarios Simulations: The WRAP Fire and Smoke Work Group (FSWG) has developed four sets of fire emissions to be modeled for the WRAP 2014-based Regional Haze modeling platform that uses the CAMx photochemical grid model. Details on the development of the fire emissions inventories for the WRAP Regional Haze modeling platform modeling can be found in the Air Sciences, Inc. report Fire Emissions Inventories for Regional Haze Planning: Methods and Results. Modeling a range of future fire emissions will help visualize potential future impacts from this sector.

Inputs / Results Reference Information - Regional Haze Modeling Platform

• Procedures for Making Visibility Projections and Adjusting Glidepaths using the WRAP-WAQS 2014 Modeling Platform (October 21, 2021, updated final draft)
• November 2020 Modeling Scenarios summary table update
• Sources of emissions sector data for the WRAP RepBase2 and 2028OTBa2 modeling scenarios (September 2020, final)