DAQ-2024-011369

Prepared for:
Utah Division of Air Quality
Science for Solutions Research Grant – FY 2025

Prepared by:
Ramboll Americas Engineering Solutions, Inc.
50 West Broadway, Suite 300
Salt Lake City, UT 84101

February 2, 2024

Assessing Global Background Ozone
Transport Pathways to the Northern
Wasatch Front

A Proposal Submitted to the Utah Division of Air
Quality Science for Solutions Research Grant
Program – FY 2025

Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front

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Contents
Contents ................................................................................................................... i
1.0 Summary Information Page ............................................................................. 1
1.1 Project Title ................................................................................................ 1
1.2 Applicant Information .................................................................................. 1
1.3 Funding Requested ...................................................................................... 1
1.4 Project Period ............................................................................................. 1
2.0 Scope of Work ................................................................................................. 2
2.1 Abstract ..................................................................................................... 2
2.2 Basis and Rationale ..................................................................................... 2
2.3 Technical Approach ..................................................................................... 5
2.4 Expected Outputs and Outcomes ................................................................... 7
2.5 Deliverables ............................................................................................... 7
2.6 Schedule .................................................................................................... 8
2.7 References ................................................................................................. 9
3.0 Budget ........................................................................................................... 11
4.0 Personnel Roles and Responsibilities ............................................................. 12
TABLES
Table 1. Ramboll proposed project budget, including breakdown by task, personnel
(rates, hours and cost), and other direct costs. .......................................... 12
FIGURES
Figure 1. Schematic conceptual model of pollutant transport from Asia to North America
(from EPA, 2020; HTAP, 2010). Blue text on left refers to continental boundary
layer processes, red text along bottom refers to low level transport, and
black/white text along top and right refers to high altitude transport. ............. 4
Figure 2. Examples of modeled surface background ozone (ppb) from (top) Baker et al.
(2015) showing July 2011 average total background from CAMx source
apportionment, and (bottom) Zhang et al. (2020) showing tracked ozone from
Asia on May 24, 2017 from the AM4 global model. ....................................... 4
Figure 3. Example of boundary condition ozone contribution from three sets of vertical
model layers (Baker et al., 2015); boundary layer (left), mid troposphere
(middle), stratosphere (right). ................................................................... 7
Figure 4. Proposed project schedule by task, including deliverable dates. ..................... 8

APPENDICES
Appendix A Resumes of Key Personnel

Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
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1.0 Summary Information Page
1.1 Project Title
Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
1.2 Applicant Information
Organization: Ramboll Americas Engineering Solutions, Inc.
Address: 5050 West Broadway, Suite 300
Salt Lake City, UT 84101
Principal Investigator: Chris Emery, Senior Managing Consultant
Phone Number: [phone]
Email Address: [e-mail]
1.3 Funding Requested
Total Project Budget: $98,012
1.4 Project Period
July 1, 2024 – September 30, 2025

Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
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2.0 Scope of Work
2.1 Abstract
In its State Implementation Plan (SIP) for the Northern Wasatch Front (NWF), the Utah
Division of Air Quality (UDAQ) tabulates the minor ozone contributions derived from local
controllable emissions within the NWF relative to more substantial contributions from
regional emissions among neighbor states and foreign sources that are consistently present
during exceedance episodes. UDAQ’s findings are consistent with those of the
Environmental Protection Agency (EPA) addressing ozone over the western US. Despite a
multitude of modeling studies in the peer-reviewed literature that consistently characterize
total global background contributions to the western US, only a few specifically assess and
confirm the importance of deep vertical transport of global ozone from the middle and upper
troposphere. However, those studies have employed relatively coarse resolution (12-50
km) with seasonal and regional perspectives, meaning that they have addressed
contributions from large-scale general circulations and perhaps some portion of the largest
terrain-induced transport mechanisms. Furthermore, the importance of vertical transport
has not been evaluated or quantified specifically for international anthropogenic (IA) ozone
arriving in the NWF. Source apportionment modeling reported by UDAQ estimates how
much IA ozone arrives in NWF but not it’s transport path. A mechanistic explanation is
needed to understand why western US background ozone is consistently highest over Utah
and to describe the specific processes that bring IA ozone into the NWF. Such information
would bolster and add weight of evidence elements for any future 179B demonstrations for
the area.
Ramboll proposes to directly assess, via high-resolution CAMx modeling, the amount of
mid/upper-tropospheric IA ozone that is transported into the NWF. The approach will utilize
UDAQ’s SIP modeling platform with source apportionment, which resolves local topography
from 1 to 4 km scale over the NWF and Utah, respectively, to characterize daily variations in
IA contributions from several different altitude ranges between the surface and the
stratosphere. The project will address several topics, including the relative importance
among transport pathways; the extent to which high pressure centered over Utah blocks or
enhances background ozone entering the area; how the relative strengths of these
transporting motions vary in time and modulate inter-daily variations of background ozone;
and the extent to which transported peroxyacetyl nitrate (PAN) impacts transported ozone
into the NWF. The proposed work addresses the FY 2025 Science for Solutions Research
Grant solicitation by targeting two research priorities: (3) Meteorology-Chemistry Coupling,
and (1) Summertime Ozone Chemistry and Sources, specifically (f) background ozone.
2.2 Basis and Rationale
Background
The Wasatch Front experiences exceedances of the ozone National Ambient Air Quality
Standard (NAAQS) during summer months. The Northern Wasatch Front (NWF), covering
all or parts of Salt Lake, Davis, Weber, and Tooele counties, is currently designated as a
moderate ozone nonattainment for the 2015 8-hour ozone standard based on exceedances
through 2020. Exceedances have continued through 2023 and thus the area will be
bumped up to serious nonattainment later in 2024 with an attainment date of August 2026.
Serious nonattainment areas are subject to stricter emissions reporting/permitting levels
and additional control measure requirements.
Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
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In its State Implementation Plan (SIP) addressing the moderate designation, the Utah
Division of Air Quality (UDAQ, 2023) tabulates the minor ozone contributions derived from
local controllable emissions within the NWF relative to more substantial contributions from
regional emissions among neighbor states and foreign sources that are consistently present
during exceedance episodes. UDAQ’s findings are consistent with a summary by the
Environmental Protection Agency (EPA, 2015) and a preliminary modeling study by Ramboll
(2021a) that shows most of the ozone in the Wasatch Front results from the combination of
natural and international anthropogenic emissions.
The Clean Air Act provides some regulatory flexibility for nonattainment areas impacted by
international contributions if they fail to attain despite reasonable efforts to control local
emissions. According to Section 179B of the Act, a State may develop a technical
demonstration showing that the nonattainment area would attain the ozone standard “but
for” the contribution from international emissions. In a previous retrospective
demonstration looking back at the 2020 marginal attainment year (UDAQ, 2021)1 and a
prospective demonstration included in the SIP looking forward to the 2023 moderate
attainment year (UDAQ, 2023), both employing detailed photochemical modeling following
EPA’s guidance (EPA, 2018; 2020), UDAQ shows that the Wasatch Front would attain the
ozone NAAQS in the absence of international anthropogenic contributions.
As summarized by EPA (2020), persistent global circulation patterns establish a direct
transport route in the mid- to upper troposphere linking Asia to the western US, which
brings pollutant-laden air to North America within days to weeks (Figure 1). Sinking air
within a high pressure dome over the western US brings transported ozone and
peroxyacetyl nitrate (PAN, an ozone precursor; Jiang et al, 2016) toward the surface, while
complex topography enhances vertical transport, and thus high-altitude locations
throughout the western US experience the greatest ozone impacts from intercontinental
transport. This transport mechanism is especially persistent throughout the summer
season. Moreover, a recent multi-decadal trend analysis through 2021 indicates that free
tropospheric ozone over western North America continues to increase despite a decreasing
trend in boundary layer ozone, affirming vertically different sources and mechanisms
(Chang et al., 2023, and references therein).
Despite a multitude of modeling studies in the peer-reviewed literature consistently
characterizing total global background contributions to the western US (Jaffe et al., 2018),
we are aware of only a few (e.g., Baker et al., 2015; Zhang et al., 2020) that specifically
assess and confirm the importance of deep vertical transport of global ozone from the
middle and upper troposphere to the western US. Interestingly, both studies referenced
above show that summer surface background ozone in the western US often peaks over
Utah as a result of transport from the mid-troposphere (Figure 2). However, those studies
employed relatively coarse resolution (12-50 km) with seasonal and regional perspectives,
meaning that they addressed contributions from large-scale general circulations and
perhaps some portion of the largest terrain-induced transport mechanisms.

1 UDAQ (2021) incorporated the Ramboll (2021a) modeling report into the agency’s 179B retrospective
demonstration to EPA of foreign ozone contributions in the Wasatch Front.
Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
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Figure 1. Schematic conceptual model of pollutant transport from Asia to North
America (from EPA, 2020; HTAP, 2010). Blue text on left refers to continental boundary
layer processes, red text along bottom refers to low level transport, and black/white text
along top and right refers to high altitude transport.

Figure 2. Examples of modeled surface background ozone (ppb) from (top) Baker et al.
(2015) showing July 2011 average total background from CAMx source apportionment, and
(bottom) Zhang et al. (2020) showing tracked ozone from Asia on May 24, 2017 from the
AM4 global model.
Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
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Furthermore, the importance of vertical transport has not been evaluated or quantified
specifically for international anthropogenic (IA) ozone arriving in the NWF. Source
apportionment modeling conducted by Ramboll (2021a) and UDAQ (2023) estimates how
much IA ozone arrives in NWF but not it’s transport path, and backward trajectories are too
simple to quantify ozone contributions from aloft. A mechanistic explanation is needed to
understand why background ozone is consistently highest over Utah and to describe the
specific processes that bring IA ozone into the NWF. Such information would bolster and
add weight of evidence elements for any future 179B demonstrations for the area.
Objectives
We propose to directly assess, via high-resolution CAMx modeling, the amount of
mid/upper-tropospheric IA ozone that is transported into the NWF. The approach will utilize
UDAQ’s SIP modeling platform with source apportionment, which resolves local topography
from 1 to 4 km scale over the NWF and Utah, respectively, to characterize daily variations in
IA contributions from several different altitude ranges from the surface to the stratosphere.
The project will help to answer the following questions:
• What is the relative importance among transport pathways; i.e., via gradual
subsidence in the high pressure dome over the western US versus local, short-term,
deep terrain-induced “fumigation” events?
• Does high pressure centered over Utah that often leads to ozone exceedances block
background ozone from entering the area and transport it around to the north, or
does it cause substantial sinking motions that bring down background ozone directly
into the NWF?
• How do the relative strengths of these transporting motions vary in time and how do
they modulate inter-daily variations of background ozone?
• Can PAN transport from Asia enhance the impact of transported ozone in Utah?
Alignment with FY 2022 Science for Solutions Goals and Priorities
Our proposed project will address two Goals and Priorities stated in the RFP. This first is (3)
Meteorology-Chemistry Coupling, specifically “models to better characterize the complex
meteorological features … associated with … summertime air pollution episodes.” While not
a monitoring study, the study also partially addresses (1) Summertime Ozone Chemistry
and Sources, specifically (f) background ozone.
2.3 Technical Approach
Task 1: Modeling Application
Ramboll will employ the UDAQ 2017 modeling platform developed to support the NWF
moderate area ozone SIP. The platform consists of the CAMx photochemical model applied
on a set of three nested grid systems, with the largest domain covering the western US at
12 km resolution and the finest resolution covering the NWF at 1.33 km resolution. The
modeling period extends from late June through July of 2017. The modeling system
includes requisite three-dimensional meteorological fields for all grids developed using the
Weather Research and Forecasting (WRF; Skamarock et al., 2019) model, as well as all
anthropogenic, biogenic, and fire emission inventories within the domain. Three-
dimensional boundary conditions (BC) for the master domain were developed from
Ramboll’s application of the GEOS-Chem global chemistry model (Ramboll, 2021b). The
GEOS-Chem runs included: (1) a full representation of ozone, PM, and precursors from the
entire globe, and (2) a scenario in which all IA emissions were removed. UDAQ used the
Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
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differences between the two global model scenarios to define an OSAT run tracking the IA
contributions to total simulated ozone at NWF monitors.
We will rerun the 2017 CAMx/OSAT modeling system based on UDAQ’s configuration, but
with a few modifications. First, we will reduce the number of sources and regions to be
tracked in order to minimize model runtimes and data generation. The model will track only
the BCs from global IA and natural contributions, along with a single all-encompassing
tracer representing all in-domain emissions. Second, we will use the latest public-released
version of CAMx (v7.3), which will include the CB6r5h halogen mechanism that Ramboll
implemented in v7.1 for UDAQ in 2022 (Ramboll, 2022). Third, we will modify CAMx OSAT
routines to separately track the BC contributions from several aggregated sets of 44 vertical
layers, similar to the approach of Baker et al. (2015), to provide additional information
about the source altitudes of IA ozone. We anticipate tracking at least four altitude ranges:
• 0-2 km: planetary boundary layer
• 2-5 km: lower troposphere
• 5-10 km: upper troposphere
• 10-18 km: stratosphere
Finally, we will conduct two CAMx sensitivity tests to assess whether PAN transport from
Asia can enhance the contribution of transported ozone to ground-level ozone in Utah. PAN
transported from Asia through the upper troposphere becomes an ozone precursor when
brought down to ground-level where PAN converts to NO2 and therefore contributes to NOx.
OSAT does not separately track the amount of ozone generated by PAN, so brute-force
sensitivity is necessary. We would compare two runs: (1) 1 ppb of PAN added to western
BCs; (2) 10 ppb of ozone added to western BCs. In both cases, concentrations would be
added in the altitude range upwind of Utah during the selected episode. An ozone
increment of 10 ppb will produce a reasonable signal without distorting the chemistry. The
rationale for a PAN increment of 1 ppb is that efficient ozone production from NO2 produces
~10 ozone molecules per NO2, so if the PAN conjecture is correct the two sensitivity runs
will produce similar impacts.
Task 2: Analysis and Synopsis
Ramboll will extensively analyze the results from the CAMx/OSAT simulation to characterize
the spatial and temporal variability of BC ozone tracers from various altitudes. Graphical
products will include maps and vertical cross sections of each of the ozone tracers at key
dates during the simulation period. Time-averaged contribution maps may be developed as
well if transport patterns are sufficiently persistent. Maps will be developed and evaluated
in terms of absolute concentrations as well as percentages of total IA and total simulated
ozone. For example, Figure 3 from Baker et al. (2015) presents surface ozone
concentrations tracked from 3 different layers of the atmosphere. Time series of IA tracer
contributions at NWF monitoring sites relative to emission contributions will be developed to
illustrate the time-variation of each IA vertical tracer. Other graphical and tabular products
will be considered and developed based on initial findings, in order to express results in the
clearest manner possible.
We will compile all information gleaned from our analysis into a conceptual model for IA
ozone transport into the NWF. The conceptual model will address each of the questions
listed with our project objectives above.
Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
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Figure 3. Example of boundary condition ozone contribution from three sets of vertical
model layers (Baker et al., 2015); boundary layer (left), mid troposphere (middle),
stratosphere (right).

Task 3: Management and Reporting
This task will comprise project management activities during the execution of the contract.
Activities include: (1) day-to-day staff and resource management; (2) internal team
meetings and external conference calls with UDAQ, including a project kickoff meeting; (3)
monthly invoicing and progress reporting to UDAQ; (4) preparation of quarterly progress
reports; (5) assembly of the draft and final project report; (6) preparation for, and
attendance at the Science for Solutions technical conference; and (7) sharing of data and
modeling system with UDAQ.
2.4 Expected Outputs and Outcomes
Based on the technical approach described above, Ramboll expects to gain new insights,
and to draw definitive, quantified conclusions on the relative strengths and variability of
different IA ozone transport pathways into the NWF area based on UDAQ’s high-resolution
seasonal SIP modeling system. Results will help to answer questions posed under the
project objectives listed in Section 2.2. Ramboll will provide UDAQ with the modeling
programs, datasets, and evaluation products from our proposed study.
2.5 Deliverables
Monthly and Quarterly Progress Reports
Ramboll is proposing to conduct the study on a time and materials basis. As such, we will
submit monthly invoices for labor and other direct costs around the 15th of each month.
Each invoice will be accompanied by a brief monthly progress report that summarizes
activities performed during the month, anticipated activities for the following month, and a
budget summary.
As required by the RFP, Ramboll will prepare quarterly progress reports over the course of
the contract. Based on information in the RFP, and assuming a start date of July 1, 2024,
quarterly reports will be submitted in October 2024, January 2025, April 2025, and July
2025. Each report will follow the example template provided by the UDAQ.

Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
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Final Report
A draft final project report is required within 90 days of project completion. Ramboll will
develop a draft report and submit it to UDAQ for review at the close of all technical work.
Ramboll will then address comments and suggestions received on the draft, compile the
final report, and submit it to UDAQ by the specified deadline. The final report will contain all
of the components required by UDAQ and listed in the RFP.
Conference Presentation
As required by the RFP, Ramboll will prepare and deliver an oral or poster presentation at
the 2025 Science for Solutions conference. The presentation will include study objectives,
approach, results, and recommendations for any additional investigation.
Data Sharing
Ramboll will share with UDAQ all datasets and models developed during the course of the
proposed project. We will arrange with UDAQ the most appropriate way to provide the
data. Following the specifications of the RFP, all data to be shared will be made available
within 8 months of project completion. We anticipate the following data will be generated
and shared from this project:
• All CAMx modeling codes, scripts and files specifically developed in this work (all
other general CAMx updates are periodically made available to the public at
Ramboll’s website www.camx.com);
• All CAMx and pre-processor inputs;
• All CAMx and post-processor output files, reduced datasets, spreadsheets, or a
subset of key files selected in coordination with UDAQ.
2.6 Schedule
Our proposed project schedule with key deliverable dates is shown in Figure 3. Per
information in the RFP, we anticipate a start date of July 1, 2024 and expect to complete all
tasks of the project by June 30, 2025, including the submission of our final report and
presentation at the 2025 Science for Solutions conference. We expect to complete all data
transfer by September 30, 2025.

Figure 4. Proposed project schedule by task, including deliverable dates.

Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
Kickoff Meeting
Task 1: Modeling Application
Task 2: Analysis and Synopsis
Task 3: Management and Reporting
Monthly Reports
Quarterly Reports
Science for Solutions Presentation
Draft/Final Report
Database Delivery
Task/Deliverable
20252024
Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
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2.7 References
Baker, K.R., C. Emery, P. Dolwick, G. Yarwood, 2015. Photochemical grid model estimates
of lateral boundary contributions to ozone and particulate matter across the
continental United States. Atmos. Environ., 123, 49-62.
http://dx.doi.org/10.1016/j.atmosenv.2015.10.055.
Chang, K.-L., O.R. Cooper, G. Rodriguez, L.T. Iraci, E.L. Yates, M.S. Johnson, et al., 2023).
Diverging ozone trends above western North America: Boundary layer decreases
versus free tropospheric increases. J. Geophys. Res.: Atmospheres, 128,
e2022JD038090. https://doi.org/10.1029/2022JD038090.
EPA, 2015. Implementation of the 2015 Primary Ozone NAAQS: Issues Associated with
Background Ozone, White Paper for Discussion (December 30, 2015).
https://www.epa.gov/ground-level-ozone-pollution/background-ozone-workshop-
and-information.
EPA, 2018. Modeling Guidance for Demonstrating Attainment of Air Quality Goals for
Ozone, PM2.5 and Regional Haze (EPA 454/R-18-009, November 2018).
https://www3.epa.gov/ttn/scram/guidance/guide/O3-PM-RH-Modeling_Guidance-
2018.pdf.
EPA, 2020. Guidance on the Preparation of Clean Air Act Section 179B Demonstrations for
Nonattainment Areas Affected by International Transport of Emissions (EPA-457/P-
20-001F, December 2020). https://www.epa.gov/sites/production/files/2020-
12/documents/final_caa_179b_guidance_december_2020_with_disclaimer_ogc.pdf.
HTAP, 2010. Hemispheric Transport of Air Pollution 2010: Part A: Ozone and Particulate
Matter Air Pollution Studies, No. 17. Prepared by the Task Force on Hemispheric
Transport of Air Pollution, F. Dentener, T. Keating, and H. Akimoto, Eds.
https://core.ac.uk/download/pdf/83641741.pdf.
Jaffe, D.A, O.R. Cooper, A.M. Fiore, B.H. Henderson, G.S. Tonnesen, A.G. Russell, D.K.
Henze, A.O. Langford, M. Lin, T. Moore, 2018. Scientific assessment of background
ozone over the U.S.: Implications for air quality management. Elem. Sci Anth, 6,
https://doi.org/10.1525/elementa.309.
Jiang, Z., Worden, J.R., Payne, V.H., Zhu, L., Fischer, E., Walker, T. and Jones, D.B., 2016.
Ozone export from East Asia: The role of PAN. Journal of Geophysical Research:
Atmospheres, 121(11), pp.6555-6563.
Ramboll, 2021a. Modeling International Ozone Contribution to Wasatch Front
Nonattainment Areas. Prepared for the Utah Petroleum Association and Utah Mining
Association, Salt Lake City, UT (February 2021).
Ramboll, 2021b. 2017 GEOS-Chem Application to Support US Regional Modeling. Prepared
for the Western States Air Resources Council, Santa Fe, New Mexico (8 April, 2021).
https://views.cira.colostate.edu/docs/IWDW/Modeling/WRAP/2017/Ramboll_WESTAR
_GEOS-Chem_Report_8Apr_2021.pdf.
Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
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Ramboll, 2022. Technical memorandum documenting the CB6r5 mechanism with halogens:
CB6r5h. Prepared for Chris Pennell and Nancy Daher, UDAQ (October 17, 2022).
Skamarock, W.C., J.B. Klemp, J. Dudhia, D.O. Gill, Z. Liu, J. Berner, J., et al., 2019. A
Description of the Advanced Research WRF Model Version 4 (No. NCAR/TN-
556+STR), doi:10.5065/1dfh-6p97.
UDAQ, 2021. Clean Air Act 179B(b) Demonstration, Northern Wasatch Front Ozone
Nonattainment Area (05/05/2021). https://documents.deq.utah.gov/air-
quality/planning/air-quality-policy/DAQ-2021-005764.pdf.
UDAQ, 2023. State Implementation Plan, 2015 Ozone NAAQS Northern Wasatch Front
Moderate Nonattainment Area, Section IX Part D.11.
https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-011344.pdf.
Zhang, L., M. Lin, A.O. Langford, L.W. Horowitz, C.J. Senff, E. Klovenski, Y. Wang, R.J.
Alvarez, I. Petropavlovskikh, P. Cullis, C.W. Sterling, J. Peischl, T.B. Ryerson, S.S.
Brown, Z.C.J. Decker, G. Kirgis, S. Conley, 2020. Characterizing sources of high
surface ozone events in the southwestern US with intensive field measurements and
two global models. Atmos. Chem. Phys., 20, 10379–10400.
https://doi.org/10.5194/acp-20-10379-2020.

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3.0 Budget
This project will be conducted by Ramboll Americas Engineering Solutions, Inc. The total
estimated cost for the entire scope of work described in Section 2 is $98,012. Table 1
presents a detailed budget workup, which includes costs by task, personnel (fully loaded
labor rates, hours, and cost), and other direct costs. Ramboll’s loaded labor rates are
defined by the labor categories shown in Table 1. The proposed rate structure for this study
is based on a 10% reduction from our floor commercial rates.
Ramboll adds 3% to direct labor costs for telephones, copier services, and facsimile
charges, and 3% to direct labor costs for computers and printers (6% total). Other direct
costs include a high-volume data disk drive to transfer project-generated modeling
datasets, programs, and scripts to UDAQ at the close of the project. Other direct costs also
include 2-day travel for a single person by air with meals and hotel accommodations to
attend the 2025 Science for Solutions conference. No other costs related to equipment,
materials/supplies, or travel is anticipated during the project.
We are proposing to conduct this study on a time and materials basis. As such, Ramboll will
submit monthly invoices for labor and other direct costs around the 15th of each month. We
request payment terms on a net 30-day basis.

Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
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Table 1. Ramboll proposed project budget, including breakdown by task, personnel
(rates, hours and cost), and other direct costs.

4.0 Personnel Roles and Responsibilities
Below we list the key personnel that will conduct the proposed scope of work, noting their
titles and describing their main roles and responsibilities. We also provide a summary
paragraph for each describing relevant qualifications and experience. Full resumes for each
are presented in Appendix A. Additional Ramboll staff, not listed here for page restrictions,
will be utilized in this project to support our key personnel.
Mr. Chris Emery, senior managing consultant, will serve as principal investigator and project
manager. As principal investigator, he will develop details of the technical approach, guide
photochemical modeling applications and evaluation, and lead quality assurance steps. As
project manager, Mr. Emery will manage Ramboll’s day-to-day project activities including
ensuring the project remains on schedule and budget, managing personnel assignments,
and communicating progress, technical issues, and results to UDAQ. He will also lead the
development of the project report.
Mr. Emery has over 30 years of experience in numerical modeling and analysis of multi-
scale air pollution and meteorology. His expertise includes design, development, and
application of air quality modeling systems. Chris co-authors the Comprehensive Air Quality
Hourly
Labor
Rate
Lbr Category/Name Hrs Dollars Hrs Dollars Hrs Dollars Hrs Dollars
Principal
Greg Yarwood 288.00 4 1,152 4 1,152 4 1,152 12 3,456
Sr. Managing Consultant
Chris Emery 274.50 24 6,588 44 12,078 84 23,058 152 41,724
Managing Consultant
Gary Wilson 247.50 40 9,900 0 1 248 41 10,148
Sr. Consultant 2
Lynsey Parker 207.00 0 8 1,656 0 0 8 1,656
Jung Chien 207.00 10 2,070 4 828 0 0 14 2,898
Pradeepa Vennam 207.00 0 12 2,484 0 0 12 2,484
Sr. Consultant 1
Trang Tran 189.00 48 9,072 32 6,048 27 5,103 107 20,223
Liji David 189.00 16 3,024 8 1,512 0 0 24 4,536
Consultant 3
Jean Guo 171.00 0 12 2,052 0 0 12 2,052
Support 103.50 0 0 19 1,967 19 1,967
Ramboll Labor Subtotal 142 31,806 124 27,810 135 31,527 401 91,143
Labor Subtotal 142 31,806 124 27,810 135 31,527 401 91,143
Other Direct Costs
Communications (1)3%954 834 946 2,734
Computing (2)3%954 834 946 2,734
Travel 0 0 1,200 1,200
Misc. 0 0 200 200
ODCs Subtotal 1,908 1,669 3,292 6,869
GRAND TOTAL 142 33,714 124 29,479 135 34,819 401 98,012
Task 1 Task 2 Task 3
Modeling Analysis &Management
Application Synopsis & Reporting
Total
All Tasks
Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front
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Model with extensions (CAMx). He has applied a variety of models for private and public
clients, in both local and regional regulatory arenas, throughout the US and abroad. His
recent projects include several for the UDAQ where he has contributed to model updates
and improvements addressing ozone and PM2.5. Chris has applied and evaluated
meteorological models and global chemical transport models to develop inputs needed by
regional photochemical modeling applications. He has served as a member of the American
Meteorological Society’s Board of the Urban Environment.
Dr. Greg Yarwood, principal, will serve as a technical advisor and as Ramboll’s contracting
representative with approval authority and administrative oversight. Dr. Yarwood is an
internationally recognized expert with over 30 years of experience in atmospheric
chemistry, air quality modeling, photochemical model development, interpreting ambient air
quality data, and emissions inventory development. He directs air quality, meteorological
and emissions modeling studies for clients in government and industry with emphasis on
photochemical air pollution issues, such as ozone, secondary particulate matter (PM),
visibility and air toxics. He implemented the CAMx methods for source attribution (OSAT
and PSAT), sensitivity analysis (DDM and HDDM) and process analysis. He is an expert
atmospheric chemist and leads development of the Carbon Bond chemical mechanisms that
are used to model ozone and PM in both CAMx and US EPA’s CMAQ model. For UDAQ, he
recently led the implementation and testing of the Regional Atmospheric Chemistry Model
(RACM) in CAMx. Greg was appointed to USEPA’s Board of Scientific Counselors for the
Clean Air Research Program.
Mr. Gary Wilson, managing consultant, will lead all model development and testing
activities. For over 30 years, he has been the primary programmer in photochemical and
emissions modeling development at Ramboll. Mr. Wilson is responsible for the ongoing
maintenance and development of the Comprehensive Air Quality Model with extensions
(CAMx), including all probing tools. Gary is proficient in all tasks necessary for carrying out
CAMx simulations. Gary is an expert in Fortran, PERL and Linux shell scripting, and has
programming experience in C, HTML C++, Visual Basic, SQL and SAS.

Dr. Trang Tran, senior/lead consultant, will lead all modeling and analysis activities during
the project. She has over 10 years of experience in air quality modeling, specializing in
weather and 3D-chemical transport modeling (e.g., WRF, WRF-Chem, CAMx) with advanced
tool utilization (e.g., data assimilation, source apportionment, and process analysis). She is
an expert in statistical model evaluation tools (e.g., AMET, SMAT-CE) and has strong
experience in emission inventory development and format processing (both top-down and
bottom-up-derived inventories) using various models/tools. Dr. Tran is experienced in
environmental impact assessment (EIA) reporting, particularly for oil and gas clients. Her
programming expertise includes both basic and visualization languages (e.g., Fortran, C, R,
python, NCL, VAPOR, IDL) and she is also comfortable working on UNIX/Linux Cluster High
Performance Computing systems.

Ramboll – Assessing Global Background Ozone Transport Pathways to the Northern Wasatch Front

APPENDIX A

Resumes of Key Personnel

1/3 CV, CHRISTOPHER A EMERY

CHRISTOPHER A. EMERY
Senior Managing Consultant
Chris Emery has over 30 years of experience in numerical modeling
and analysis of multi-scale air pollution and meteorology. His
expertise includes design, development and application of air quality
modeling systems. Chris co-authors the Comprehensive Air Quality
Model with extensions (CAMx—a regional nested grid photochemical
model with Probing Tool extensions), prepares the CAMx User’s
Guide, and manages public distributions of CAMx and support
programs. He has delivered training on photochemical modeling for
numerous US and international clients including private,
governmental, and academic institutions. He has applied a variety of
models for private and public clients, in both local and regional
regulatory arenas, throughout the US and abroad. His projects have
included ozone, particulate matter and carbon monoxide modeling to
support regulatory planning; analyzing source contributions and
emission sensitivity; modeling fate of toxic air pollutants;
determining effects of alternative and innovative air quality
management strategies including urban heat island mitigation;
studying prospective and retrospective air quality trends; and
estimating North American background ozone. Chris has applied
and evaluated meteorological models and global chemical transport
models to develop inputs needed by regional photochemical
modeling applications. He has served as a member of the American
Meteorological Society’s Board of the Urban Environment.
CAREER
1995-Present
Senior Managing Consultant
Ramboll / ENVIRON International Corporation

1990-1995
Staff and Senior Scientist
ICF Systems Applications International, San Rafael, California,
United States
EDUCATION
1988-1990
MS, Meteorology
San Jose State University, San Jose, California, United States
1985-1988
BS, Meteorology
San Jose State University, San Jose, California, United States

CONTACT INFORMATION
Christopher A. Emery

[e-mail]
[phone]

Ramboll
7250 Redwood Boulevard
Suite 105
Novato, 94945
United States of America

2/3 CV, CHRISTOPHER A EMERY

MEMBERSHIPS
Air and Waste Management Association (AWMA)
American Meteorological Society (AMS)
RECENT EXPERIENCE
Air Quality Model Development
− Co-developer of Ramboll’s Comprehensive Air Quality Model with extensions (CAMx); manages updates and distribution of CAMx, associated pre- and postprocessors, and model documentation; conducts CAMx training for numerous US and international private, governmental, and academic institutions.
− Assisted in implementing updates to the CAMx surface model and chemistry mechanisms for the State of Utah.
− Led the development of a hemispheric CAMx modeling capability.
− Co-developer of emission estimating models for fires, sea salt, wind-blown dust, and lightning NOx.
− Assisted the development and testing of a near-real-time CAMx air quality system for Texas.
− Co-developer of the Mesoscale Model InterFace (MMIF) program that directly translates MM5 and
WRF meteorological output to CALPUFF and AERMOD input format.
Air Quality Model Applications
− Managing photochemical modeling applications to support the Clark County Ozone State
Implementation Plan.
− Managing modeling analyses of toxic air pollutants and deposition at the Hanford, Washington Site.
− Assessed international anthropogenic pollutant contributions to ozone air quality along the Wasatch Front, Utah and in El Paso, Texas.
− Investigated causes of ammonia emission shortfalls in CAMx modeling of PM2.5 for the Salt Lake City, Utah, State Implementation Plan.
− Assessed contributions of California natural gas power plants to Statewide ozone and PM2.5 using the CAMx source apportionment tool.
− Managed an analysis of and comments on EPA’s draft guidance on Modeled Emissions Rates for Precursors (MERP) addressing single-source impacts on ozone and PM2.5.
− Evaluated global chemical transport models (GEOS-Chem, MOZART, AM3) to characterize US
background sources of ozone and to supply boundary conditions for regional models (CAMx and
CMAQ).
− Assisted in the development of international CAMx ozone and PM modeling programs for the
Marseille area of France, Rhine area of France/Germany, Po Valley (Milan) area of Italy, Medellin
area of Colombia, and several areas of Spain.
− Managed a modeling project to estimate ozone sensitivity to US anthropogenic precursor reductions
to help inform the EPA ozone NAAQS review process.
− Managed a North American modeling analysis to estimate spatial and temporal patterns in
background ozone over the US, and related source attribution, for input to the EPA ozone NAAQS review process.
Meteorological Model Applications and Analysis
− Managed the application of WRF to support the 2017 Western Air Quality Study for the Western States Air Resources Council (WESTAR).
− Managed a high-resolution application of WRF to the Upper Green River Basin in southwest Wyoming to support winter photochemical modeling of the area.
− Managed an application of WRF to provide boundary conditions for highly refined computational fluid dynamics (CFD) windflow modeling of a neighborhood in the South Coast air basin in California.

3/3 CV, CHRISTOPHER A EMERY

− Managed testing of WRF meteorological model improvements that allow for more detailed treatment of clouds and vertical diffusion in the CAMx photochemical model.
Specialized Analyses
− Reviewed and developed new recommendations on photochemical model performance evaluation and benchmarks for statistical performance metrics.
− Assisted in an EPA evaluation of various modeling platforms for the purpose of simulating single-source impacts on ozone, PM, visibility, and AQRVs for NEPA, PSD, and NSR assessments.
− Applied and evaluated modeling methodologies that simulate the impacts of Urban Heat Island
(Cool Communities) measures involving intensive tree planting and use of light-colored building
materials to lower urban temperatures and ambient pollutant concentrations in Los Angeles and
Houston.
RECENT PUBLICATIONS Zhai, H., Huang, L., Emery, C., Zhang, X., Wang, Y., Yarwood, G., Fu, J.S., Li, L., 2024.
Recommendations on benchmarks for photochemical air quality model applications in China — NO2,
SO2, CO and PM10, Atmos Environ, https://doi.org/10.1016/j.atmosenv.2023.120290.
Huang, L., Zhu, Y., Zhai, H., Xue, S., Zhu, T., Shao, Y., Liu, Z., Emery, C., Yarwood, G., Wang, Y., Fu,
J., Zhang, K., and Li, L. 2021. Recommendations on benchmarks for numerical air quality model applications in China – Part 1: PM2.5 and chemical species, Atmos. Chem. Phys., 21, 2725–2743, https://doi.org/10.5194/acp-21-2725-2021.
Huang, L., Q. Wang, Y. Wang, C. Emery, A. Zhu, Y. Zhu, S. Yin, G. Yarwood, K. Zhang, L. Li, 2021. Simulation of secondary organic aerosol over the Yangtze River Delta region: The impacts from the emissions of intermediate volatility organic compounds and the SOA modeling framework. Atmos. Environ, 246, 118079, https://doi.org/10.1016/j.atmosenv.2020.118079.
Koo, B., Metzger, S., Vennam, P., Emery, C., Wilson, G. and Yarwood, G., 2019. Comparing the
ISORROPIA and EQSAM Aerosol Thermodynamic. Air Pollution Modeling and its Application XXVI, p.93.
Emery, C., Z. Liu, A.G. Russell, M.T. Odman, G. Yarwood, N. Kumar. 2017. Recommendations on
statistics and benchmarks to assess photochemical model performance. Journal of the Air and
Waste Management Association, DOI: 10.1080/10962247.2016.1265027.
Downey, N., C. Emery, J. Jung, T. Sakulyanontvittaya, L. Hebert, D. Blewitt, G. Yarwood. 2015.
Emission Reductions and Urban Ozone Responses Under more Stringent US Standards. Atmos.
Environ., 101, 209-216, http://dx.doi.org/10.1016/j.atmosenv.2014.11.018.
Baker, K.R., C. Emery, P. Dolwick, G. Yarwood. 2015. Photochemical Grid Model Estimates of Lateral Boundary Contributions to Ozone and Particulate Matter across the Continental United States. Atmos. Environ., 123, 49-62.
Karamchandani, P., C. Emery, G. Yarwood, B. Lefer, J. Stutz, E. Couzo & W. Vizuete. 2015. “Implementation and Refinement of a Surface Model for Heterogeneous HONO Formation in a 3-D Chemical Transport Model”. Atmos. Environ.; 2015 January; doi: 1016/j.atmosenv.2015.01.046.
Nopmongcol, U., C. Emery, T. Sakulyanontvittaya, J. Jung, E. Knipping, G. Yarwood. 2014. A modeling analysis of alternative primary and secondary US ozone standards in urban and rural areas. Atmos. Environ., 99, 266-276, http://dx.doi.org/10.1016/j.atmosenv.2014.09.062.
Yarwood, G., C. Emery, K. Baker, and P. Dolwick. 2014. Resolving and Quantifying Ozone Contributions
from Boundary Conditions Within Regional Models. Air Pollution Modeling and its Application XXIII.
Springer Proceedings in Complexity, DOI: 10.1007/978-3-319-04379-1_17. Springer International
Publishing Switzerland.
Lefohn, A., C. Emery, D. Shadwick, H. Wernli, J Jung, S. Oltmans. 2014. Estimates of Background
Surface Ozone Concentrations in the United States Based on Model-Derived Source Apportionment.
Atmos. Environ., 84., 275-288, http://dx.doi.org/10.1016/j.atmosenv.2013.11.033.
Yarwood, G., C. Emery, J. Jung, U. Nopmongcol, T. Sakulyanontvittaya. 2013. A Method to Represent Ozone Response To Large Changes In Precursor Emissions Using High-Order Sensitivity Analysis In Photochemical Models. Geosci. Model Dev., 6, 1601–1608, doi:10.5194/gmd-6-1601-2013.

1/3 CV, GREGORY YARWOOD

GREGORY YARWOOD, PhD
Principal
Dr. Greg Yarwood is an internationally recognized expert with over 30
years of experience in atmospheric chemistry, air quality modeling,
photochemical model development, interpreting ambient air quality
data, and emissions inventory development. He directs air quality,
meteorological and emissions modeling studies for clients in
government and industry with emphasis on photochemical air
pollution issues, such as ozone, fine particulate matter (PM2.5),
visibility and air toxics. Greg designs and directs complex
photochemical modeling studies using models such as CAMx, CMAQ,
GEOS-Chem, SCICHEM and WRF. He oversees development of
Ramboll’s Comprehensive Air quality Model with extensions (CAMx:
http://www.camx.com) and he implemented the CAMx methods for
source attribution (OSAT and PSAT), sensitivity analysis (DDM and
HDDM) and process analysis. He is an expert atmospheric chemist
and leads development of the Carbon Bond chemical mechanisms
(including CB05, CB6 and CB7) that are used to model ozone and
PM2.5 in both CAMx and USEPA’s CMAQ model. He has specialized
expertise in characterizing air emissions from biogenic sources,
combustion engines and industrial flares. He directs research
studies that develop emission inventories from satellite
measurements of greenhouse gases (GHGs) and nitrogen oxides
(NOx). He has performed international air quality studies in Europe,
the Middle East, China, Australia and Africa. In the US, Greg advises
regional, state and local planning agencies as they develop and
implement plans to address air quality (non-attainment) issues. He
is experienced in communicating on air quality matters in settings
that range from international scientific conferences to community
meetings with diverse audiences. His scientific publication record is
highly ranked with an H-index of 44. Greg was appointed to
USEPA’s Board of Scientific Counselors for the Clean Air Research Program.
CAREER
1995-Present
Principal, Ramboll (formerly Environ)

1991-1995
Senior Scientist, ICF Systems Applications International, San Rafael, California

1988-1991
Post-Doctoral Researcher, Centre for Atmospheric Chemistry, York University, Canada

1987-1988
Post-Doctoral Researcher, Brookhaven National Laboratory, New York

CONTACT INFORMATION
Gregory Yarwood

[e-mail]
[phone]

Ramboll
7250 Redwood Boulevard
Suite 105
Novato, CA 94945
United States of America

2/3 CV, GREGORY YARWOOD

EDUCATION
1987
PhD, Chemistry, University of Cambridge, United Kingdom

1982
BSc, Chemistry, University of Bath, United Kingdom
EXPERIENCE
Regional Air Quality Planning
− Evaluating air quality (O3 and PM2.5) benefits of electrification and decarbonization strategies across
the US out to 2050.
− Near-real-time (NRT) photochemical modeling for Texas. The WRF/CAMx-based system models US-
wide air quality with fine-scale resolution for Dallas and Houston.
− Global modelling using GEOS-Chem to determine contributions of US and foreign emissions to background ozone in Texas’ ozone non-attainment areas.
− Developed ozone control strategies for the Northeast Texas region through a multi-stakeholder
process. These measures are included in the Texas State Implementation Plan (SIP) and the region
is attaining the National Ambient Air Quality Standards (NAAQS).
− Directed technical studies to support Texas’ State Implementation Plan (SIP) for the Houston and
Dallas ozone nonattainment areas including air quality, meteorological and emissions modeling and
the design and evaluation of emissions reduction strategies.
− Regional air quality planning studies for the Arabian Gulf (confidential client), China (Pearl River
Delta) and Southern Africa (Cross-border Air Pollution Impact Assessment).
Photochemical Model Development
− Ramboll’s Comprehensive Air quality Model with extensions (CAMx). Greg is responsible for the
model chemistry for O3 and PM2.5 and the advanced “probing tools” for source apportionment
(OSAT and PSAT), sensitivity analysis (DDM) and chemical process analysis (CPA).
− Designed the Ramboll Shair real-time air quality model (https://ramboll-shair.com) with hyperlocal
resolution and integration with sensor data to address community-level issues including
environmental justice.
Air Quality Data
− Designed aircraft-based monitoring studies for ozone and precursors in Texas.
− Directed ground-level monitoring of ozone, nitrogen oxides (NOx and NOy) and volatile organic
compounds (VOC).
− Reviewed VOC receptor modeling and ambient ratio (VOC/NOx and CO/NOx) studies for evidence of systematic biases between emission inventories and ambient data.
− Evaluated the air quality impacts of offshore oil drilling near Prudhoe Bay and the Arctic National
Wildlife Refuge ANWR) in Alaska.
− Testified on the PM impacts of re-powering a large utility boiler from oil to gas in a major
Northeastern US city.
Atmospheric Chemistry
− Member of the CRC Research Panel on the Atmospheric Chemistry of Hydrocarbons (RPACH) that
published reviews of the chemistry of alkenes and aromatic hydrocarbons.
− Developer of Carbon Bond gas-phase chemical mechanisms including CB05, CB6 used in EPA
regulatory modeling studies of ozone, particulate matter and air toxics, and the latest version CB7.
− Created chemical mechanisms describing atmospheric transformations of polyfluorinated
substances (PFAS) to perfluorooctanoic acid (PFOA) for regional and global modeling.
− Made laboratory measurements of reaction rates for NOx species under high temperature
(combustion) and low temperature (stratospheric) conditions.

3/3 CV, GREGORY YARWOOD

Emission Inventories
− Directed development of a Northeast Texas emission inventory for SIP modeling and submission to
the National Emission Inventory (NEI). Local surveys were conducted to improve the area, off-road
and biogenic emission inventories.
− Directed optical remote sensing studies to measure VOC, NOx and SOx emissions from chemical
industry facilities in Texas and the Middle East.
− Analyzed the effects of reformulated/alternative fuels and advanced vehicles on mobile source emissions for the joint Auto/Oil Air Quality Improvement Research Program (AQIRP).
MEMBERSHIPS
Air and Waste Management Association (AWMA)
American Chemical Society (ACS)
American Geophysical Union (AGU)
RECENT PUBLICATIONS Nawaz, M.O., Johnson, J., Yarwood, G., de Foy, B., Judd, L.M. and Goldberg, D.L., 2023. An
intercomparison of satellite, airborne, and ground-level observations with WRF-CAMx simulations of
NO 2 columns over Houston, TX during the September 2021 TRACER-AQ campaign. EGUsphere,
2023, pp.1-34.
Huang, L., Liu, H., Yarwood, G., Wilson, G., Tao, J., Han, Z., Ji, D., Wang, Y. and Li, L., 2023. Modeling
of secondary organic aerosols (SOA) based on two commonly used air quality models in China:
Consistent S/IVOCs contribution but large differences in SOA aging. Science of The Total
Environment, 903, p.166162.
Huang, L., Fang, J., Liao, J., Yarwood, G., Chen, H., Wang, Y. and Li, L., 2023. Insights into soil NO
emissions and the contribution to surface ozone formation in China. Atmospheric Chemistry and
Physics, 23(23), pp.14919-14932.
Bistline, J.E., Blanford, G., Grant, J., Knipping, E., McCollum, D.L., Nopmongcol, U., Scarth, H., Shah, T.
and Yarwood, G., 2022. Economy-wide evaluation of CO2 and air quality impacts of electrification in
the United States. Nature Communications, 13(1), p.6693.
Goldberg, D.L., Harkey, M., de Foy, B., Judd, L., Johnson, J., Yarwood, G. and Holloway, T., 2022. Evaluating NO x emissions and their effect on O3 production in Texas using TROPOMI NO2 and
HCHO. Atmospheric Chemistry and Physics, 22(16), pp.10875-10900.
Dunker, A.M., Wilson, G., Bates, J. and Yarwood, G., 2020. Chemical Sensitivity Analysis and
Uncertainty Analysis of Ozone Production in the Comprehensive Air Quality Model with Extensions
Applied to Eastern Texas. Environmental Science & Technology. doi.org/10.1021/acs.est.9b07543
Luecken, D.J., Yarwood, G., Hutzell, W. H., 2019. Multipollutant modeling of ozone, reactive nitrogen
and HAPs across the continental US with CMAQ-CB6. Atmos. Environ. 201, 62–72.
Guenther, A., Jiang, X., Shah, T., Huang, L., Kemball-Cook, S. and Yarwood, G., 2019. Model of
Emissions of Gases and Aerosol from Nature Version 3 (MEGAN3). Air Pollution Modeling and its
Application XXVI, p.187.
Emery, C., Liu, Z., Russell, A.G., Odman, M.T., Yarwood, G. and Kumar, N., 2017. Recommendations on
statistics and benchmarks to assess photochemical model performance. Journal of the Air & Waste
Management Association, 67(5), pp.582-598. doi.org/10.1080/10962247.2016.1265027.
Dunker, A.M., B. Koo, G. Yarwood. “Ozone Sensitivity to Isoprene Chemistry and Emissions and
Anthropogenic Emissions in Central California.” Atmos. Environ., 145, 326-337, 2016.
Nopmongcol, U., J. Jung, N. Kumar, G. Yarwood. 2016. “Changes in US Background Ozone Due to
Global Anthropogenic Emissions from 1970 to 2020.” Atmos. Environ., 140, 446-455.
Dunker, A. M., B. Koo, and G. Yarwood. 2015. “Source Apportionment of the Anthropogenic Increment
to Ozone, Formaldehyde, and Nitrogen Dioxide by the Path-Integral Method in a 3D Model.” Environ.
Sci. Technol., 49, 6751-6759.

1/3 CV, GARY M WILSON

GARY M. WILSON
Managing Consultant
Gary Wilson is the primary programmer in photochemical modeling
and emissions modeling development at Ramboll. He has over 30
years of experience with emissions models, including NONROAD,
EPS3, MOVES, SMOKE, EMS95, MOBILEx, EMFAC7x, DTIM2, EXPLORA
and GloBEIS. Working with the Office of Mobile Sources at USEPA, he
developed NONROAD, a FORTRAN-based model that estimates the
county-level emissions from non-road mobile sources. Gary also
worked with a team headed by USEPA to incorporate the NONROAD
model into the MOVES subsystem, adding the capability of MOVES to
generate estimates for NONROAD sources. Gary is responsible for the
ongoing maintenance and development of the Comprehensive Air
Quality Model with extensions (CAMx), a state-of-the-science
photochemical grid model. He is the principal programmer in
incorporating all probing tools add-on tools into the CAMx model,
each of which provides the ability to analyze the behavior of the
photochemical model in a unique way. Gary is proficient in all tasks
necessary for carrying out a modeling simulation using the CAMx
model, from the preparation of all necessary inputs, to the
configuring and execution of the model simulation, to the analysis
of the model results using graphics of model predictions and
statistics of model performance. Gary is an expert in FORTRAN,
PERL and Linux shell scripting, and has programming experience in
C, HTML C++, Visual Basic, SQL and SAS. He has provided training
to other agencies in the use of modeling systems. In his capacity as
system administrator, Gary possesses expert knowledge of the
Linux, Windows Desktop and Windows Server operating systems.
CAREER
1995-present
Systems Administrator/Programmer
Ramboll / ENVIRON International Corporation

1993-present
Mathematics Teacher
Santa Rosa Junior College, Santa Rosa, California

1990-1995
Staff Scientist
ICF Systems Applications International, San Rafael, California

CONTACT INFORMATION
Gary M Wilson

[e-mail]
[phone]

Ramboll
7250 Redwood Boulevard
Suite 105
Novato, CA 94945
United States of America
EDUCATION
1991
MS, Mathematics
San Jose State University,
San Jose, California

1987
BS, Mathematics
California Polytechnic State
University, San Luis Obispo,
California

2/3 CV, GARY M WILSON

EXPERIENCE
High Performance Computing System Administration
- Chief IT/Systems Administrator for Ramboll’s high performance Linux computer system, including
hardware, networking, security, and OS/application/library software installation and maintenance.

Air Quality Model Development and Application
- Co-developer of the Comprehensive Air Quality Model with extensions (CAMx), including core
model and Probing Tools, tracks and fixes reported bugs, prepares code for public distribution,
applies extensive testing protocols, develops, tests, and distributes many pre- and post-processing
systems.
- Developed and managed a near-real time automated modeling system for the State of Texas,
including meteorological and global model simulations, to track impacts from biomass burning in
Mexico and Central America, stratospheric ozone intrusion, and anthropogenic emissions from
Mexico.
- Assisted in developing a Regional Air Quality Assessment for proposed Western Sydney Airport.

Emission Processing System Development and Application
- Designed and developed the Emissions Preprocessing System (EPS3), a FORTRAN-based model
used to prepare emission inventories for photochemical modeling.
- Developed detailed “bottom up” emission inventories using EPS3 to support the PM10 Maintenance
Plan (SIP) for Northern Ada County, Idaho.
- Designed and developed DTIM2, an emissions inventory model for on-road motor vehicle sources
that works with traffic network demand model datasets.
- Designed and implemented the approach to incorporate the NONROAD model, a FOTRTAN based
model that estimates emissions from non-road mobile sources, into the MOVES model, a Java/SQL
based model that estimates emissions for on-road mobile sources.
- Developed complete emission inventories for the San-Antonio/Austin, Texas, ozone near-
nonattainment areas, and assisted in training Alamo Area Council of Government staff on emissions
processing systems.
- Generated on-road motor vehicle emissions inventories for urban and regional scale modeling to
develop control strategies for 1-hour and 8-hour ozone in East Texas.
- Designed and developed the Global Biosphere Emissions and Interactions System (GLOBEIS), an
ACCESS-based model that estimates emissions from natural (biogenic) sources.
- Chief programmer for the EPA’s original NONROAD emissions model, an integrated system
including a FORTRAN based core model for estimating emissions, an ACCESS based reporting utility
for generating tables and reports, and a Visual Basic based graphical user interface.
PUBLICATIONS
Dunker, A.M., Wilson, G., Bates, J. and Yarwood, G., 2020. Chemical Sensitivity Analysis and
Uncertainty Analysis of Ozone Production in the Comprehensive Air Quality Model with Extensions
Applied to Eastern Texas. Environmental Science & Technology. doi.org/10.1021/acs.est.9b07543’
Koo, B., G. M. Wilson, R. E. Morris, A. M. Dunker, and G. Yarwood. 2009. “Comparison of Source
Apportionment and Sensitivity Analysis in a Particulate Matter Air Quality Model.” Environ. Sci.
Technol., 43, 6669-6675. July.
Sowden, M., E. Cairncross, G. Wilson, M. Zunckel, E. Kirillova, V. Reddy, and S. Hietkamp. 2008.
“Developing a Spatially and Temporally Resolved Emission Inventory for Photochemical Modeling in the City of Cape Town and Assessing Its Uncertainty.” Atmos. Environ, 42: 7155-7164. September.
Wagstrom, K., M. Spyros, N. Pandis, G. Yarwood, G.M. Wilson and R.E. Morris. 2008. “Development and
Application of a Computationally Efficient Particulate Matter Apportionment Algorithm in a Three-
Dimensional Chemical Transport Model.” Atmos. Environ., 42: 5650-5659. July.
Wilson, G.M., A. Dunker, G. Yarwood, and J. Ortmann. 2002. “The Decoupled Direct Method for
Sensitivity Analysis in a Three-Dimensional Air Quality Model – Implementation.” Environ. Sci.
Technol., Vol. 367, No. 13, July.

3/3 CV, GARY M WILSON

PRESENTATIONS
Emery, C., B. Koo, G. Wilson, G. Yarwood. 2016. “CAMx: Overview and Recent Updates.” Presentation
at the 15th Annual CMAS Conference, Chapel Hill, NC, October.
Emery, C., B. Koo, G. Wilson, G. Yarwood. 2016. “CAMx: Modeling System Overview.” Presentation at
the LADCO/CenSARA Modelers Meeting. St. Louis, MO, 22 June.
Koo, B., G.M. Wilson, R.E. Morris, G. Yarwood. 2009. “Comparison of PM Source Apportionment and Sensitivity Analysis in CAMx.” Presented at CMAS 8th Annual Conference, Chapel Hill, NC. October.
Wilson, G., B. Wang, C. Emery, R. Morris and G. Yarwood. 2008. “Applying a 3-D Photochemical Model
(CAMx) in Multi-Processor Cluster (MPI) and Shared-Memory (Open-MP) Computing Environments.”
Presented at the 7th Annual CMAS Conference, University of North Carolina, October.
Morris, R.E., G. Yarwood, C. Emery, G. Wilson, B. Koo. 2006. “Regional Modeling Using One-
Atmospheric Models to Address Regional Haze, 8-Hour Ozone and PM2.5 Air Quality Issues.”
Presented at the 99th Annual AWMA Conference, New Orleans, LA, June.
Wilson, G.M., R.E. Morris, G. Yarwood, C.A. Emery. 2001. “Recent Advances in CAMx Air Quality
Modeling.” Presented at the 94th A&WMA Annual Conference, Orlando, FL, June.
Wilson, G.M., R.E. Morris, G. Yarwood, C.A. Emery. 2001. “Recent Development and Applications of the
Comprehensive Air Quality Model with extensions (CAMx).” Presented at Guideline on Air Quality
Models: A New Beginning. Newport, Rhode Island, April.
Wilson, G.M., (with others). 1998. “Use of Advanced Ozone Source Apportionment Techniques to
Estimate Are of Influence (AOI) of Emissions Contributions to Elevated Ozone Concentrations.”
Presented at the 1998 Annual AAMA Meeting.

1/3 CV, TRANG TRAN

TRANG TRAN, PHD

Senior Consultant
Dr. Trang Tran has over 10 years’ experience in air quality modeling,
specializing in weather and 3D-chemical transport modeling (e.g.,
WRF, WRF-Chem, CAMx) with advance tool utilization (e.g., data
assimilation, source apportionment, and process analysis). She is an
expert in statistical model evaluation tools (e.g., AMET, SMAT-CE) and
has strong experience in emission inventory development and format
processing (both top-down and bottom-up-derived inventories) using
various models/tools such as SMOKE, Prep_chem_sources,
anthro_emiss, and EPA_anthro_emiss. Dr. Tran is experienced in
environmental impact assessment (EIA) reporting, particularly for oil
and gas clients. Her programming expertise includes both basic and
visualization languages (e.g., Fortran, C, R, python, NCL, VAPOR,
IDL) and she is also comfortable working on UNIX/Linux Cluster High
Performance Computing systems.

PROJECT EXPERIENCE
2022-2023
Clark County Ozone State Implementation Plan
Processing and QA’ing emission input files for control strategies,
performing photochemical simulations, Weigh of Evidence analysis,
and model performance evaluation. In this project Ramboll is
conducting and documenting the photochemical modeling and
ancillary weight-of-evidence analyses that support an ozone
attainment demonstration for the Clark County Non-Attainment Area
Moderate Ozone SIP.

2019-2023
BLM Montana/Dakotas PGM Modeling Study
Developing air quality modeling emissions for the BLM
Montana/Dakotas PGM modeling study to assess the air quality and
Air Quality Related Value (AQRV) impacts due to oil and gas
development. The Bakken Shale formation in the Montana/Dakotas
region is the most rapidly growing oil and gas development area in
the U.S. Under this study, Ramboll is developing a comprehensive oil
and gas emissions inventory and performing base year 2012/2013
and future year 2032 modeling using the CAMx photochemical grid
model.

2022-2023
PGM for the Tennessee Department of Environment and Conservation
Provided technical support in emission input preparation, QA’d on
SMOKE output files, performed photochemical simulations and model
performance evaluation. Ramboll provided PGM modeling assistance
to: 1) assess The Tennessee Valley Authority Coal Plant Retirement
impacts; 2) model Sullivan County SO2 NAA around Eastman

CONTACT INFORMATION
Trang Tran

[e-mail]

Ramboll
7250 Redwood Blvd.
Suite 105
Novato, CA 94945

EDUCATION
2013 Ph.D., Environmental Chemistry (majoring in air quality modeling)
University of Alaska, Fairbanks
2008
M.S., Environmental Engineering and
Management
Asian Institute of Technology, Thailand
2005
B.A., Environmental Sciences
HCMC University of Natural Sciences,
Vietnam

2/3 CV, TRANG TRAN

Chemical Facility and 3) provide PGM training for the Tennessee Department of Environment and
Conservation Staff.

2022-2023
Modeling the Visibility Impacts of Petroleum Refineries in the State of Washington
Provided technical support in emission data processing, photochemical simulations, model performance
evaluation and visibility impact analysis. Under this project, Ramboll provided technical support to
satisfy the requirements in Western States Petroleum Association’s March 17, 2022 “Request for
Proposal – Regional Haze Visibility Modeling” to estimate the effects on visibility due to emissions from
the major five refineries.

2022-2023
FEI Processor Developments and Virtual Workshop for Texas Commission on Environmental, United
States
Processed observed and modeled data for CAMx Model Performance Evaluation. Ramboll assisted the
Texas Commission on Environmental Quality to improve and expand usability of the FEI tool and
conduct a workshop on photochemical modeling best practices.

2022-2023
WESTAR: WY CSAPR
Western States Air Resources Council (WESTAR), United States
Processed EPA’s AQS data to calculate O3 design values with and without wildfire exceptional events.
Ramboll is analyzing EPA’s 2015 Ozone NAAQS Good Neighbor FIP for Wyoming as a subcontractor to
WESTAR where EPA claims WY contributes significantly to ozone nonattainment at a monitor in
Colorado.

2020-2023
Trinity: ADEC Fairbanks CMAQ PM2.5 SIP
Processed observed and modeled data for CMAQ Model Performance Evaluation. Ramboll conducted
CMAQ modeling for the Fairbanks region for the Alaska Department of Environmental Conservation
(ADEC) to support the development of a PM2.5 State Implementation Plan (SIP) under subcontract to
Trinity Consultants.

2022-2023
MAG TO#1: 03 Precursor Controls: Comprehensive List
Maricopa Assoc. of Governments, United States
Reviewed and documented emission control measures. Task Order 1: Ramboll developed a
comprehensive list of ozone precursor emission control measures in Maricopa County in support of State
Implementation Planning.

2022-2023
MAG TO#2: 03 Precursors Controls: Emission and Cost Analysis
Maricopa Assoc. of Governments, United States
Reviewed and documented emission control measures. Task Order 2: Ramboll developed emission
reductions and cost analysis for ozone precursors in Maricopa County in support of State
Implementation Planning.

2022
Alberta Environment and Parks Task3 DIZ CMAQ Deposition
Alberta Environment and Park, Canada
Developed deposition results from the DIZ CMAQ modeling database.

3/3 CV, TRANG TRAN

2022-2023
Toyota: Future Year PM and Ozone Modeling
Toyota Motor North America, Inc., United States
Performed SMAT analysis. Ramboll conducted emissions development and air quality modeling to
determine PM source attribution and ozone sensitivity to NOx and VOC emissions

2018-2022
Regional Air Quality Council: Denver Ozone SIP RAQC, Colorado, United States
Provided technical support on emissions processing in conducting ozone SIP modeling to demonstrate
that the Denver region will attain the 2015 ozone NAAQS by 2023 for the Denver Regional Air Quality
Council.

CAREER
7/2022 – present
Ramboll, Senior Consultant I
- Preparing SMOKE model input data, QA’ing on SMOKE emission output files.
- Performing Photochemical Grid Model simulations, model performance evaluation, and other
post-process analysis.
- Technical report writing

9/2020 – 6/2022
Desert Research Institute, Air Quality Modeler – Assistant Research Professor
- Conducted air quality modeling projects to study ozone sensitivity in response to emission
changes in New York City area
- Air quality/ wildfire forecasting using numerical models
- Published and contributed to proposal development

6/2013 – 8/2020
Bingham Research Center – Utah State University, Senior Research Scientist/Postdoctoral Researcher
- Conducted air quality modeling projects to study winter ozone pollution due to oil and gas
exploration activities in Uinta Basin.
- Contributed to air monitoring projects funded for Energy and Minerals Department, Ute Indian
Tribe
- Published, prepared technical reports, proposal development and project management

2/2009 – 5/2013
Department of Environmental Chemistry – University of Alaska, Fairbanks, Research Assistant
- Developed and conducted research to investigate the reasons for air quality degradation in the
wilderness areas of Alaska.
- Research focus: air quality modeling with WRF/Chem, CMAQ, HYSPLIT, AEMOD, GIS
- Published and presented research findings in conferences/meetings

PUBLICATIONS
Available upon request