TEIPS

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Comparison of Emission Estimates from SMOKE and
EPS2 Used for Studying Houston-Galveston Air
Quality
- Based on Area/Nonroad, Point and Biogenic
emissions in Texas Emissions Inventory
Soontae Kim and Daewon W. Byun
Institute for Multidimensional Air Quality
Studies (IMAQS) University of Houston
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Outline
Houston-Galveston area, Texas EI
Emissions processing with SMOKE EPS2
Spatial allocation
Chemical speciation
Temporal allocation
BEIS3 GloBEIS3
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The Houston-Galveston Area
Non-attainment area due to high ground-level
ozone concentrations
Several air quality modeling studies
CMAQ, CAMx and etc.
Available Emissions Inventories
National - NET96, NEI99 from U.S. EPA
State - Texas Emissions Inventory from
TCEQ (Texas Commission on
Environmental Quality)
Emissions processing systems
SMOKE - NET96, NEI99
EPS2 - Texas Emission Inventory (TEI)
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NEI99 Texas EI
For the HGA 8-county
Source type NOx (tons/day) NOx (tons/day) VOC (tons/day) VOC (tons/day)
Source type NEI99 1) TEI 2) NEI99 TEI
On-road mobile [phone]
Area/Nonroad mobile [phone]
Point 521 490 152 327 (178) 3)
8-County total anthropogenic emissions 1066 929 633 724 (575)
lt
gt
Data sources 1) National Calculated based on
U.S. EPA NEI 1999 final version 2 2) State
TCEQ documents (available at ftp//ftp.tnrcc.state
.tx.us/pub/OEPAA/ TAD/
Modeling/HGAQSE/Modeling/Doc/TSD_PHASE1/attachm
ent3-emissions_inventory.pdf )
3) Parenthesis presents regular case
emissions.
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Emissions Inventory Processing
Same processes in SMOKE EPS2
Different inputs for SMOKE EPS2
Depend on cross-reference profile files
Present different AQM-ready emissions
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Objectives
Compare two emission modeling systems, SMOKE and
EPS2, to identify uncertainties arising during
each step of processing spatial gridding,
chemical speciation and temporal allocation
Texas EI was processed for the HGA 2-km grid
domain (166 x 130 cells) during the period of the
TexAQS 2000 Experiment (Aug. 23rd - Sept. 1st,
2000) .
Focusing on the effects of differences in
cross-reference and profile files.
SMOKE and EPS2 used U.S. EPAs and TCEQs
cross-reference and profile files, respectively.
BEIS3 and GloBEIS3 were also compared.
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SMOKE EPS2 General comparison
Process
EPS2
SMOKE
U.S. EPAs 15 surrogates. New surrogating system
(64 srgs) are applicable. No surrogates for
off-shore emissions.
TCEQ has developed 27 surrogates. Unique
surrogates for the HGA including off-shore
surrogates.
Spatial allocation
Nationwide spilt factors. Mostly depends on SCC.
Chemical speciation
Uses Plant ID, Stack ID, SCC FIPS for points.
PO/hourly emissions at the same time. No diurnal
variation for NEGU point emissions.
Separate treatments for PO and hourly
emissions. Additional profiles for hourly
emissions prepared.
Temporal allocation
GloBEIS3, Texas LULC / Observed met. data
Biogenic
BEIS3, BELD3 / MM5
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Surrogates used for EPS2
Surrogate
Surrogate
SMOKE1)
SMOKE
Population Urban population Rural
population Commercial airports General airports
Gas stations Dry cleaner Restaurants Residential
area Forest
A, B A, B A, B - A, B
B B B B A, B
Military airports County yards Water Ships Harbors
Agriculture Commercial industrial Commercial
residential Oil and gas wells (Inland) Offshore
oil and gas wells
B A, B A, B B A, B
A, B B B - -
Canal Railroad Auto body shops Marine coating
facilities
Offshore Shipping lanes Platforms
- A, B - -
- - -
Note 1) A Included in U.S. EPAs 15
surrogates. B Included in U.S.
EPAs 64 surrogates (New surrogating system).

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Difference in Surrogates
Population
SMOKETOOL (Shp1996 US Census Bureau, 1990)
MIMS Spatial allocator (Shp2003 US Census
Bureau, 2000)
TCEQ (US Census Bureau, 2000)
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Unique surrogates for the HGA
From TCEQs surrogates
Offshore oil and gas wells
Platforms
Shipping lanes
Marine coating facilities
Auto body shops
Restaurants
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Example of Spatial Allocation
Area/Nonroad mobile emissions NO
EPS2
SMOKE
Without offshore surrogates from TCEQ
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Example of Spatial Allocation
Area/Nonroad mobile emissions NO
EPS2
SMOKE
After implementing TCEQs surrogates for offshore
emissions.
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Example of Spatial Allocation
Area/Nonroad mobile emissions ETH
EPS2
SMOKE
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Chemical Speciation
Split factors (Chemical speciation profile)
Applied to lumped VOC species (CB-IV mechanism).
Split factors for point source emissions show
large differences.
SMOKE assigns SCC-related profile codes provided
by U.S. EPA.
EPS2 uses SCC, FIPS code, Plant ID and Stack ID
to assign profile codes developed by TCEQ.
Example of split factors
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NEGU point - SCC 30118701 Chemical
Manufacturing, Ethylene General (FIPS 48000)

Units mol/kg
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Example of Chemical Speciation
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Temporal Allocation
Peak ozone day and annual average emissions
Area nonroad mobile and regular point
emissions.
SMOKE uses U.S. EPAs profiles.
EPS2 uses Texas-specified profiles.
Hourly emissions
Supplementary and special point emissions.
Source- and hour-specific profiles are prepared
for SMOKE based on emission patterns.
No Profiles are used. ? No difference in SMOKE
and EPS2.
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Example of Temporal Allocation
Area emissions
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Example of Temporal Allocation
Nonroad mobile emissions
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Example of Temporal Allocation
EGU point emissions
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Example of Temporal Allocation
NEGU point emissions
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Biogenic emissions different inputs
Land use land cover data
SMOKE uses BELD3 provided by U.S. EPA for BEIS3.
TCEQ developed Texas LULC data for GloBEIS3. (
e.g. Texas Forest Service, )
Meteorological data
SMOKE uses MM5 / MCIP output.
GloBEIS3 uses the observed temperatures.
TCEQ uses Photosynthetically Active Solar
Radiation fields processed thru GOES satellite
data analysis.
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Split factors in BEIS3 and GloBEIS3
MONOTERPINES
Species
BEIS3 2) (mole/kg)
GloBEIS3 1) (mole/kg)
7.4 53.2 0.329 6.2 0.311
OLE PAR XYL ALD2 NR
4.17 70.83 - - 4.17
Data sources 1) Texas Commission on
Environmental Quality, 2002 Attachment 3
Emissions Inventory
Development and Modeling for the
August 25-September 1, 2000 Episode November 15,
2002.
2) Calculated based on GSPRO profiles for
BV309.
OVOCs
Species
BEIS3 (mole/kg)
GloBEIS3 (mole/kg)
4.3 12.8 1.2 3 2.1 45 21 1.29 -
OLE PAR FORM ALD2 ETH MEOH ETOH NR TERPB
4.17 50.00 - 12.50 - - - -
8.33
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Biogenic emissions ISOP
GloBEIS3 (TCEQ)
BEIS3
Biogenic 4km, GloBEIS3 BEIS3, TexAQS 2000
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Biogenic emissions OLE
GloBEIS3 (TCEQ)
BEIS3
Biogenic 4km, GloBEIS3 BEIS3, TexAQS 2000
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Biogenic emissions ETH
GLOBEIS3 (TCEQ)
BEIS3
No speciation ? No emissions!!
Biogenic 4km, GloBEIS3 BEIS3, TexAQS 2000
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Biogenic emissions
Biogenic 4km, GLOBEIS3 BEIS3, TexAQS 2000
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Domain total emissions OLE
The SMOKE system (BEIS3)
Biogenic emissions
The EPS2 system (GloBEIS3)
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Domain total emissions ETH
The SMOKE system (BEIS3)
No biogenic emissions!!
The EPS2 system (GloBEIS3)
Biogenic emissions
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CMAQ results Daily Max. O3 Concentration
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CMAQ results O3(EPS2GB3) O3(SMOKEB3)
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CMAQ results O3(EPS2GB3) O3(SMOKEGB3)
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CMAQ results O3(SMOKEB3) O3(SMOKEGB3)
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Conclusions
SMOKE and EPS2 present different emission rates
of each VOC species for Texas EI after spatial
allocation, chemical speciation, and temporal
allocation due to different inputs of
cross-reference and profile data.
Different VOC split factors including land use
land cover and meteorological data present
different biogenic emissions in BEIS3 and
GloBEIS3.
After CMAQ simulations using TEI, the SMOKE and
EPS2 systems present more than 20 ppb differences
in localized ambient ozone concentrations for the
HGA.
Surrogates, chemical split factors and temporal
profiles will be harmonized to test the system
algorithm differences in SMOKE and EPS2 in the
near future.
BEIS3 will reprocessed with PAR, LULC and
temperature data used in GloBEIS3.