**CALPUFF Evaluation Tool Document**

**TABLE OF CONTENTS**

**1. INTRODUCTION**

**2. DESCRIPTION OF SCENARIOS**

**3. RUNNING THE SCENARIOS**

**4. ANALYSES OF SCENARIOS**

**1. INTRODUCTION**

Before EPA can introduce an update for one of its preferred/recommended
dispersion models, it has historically conducted a design concentration
analysis to illuminate discontinuities and differences in predictions
for a robust suite of source-receptor scenarios and meteorological input
conditions. These results provide a basis for EPA to issue a model
change bulletin (MCB) that would announce to the user community that a
new version is being approved for use.

A standardized test data and an analysis tool were developed to assess
the impact of coding changes and enhancements to the CALPUFF modeling
system. The test data set involves various types of sources (tall
stacks, short stacks, area sources and volume sources), modeling
domains, meteorological assumptions, and model options. The data set has
been designed to provide a reasonably comprehensive comparison of old
versus new versions of the CALPUFF modeling system, and to show how
changes may affect concentration values of particular interest to the
EPA and air quality modelers. Run in a batch mode, the analysis program
runs the two versions of CALPUFF through the input scenarios and
compares the results.

The way in which the *Beta* versions of CALMET and CALPUFF were tested
against their Base case counterparts is illustrated in this matrix:

+---------------------+------------------------+----------------------+
|                     | CALPUFF base           | **CALPUFF new**      |
+---------------------+------------------------+----------------------+
| CALMET base         | Base Case              | new CALPUFF effects  |
|                     |                        |                      |
|                     |                        | (not run)            |
+---------------------+------------------------+----------------------+
| **CALMET new**      | new CALMET effects     | new CALMET & CALPUFF |
|                     |                        |                      |
|                     | (run for Secondary     |                      |
|                     | analysis)              |                      |
+---------------------+------------------------+----------------------+

A Primary analysis of combined effects involved comparing Base Case
(base CALMET & base CALPUFF) predictions with those from new Beta CALMET
& CALPUFF combined. For scenarios that showed differences, a Secondary
analysis can determine whether the differences are attributable to
CALMET, CALPUFF or both. The Secondary analysis is performed by running
the Base version of CALPUFF with the meteorological data generated by
the Beta version of CALMET. The results of this model run are compared
to the Base/Base and Beta/Beta runs performed under the Primary analysis
in order to isolate the cause of the differences.

In this comparison, the version of CALPUFF promulgated on 15 April 2003
(base) is compared to the version dated July 2003 (*beta*). As new and
revised algorithms are developed, it is expected that newer versions of
the CALPUFF modeling system will be released from time to time. It
therefore becomes important to evaluate continuity and consistency of
model predictions when moving from one version to the next.

2.  **DESCRIPTION OF SCENARIOS**

The purpose in developing a standard set of scenarios is to provide a
reasonably comprehensive assessment of how changes in the CALPUFF
modeling system may affect concentration estimates generated by CALPUFF.
Two main areas of regulatory application of CALPUFF are of interest to
the U.S. Environmental Protection Agency (US EPA): 1) long range
transport focusing on Prevention of Significant Deterioration (PSD)
increments in Class I areas, and 2) complex wind scenarios with a focus
on National Ambient Air Quality Standards (NAAQS) and PSD increments of
criteria pollutants. The scenarios described below address both of these
areas of interest. In addition, an optional scenario is included that
addresses application of the CALPUFF model to assess Air Quality Related
Value (AQRV) impacts in Class I areas, which utilizes the chemistry and
deposition algorithms of the CALPUFF model. The scenarios have been
designed to challenge the CALPUFF modeling system for a range of source
configurations and modeling options in order to provide a thorough
evaluation of the coding changes.

**2.1 Source Characteristics**

The sources included in the test dataset can be divided into two groups,
a core group of sources used in all scenarios and supplementary sources
that are scenario-specific. Each of these groupings is described below.
The source characteristics for the core sources are specified in Table
2-1, and the characteristics for the additional sources are specified in
Table 2-2.

1.  **Sources common to all scenarios**

This core group consists of four sources that reflect the release into
and plume rise through different vertical layers of the model. This
group represents some of the commonly modeled sources in regulatory
applications and is therefore included in all scenarios. These sources
are as follows:

1.  Point source, non-buoyant, 30-meter release height.

2.  Point source, buoyant, 65-meter release height.

3.  Volume source, ground-based, 10-meter release height.

4.  Area source, ground-level, non-buoyant, 20m x 200m, with initial
    vertical dimension.

**2.1.2 Additional sources**

Several additional sources are used for various scenarios, depending on
the specific design of a scenario. These additional sources are:

1\. Three stacks that are subject to various levels of building
downwash:

\- One 35m capped stack located on a 34m building;

\- One 35m non-capped stack located on a 34m building; and

\- One 50m non-capped stack located on a 34m building.

2\. Buoyant area source, ground-based, 1 km diameter (approx. 200
acres), e.g., forest fire,

landfill, smelter.

3\. Tall point source (99 meters) located on the coast.

For the dispersion modeling, the sources common to all scenarios are
collocated, i.e., the x-coordinate and y-coordinate of the point sources
and volume source and the center of the area source share a common
location.

2.  **Standardized Scenarios**

To accomplish the goals noted above, a standard series of modeling
scenarios were identified. These scenarios were intended to address the
interests of the US EPA, as well as challenge the CALPUFF model, by
providing insight into the effects of model changes on the resulting
concentration field. As newer versions of the modeling system are
released, these standardized scenarios can be used to assess how the
model-predicted concentrations are affected. Note that most of the
scenarios are designed to provide a comparison of the concentration
outputs only, and not any other types of outputs such as deposition
rates. The focus of the scenarios is on concentration outputs due to the
fact that regulatory application of the CALPUFF model under EPA's
Guideline on Air Quality Models (40 CFR Part 51, Appendix W) is limited
demonstrating compliance with PSD increments and NAAQS. An optional
scenario is also included that addresses applications of the model to
estimate visibility and deposition impacts to address AQRVs established
by Federal Land Managers under the U.S. National Park Service and other
agencies.

The scenarios can be divided into three groups based on the scale of the
modeling domain, i.e., large-scale, medium-scale, and small-scale
simulations. The large-scale scenarios are designed to test the model
for long range transport situations on the order of 500 kilometers where
the curvature of the earth becomes significant enough to require the use
of the Lambert Conformal projection option, and where puff splitting can
become significant. The medium-scale and small-scale scenarios utilize
the Universal Transverse Mercator (UTM) projection option. The main
focus of each of the scenarios is briefly described below:

[Large-scale:]{.underline}

> 1\) large complex terrain domain with use of National Weather Service
> (NWS) meteorological observations (i.e., airport data);
>
> 2\) same as Scenario 1 with prognostic model data and without use of
> meteorological observations (NOOBS option); and

[Medium-scale:]{.underline}

> 3\) medium scale domain (subset of domain for Scenarios 1 and 2) with
> complex terrain and coastal effects;
>
> 4\) typical Class I area impact assessment with long range transport
> in complex terrain on the order of 50-100 kilometers; and

11\) same as Scenario 3 with chemistry and deposition.

[Small-scale:]{.underline}

5\) complex flow scenario in a deep valley;

6\) idealized hill with simulated steady-state meteorology and
similarity theory;

7\) idealized hill with simulated steady-state meteorology and PG
stability theory;

8\) flat terrain with simulated steady-state meteorology and similarity
theory;

9\) flat terrain with simulated steady-state meteorology and PG
stability theory; and

10\) same as Scenario 6 with simulated wind shear.

Details of each of these scenarios identifying the location, the various
grid sizes and resolution, meteorological data, vertical layers, and
modeling options for both CALMET and CALPUFF are discussed below. Only
those modeling options that differ from the default value or require an
input are identified.

1.  **Scenario 1 - Large-Scale, Lambert-Conformal**

The first of the large-scale scenarios is set in the western part of the
United States. The center of the meteorological domain is located about
150 kilometers (km) south of Pendleton, OR, at 44.5° North, 119° West.
The center of the domain was assigned false Easting and Northing
coordinates of (0,0). This domain extends 480 km in all directions
(i.e., 960 km on all sides), from just off the northern California coast
west of Eureka to just east of Glacier National Park in northwest
Montana. This area includes Oregon, Washington, most of Idaho, and the
northern parts of California and Nevada and Utah. A meteorological grid
spacing of 12 kilometer is used, resulting in 80 x 80 grid cells. The
Lambert-Conformal option was used with this size domain.

[Source location(s)]{.underline}: Two sets of the sources common to all
scenarios were used. One set was located near Salem, Oregon at 498.7
Easting and 4973.5 Northing in UTM zone 10 at an elevation of 58 meters.
The other set was located in Jordan Valley, Oregon at 495.6 Easting and
4757.9 Northing in UTM zone 11, about 2 kilometers from the Oregon-Idaho
border, at an elevation of 1335 meters.

Salem source coordinates: Lat = 44.9149N; Long = 123.0165W

LCCX = -316.603km; LCCY = 53.827km

UTMX = 498.7km E; UTMY = 4,973.5km N

Jordan Valley source coordinates: Lat = 42.9737N; Long = 117.0540W

LCCX = 158.572km; LCCY = -167.484

[Meteorological Grid]{.underline}: 12 kilometer grid spacing, resulting
in 80 x 80 grid cells.

[Vertical layers]{.underline}: Eight layers, with the cell faces at 0,
20, 50, 100, 250, 500, 1000, 2000, and 3300 meters.

[Meteorology]{.underline}: All available National Weather Service upper
air and surface observation data within the domain and the nearest
stations outside the domain on all sides were used. For this scenario,
there are 11 upper air stations and 32 surface stations.

[Barriers]{.underline}: None

[Time Period]{.underline}: One month (720 hours).

[Receptors]{.underline}: The sampling grid covered the entire
meteorological grid except the two outermost grid cells on all
meteorological grid borders, resulting in a receptor grid size of 76 x
76, for a total of 5,776 receptors.

[Modeling options -- CALMET]{.underline}: If an option is not shown
below, the default value was used.

PMAP = LCC (Lambert-Conformal Conic map projection)

RLAT0 = 44.5°N (Latitude of projection origin)

RLON0 = 119°W (Longitude of projection origin)

XLAT1 = 41.5°N (First reference latitude parallel)

XLAT2 = 47.5°N (Second reference latitude parallel)

IPROG = 0 (do not use prognostic wind filed model output)

RMIN2 = -1.0 (extrapolate all surface stations)

RMAX1 = 10 km (maximum radius of influence over land in surface layer)

RMAX2 = 20 km (maximum radius of influence over land aloft)

RMAX3 = 50 km (maximum radius of influence over water)

TERRAD = 100 km (radius of influence of terrain features)

R1 = 5 km (relative weighting of 1st guess field & obs. in surface
layer)

R2 = 5 km (relative weighting of 1st guess field & obs. in the layers
aloft)

[Modeling options -- CALPUFF]{.underline}: If an option is not shown
below, the default value was used.

MSPLIT = 1 (puff splitting)

MCHEM = 0 (no chemical transformations)

MWET = 0 (no wet removal)

MDRY = 0 (no dry removal)

MDISP = 2 (similarity theory)

MPDF = 1 (pdf for convective dispersion)

MREG = 0 (do not test for conformity to regulatory options)

PMAP = LCC (Lambert-Conformal Conic map projection)

IBCOMP = 1 (x index of lower left grid cell for computational grid)

JBCOMP = 1 (y index of lower left grid cell for computational grid)

IECOMP = 80 (x index of upper right grid cell for computational grid)

JECOMP = 80 (y index of upper right grid cell for computational grid)

IBSAMP = 3 (x index of lower left grid cell for the sampling grid)

JBSAMP = 3 (y index of lower left grid cell for the sampling grid)

IESAMP = 78 (x index of upper right grid cell for the sampling grid)

JESAMP = 78 (y index of upper right grid cell for the sampling grid)

With the settings for IBCOMP, JBCOMP, IECOMP, and JECOMP shown above,
the computational grid was the same as the meteorological grid.

2.  **Scenario 2 - Large-Scale, Lambert-Conformal, without
    Observations**

This scenario is identical to Scenario 1 except that the standard NWS
observations were not used. In other words, the modeling is performed
only with the MM5 data. Elimination of these data impose the use of the
following options for CALMET:

NOOBS = 2 (use model output for surface, overwater, and upper air data)

IPROG = 13 (use MM5.DAT file as observations)

3.  **Scenario 3 - Medium-Scale, UTM, with NWS Observations and MM5
    Data**

This scenario uses a subset of the domain in Scenarios 1 and 2 and only
one core source group (the Salem group). This domain extends 100 km in
all directions (i.e., 200 km on all sides). The UTM map projection is
used rather than the Lambert Conformal projection, and MM5 data are used
to initialize the wind field. Additionally, a tall, buoyant point source
was included in this scenario located near the Pacific coast.

[Source location(s)]{.underline}: One set of the common sources was
used, located near Salem, Oregon at 498.7 Easting and 4973.5 Northing in
UTM zone 10 at an elevation of 58 meters. A 99-meter point source
located at sea level near Tillamook, Oregon (a coastal source) was
included in this scenario.

Salem source coordinates: Lat = 44.9149N; Long = 123.0165W

LCCX = -316.603km; LCCY = 53.827km

UTMX = 498.7km E; UTMY = 4,973.5km N

Tillamook source coordinates: UTMX = 432.050km E; UTMY = 5,035.15km N

[Meteorological Grid]{.underline}: 4 kilometer grid spacing, resulting
in 50 x 50 grid cells.

[Vertical layers]{.underline}: Eight layers, with the cell faces at 0,
20, 50, 100, 250, 500, 1000, 2000, and 3300 meters.

[Meteorology]{.underline}: All available National Weather Service upper
air and surface observation data within the domain and the nearest
stations outside the domain on all sides were used. For this scenario,
there are 5 upper air stations and 11 surface stations. In addition to
the standard observations, MM5 data were included in this scenario to
initialize the wind field.

[Time Period]{.underline}: 28 days (672 hours).

[Receptors]{.underline}: The sampling grid covered the entire
meteorological grid except the two outermost grid cells on all
meteorological grid borders, resulting in a receptor grid size of 46 x
46, for a total of 2,116 receptors.

The CALMET options for Scenario 3 were the same as for Scenario 1,
except for the following:

PMAP = UTM (map projection)

IPROG = 14 (use MM5 input to initialize wind field)

RMAX3 = 20 km (maximum radius of influence over water)

TERRAD = 50 km (radius of influence of terrain features).

The CALPUFF modeling options for Scenario 3 were the same as for
Scenario 1, except for the following:

PMAP = UTM (map projection)

MREG = 0 (do not test for conformity to regulatory options)

IECOMP = 50 (x index of upper right grid cell for computational grid)

JECOMP = 50 (y index of upper right grid cell for computational grid)

IESAMP = 48 (x index of upper right grid cell for the sampling grid)

JESAMP = 48 (y index of upper right grid cell for the sampling grid)

4.  **Scenario 4 - Medium-Scale, Complex Flow**

The medium-scale, complex terrain scenario was designed to represent a
typical PSD application for a Class I area. The site selected was the
Shenandoah National Park in western Virginia. The meteorological domain
extends approximately 200 km on all sides. The domain also includes the
Otter Creek and Dolly Sods Wilderness Areas, which are Class I areas.

[Source location(s)]{.underline}: The core set of sources common to all
scenarios were located approximately 25 km NE of Lynchburg, VA,
approximately 50 kilometers south of the southernmost tip of Shenandoah
National Park. An additional source, a buoyant area source, was included
to simulate a source such as a forest fire (data defining the source
parameters are in the file BAEMARB.DAT).

Core source coordinates: UTMX = 695.0 km E; UTMY = 4,166.0 km N

Buoyant area source coordinates: UTMX = 651.22 km E; UTMY = 4,235.65 km
N

[Meteorological Grid]{.underline}: A grid spacing of 2 km was used for
the meteorological domain, resulting in 100 x 100 grid cells. The
southwest corner of the domain was located at 568.72 km Easting and
4,116.15 km Northing in Zone 17, which is about 130 km west-southwest of
the source location.

[Vertical layers]{.underline}: Ten layers, with the cell faces at 0, 20,
50, 100, 250, 500, 750, 1000, 1500, 2000, and 3000 meters.

[Meteorology]{.underline}: All available National Weather Service upper
air and surface observation data within the domain and the nearest
stations outside the domain on all sides were used. For this scenario,
there are 3 upper air stations and 15 surface stations. In addition to
the standard observations, MM5 data were included in this scenario {if
available}.

[Time Period]{.underline}: One month (720 hours).

[Receptors]{.underline}: A total of 585 discrete receptors were placed
at 2-km spacing along the Class I area boundaries and within the Class I
areas. Additionally, a 60‑km by 70‑km sampling grid with 2‑km spacing
(nesting factor of 1) was positioned between the Shenandoah National
Park and the Dolly Sods Wilderness Area (West Virginia), in the valley
between these two areas. This resulted in a total of 1,635 receptors for
this scenario.

[Modeling options -- CALMET]{.underline}: If an option is not shown
below, the default value was used.

PMAP = UTM (Universal Transverse Mercator)

XORIGKM= 568.72 (Easting coordinate of southwest corner of domain, Zone
17)

YORIGKM= 4116.15 (Northing coordinate of southwest corner of domain,
Zone 17)

IPROG = 0 (do not use prognostic wind filed model output)

RMIN2 = 4 (extrapolate all surface stations)

RMAX1 = 50 km (maximum radius of influence over land in surface layer)

RMAX2 = 50 km (maximum radius of influence over land aloft)

RMAX3 = 500 km (maximum radius of influence over water)

TERRAD = 10 km (radius of influence of terrain features)

R1 = 5 km (relative weighting of 1st guess field & obs. in surface
layer)

R2 = 10 km (relative weighting of 1st guess field & obs. in the layers
aloft)

TRADKM = 50 (radius of influence for temperature interpolation)

[Modeling options -- CALPUFF]{.underline}: If an option is not shown
below, the default value was used.

MCHEM = 0 (no chemical transformations)

MWET = 0 (no wet removal)

MDRY = 0 (no dry removal)

MDISP = 2 (similarity theory)

MPDF = 1 (pdf for convective dispersion)

PMAP = UTM (Universal Transverse Mercator)

MREG = 0 (do not test for conformity to regulatory options)

NAR2 = 1 (number of buoyant polygon area sources)

IBCOMP = 1 (x index of lower left grid cell for computational grid)

JBCOMP = 1 (y index of lower left grid cell for computational grid)

IECOMP = 100 (x index of upper right grid cell for computational grid)

JECOMP = 100 (y index of upper right grid cell for computational grid)

LSAMPL = True (use a sampling grid)

IBSAMP = 42 (x index of lower left grid cell for the sampling grid)

JBSAMP = 65 (y index of lower left grid cell for the sampling grid)

IESAMP = 71 (x index of upper right grid cell for the sampling grid)

JESAMP = 99 (y index of upper right grid cell for the sampling grid)

With the settings for IBCOMP, JBCOMP, IECOMP, and JECOMP shown above,
the computational grid was the same as the meteorological grid.

5.  **Scenario 5 - Small-Scale, Complex Valley Flow**

This small-scale complex wind scenario is located in the Columbia River
Gorge near Wenatchee, Washington. The river valley is over 500 meters
deep in this region, and about 5 km wide, resulting in complex
upslope/downslope and valley channeling flows. The origin of the
meteorological domain is 699.00 km Easting, 5236.75 km Northing, in UTM
zone 10 with 27 km east-west and 21 km north-south extents.

[Source Location(s)]{.underline}: One set of core sources common to all
scenarios was located at the center of the meteorological grid on
Jumpoff Ridge near the top edge of the bluff overlooking Malaga and the
airport. A second set of the core sources was placed in the river valley
on the southwest side of the river (same side as the sources on Jumpoff
Ridge) near the Rock Island Dam (in the bend of the river where the
orientation changes from east-west to north-south). The sources on
Jumpoff Ridge are located at 712.6 E, 5247.0 N in UTM Zone 10 at an
elevation of 850 meters. The sources nearer the river are located at
719.4 N, 5246.0 E at an elevation of 235 meters.

[Meteorological Grid]{.underline}: A grid spacing of 250 meters was used
for the meteorological domain, resulting in 108 x 84 grid cells. This
grid resolution allows for the depiction of diurnal slope and valley
flows.

[Vertical layers]{.underline}: Nine layers, with the cell faces at 0,
20, 80, 160, 300, 600, 1000, 1500, 2200, and 3000 meters.

[Meteorology]{.underline}: One upper air station at Spokane, WA (WBAN
No. 24157) and one surface station at Wenatchee (WBAN No. 94239) were
used for this scenario.

[Time Period]{.underline}: One month (720 hours).

[Receptors]{.underline}: To create the sampling grid, the size of the
grid was reduced by 10 km on the west and 5 km on the north and south
sides relative to the meteorological grid. The eastern boundary of the
sampling grid was aligned with the eastern edge of the meteorological
grid. This resulted in a 17‑km (east-west) by 11‑km (north-south)
sampling grid for a total of 2,992 receptors based on the 250‑meter
receptor spacing.

[Modeling options -- CALMET]{.underline}: If an option is not shown
below, the default value was used.

PMAP = UTM (Universal Transverse Mercator)

XORIGKM= 699.0 (Easting coordinate of southwest corner of domain, Zone
10)

YORIGKM= 5236.75 (Northing coordinate of southwest corner of domain,
Zone 10)

BIAS = -1, -1, -1, -1, 0.5, 0.8, 1, 1, 1

(layer-dependent biases in the weighting of met. stations)

RMIN2 = -1.0 (extrapolate all surface stations)

RMAX1 = 10 km (maximum radius of influence over land in surface layer)

RMAX2 = 10 km (maximum radius of influence over land aloft)

RMAX3 = 10 km (maximum radius of influence over water)

TERRAD = 15 km (radius of influence of terrain features)

R1 = 5 km (relative weighting of 1st guess field & obs. in surface
layer)

R2 = 5 km (relative weighting of 1st guess field & obs. in the layers
aloft)

TRADKM = 5 km (radius of influence for temperature interpolation)

[Modeling options -- CALPUFF]{.underline}: If an option is not shown
below, the default value was used.

MCTADJ = 2 (simple, CALPUFF-type of terrain adjustment)

MSLUG = 1 (near-field puffs modeled as elongated 'slugs')

MSHEAR = 1 (vertical wind shear modeled above stack top in plume rise)

MCHEM = 0 (no chemical transformations)

MWET = 0 (no wet removal)

MDRY = 0 (no dry removal)

MDISP = 2 (similarity theory)

MPDF = 1 (pdf for convective dispersion)

MREG = 0 (do not test for conformity to regulatory options)

PMAP = UTM (Universal Transverse Mercator)

IBCOMP = 1 (x index of lower left grid cell for computational grid)

JBCOMP = 1 (y index of lower left grid cell for computational grid)

IECOMP = 108 (x index of upper right grid cell for computational grid)

JECOMP = 84 (y index of upper right grid cell for computational grid)

LSAMPL = True (use a sampling grid)

IBSAMP = 41 (x index of lower left grid cell for the sampling grid)

JBSAMP = 21 (y index of lower left grid cell for the sampling grid)

IESAMP = 108 (x index of upper right grid cell for the sampling grid)

JESAMP = 64 (y index of upper right grid cell for the sampling grid)

With the settings for IBCOMP, JBCOMP, IECOMP, and JECOMP shown above,
the computational grid was the same as the meteorological grid.

6.  **Scenario 6 - Small-Scale, Idealized Hill, Steady State Meteorology
    Using Similarity Theory**

This scenario evaluates the effects of simulated steady-state
meteorology over an idealized hill. The sources for this scenario
include the core group of sources, and three PRIME downwash sources.

In this idealized scenario, a GEO.DAT file was created to reflect
uniform land use representative of open rangeland. Additionally, an
idealized bi‑gaussian, elongated hill was defined. The long-axis of the
hill extends 5000 m east‑west and the cross-axis extends 2500 m
north‑south. The top of the hill was located at the center of the
meteorological domain at a height of 300 m.

In addition to the core sources, three downwash sources were defined: a
35-meter capped point source, a 35-meter uncapped point source, and a
50-meter uncapped point source.

[Source Location]{.underline}: All sources were located on the western
boundary of the meteorological domain, "upwind" of the hill center and
on the long-axis of the hill.

[Meteorological Grid]{.underline}: A 10 km by 10 km grid cell network
with 250‑m node spacing with a nesting factor of 1, resulting in 40 by
40 cells.

[Vertical Layers]{.underline}: Eleven layers, with the cell faces at 0,
20, 50, 100, 200, 400, 700, 1000, 1500, 2000, 2500, and 3000 meters.

[Meteorology]{.underline}: A standardized set of meteorological
conditions were generated to simulate steady-state conditions and allow
the plume material to traverse the domain. The date of the meteorology
was assumed to be March 15, near the vernal equinox when the lengths of
day and night are nearly equal. The hourly surface meteorology covered
three distinct conditions shown below; nighttime stable conditions,
near-neutral conditions, and daytime convective conditions.

> Hours 1-6 (stable): clear skies, low temperature, wind = 2 m/s
> westerly, relative humidity (RH) = 80%, station pressure (p) = 1000
> mb, no precipitation.
>
> Hours 7-12 (near-neutral): overcast (10/10 cloud cover), medium
> temperature, wind = 10 m/s westerly, RH = 90%, p = 1000 mb, no
> precipitation.
>
> Hours 13-18 (convective): clear skies, high temperature, wind = 2 m/s
> westerly, RH = 30%, p = 1000 mb, no precipitation.

The upper air data were generated with uniform winds matching the
surface winds in a standardized atmosphere.

The meteorological station was collocated with the sources on the
western boundary of the meteorological grid. CALMET and CALPUFF were run
three separate times corresponding to the three different sets of
meteorological conditions.

[Time Period]{.underline}: 18 hours, as noted in the definition of the
meteorology.

[Receptors]{.underline}: A sampling grid covered the entire
meteorological grid, resulting in 1,600 receptors (40 grid cells in each
direction).

[CALMET Options]{.underline}: If an option is not shown below, the
default value was used.

RMIN2 = -1.0 (extrapolate all surface stations)

RMAX1 = 10 km (maximum radius of influence over land in surface layer)

RMAX2 = 10 km (maximum radius of influence over land aloft)

RMAX3 = 10 km (maximum radius of influence over water)

TERRAD = 10 km (radius of influence of terrain features)

R1 = 5 km (relative weighting of 1st guess field & obs. in surface
layer)

R2 = 5 km (relative weighting of 1st guess field & obs. in the layers
aloft)

[CALPUFF Options]{.underline}: If an option is not shown below, the
default value was used.

MCTADJ = 2 (simple, CALPUFF-type terrain adjustment)

MSLUG = 1 (near-field puffs modeled as elongated 'slugs')

MCHEM = 0 (no chemical transformations)

MWET = 0 (no wet removal)

MDRY = 0 (no dry removal)

MDISP = 2 (dispersion coefficients based on similarity theory)

MPDF = 1 (pdf for convective dispersion)

MREG = 0 (do not test for conformity to regulatory options)

7.  **Scenario 7 - Small-Scale, Idealized Hill, Steady State Meteorology
    Using PG Stability**

This scenario is identical to Scenario 6, with the additional downwash
sources, except that the PG dispersion coefficients were used instead of
similarity theory. Compared to Scenario 6, the CALPUFF model options
were changed to the following default options:

MCTADJ = 3 (default, partial plume path adjustments)

MDISP = 3 (default, PG dispersion coefficients)

MPDF = 0 (default, no pdf for convective dispersion)

MREG = 0 (default, check for conformity with regulatory options)

8.  **Scenario 8 - Small-Scale, Flat Terrain, Steady State Meteorology
    Using Similarity Theory**

This scenario evaluates the effects of steady-state meteorology over a
small, flat domain. The dispersion coefficients in this scenario were
calculated by the model internally using the similarity theory. The
modeled sources included the core group of four sources.

[Source Location]{.underline}: The sources were located on the western
boundary of the meteorological domain, "upwind" of the center of the
domain.

[Meteorological Grid]{.underline}: A 10 km by 10 km grid cell network
with 250 m node spacing, resulting in 40 by 40 cells.

[Vertical Layers]{.underline}: Eleven layers, with the cell faces at 0,
20, 50, 100, 200, 400, 700, 1000, 1500, 2000, 2500, and 3000 meters..

[Meteorology]{.underline}: Same meteorology as used in Scenario 6, i.e.,
steady-state westerly winds with three distinct meteorological
conditions; nighttime stable conditions, near-neutral conditions, and
daytime convective conditions. The meteorological station was collocated
with the sources on the western boundary of the meteorological grid.
CALMET and CALPUFF were run three separate times corresponding to the
three sets of meteorological conditions.

[Time Period]{.underline}: 18 hours of steady state meteorology as noted
in Scenario 6.

[Receptors]{.underline}: A sampling grid was used that covers the entire
meteorological grid, with a nesting factor of 1. Using a receptor
spacing of 250 m resulted in a grid of size 40 x 40, or 1,600 receptors.

[CALMET Options]{.underline}: If an option is not shown below, the
default value was used.

RMAX1 = 10 km (maximum radius of influence over land in surface layer)

RMAX2 = 10 km (maximum radius of influence over land aloft)

RMAX3 = 10 km (maximum radius of influence over water)

TERRAD = 10 km (radius of influence of terrain features)

R1 = 5 km (relative weighting of 1st guess field & obs. in surface
layer)

R2 = 5 km (relative weighting of 1st guess field & obs. in the layers
aloft)

[CALPUFF Options]{.underline}: If an option is not shown below, the
default was used.

MCTADJ = 0 (no terrain adjustment - this is a flat-terrain scenario)

MSLUG = 1 (near-field puffs modeled as elongated 'slugs')

MCHEM = 0 (no chemical transformations)

MWET = 0 (no wet removal)

MDRY = 0 (no dry removal)

MDISP = 2 (similarity theory)

MPDF = 1 (pdf for convective dispersion)

MREG = 0 (do not test for conformity to regulatory options)

9.  **Scenario 9 - Small-Scale, Flat Terrain, Steady State Meteorology
    Using PG Stability**

This scenario is identical to Scenario 8 except that the PG dispersion
coefficients were used instead of similarity theory. Compared to
Scenario 8, the CALPUFF model options were changed to the following
default options:

MDISP = 3 (default, PG dispersion coefficients)

MPDF = 0 (default, no pdf for convective dispersion)

MREG = 0 (default, check for conformity with regulatory options)

10. **Scenario 10 - Small-Scale, Idealized Hill, Steady State
    Meteorology Using Similarity Theory with Simulated Wind Shear**

This scenario uses the idealized hill described in Scenario 6. The
modeled sources only included the core group of sources. The modeled
meteorological conditions included simulated wind-direction and
wind-speed shear to allow examination of puff splitting in the
near-field.

[Source Location]{.underline}: The sources were located on the western
boundary of the meteorological domain, "upwind" of the hill center and
on the long-axis of the hill.

[Meteorological Grid]{.underline}: A 10 km by 10 km grid cell network
with 250‑m node spacing, resulting in 40 by 40 cells.

[Vertical Layers]{.underline}: Twelve layers, with the cell faces at 0,
20, 40, 60, 80, 100, 150, 200, 300, 500, 1000, 1500, and 2000 meters.

[Meteorology]{.underline}: Neither NWS nor MM5 data were used in this
scenario. To simulate vertical wind direction and wind speed shear, the
meteorological conditions were defined by CTDMPLUS-type PROFILE.DAT and
SURFACE.DAT files. The date of the meteorology was assumed to be March
15, near the vernal equinox when the lengths of day and night are nearly
equal. The hourly surface meteorology covered two distinct conditions
shown below; light-wind stable and high-wind neutral conditions.

> Hours 1-6 (stable): clear skies, low temperature, wind = 2 m/s
> westerly, relative humidity (RH) = 80%, station pressure (p) = 1000
> mb, no precipitation.
>
> Hours 7-12 (neutral): overcast (10/10 cloud cover), medium
> temperature, wind = 2 m/s westerly, RH = 90%, p = 1000 mb, no
> precipitation

The meteorological data were constructed to simulate wind-direction and
wind-speed vertical shear. The CTDMPLUS-style PROFILE file consisted of
eight levels -- 10, 30, 50 70, 90, 125, 175, and 250 meters For the
stable hours, the wind-speed shear was achieved by applying a power law
profile using an exponent of 0.55, corresponding to F stability, through
all vertical layers. For the neutral hours, the wind speed was varied
linearly from 2 m/s at the lowest level to 20 m/s at 200 meters in the
in the PROFILE file. For the wind-direction shear, the direction was
varied from due westerly (270 degrees) at 10 meters to south-southwest
(210 degrees) at the top level in the PROFILE file for both the stable
and neutral hours.

The meteorological station was collocated with the sources on the
western boundary of the meteorological grid. CALMET and CALPUFF were run
two times corresponding to the two sets of meteorological conditions.

[Time Period]{.underline}: 12 hours, as noted in the definition of the
meteorology.

[Receptors]{.underline}: Discrete receptors, with terrain elevations,
were placed at the center of each cell of the meteorological grid,
resulting in a total of 1,600 discrete receptors.

CALMET Options: CALMET was not run for this scenario. The meteorology
was defined by CTDMPLUS-style PROFILE and SURFACE files.

[CALPUFF Options]{.underline}: If an option is not shown below, the
default value was used.

METFM = 4 (CTDMPLUS tower and surface parameter files)

MSLUG = 1 (near-field puffs modeled as elongated 'slugs')

MSHEAR = 1 (vertical wind shear option)

MSPLIT = 1 (puff splitting)

MCTADJ = 3 (simple, CALPUFF-type of terrain adjustment)

MCHEM = 0 (no chemical transformations)

MWET = 0 (no wet removal)

MDRY = 0 (no dry removal)

MDISP = 2 (similarity theory)

MPDF = 1 (pdf for convective dispersion)

MREG = 0 (do not test for conformity to regulatory options)

11. **Scenario 11 - Medium-Scale, UTM, with NWS Observations and MM5
    Data, Chemistry and Deposition**

    This scenario is identical to Scenario 3 but also includes chemistry
    and deposition.

[Source location(s)]{.underline}: One set of the common sources was
used, located near Salem, Oregon at 498.7 Easting and 4973.5 Northing in
UTM zone 10 at an elevation of 58 meters. A 99-meter point source
located at sea level near Tillamook, Oregon (a coastal source) was
included in this scenario.

Salem source coordinates: Lat = 44.9149N; Long = 123.0165W

LCCX = -316.603km; LCCY = 53.827km

UTMX = 498.7km E; UTMY = 4,973.5km N

Tillamook source coordinates: UTMX = 432.050km E; UTMY = 5,035.15km N

[Meteorological Grid]{.underline}: 4 kilometer grid spacing, resulting
in 50 x 50 grid cells.

[Vertical layers]{.underline}: Eight layers, with the cell faces at 0,
20, 50, 100, 250, 500, 1000, 2000, and 3300 meters.

[Meteorology]{.underline}: All available National Weather Service upper
air and surface observation data within the domain and the nearest
stations outside the domain on all sides were used. For this scenario,
there are 5 upper air stations and 11 surface stations. In addition to
the standard observations, MM5 data were included in this scenario to
initialize the wind field.

[Time Period]{.underline}: 28 days (672 hours).

[Receptors]{.underline}: The sampling grid covered the entire
meteorological grid except the two outermost grid cells on all
meteorological grid borders, resulting in a receptor grid size of 46 x
46, for a total of 2,116 receptors.

The CALMET options for Scenario 11 were the same as for Scenario 3,
including the following:

PMAP = UTM (map projection)

IPROG = 14 (use MM5 input to initialize wind field)

RMAX3 = 20 km (maximum radius of influence over water)

TERRAD = 50 km (radius of influence of terrain features).

The CALPUFF modeling options for Scenario 11 were the same as for
Scenario 3, including the following:

PMAP = UTM (map projection)

MCHEM = 1 (transformation rates computed internally (MESOPUFF II))

MWET = 1 (wet removal modeled)

MDRY = 1 (dry deposition modeled)

MDISP = 2 (similarity theory)

MREG = 0 (do not test for conformity to regulatory options)

IECOMP = 50 (x index of upper right grid cell for computational grid)

JECOMP = 50 (y index of upper right grid cell for computational grid)

IESAMP = 48 (x index of upper right grid cell for the sampling grid)

JESAMP = 48 (y index of upper right grid cell for the sampling grid)

Chemistry Parameters: The MESOPUFF II chemical transformation option
(MCHEM = 1) is designed to simulate the conversion of SO2 −\> SO4 and
NOX −\> HNO3 \<−\> NO3.

Species Modeled: SO~2~, SO~4~, NO, HNO~3~, NO~3~

Species Emitted: SO~2~, SO~4~, NO~X~

> All parameters related to chemistry and deposition of these species
> are from the CALPUFF User's Guide (Table 4-3).

**Table 2-1. Source Characteristics for CALPUFF Test Datasets -- Core
Sources**

  ----------------- ----------------- ----------------- -----------------
  **Point                                               
  Sources:**                                            

  **Stack Height    **Exit Velocity   **Exit            **Stack Diameter
  (m)**             (m/s)**           Temperature (K)** (m)**

  30                0                 Ambient (293 K)   2.0

  65                20.0              450               3.0

  **Volume                                              
  Source:**                                             

  **Release Height  **Initial Sigma-y **Initial Sigma-z 
  (m)**             (m)**             (m)**             

  10                7                 5                 

  **Area Source:**                                      

  **Release Height  **Length of Side  **Length of Side  **Initial Sigma-z
  (m)**             (m)**             (m)**             (m)**

  0                 20                200               2
  ----------------- ----------------- ----------------- -----------------

**Table 2-2. Source Characteristics for CALPUFF Test Datasets --
Additional Sources**

  ----------------- ----------------- ----------------- -----------------
  **Point Sources                                       
  with Downwash                                         
  (Scenarios 6 and                                      
  7):**                                                 

  **Stack Height    **Exit Velocity   **Exit            **Stack Diameter
  (m)**             (m/s)**           Temperature (K)** (m)**

  35 (FMFAC = 0.0)  10.0              350               2.4

  35 (FMFAC = 1.0)  11.7              432               2.4

  50                18.8              416               4.6

  **Building                                            
  Dimensions for                                        
  Point Sources                                         
  (Scenarios 6 and                                      
  7):**                                                 

  **Building Height **Building Width  **Building Length 
  (m)**             (m)**             (m)**             

  34                60                120               

  **Tall Buoyant                                        
  Point Source                                          
  (Scenarios 3 and                                      
  11):**                                                

  **Stack Height    **Exit Velocity   **Exit            **Stack Diameter
  (m)**             (m/s)**           Temperature (K)** (m)**

  99                25.0              450               5.0

  **Buoyant Area                                        
  Source (Scenario                                      
  4):**                                                 

  **Effective       **Effective       **Temperature     **Effective
  Height (m)**      Velocity (m/s)**  (K)**             Radius (m)**

  1                 1                 600               500
  ----------------- ----------------- ----------------- -----------------

3.  **RUNNING THE SCENARIOS**

    **3.1 FOLDER STRUCTURE**

The scenarios are stored in a folder hierarchy as shown in Figure 3.1.
The top level folder is *CPufTest* with five subfolders immediately
below it:

-   *Code --* folders with the data analysis program (*Analysis*
    folder), the base model extra large executables of the CALPUFF
    modeling system (*Base* folder), and the beta model extra large
    executables (*Beta* folder).

-   *MM5Data* -- MM5 data for scenarios 2, 3, and 11; the data are in
    two files, apr02a.mm5 with data for April 1 - 14 and apr02b.mm5 with
    data for April 15 -- 28. The reason for splitting the data into two
    files is the file size limitation of FAT32 file systems (4 GB).
    FAT32 is used to facilitate transfer of files between Windows and
    Linux operating systems.

-   *Primary --* files for all the scenarios of the Primary analysis of
    base and beta model runs for CALMET, CALPUFF, and CALPOST.

-   *Secondary -* files for all the scenarios for the Secondary analysis
    using the base model with beta meteorology, to determine whether
    differences found in the Primary analysis are attributable to
    changes in CALMET, CALPUFF or both.

Within the *Primary* subfolder, there are eleven subfolders, one for
each scenario. Each of these scenario folders contains the folders:

-   *Analysis* -- input control files and the output files from the
    analysis tool as well as batch files to run the analysis tool in
    batch mode.

-   *Base* -- folders and files to run CALMET, CALPUFF, and CALPOST base
    model scenario; the input control files for each processor and the
    model, batch files, and output files are included.

-   *Beta -* folders and files to run CALMET, CALPUFF, and CALPOST beta
    model scenario; the input control files for each processor and the
    model, batch files, and output files are included.

Within the *Secondary* subfolder, there are eleven subfolders, one for
each scenario. Each of these scenario folders contains the folders:

-   *Analysis* - input control files and the output files from the
    analysis tool as well as batch files to run the analysis tool in
    batch mode.

-   *Base_Beta -* folders and files to run the CALPUFF base model with
    the beta CALMET data and process the results with CALPOST.

    2.  **NAMING CONVENTION**

        1.  [Input Control Files]{.underline}

The CALPUFF input control files have a unique naming convention that
associates the file name with a scenario and a source type. The file
names use the following convention for Scenarios 1-5 and 11:
PUF*nnsssx*.INP, where PUF refers to the dispersion model (CALPUFF),
*nn* refers to the scenario (01, 02, ..., 11), *sss* refers to the
source, and *x* identifies the source group (1 or 2) if more than one
group is modeled in the scenario. The group identifier does not appear
if only one set of sources is modeled. The .INP extension identifes the
file as an input control file.

The source identifiers (*sss* in the naming convention) are named as
follows:

-   P30 -- 30-meter point source (a core source)

-   P65 -- 65-meter point source (a core source)

-   P99 -- 99-meter point source (a special source for Scenarios 3 and
    11)

-   ARE -- Area source

-   VOL -- Volume source

Scenarios 6-10 use two slightly different conventions: PUF*nnnsss*.INP.
PUF and *sss* are the same as before, but the *nnn* has an extended
meaning. For these scenarios, the first two digits continue to represent
the scenario and the last digit represents the time period within a day.
Scenarios 6-9 modeled three 6-hour periods for a single day, with the
first 6 hours (0-5) representing stable conditions and *n=1*, the second
6 hours (6-11) representing neutral conditions and *n*=2, and the third
group of 6 hours representing convective conditions (12-17) and n=3.
Scenario 10 only modeled two 6-hour periods for a single day, with the
first 6 hours (0-5) representing stable conditions, and the second 6
hours (6-11) representing neutral conditions. For example PUF061P30.INP
is the CALPUFF input control file for the 30-meter source for stable
conditions in scenario 6.

Scenarios 6 and 7 also have a third type of naming convention:
PUF*nnnDd*.INP where *D* indicates a downwash source. These are the only
scenarios to include a building in the modeling. The lower case *d* can
be 1, 2, or 3 representing the downwash sources: a 35-meter capped point
source, 35-meter uncapped point source, and a 50-meter uncapped source,
respectively. For example, PUF061D1.INP is the 35-meter capped downwash
point source for stable conditions in Scenario 6.

For each CALPUFF input control file there is a corresponding CALPOST
input control file used to post-process the results for each scenario
and source type. The naming convention for the CALPOST control files is
identical to the naming convention for the CALPUFF control files, except
that the leading characters 'PUF' are replaced with 'PST'.

1.  [Analysis Files]{.underline}

The naming convention for the output files from the analysis tool is
identical to the input control file name except that the "PUF" is
omitted and the file extension is ".out". These are the names of the
files that appear in the Analysis folders for each scenario and the
names that appear in the summary file for each scenario.

2.  **RUNNING THE SCENARIOS AND ANALYSES**

There are batch files at different levels within the folder hierarchy
that run all or portions of the test datasets and the analysis. This
structure provides flexibility in running all or parts of the models and
analyses. All batch files use relative referencing for identifying the
input and output file locations to permit flexibility in the drive and
folder location used for installing the test dataset.

Batch files in the *Primary* and *Secondary* folders (see Figure 3.1)
run all the scenarios for the Primary and Secondary analyses. These two
'master' batch files take one or more command line arguments. By
including the word "ALL" or "all" (omitting the quotation marks), the
CALPUFF modeling system is run for all the scenarios. Selected scenarios
are run by including scenario numbers on the command line (with spaces
between scenarios). For example, to run scenarios 6, 7, 8, 9, and 10 for
the primary analyses one would type at a command prompt: RUNPRIMARY 06
07 08 09 10. Notice that for scenarios 1-9, the leading zero is
required. Otherwise, the batch files will not be able to traverse the
hierarchy properly. The RUNPRIMARY.BAT and RUNSECONDARY.BAT batch files
run all components of the CALPUFF modeling system (CALMET, CALPUFF and
CALPOST) and the analysis programs (Analysis.exe and Summary.exe,
described below).

Within each scenario, there is a batch file to run both the base model
and the beta model for that one scenario, and within the *Base* and
*Beta* folders there are batch files that run CALMET, CALPUFF, and
CALPOST. To run any one of the batch files, simply type the batch file
name at the command prompt. These batch files in the subfolders do not
require any command line arguments.

There are two programs that were developed to compare the results from
the Base and Beta modeling systems: Analysis.exe and Summary.exe. The
first program analyzes the results from the CALPOST output files from
the Base and Beta versions of the model. The second program summarizes
the results of the analyses generated by the first program. These two
programs (source code and executable) are in the *Code\\Analysis* folder

Separate batch files are available for running only the analysis tool
based on existing model output files. Batch files are included in the
*Primary* and *Secondary* folders (called RUNANALYSIS.BAT) to run the
analysis tool (both Analysis.exe and Summary.exe) for all or a subset of
the scenarios. These two 'master' batch files take one or more command
line arguments. By including the word "ALL" or "all" (omitting the
quotation marks), the tool runs for all the scenarios. Selected analyses
are run by including scenario numbers on the command line (remember to
include the leading zero in the scenario number). The analysis program
prompts the user for a number of inputs. The responses to these inputs
are in files with the extension .IN. Redirection is used in the batch
files that run the analysis program to respond to the prompts. There are
also batch files (called RUNANALYSIS.BAT and RUNSUMMARY.BAT) located in
the *Analysis* folder for each scenario to run the programs for
individual scenarios.

The summary program will identify whether differences are found between
the base and beta modeling systems for each source, and if differences
are found and the Secondary analysis is performed, the summary program
ascribes those differences to changes in CALMET, CALPUFF, or both. In
addition, the highest values by averaging period and rank are compared
as well as design values and the percent difference between the Base and
Beta models. As an example of this file, see the file Scen01.sum in the
folder \\CPufTest\\Primary\\Scen01\\Analysis. The general structure of
this summary file for the Primary modeling is:

-   Differences found (YES/NO) between Base and Beta models for each
    source

-   For each source

    -   Files being compared/analyzed

    -   Title records from base and beta model runs

    -   Label if differences were found for the source

    -   Overall minimum and maximum differences

    -   Comparison of design values by averaging period and rank (base
        and beta concentration and the percent difference).

A more detailed explanation of the comparisons is presented in the next
section.

The summary for the Secondary modeling has an expanded structure. In the
secondary analyses, the results are presented in pairs as follow:

-   Differences found (YES/NO) for each source in the analysis between
    the base model using beta meteorology and the base model with base
    meteorology (identified as the "a" output) followed by differences
    between the base model using beta meteorology and the beta model
    with beta meteorology (identified as the "b" output). If differences
    are found, then the summary program will identify (on the same line
    as the "b" output) whether the differences can be attributable to
    changes in CALMET, CALPUFF or both.

-   For each source, two summaries showing

    -   Files being compared/analyzed

    -   Title records from base and beta model runs

    -   Label if differences were found for the source

    -   Overall minimum and maximum differences

    -   Comparison of design values by averaging period and rank (1^st^
        and 2^nd^ model concentration and the percent difference).

In addition to the Analysis program developed for use with the CALPUFF
test dataset, there is a single batch file named RUNFC.BAT in the
*Primary* folder that performs a simple DOS file comparison between each
source model output (from base CALPOST) for the base model with the same
source model output (from beta CALPOST) from the beta model, writing the
result to a text file. This comparison may be used to identify the
location of specific differences between the Base and Beta version
within the CALPOST output files.

**4.0 ANALYSES OF SCENARIOS**

Results from the Analysis Tool are summarized in a series of files
generated by the Summary.exe program. Figure 4.1 provides an example of
the type of output that is generated when differences are found. The
example documents the differences found for the 65-meter point source in
scenario 1. There are three components to the output as follows: (1)
overall results; (2) overall results normalized by the high value; and
(3) results by rank. The three components of the output are discussed in
the following..

**4.1 OVERALL RESULTS**

The overall result for a given source/scenario is the maximum percent
difference (either negative or positive) regardless of averaging time or
rank. The percent difference is calculated as:

\[(*Beta* - Base)/Base\] X 100

Two values are reported, the maximum negative percent difference
(indicated by 'MIN % DIFF' in the output) and the maximum positive
percent difference (indicated by 'MAX % DIFF' in the output). Additional
information reported for each of these cases include the averaging
period, the rank, and the receptor location associated with the
identified extreme. For the example in Figure 4.1, the maximum percent
difference is 6.43 ; this value is associated with the receptor located
at grid point (25, 38), an averaging period of 8 hours, and a rank of 8.

2.  **OVERALL RESULTS NORMALIZED BY HIGH VALUE**

For this component, the differences between *Base* and *Beta*
concentration estimates are normalized by the high value for the
corresponding averaging period and rank; again, the maximum percent
difference (either negative or positive) is identified. The normalized
percent difference is calculated as follows:

\[(*Beta* - *Base*)/High\] X 100

For the example in Figure 4.1, the maximum normalized percent difference
is 0.20 ; this value is associated with the receptor located at grid
point (25, 42), an averaging period of 3 hours, and a rank of 4.

3.  **RESULTS BY RANK**

The comparison of high values by rank is of particular importance as
these metrics are directly related to design values. In this case, the
/Q estimates are ranked and a straight percent difference between the
Base and *Beta* ranked values is calculated. For the example in Figure
4.1, the maximum absolute percent difference is -0.295 ; this value is
associated with an averaging period of 8 hours, and a rank of 4.

A summary of the results for the ranked is provided in Figures 4.2 (for
scenarios 1-5) and 4.3 (for scenarios 6-10). The largest difference in a
ranked value (-5.25 %) occurred with the volume source in scenario 4. Of
all the results, this was the only difference in a ranked value to
exceed 1 percent. The next highest difference in a ranked value (-0.295
%) occurred with the 65 meter point source in scenario 1.

[Scenario 2]{.underline}: Large-scale regime in which all cases use MM5
meteorological data only (NOOBS = 2)

Differences between the CALMET/CALPUFF Base case and the combined *Beta*
versions were seen in all 8 cases (sources) examined. In the Overall
Results, the greatest + or - percent differences involved predicted
concentrations that were either zero, of very close to zero. These
concentrations occurred relatively far from the sources - at the edge of
the simulated plumes.

The Overall Results Normalized by High Value show greatest + and -
percent differences to be typically 0.3% or less of the maximum value.
There was one case (02p651, a 65-m buoyant plume) where the value was
4.3%, and another (02p652, another 65-m buoyant plume) where the value
was 1.5% of the max.

The Ranked Values showed differences in only 2 of the 8 cases, and these
were for period (672 hours) averages. The differences were a scant 0.09%
and 0.005%, respectively.

Results of the Secondary analysis (Secondary.zip), which isolated the
differences as being attributable to the *Beta* CALMET model, were
consistent. It appears that much of the differences seen in Scenario 2
may by attributable to the use of MM5 meteorological data for driving
CALMET. It should also be noted that the differences generally occur at
a coastal location within the domain.

[Scenario 3]{.underline}: Medium-scale regime in which all cases use
both NWS and MM5 meteorological data, with MM5 data used to initialize
the wind field (IPROG = 14)

Differences between the CALMET/CALPUFF Base case and the combined *Beta*
versions were seen in one of the 5 cases (sources) examined: 03p99,
which featured a 99-m stack located near the coast. In the Overall
Results, the greatest + difference was 0.87%, while the greatest -
difference was -0.35%. These differences involved predicted
concentrations that were very close to zero, and occurred relatively far
from the source - at the edge of the simulated plume.

The Overall Results Normalized by High Value show greatest + and -
differences to be \<0.02% of the maximum values.

The Ranked Values showed only one case (3hr average for Rank 1) in which
the difference (0.0061%) was \>0.

Results of the Secondary analysis (Secondary.zip), which isolated the
differences as being attributable to the *Beta* CALMET model, were
consistent.

For the cases cited above for Scenarios 2 and 3, the Secondary analysis
showed that the observable differences were due solely to changes made
to CALMET, which is consistent with the information posted on Earth
Tech's website regarding the effects of changes made in the *Beta*
version.

**Figure 4.1 Example output from Evaluation Tool**

![](media/image1.png){width="8.625in" height="5.5in"}**Figure 4.2
Percent differences in ranked estimates for scenarios 1 - 5**

![](media/image2.png){width="7.375in" height="5.25in"}

**Figure 4.3 Percent differences in ranked estimates for scenarios 6 -
10**