EPA’s 2002 Multi-Pollutant EPA’s 2002 Multi-Pollutant Platform: Platform: Model Applications and Model Applications and Evaluation of Ozone, Particulate Evaluation of Ozone, Particulate Matter, and Toxics Matter, and Toxics OAQPS / AQAD / AQMG & EIAG Sharon Phillips, Madeleine Strum, Norm Possiel, Carey Jang, Pat Dolwick, Brian Timin, Karen Wesson, Marc Houyoux, Rich Mason, Kai Wang and Tyler Fox 6 th Annual CMAS Conference – October 1- 3, 2007
Transcript
EPA’s 2002 Multi-Pollutant Platform:EPA’s 2002 Multi-Pollutant Platform: Model Applications and Evaluation of Model Applications and Evaluation of Ozone, Particulate Matter, and ToxicsOzone, Particulate Matter, and Toxics
OAQPS / AQAD / AQMG & EIAG
Sharon Phillips, Madeleine Strum, Norm Possiel, Carey Jang, Pat Dolwick, Brian Timin, Karen Wesson, Marc
Houyoux, Rich Mason, Kai Wang and Tyler Fox
6th Annual CMAS Conference – October 1-3, 2007
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OutlineOutline• Introduce concept of a modeling platform
• Introduce 2002 modeling platform and components– Criteria Air Pollutants Only “CAP-only”– Criteria Air Pollutants + Hazardous Air Pollutants
“CAP+HAP”
• Initial Model Evaluation CAP-only
• Initial look at differences in CAP-only vs CAP+HAP results
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What is a “Modeling Platform”?What is a “Modeling Platform”?
• Structured system of connected modeling-related tools and data that provide a consistent and transparent basis for assessing the air quality response to changes in emissions and/or meteorology
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2002 Modeling Platform Overview2002 Modeling Platform Overview• CAP-only with CMAQ 4.6.1i Base Model, cb05, without Chlorine
• 2002 NEI – Criteria pollutants only• Ozone, PM• Some CB05 model species considered explicit
– FORM– ALD2– MEOH– ETOH
• Projection years developed to support regulatory applications
• CAP+HAP with CMAQ 4.6.1i Multipollutant model, cb05txhg, with chlorine chemistry
• 2002 NEI – Criteria pollutants and HAPs• Ozone, PM, and additional 38 HAPs • Does not include projections
• AERMOD used for local scale modeling in Detroit
• Ultimately, certain aspects of these two platforms may merge into a single platform
• Created SMOKE 2.3.2 specifically for platform• Day-and-location specific wildfires and
prescribed burning• Biogenics from BEIS 3.13 with 2002
meteorology• EGUs: Hourly CEM data for SO2 and NOx
(other pollutants follow hourly heat input)• Ancillary data updates
– SPECIATE4.1 speciation profiles via EMF’s Speciation Tool
– New spatial surrogates vis EMF’s Surrogate Tool
– Some temporal profile changes from 2001 platform
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Special Features of SMOKE Special Features of SMOKE Processing for CAP+HAPProcessing for CAP+HAP
• We chose to “integrate” HAP VOC with VOC for sources which we felt had consistent set of VOC and HAP VOC– Nearly all onroad and nonroad– Most EPA-generated nonpoint– Some nonEGU point
• Integrate means HAP emissions are used to modify the speciation of VOC
• We used only HAP emissions for HAP model species (not speciation of VOC)
• For formaldehyde, acetaldehyde and methanol, use HAP inventory
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VOC
NONHAPVOC
TOG
VOC TOG FORM
FORM
CAP-Only:
CAP + HAPIntegrate
NONHAPTOG FORM
FORMALD FORM
Profile with FORMALD removed
No-Integrate
FORMALD FORM
Not explicit formald
Difference in Speciation CAP-only vs CAP+HAP Example for FORM
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2002 Meteorological Data2002 Meteorological Data(presentation by Pat Dolwick, Session 3)(presentation by Pat Dolwick, Session 3)
• Annual MM-5 Simulations– 36 km US,12 km EUS,12 km WUS (from WRAP)– Similar configuration as 2001 MM5 (but not identical)
• MM5 data processed via MCIP v3.1 into CMAQ
• Model evaluation indicated similar model performance as the 2001 MM5 simulations– Reasonable approximation of the actual meteorology– Primary concern: 2-3 deg C underestimation of temperature in
the winter months.– Journal article fully summarizing evaluation findings will be
• GEOSChem – Global Chemistry Transport Model developed at Harvard Univ.– 2002 simulations of GEOSChem provided via ICAP – Domain covers entire globe: 2o x 2o grids and 30
layers up to the Stratosphere– Provides Boundary Conditions for CAPs and mercury
and some other HAPS (e.g., formaldehyde) for our 36 km CONUS domain
• For toxics not simulated by GEOSChem we used concentrations based on remote measurements and values in the literature
• Graphics and Statistics: hourly, daily, monthly, seasonal & annual– Spatial maps comparing observed and predicted species
concentrations/deposition – Scatter plots of observations vs predictions– Time-series plots of observations vs predictions– Statistics:
• Normalized Mean Bias (NMB) / Fractional Bias (FB)• Normalized Mean Error (NME) / Fractional Error (FE)• Root Mean Square Error (RMSE)
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Highlights of 2002 Model Evaluation for CAPsHighlights of 2002 Model Evaluation for CAPs
• Ozone – Under predicted for 1-hr and 8-hr daily max. especially O3 > 60 ppb – Similar to performance for 2001 platform
• Sulfate PM – Under predicted (~up to 25%) for all seasons in the East and West– Similar to performance for 2001 platform
• Sulfur Dioxide– Over predicted (~35 to >100%) in all seasons in the East and West– Similar to performance for 2001 platform
• Sulfate Wet Deposition– Under predicted (~10 to 25%) in the Winter and Fall and over predicted
(~10%) in the Spring and Summer in the East– Under predicted (~13 to 45%) in the Spring, Summer, and Fall and over
predicted in the Winter in the West
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• Nitrate PM – Over predicted (~30 to > 100%) in the Fall, Winter, and in northern areas of the
East in the Spring– Significantly different than performance for 2001 platform
• Nitrogen Wet Deposition– Under predicted (~10 to 70%) in all seasons in the East and West– Similar to performance for 2001 platform
• Organic PM– Over predicted in the North and under predicted in South and West in the Winter– Under predicted in all areas (~25 to 65%) in Fall, Spring, and Summer– Similar to performance for 2001 platform
• Elemental Carbon– Mostly over predicted in urban areas (~45 to >100%) in all seasons in the East
and West– Mostly under predicted in rural areas (0 to >35%) in all seasons in the East and
West– Similar to performance for 2001 platform
Highlights of 2002 Model Evaluation for CAPsHighlights of 2002 Model Evaluation for CAPs
• Initial 36 km nationwide annual run completed (12km Eastern US is underway)
• Model evaluation underway- Initial run results indicate the need to more fully understand ambient toxics data in terms of the proximity of monitors to sources and the sampling time of measurements
• Initial comparison with CAP-only results for select species
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CAP+HAP vs CAP-only differencesCAP+HAP vs CAP-only differences• Emission Differences-
– Use HAPs for speciation for select sources– Use formaldehyde, acetaldehyde and methanol for all sources– Very small spatial/temporal profile differences in some
geographic areas
• Model Differences-– Chlorine chemistry– Added air toxics
• Differences in Predictions-– Slight differences in Summer & Winter Ozone (Northeast, CA,
UT)– Slight differences in Winter NO3 (Northeast, GA, UT)– Negligible differences in Summer SO4
– Some differences in Winter & Summer Formaldehyde & Acetaldehyde
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2002 July Ozone: CAP+HAP – CAP-only
• July: CAP+HAP slightly less ozone in Northeast, more ozone in Utah in vicinity of large source of chlorine emissions.
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8hr max Ozone: CAP+HAP – CAP-only
July 23, 2002 July 8, 2002
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• January: more prominent impacts for Utah source, larger geographic area in which CAP+HAP ozone less than CAP-only ozone.
2002 January Ozone: CAP+HAP – CAP-only
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2002 January Nitrate PM: CAP-only vs CAP+HAP
CAP CAP+HAPs – CAPs
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2002 January Formaldehyde:
CAP+HAP – CAP-only
Difference in CMAQ FORM Difference in FORM Emissions
• CMAQ differences in winter appear to be due to differences in speciation of residential wood combustion CAP VOC vs formaldehyde in the HAP inventory (CAP << HAP)
CMAQ CAP FORM
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2002 July Formaldehyde:
CAP+HAP – CAP-only
Difference in CMAQ FORM Difference in FORM Emissions
• CMAQ differences in summer appear to be due to differences in formaldehyde computed from wildfires (CAP+HAP) vs speciated from VOC (CAP-only)
