0.0261
                                                                    0.012797085
                                                                           0.22
                                                                    0.003585907
PM2_5
PFE
                                                                          0.115
                                                                    0.213901692
                                                                         0.0046
                                                                     0.00024779
PM2_5
PH2O
                                                                      0.0080232

                                                                       0.007506

PM2_5
PK
                                                                       1.90E-04
                                                                    0.000687447
                                                                       3.80E-04
                                                                    4.33129E-05
PM2_5
PMG
                                                                         0.1105
                                                                    0.002961309
                                                                       3.75E-04
                                                                    0.000018131
PM2_5
PMN
                                                                       0.001065
                                                                    0.001373836
                                                                       1.00E-04
                                                                       1.41E-06
PM2_5
PMOTHR
                                                                         0.4498
                                                                    0.691704999
                                                                         0.0625
                                                                    0.100663209
PM2_5
PNA
                                                                       1.60E-04
                                                                    0.002749787
                                                                       6.10E-04
                                                                    7.35312E-05
PM2_5
PNCOM
                                                                         0.0428
                                                                    0.020115749
                                                                         0.1886
                                                                    0.255808124
PM2_5
PNH4
                                                                       3.00E-05

                                                                       1.90E-04

PM2_5
PNO3
                                                                         0.0016

                                                                         0.0015

PM2_5
POC
                                                                          0.107
                                                                    0.050289372
                                                                         0.4715
                                                                    0.639520309
PM2_5
PSI
                                                                          0.088

                                                                        0.00115

PM2_5
PSO4
                                                                         0.0334

                                                                         0.0311

PM2_5
PTI
                                                                         0.0036
                                                                    0.000933341
                                                                       3.60E-04
                                                                       5.04E-06

 The formulas used based on brake wear profile 95462 and tire wear profile 95460 are as follows:

      POC = 0.6395 * PM25TIRE + 0.0503 * PM25BRAKE
      PEC = 0.0036 * PM25TIRE + 0.0128 * PM25BRAKE
      PNO3 = 0.000 * PM25TIRE + 0.000 * PM25BRAKE
      PSO4 = 0.0 * PM25TIRE + 0.0 * PM25BRAKE
      PNH4 = 0.000 * PM25TIRE + 0.0000 * PM25BRAKE
      PNCOM = 0.2558 * PM25TIRE + 0.0201 * PM25BRAKE

For California onroad emissions, adjustment factors were applied to SMOKE-MOVES to produce California adjusted model-ready files.  California did not supply speciated PM, therefore, the adjustment factors applied to PM2.5 were also applied to the speciated PM components.  By applying the ratios through SMOKE-MOVES, the CARB inventories are essentially speciated to match EPA estimated speciation.

For nonroad PM2.5, speciation is partially done within MOVES such that it does not need to be run for a specific chemical mechanism.  For nonroad, MOVES outputs emissions of PM2.5 split by speciation profile.  Similar to how VOC and NONHAPTOG are speciated, PM2.5 is now also speciated this way starting with MOVES2014b. California nonroad emissions, which are not from MOVES, continue to be speciated the traditional way with speciation profiles assigned by SMOKE using the GSREF cross-reference.  The PM2.5 profiles assigned to nonroad sources are listed in Table 3-15.
Table 3-15.  Nonroad PM2.5 profiles
                                                       SPECIATE4.5 Profile Code
SPECIATE4.5 Profile Name
Assigned to Nonroad sources based on Fuel Type
                                                                           8996
Diesel Exhaust - Heavy-heavy duty truck - 2007 model year with NCOM
Diesel
                                                                          91106
HDDV Exhaust  -  Composite
Diesel
                                                                          91113
Nonroad Gasoline Exhaust  -  Composite
Gasoline
                                                                          91156
Residential Natural Gas Combustion
CNG and LPG (California only)
                                                                          95219
CNG Transit Bus Exhaust
CNG and LPG

 NOX speciation
NOx emission factors and therefore NOx inventories are developed on a NO2 weight basis. For air quality modeling, NOX is speciated into NO, NO2, and/or HONO.  For the non-mobile sources, the EPA used a single profile "NHONO" to split NOX into NO and NO2.

The importance of HONO chemistry, identification of its presence in ambient air and the measurements of HONO from mobile sources have prompted the inclusion of HONO in NOx speciation for mobile sources.  Based on tunnel studies, a HONO to NOx ratio of 0.008 was chosen (Sarwar, 2008).  For the mobile sources, except for onroad (including nonroad, cmv, rail, othon sectors), and for specific SCCs in othar and ptnonipm, the profile "HONO" is used.  Table 3-16 gives the split factor for these two profiles.  The onroad sector does not use the "HONO" profile to speciate NOX.  MOVES2014 produces speciated NO, NO2, and HONO by source, including emission factors for these species in the emission factor tables used by SMOKE-MOVES.  Within MOVES, the HONO fraction is a constant 0.008 of NOX.  The NO fraction varies by heavy duty versus light duty, fuel type, and model year.
The NO2 fraction = 1  -  NO  -  HONO.  For more details on the NOX fractions within MOVES, see EPA report "Use of data from `Development of Emission Rates for the MOVES Model,'
Sierra Research, March 3, 2010" available at https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P100F1A5.pdf.
Table 3-16.  NOX speciation profiles
Profile
pollutant
species
split factor
HONO
NOX
NO2
0.092
HONO
NOX
NO
0.9
HONO
NOX
HONO
0.008
NHONO
NOX
NO2
0.1
NHONO
NOX
NO
0.9

 Creation of Sulfuric Acid Vapor (SULF)
Since at least the 2002 Platform, sulfuric acid vapor (SULF) has been estimated through the SMOKE speciation process for coal combustion and residual and distillate oil fuel combustion sources.  Profiles that compute SULF from SO2 are assigned to coal and oil combustion SCCs in the GSREF ancillary file.  The profiles were derived from information from AP-42 (EPA, 1998), which identifies the fractions of sulfur emitted as sulfate and SO2 and relates the sulfate as a function of SO2.

Sulfate is computed from SO2 assuming that gaseous sulfate, which is comprised of many components, is primarily H2SO4. The equation for calculating H2SO4 is given below.

Emissions of SULF as H2SO4=SO2 emissions xfraction of S emitted as sulfatefraction of S emitted as SO2xMW H2SO4MW SO2

In the above, MW is the molecular weight of the compound.  The molecular weights of H2SO4 and SO2 are 98 g/mol and 64 g/mol, respectively.

This method does not reduce SO2 emissions; it solely adds gaseous sulfate emissions as a function of SO2 emissions.  The derivation of the profiles is provided in Table 3-17; a summary of the profiles is provided in Table 3-18.
Table 3-17.  Sulfate split factor computation
fuel
SCCs
Profile Code
Fraction as SO2
Fraction as
sulfate
Split factor (mass fraction)
Bituminous
1-0X-002-YY, where X is 1, 2 or 3 and YY is 01 thru 19 and 21-ZZ-002-000 where ZZ is 02,03 or 04
95014
0.95
0.014
.014/.95 * 98/64 = 0.0226

Subbituminous
1-0X-002-YY, where X is 1, 2 or 3 and YY is 21 thru 38
87514
.875
0.014
.014/.875 * 98/64 = 0.0245

Lignite
1-0X-003-YY, where X is 1, 2 or 3 and YY is 01 thru 18 and 21-ZZ-002-000 where ZZ is 02,03 or 04
75014
0.75
0.014
.014/.75 * 98/64 = 0.0286

Residual oil
1-0X-004-YY, where X is 1, 2 or 3 and YY is 01 thru 06 and 21-ZZ-005-000 where ZZ is 02,03 or 04
99010
0.99
0.01
.01/.99 * 98/64 = 0.0155

Distillate oil
1-0X-005-YY, where X is 1, 2 or 3 and YY is 01 thru 06 and 21-ZZ-004-000 where ZZ is 02,03 or 04
99010
0.99
0.01
Same as residual oil
Table 3-18.  SO2 speciation profiles
Profile
pollutant
species
split factor
95014
SO2
SULF
                                    0.0226
95014
SO2
SO2
                                       1
87514
SO2
SULF
                                     0.0245
87514
SO2
SO2
                                       1
75014
SO2
SULF
                                    0.0286
75014
SO2
SO2
                                       1
99010
SO2
SULF
                                    0.0155
99010
SO2
SO2
                                       1

 Temporal Allocation
Temporal allocation is the process of distributing aggregated emissions to a finer temporal resolution, thereby converting annual emissions to hourly emissions as is required by CMAQ.  While the total emissions are important, the timing of the occurrence of emissions is also essential for accurately simulating ozone, PM, and other pollutant concentrations in the atmosphere.  Many emissions inventories are annual or monthly in nature.  Temporal allocation takes these aggregated emissions and distributes the emissions to the hours of each day.  This process is typically done by applying temporal profiles to the inventories in this order: monthly, day of the week, and diurnal, with monthly and day-of-week profiles applied only if the inventory is not already at that level of detail.

The temporal factors applied to the inventory are selected using some combination of country, state, county, SCC, and pollutant.  Table 3-19 summarizes the temporal aspects of emissions modeling by comparing the key approaches used for temporal processing across the sectors.  In the table, "Daily temporal approach" refers to the temporal approach for getting daily emissions from the inventory using the SMOKE Temporal program.  The values given are the values of the SMOKE L_TYPE setting.  The "Merge processing approach" refers to the days used to represent other days in the month for the merge step.  If this is not "all," then the SMOKE merge step runs only for representative days, which could include holidays as indicated by the right-most column.  The values given are those used for the SMOKE M_TYPE setting (see below for more information).
Table 3-19.  Temporal settings used for the platform sectors in SMOKE
Platform sector short name
Inventory resolutions
Monthly profiles used?
Daily temporal approach
Merge processing approach
Process holidays as separate days
afdust_adj
Annual
Yes
week
All
Yes
afdust_ak_adj
Annual
Yes
week
All
Yes
ag
Monthly
 No
all
All
No
airports
Annual
Yes
week
week
Yes
beis
Hourly
 No
n/a
All
No
cmv_c1c2
Annual
Yes
aveday
aveday
No
cmv_c3
Annual
Yes
aveday
aveday
No
nonpt
Annual
Yes
week
week
Yes
nonroad
Monthly
 No
mwdss
mwdss
Yes
np_oilgas
Annual
Yes
aveday
aveday
No
onroad
Annual & monthly[1]
 No
all
all
Yes
onroad_ca_adj
Annual & monthly[1]
 No
all
all
Yes
onroad_nonconus
Annual & monthly[1]
 No
all
all
Yes
othafdust_adj
Annual
Yes
week
all
No
othar
Annual & monthly
Yes
week
week
No
onroad_can
Monthly
No
week
week
No
onroad_mex
Monthly
No
week
week
No
othpt
Annual & monthly
Yes
mwdss
mwdss
No
othptdust_adj
Monthly
No
week
all
No
pt_oilgas
Annual
Yes
mwdss
mwdss
Yes
ptegu
Annual & hourly
Yes[2]
all
all
No
ptnonipm
Annual
Yes
mwdss
mwdss
Yes
ptagfire
Daily
No
all
all
No
ptfire
Daily
No
all
all
No
ptfire_othna
Daily
No
all
all
No
rail
Annual
Yes
aveday
aveday
No
rwc
Annual
No[3]
met-based[3]
all
No[3]
      [1]Note the annual and monthly "inventory" actually refers to the activity data (VMT, hoteling, and VPOP) for onroad. VMT and hoteling is monthly and VPOP is annual. The actual emissions are computed on an hourly basis.
      [2]Only units that do not have matching hourly CEMS data use monthly temporal profiles.
      [3]Except for 2 SCCs that do not use met-based speciation

The following values are used in the table.  The value "all" means that hourly emissions are computed for every day of the year and that emissions potentially have day-of-year variation.  The value "week" means that hourly emissions computed for all days in one "representative" week, representing all weeks for each month.  This means emissions have day-of-week variation, but not week-to-week variation within the month.  The value "mwdss" means hourly emissions for one representative Monday, representative weekday (Tuesday through Friday), representative Saturday, and representative Sunday for each month. This means emissions have variation between Mondays, other weekdays, Saturdays and Sundays within the month, but not week-to-week variation within the month.  The value "aveday" means hourly emissions computed for one representative day of each month, meaning emissions for all days within a month are the same.  Special situations with respect to temporal allocation are described in the following subsections.

In addition to the resolution, temporal processing includes a ramp-up period for several days prior to January 1, 2016, which is intended to mitigate the effects of initial condition concentrations.  The ramp-up period was 10 days (December 22-31, 2015).  For most sectors, emissions from December 2016 (representative days) were used to fill in emissions for the end of December 2015.  For biogenic emissions, December 2015 emissions were processed using 2015 meteorology.
 Use of FF10 format for finer than annual emissions
The FF10 inventory format for SMOKE provides a consolidated format for monthly, daily, and hourly emissions inventories.  With the FF10 format, a single inventory file can contain emissions for all 12 months and the annual emissions in a single record.  This helps simplify the management of numerous inventories.  Similarly, daily and hourly FF10 inventories contain individual records with data for all days in a month and all hours in a day, respectively.

SMOKE prevents the application of temporal profiles on top of the "native" resolution of the inventory.  For example, a monthly inventory should not have annual-to-month temporal allocation applied to it; rather, it should only have month-to-day and diurnal temporal allocation.  This becomes particularly important when specific sectors have a mix of annual, monthly, daily, and/or hourly inventories.  The flags that control temporal allocation for a mixed set of inventories are discussed in the SMOKE documentation.  The modeling platform sectors that make use of monthly values in the FF10 files are ag, nonroad, onroad, onroad_can, onroad_mex, othar, and othpt.
 Electric Generating Utility temporal allocation (ptegu)
 Base year temporal allocation of EGUs
The 2016 annual EGU emissions not matched to CEMS sources use region/fuel specific profiles based on average hourly emissions for the region and fuel.  Peaking units were removed during the averaging to minimize the spikes generated by those units.  The non-matched units are allocated to hourly emissions using the following three-step methodology: annual value to month, month to day, and day to hour.  First, the CEMS data were processed using a tool that reviewed the data quality flags that indicate the data were not measured.  Unmeasured data can be filled in with maximum values and thereby cause erroneously high values in the CEMS data.  The CEMCorrect tool identifies hours for which the data were not measured.  When those values are found to be more than three times the annual mean for that unit, the data for those hours are replaced with annual mean values (Adelman et al., 2012).  These adjusted CEMS data were then used for the remainder of the temporal allocation process described below (see Figure 3-5 for an example).  Winter and summer seasons are included in the development of the diurnal profiles as opposed to using data for the entire year because analysis of the hourly CEMS data revealed that there were different diurnal patterns in winter versus summer in many areas.  Typically, a single mid-day peak is visible in the summer, while there are morning and evening peaks in the winter as shown in Figure 3-6.

The temporal allocation procedure is differentiated by whether or not the source could be directly matched to a CEMS unit via ORIS facility code and boiler ID.  Note that for units matched to CEMS data, annual totals of their emissions input to CMAQ may be different than the annual values in 2016 because the CEMS data replaces the NOx and SO2 inventory data for the seasons in which the CEMS are operating.  If a CEMS-matched unit is determined to be a partial year reporter, as can happen for sources that run CEMS only in the summer, emissions totaling the difference between the annual emissions and the total CEMS emissions are allocated to the non-summer months.
Figure 3-5.  Eliminating unmeasured spikes in CEMS data

Figure 3-6.  Seasonal diurnal profiles for EGU emissions in a Virginia Region

For sources not matched to CEMS units, temporal profiles are calculated that are used by SMOKE to allocate the annual emissions to hourly values.  For these units, the allocation of the inventory annual emissions to months is done using average fuel-specific annual-to-month factors generated for regions with similar climate.  These factors are based on 2016 CEMS data only.  In each region, separate factors were developed for the fuels:  coal, natural gas, and "other," where the types of fuels included in "other" vary by region.  Separate profiles were computed for NOX, SO2, and heat input.  An overall composite profile was also computed and used when there were no CEMS units with the specified fuel in the region containing the unit.  For both CEMS-matched units and units not matched to CEMS, NOX and SO2 CEMS data are used to allocate NOX and SO2 emissions to monthly emissions, respectively, while heat input data are used to allocate emissions of all pollutants from monthly to daily emissions.
Daily temporal allocation of units matched to CEMS was performed using a procedure similar to the approach to allocate emissions to months in that the CEMS data replaces the inventory data for each pollutant.  For units without CEMS data, emissions were allocated from month to day using IPM-region and fuel-specific average month-to-day factors based on the 2016 CEMS heat data.  Separate month-to-day allocation factors were computed for each month of the year using heat input for the fuels coal, natural gas, and "other" in each region.  For CEMS matched units, NOX and SO2 CEMS data are used to replace inventory NOX and SO2 emissions, while CEMS heat input data are used to allocate all other pollutants.

For units matched to CEMS data, hourly emissions use the hourly CEMS values for NOX and SO2, while other pollutants are allocated according to heat input values.  For units not matched to CEMS data, temporal profiles from days to hours are computed based on the season-, region- and fuel-specific average day-to-hour factors derived from the CEMS data for those fuels and regions using the appropriate subset of data.  For the unmatched units, CEMS heat input data are used to allocate all pollutants (including NOX and SO2) because the heat input data was generally found to be more complete than the pollutant-specific data.  SMOKE then allocates the daily emissions data to hours using the temporal profiles obtained from the CEMS data for the analysis base year (i.e., 2016 in this case).

Certain sources without CEMS data, such as specific municipal waste combustors (MWCs) and cogeneration facilities (cogens), were assigned a flat temporal profile by source. The emissions for these sources have an equal value for each hour of the year.

For additional information on EGU temporal allocation, please see the Point-EGU-IPM specification sheet provided with the 2016v1 platform.
 Airport Temporal allocation (airports)
Airport temporal profiles were updated in 2014v7.0 and were kept the same for the 2016v1 platform.  All airport SCCs (i.e., 2275*,<PHONE_NUMBER>,<PHONE_NUMBER>,<PHONE_NUMBER> and<PHONE_NUMBER>) were given the same hourly, weekly and monthly profile for all airports other than Alaska seaplanes (which are not in the CMAQ modeling domain).  Hourly airport operations data were obtained from the Aviation System Performance Metrics (ASPM) Airport Analysis website (https://aspm.faa.gov/apm/sys/AnalysisAP.asp).  A report of 2014 hourly Departures and Arrivals for Metric Computation was generated.  An overview of the ASPM metrics is at http://aspmhelp.faa.gov/index.php/Aviation_Performance_Metrics_%28APM%29.  Figure 3-7 shows the diurnal airport profile.

Weekly and monthly temporal profiles are based on 2014 data from the FAA Operations Network Air Traffic Activity System (http://aspm.faa.gov/opsnet/sys/Terminal.asp).  A report of all airport operations (takeoffs and landings) by day for 2014 was generated.  These data were then summed to month and day-of-week to derive the monthly and weekly temporal profiles shown in Figure 3-7, Figure 3-8, and Figure 3-9.  An overview of the Operations Network data system is at http://aspmhelp.faa.gov/index.php/Operations_Network_%28OPSNET%29.

Alaska seaplanes, which are outside the CONUS domain use the same monthly profile as in the 2011 platform shown in Figure 3-10.  These were assigned based on the facility ID.

Figure 3-7.  Diurnal Profile for all Airport SCCs

Figure 3-8.  Weekly profile for all Airport SCCs

Figure 3-9.  Monthly Profile for all Airport SCCs

Figure 3-10.  Alaska Seaplane Profile

 Residential Wood Combustion Temporal allocation (rwc)
There are many factors that impact the timing of when emissions occur, and for some sectors this includes meteorology.  The benefits of utilizing meteorology as a method for temporal allocation are: (1) a meteorological dataset consistent with that used by the AQ model is available (e.g., outputs from WRF); (2) the meteorological model data are highly resolved in terms of spatial resolution; and (3) the meteorological variables vary at hourly resolution and can, therefore, be translated into hour-specific temporal allocation.

The SMOKE program Gentpro provides a method for developing meteorology-based temporal allocation.  Currently, the program can utilize three types of temporal algorithms: annual-to-day temporal allocation for residential wood combustion (RWC); month-to-hour temporal allocation for agricultural livestock NH3; and a generic meteorology-based algorithm for other situations.  Meteorological-based temporal allocation was used for portions of the rwc sector and for the entire ag sector.

Gentpro reads in gridded meteorological data (output from MCIP) along with spatial surrogates and uses the specified algorithm to produce a new temporal profile that can be input into SMOKE.  The meteorological variables and the resolution of the generated temporal profile (hourly, daily, etc.) depend on the selected algorithm and the run parameters.  For more details on the development of these algorithms and running Gentpro, see the Gentpro documentation and the SMOKE documentation at http://www.cmascenter.org/smoke/documentation/3.1/GenTPRO_TechnicalSummary_Aug2012_Final.pdf and https://www.cmascenter.org/smoke/documentation/4.5/html/ch05s03s05.html, respectively.

For the RWC algorithm, Gentpro uses the daily minimum temperature to determine the temporal allocation of emissions to days.  Gentpro was used to create an annual-to-day temporal profile for the RWC sources.  These generated profiles distribute annual RWC emissions to the coldest days of the year.  On days where the minimum temperature does not drop below a user-defined threshold, RWC emissions for most sources in the sector are zero.  Conversely, the program temporally allocates the largest percentage of emissions to the coldest days.  Similar to other temporal allocation profiles, the total annual emissions do not change, only the distribution of the emissions within the year is affected.  The temperature threshold for RWC emissions was 50 ˚F for most of the country, and 60 ˚F for the following states:  Alabama, Arizona, California, Florida, Georgia, Louisiana, Mississippi, South Carolina, and Texas.

Figure 3-11 illustrates the impact of changing the temperature threshold for a warm climate county.  The plot shows the temporal fraction by day for Duval County, Florida, for the first four months of 2007.  The default 50 ˚F threshold creates large spikes on a few days, while the 60 ˚F threshold dampens these spikes and distributes a small amount of emissions to the days that have a minimum temperature between 50 and 60 ˚F.
Figure 3-11.  Example of RWC temporal allocation in 2007 using a 50 versus 60 ˚F threshold

The diurnal profile used for most RWC sources (see Figure 3-12) places more of the RWC emissions in the morning and the evening when people are typically using these sources. This profile is based on a 2004 MANE-VU survey based temporal profiles (https://s3.amazonaws.com/marama.org/wp-content/uploads/2019/11/04184303/Open_Burning_Residential_Areas_Emissions_Report-2004.pdf). This profile was created by averaging three indoor and three RWC outdoor temporal profiles from counties in Delaware and aggregating them into a single RWC diurnal profile. This new profile was compared to a concentration-based analysis of aethalometer measurements in Rochester, New York (Wang et al. 2011) for various seasons and days of the week and was found that the new RWC profile generally tracked the concentration based temporal patterns.
Figure 3-12.  RWC diurnal temporal profile

The temporal allocation for "Outdoor Hydronic Heaters" (i.e., "OHH," SCC=2104008610) and "Outdoor wood burning device, NEC (fire-pits, chimneas, etc.)" (i.e., "recreational RWC," SCC=21040087000) is not based on temperature data, because the meteorologically-based temporal allocation used for the rest of the rwc sector did not agree with observations for how these appliances are used.
For OHH, the annual-to-month, day-of-week and diurnal profiles were modified based on information in the New York State Energy Research and Development Authority's (NYSERDA) "Environmental, Energy Market, and Health Characterization of Wood-Fired Hydronic Heater Technologies, Final Report" (NYSERDA, 2012), as well as a Northeast States for Coordinated Air Use Management (NESCAUM) report "Assessment of Outdoor Wood-fired Boilers" (NESCAUM, 2006).  A Minnesota 2008 Residential Fuelwood Assessment Survey of individual household responses (MDNR, 2008) provided additional annual-to-month, day-of-week, and diurnal activity information for OHH as well as recreational RWC usage.
Data used to create the diurnal profile for OHH, shown in Figure 3-13, are based on a conventional single-stage heat load unit burning red oak in Syracuse, New York.  As shown in Figure 3-14, the NESCAUM report describes how for individual units, OHH are highly variable day-to-day but that in the aggregate, these emissions have no day-of-week variation.  In contrast, the day-of-week profile for recreational RWC follows a typical "recreational" profile with emissions peaked on weekends.
Annual-to-month temporal allocation for OHH as well as recreational RWC were computed from the MDNR 2008 survey and are illustrated in Figure 3-15.  The OHH emissions still exhibit strong seasonal variability, but do not drop to zero because many units operate year-round for water and pool heating.  In contrast to all other RWC appliances, recreational RWC emissions are used far more frequently during the warm season.
Figure 3-13.  Data used to produce a diurnal profile for OHH, based on heat load (BTU/hr)

Figure 3-14.  Day-of-week temporal profiles for OHH and Recreational RWC

Figure 3-15.  Annual-to-month temporal profiles for OHH and recreational RWC

 Agricultural Ammonia Temporal Profiles (ag)
For the agricultural livestock NH3 algorithm, the GenTPRO algorithm is based on an equation derived by Jesse Bash of the EPA's ORD based on the Zhu, Henze, et al. (2013) empirical equation.  This equation is based on observations from the TES satellite instrument with the GEOS-Chem model and its adjoint to estimate diurnal NH3 emission variations from livestock as a function of ambient temperature, aerodynamic resistance, and wind speed.  The equations are:
      Ei,h = [161500/Ti,h x e[(-1380/T]i,h[)]] x ARi,h
      PEi,h = Ei,h / Sum(Ei,h)
where
 PEi,h = Percentage of emissions in county i on hour h
 Ei,h = Emission rate in county i on hour h
 Ti,h = Ambient temperature (Kelvin) in county i on hour h
 ARi,h = Aerodynamic resistance in county i
GenTPRO was run using the "BASH_NH3" profile method to create month-to-hour temporal profiles for these sources.  Because these profiles distribute to the hour based on monthly emissions, the monthly emissions are obtained from a monthly inventory, or from an annual inventory that has been temporalized to the month.  Figure 3-16 compares the daily emissions for Minnesota from the "old" approach (uniform monthly profile) with the "new" approach (GenTPRO generated month-to-hour profiles) for 2014.  Although the GenTPRO profiles show daily (and hourly variability), the monthly total emissions are the same between the two approaches.
Figure 3-16.  Example of animal NH3 emissions temporal allocation approach, summed to daily emissions

For the 2016 platform, the GenTPRO approach is applied to all sources in the ag sector, NH3 and non- NH3, livestock and fertilizer.  Monthly profiles are based on the daily-based EPA livestock emissions and are the same as were used in 2014v7.0.  Profiles are by state/SCC_category, where SCC_category is one of the following: beef, broilers, layers, dairy, swine.
 Oil and gas temporal allocation (np_oilgas)

Monthly oil and gas temporal profiles by county and SCC were updated to use 2016 activity information for the 2016v1 platform. Weekly and diurnal profiles are flat and are based on comments received on a version of the 2011 platform.
 Onroad mobile temporal allocation (onroad)
For the onroad sector, the temporal distribution of emissions is a combination of traditional temporal profiles and the influence of meteorology.  This section will discuss both the meteorological influences and the development of the temporal profiles for this platform.
The "inventories" referred to in Table 3-19 consist of activity data for the onroad sector, not emissions.  For the off-network emissions from the rate-per-profile (RPP) and rate-per-vehicle (RPV) processes, the VPOP activity data is annual and does not need temporal allocation.  For rate-per-hour (RPH) processes that result from hoteling of combination trucks, the HOTELING inventory is annual and was temporalized to month, day of the week, and hour of the day through temporal profiles.
For on-roadway rate-per-distance (RPD) processes, the VMT activity data is annual for some sources and monthly for other sources, depending on the source of the data.  Sources without monthly VMT were temporalized from annual to month through temporal profiles.  VMT was also temporalized from month to day of the week, and then to hourly through temporal profiles.  The RPD processes require a speed profile (SPDPRO) that consists of vehicle speed by hour for a typical weekday and weekend day.  For onroad, the temporal profiles and SPDPRO will impact not only the distribution of emissions through time but also the total emissions.  Because SMOKE-MOVES (for RPD) calculates emissions based on the VMT, speed and meteorology, if one shifted the VMT or speed to different hours, it would align with different temperatures and hence different emission factors.  In other words, two SMOKE-MOVES runs with identical annual VMT, meteorology, and MOVES emission factors, will have different total emissions if the temporal allocation of VMT changes.  Figure 3-17 illustrates the temporal allocation of the onroad activity data (i.e., VMT) and the pattern of the emissions that result after running SMOKE-MOVES.  In this figure, it can be seen that the meteorologically varying emission factors add variation on top of the temporal allocation of the activity data.
Meteorology is not used in the development of the temporal profiles, but rather it impacts the calculation of the hourly emissions through the program Movesmrg.  The result is that the emissions vary at the hourly level by grid cell.  More specifically, the on-network (RPD) and the off-network parked vehicle (RPV, RPH, and RPP) processes use the gridded meteorology (MCIP) either directly or indirectly.  For RPD, RPV, and RPH, Movesmrg determines the temperature for each hour and grid cell and uses that information to select the appropriate emission factor for the specified SCC/pollutant/mode combination.  For RPP, instead of reading gridded hourly meteorology, Movesmrg reads gridded daily minimum and maximum temperatures.  The total of the emissions from the combination of these four processes (RPD, RPV, RPH, and RPP) comprise the onroad sector emissions.  The temporal patterns of emissions in the onroad sector are influenced by meteorology.
Figure 3-17.  Example of temporal variability of NOX emissions

New VMT day-of-week and hour-of-day temporal profiles were developed for use in the 2014NEIv2 and later platforms as part of the effort to update the inputs to MOVES and SMOKE-MOVES under CRC A-100 (Coordinating Research Council, 2017). CRC A-100 data includes profiles by region or county, road type, and broad vehicle category. There are three vehicle categories: passenger vehicles (11/21/31), commercial trucks (32/52), and combination trucks (53/61/62). CRC A-100 does not cover buses, refuse trucks, or motor homes, so those vehicle types were mapped to other vehicle types for which CRC A-100 did provide profiles as follows: 1) Intercity/transit buses were mapped to commercial trucks; 2) Motor homes were mapped to passenger vehicles for day-of-week and commercial trucks for hour-of-day; 3) School buses and refuse trucks were mapped to commercial trucks for hour-of-day and use a new custom day-of-week profile called LOWSATSUN that has a very low weekend allocation, since school buses and refuse trucks operate primarily on business days.  In addition to temporal profiles, CRC A-100 data were also used to develop the average hourly speed data (SPDPRO) used by SMOKE-MOVES.  In areas where CRC A-100 data does not exist, hourly speed data is based on MOVES county databases.
The CRC A-100 dataset includes temporal profiles for individual counties, Metropolitan Statistical Areas (MSAs), and entire regions (e.g. West, South).  For counties without county or MSA temporal profiles specific to itself, regional temporal profiles are used.  Temporal profiles also vary by each of the MOVES road types, and there are distinct hour-of-day profiles for each day of the week.  Plots of hour-of-day profiles for passenger vehicles in Fulton County, GA, are shown in Figure 3-18.  Separate plots are shown for Monday, Friday, Saturday, and Sunday, and each line corresponds to a particular MOVES road type (i.e., road type 2 = rural restricted, 3 = rural unrestricted, 4 = urban restricted, and 5 = urban unrestricted).  Figure 3-19 shows which counties have temporal profiles specific to that county, and which counties use regional average profiles.
Figure 3-18.  Sample onroad diurnal profiles for Fulton County, GA

Figure 3-19.  Counties for which MOVES Speeds and Temporal Profiles could be Populated

For hoteling, day-of-week profiles are the same as non-hoteling for combination trucks, while hour-of-day non-hoteling profiles for combination trucks were inverted to create new hoteling profiles that peak overnight instead of during the day.  The combination truck profiles for Fulton County are shown in Figure 3-20.

The CRC A-100 temporal profiles were used in the entire contiguous United States, except in California.  All California temporal profiles were carried over from 2014v7.0, although California hoteling uses CRC A-100-based profiles just like the rest of the country, since CARB didn't have a hoteling-specific profile. Monthly profiles in all states (national profiles by broad vehicle type) were also carried over from 2014v7.0 and applied directly to the VMT.  For California, CARB supplied diurnal profiles that varied by vehicle type, day of the week, and air basin.  These CARB-specific profiles were used in developing EPA estimates for California.  Although the EPA adjusted the total emissions to match California-submitted emissions for 2016, the temporal allocation of these emissions took into account both the state-specific VMT profiles and the SMOKE-MOVES process of incorporating meteorology.

Figure 3-20.  Example of Temporal Profiles for Combination Trucks

 Additional sector specific details (afdust, beis, cmv, rail, nonpt, ptnonipm, ptfire)
For the afdust sector, meteorology is not used in the development of the temporal profiles, but it is used to reduce the total emissions based on meteorological conditions.  These adjustments are applied through sector-specific scripts, beginning with the application of land use-based gridded transport fractions and then subsequent zero-outs for hours during which precipitation occurs or there is snow cover on the ground.  The land use data used to reduce the NEI emissions explains the amount of emissions that are subject to transport.  This methodology is discussed in (Pouliot et al., 2010), and in "Fugitive Dust Modeling for the 2008 Emissions Modeling Platform" (Adelman, 2012).  The precipitation adjustment is applied to remove all emissions for hours where measurable rain occurs, or where there is snow cover.  Therefore, the afdust emissions vary day-to-day based on the precipitation and/or snow cover for each grid cell and hour.  Both the transport fraction and meteorological adjustments are based on the gridded resolution of the platform; therefore, somewhat different emissions will result from different grid resolutions.  For this reason, to ensure consistency between grid resolutions, afdust emissions for the 36US3 grid are aggregated from the 12US1 emissions. Application of the transport fraction and meteorological adjustments prevents the overestimation of fugitive dust impacts in the grid modeling as compared to ambient samples.

Biogenic emissions in the beis sector vary by every day of the year because they are developed using meteorological data including temperature, surface pressure, and radiation/cloud data.  The emissions are computed using appropriate emission factors according to the vegetation in each model grid cell, while taking the meteorological data into account.

For the cmv sectors, most areas use hourly emission inventories derived from the 5-minute AIS data.  In some areas where AIS data are not available, such as in Canada between the St. Lawrence Seaway and the Great Lakes and in the southern Carribbean, the flat temporal profiles are used for hourly and day-of-week values. Most regions without AIS data also use a flat monthly profile, with some offshore areas using an average monthly profile derived from the 2008 ECA inventory monthly values. These areas without AIS data also use flat day of week and hour of day profiles.

For the rail sector, new monthly profiles were developed for the 2016 platform.  Monthly temporal allocation for rail freight emissions is based on AAR Rail Traffic Data, Total Carloads and Intermodal, for 2016.  For passenger trains, monthly temporal allocation is flat for all months.  Rail passenger miles data is available by month for 2016 but it is not known how closely rail emissions track with passenger activity since passenger trains run on a fixed schedule regardless of how many passengers are aboard, and so a flat profile is chosen for passenger trains.  Rail emissions are allocated with flat day of week profiles, and most emissions are allocated with flat hourly profiles.

For the ptagfire sector, the inventories are in the daily point fire format FF10 PTDAY. The diurnal temporal profile for ag fires reflects the fact that burning occurs during the daylight hours - see Figure 3-21 (McCarty et al., 2009).  This puts most of the emissions during the work day and suppresses the emissions during the middle of the night.
Figure 3-21.  Agricultural burning diurnal temporal profile

Industrial processes that are not likely to shut down on Sundays, such as those at cement plants, use profiles that include emissions on Sundays, while those that would shut down on Sundays use profiles that reflect Sunday shutdowns.

For the ptfire sectors, the inventories are in the daily point fire format FF10 PTDAY.  Separate hourly profiles for prescribed and wildfires were used.  Figure 3-22 below shows the profiles used for each state for the 2014v7.0 and 2014v7.1 modeling platforms. They are similar but not the same and vary according to the average meteorological conditions in each state. The 2016 alpha platform uses the ptfire diurnal profiles form 2014v7.1 platform.
Figure 3-22.  Prescribed and Wildfire diurnal temporal profiles

For the nonroad sector, while the NEI only stores the annual totals, the modeling platform uses monthly inventories from output from MOVES.  For California, CARB's annual inventory was temporalized to monthly using monthly temporal profiles applied in SMOKE by SCC.  This is an improvement over the 2011 platform, which applied monthly temporal allocation in California at the broader SCC7 level.

 Spatial Allocation
The methods used to perform spatial allocation are summarized in this section.  For the modeling platform, spatial factors are typically applied by county and SCC.  As described in Section 3.1, spatial allocation was performed for national 36-km and 12-km domains.  To accomplish this, SMOKE used national 36-km and 12-km spatial surrogates and a SMOKE area-to-point data file.  For the U.S., the EPA updated surrogates to use circa 2014 data wherever possible.  For Mexico, updated spatial surrogates were used as described below.  For Canada, updated surrogates were provided by Environment Canada for the 2016v7.2 platform.  The U.S., Mexican, and Canadian 36-km and 12-km surrogates cover the entire CONUS domain 12US1 shown in Figure 3-1. The 36US3 domain includes a portion of Alaska, and since Alaska emissions are typically not included in air quality modeling, special considerations are taken to include Alaska emissions in 36-km modeling.

Documentation of the origin of the spatial surrogates for the platform is provided in the workbook US_SpatialSurrogate_Workbook_v07172018 which is available with the reports for the 2014v7.1 platform. The remainder of this subsection summarizes the data used for the spatial surrogates and the area-to-point data which is used for airport refueling.
 Spatial Surrogates for U.S. emissions
There are more than 100 spatial surrogates available for spatially allocating U.S. county-level emissions to the 36-km and 12-km grid cells used by the air quality model.  As described in Section 3.4.2, an area-to-point approach overrides the use of surrogates for an airport refueling sources.  Table 3-20 lists the codes and descriptions of the surrogates.  Surrogate names and codes listed in italics are not directly assigned to any sources for the 2016 alpha platform, but they are sometimes used to gapfill other surrogates, or as an input for merging two surrogates to create a new surrogate that is used.
Many surrogates were updated or newly developed for use in the 2014v7.0 platform (Adelman, 2016). They include the use of the 2011 National Land Cover Database (the previous platform used 2006) and development of various development density levels such as open, low, medium high and various combinations of these.  These landuse surrogates largely replaced the FEMA category surrogates that were used in the 2011 platform.  Additionally, onroad surrogates were developed using average annual daily traffic counts from the highway monitoring performance system (HPMS).  Previously, the "activity" for the onroad surrogates was length of road miles.  This and other surrogates are described in a reference (Adelman, 2016).
Several surrogates were updated or developed as new surrogates for the 2016v7.1 (aka alpha) platform:
 Oil and gas surrogates were updated to correct errors found after they were used for 2014v7.0;
 Onroad spatial allocation uses surrogates that do not distinguish between urban and rural road types, correcting the issue arising in some counties due to the inconsistent urban and rural definitions between MOVES and the surrogate data and were further updated for the 2016v1 platform;
 Correction was made to the water surrogate to gap fill missing counties using the 2006 National Land Cover Database (NLCD).
In addition, spatial surrogates 201 through 244, which concern road miles, annual average daily traffic (AADT), and truck stops, were further updated for the 2016 beta and regional haze platforms. The surrogates for the U.S. were mostly generated using the Surrogate Tool to drive the Spatial Allocator, but a few surrogates were developed directly within ArcGIS or using scripts that manipulate spatial data in PostgreSQL.  The tool and documentation for the Surrogate Tool is available at https://www.cmascenter.org/sa-tools/documentation/4.2/SurrogateToolUserGuide_4_2.pdf.

Table 3-20.  U.S. Surrogates available for the 2016v1 modeling platforms
                                                                           Code
Surrogate Description
                                                                           Code
Surrogate Description
                                                                            N/A
Area-to-point approach (see 3.6.2)
                                                                            506
Education
                                                                            100
Population
                                                                            507
Heavy Light Construction Industrial Land
                                                                            110
Housing
                                                                            510
Commercial plus Industrial
                                                                            131
urban Housing
                                                                            515
Commercial plus Institutional Land
                                                                            132
Suburban Housing
                                                                            520
Commercial plus Industrial plus Institutional
                                                                            134
Rural Housing
                                                                            525
Golf Courses plus Institutional plus Industrial plus Commercial
                                                                            137
Housing Change
                                                                            526
Residential  -  Non-Institutional
                                                                            140
Housing Change and Population
                                                                            527
Single Family Residential
                                                                            150
Residential Heating  -  Natural Gas
                                                                            535
Residential + Commercial + Industrial + Institutional + Government
                                                                            160
Residential Heating  -  Wood
                                                                            540
Retail Trade (COM1)
                                                                            170
Residential Heating  -  Distillate Oil
                                                                            545
Personal Repair (COM3)
                                                                            180
Residential Heating  -  Coal
                                                                            555
Professional/Technical (COM4) plus General Government (GOV1)
                                                                            190
Residential Heating  -  LP Gas
                                                                            560
Hospital (COM6)
                                                                            201
Urban Restricted Road Miles
                                                                            575
Light and High Tech Industrial (IND2 + IND5)
                                                                            202
Urban Restricted AADT
                                                                            580
Food Drug Chemical Industrial (IND3)
                                                                            205
Extended Idle Locations
                                                                            585
Metals and Minerals Industrial (IND4)
                                                                            211
Rural Restricted Road Miles
                                                                            590
Heavy Industrial (IND1)
                                                                            212
Rural Restricted AADT
                                                                            595
Light Industrial (IND2)
                                                                            221
Urban Unrestricted Road Miles
                                                                            596
Industrial plus Institutional plus Hospitals
                                                                            222
Urban Unrestricted AADT
                                                                            650
Refineries and Tank Farms
                                                                            231
Rural Unrestricted Road Miles
                                                                            670
Spud Count  -  CBM Wells
                                                                            232
Rural Unrestricted AADT
                                                                            671
Spud Count  -  Gas Wells
                                                                            239
Total Road AADT
                                                                            672
Gas Production at Oil Wells
                                                                            240
Total Road Miles
                                                                            673
Oil Production at CBM Wells
                                                                            241
Total Restricted Road Miles
                                                                            674
Unconventional Well Completion Counts
                                                                            242
All Restricted AADT
                                                                            676
Well Count  -  All Producing
                                                                            243
Total Unrestricted Road Miles
                                                                            677
Well Count  -  All Exploratory
                                                                            244
All Unrestricted AADT
                                                                            678
Completions at Gas Wells
                                                                            258
Intercity Bus Terminals
                                                                            679
Completions at CBM Wells
                                                                            259
Transit Bus Terminals
                                                                            681
Spud Count  -  Oil Wells
                                                                            260
Total Railroad Miles
                                                                            683
Produced Water at All Wells
                                                                            261
NTAD Total Railroad Density
                                                                            685
Completions at Oil Wells
                                                                            271
NTAD Class 1 2 3 Railroad Density
                                                                            686
Completions at All Wells
                                                                            272
NTAD Amtrak Railroad Density
                                                                            687
Feet Drilled at All Wells
                                                                            273
NTAD Commuter Railroad Density
                                                                            691
Well Counts -  CBM Wells
                                                                            275
ERTAC Rail Yards
                                                                            692
Spud Count  -  All Wells
                                                                            280
Class 2 and 3 Railroad Miles
                                                                            693
Well Count  -  All Wells
                                                                            300
NLCD Low Intensity Development
                                                                            694
Oil Production at Oil Wells
                                                                            301
NLCD Med Intensity Development
                                                                            695
Well Count  -  Oil Wells
                                                                            302
NLCD High Intensity Development
                                                                            696
Gas Production at Gas Wells
                                                                            303
NLCD Open Space
                                                                            697
Oil Production at Gas Wells
                                                                            304
NLCD Open + Low
                                                                            698
Well Count  -  Gas Wells
                                                                            305
NLCD Low + Med
                                                                            699
Gas Production at CBM Wells
                                                                            306
NLCD Med + High
                                                                            710
Airport Points
                                                                            307
NLCD All Development
                                                                            711
Airport Areas
                                                                            308
NLCD Low + Med + High
                                                                            801
Port Areas
                                                                            309
NLCD Open + Low + Med
                                                                            802
Shipping Lanes
                                                                            310
NLCD Total Agriculture
                                                                            805
Offshore Shipping Area
                                                                            318
NLCD Pasture Land
                                                                            806
Offshore Shipping NEI2014 Activity
                                                                            319
NLCD Crop Land
                                                                            807
Navigable Waterway Miles
                                                                            320
NLCD Forest Land
                                                                            808
2013 Shipping Density
                                                                            321
NLCD Recreational Land
                                                                            820
Ports NEI2014 Activity
                                                                            340
NLCD Land
                                                                            850
Golf Courses
                                                                            350
NLCD Water
                                                                            860
Mines
                                                                            500
Commercial Land
                                                                            890
Commercial Timber
                                                                            505
Industrial Land

For the onroad sector, the on-network (RPD) emissions were allocated differently from the off-network (RPP and RPV).  On-network used AADT data and off network used land use surrogates as shown in Table 3-21. Emissions from the extended (i.e., overnight) idling of trucks were assigned to surrogate 205, which is based on locations of overnight truck parking spaces. This surrogate's underlying data were updated for use in the 2016 platforms to include additional data sources and corrections based on comments received.
Table 3-21.  Off-Network Mobile Source Surrogates
                                  Source type
Source Type name
                                 Surrogate ID
                                  Description
                                      11
Motorcycle
                                      307
                             NLCD All Development
                                      21
Passenger Car
                                      307
                             NLCD All Development
                                      31
Passenger Truck
                                      307
                             NLCD All Development
                                      32
Light Commercial Truck
                                      308
                             NLCD Low + Med + High
                                      41
Intercity Bus
                                      258
                            Intercity Bus Terminals
                                      42
Transit Bus
                                      259
                             Transit Bus Terminals
                                      43
School Bus
                                      506
                                   Education
                                      51
Refuse Truck
                                      306
                                NLCD Med + High
                                      52
Single Unit Short-haul Truck
                                      306
                                NLCD Med + High
                                      53
Single Unit Long-haul Truck
                                      306
                                NLCD Med + High
                                      54
Motor Home
                                      304
                                NLCD Open + Low
                                      61
Combination Short-haul Truck
                                      306
                                NLCD Med + High
                                      62
Combination Long-haul Truck
                                      306
                                NLCD Med + High

For the oil and gas sources in the np_oilgas sector, the spatial surrogates were updated to those shown in Table 3-22 using 2016 data consistent with what was used to develop the 2016 beta nonpoint oil and gas emissions.  The primary activity data source used for the development of the oil and gas spatial
surrogates was data from Drilling Info (DI) Desktop's HPDI database (Drilling Info, 2017).  This
database contains well-level location, production, and exploration statistics at the monthly level.
Due to a proprietary agreement with DI Desktop, individual well locations and ancillary
production cannot be made publicly available, but aggregated statistics are allowed.  These data were supplemented with data from state Oil and Gas Commission (OGC) websites (Illinois, Idaho, Indiana, Kentucky, Missouri, Nevada, Oregon and Pennsylvania, Tennessee).  In many cases, the correct surrogate parameter was not available (e.g., feet drilled), but an alternative surrogate parameter was available (e.g., number of spudded wells) and downloaded.  Under that methodology, both completion date and date of first production from HPDI were used to identify wells completed during 2016.  In total, over 1.43 million unique wells were compiled from the above data sources.  The wells cover 34 states and 1,158 counties. (ERG, 2016b). Corrections to these data were made for the 2014v7.1 platform, and carried forward into the 2016 platforms, after errors were discovered in some counties.
Table 3-22.  Spatial Surrogates for Oil and Gas Sources
                                Surrogate Code
                             Surrogate Description
                                      670
Spud Count - CBM Wells
                                      671
Spud Count - Gas Wells
                                      672
Gas Production at Oil Wells
                                      673
Oil Production at CBM Wells
                                      674
Unconventional Well Completion Counts
                                      676
Well Count - All Producing
                                      677
Well Count - All Exploratory
                                      678
Completions at Gas Wells
                                      679
Completions at CBM Wells
                                      681
Spud Count - Oil Wells
                                      683
Produced Water at All Wells
                                      685
Completions at Oil Wells
                                      686
Completions at All Wells
                                      687
Feet Drilled at All Wells
                                      691
Well Counts -  CBM Wells
                                      692
Spud Count - All Wells
                                      693
Well Count - All Wells
                                      694
Oil Production at Oil Wells
                                      695
Well Count - Oil Wells
                                      696
Gas Production at Gas Wells
                                      697
Oil Production at Gas Wells
                                      698
Well Count - Gas Wells
                                      699
Gas Production at CBM Wells

Not all of the available surrogates are used to spatially allocate sources in the modeling platform; that is, some surrogates shown in Table 3-20 were not assigned to any SCCs, although many of the "unused" surrogates are actually used to "gap fill" other surrogates that are used.  When the source data for a surrogate has no values for a particular county, gap filling is used to provide values for the surrogate in those counties to ensure that no emissions are dropped when the spatial surrogates are applied to the emission inventories. Table 3-23 shows the CAP emissions (i.e., NH3, NOx, PM2.5, SO2, and VOC) by sector assigned to each spatial surrogate.
Table 3-23. Selected 2016 CAP emissions by sector for U.S. Surrogates (short tons in 12US1)
Sector
ID
Description
 NH3
 NOX
 PM2_5
 SO2
 VOC
afdust
                                                                            240
Total Road Miles

                                                                        294,379

afdust
                                                                            304
NLCD Open + Low

                                                                      1,053,145

afdust
                                                                            306
NLCD Med + High

                                                                         43,633

afdust
                                                                            308
NLCD Low + Med + High

                                                                        123,524

afdust
                                                                            310
NLCD Total Agriculture

                                                                        988,012

ag
                                                                            310
NLCD Total Agriculture
                                                                      3,409,761

                                                                        194,779
nonpt
                                                                            100
Population
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                      1,240,692
nonpt
                                                                            150
Residential Heating - Natural Gas
                                                                         42,973
                                                                        219,189
                                                                          3,632
                                                                          1,442
                                                                         13,296
nonpt
                                                                            170
Residential Heating - Distillate Oil
                                                                          1,563
                                                                         31,048
                                                                          3,356
                                                                         41,193
                                                                          1,051
nonpt
                                                                            180
Residential Heating - Coal
                                                                             20
                                                                            101
                                                                             53
                                                                          1,086
                                                                            111
nonpt
                                                                            190
Residential Heating - LP Gas
                                                                            111
                                                                         33,230
                                                                            175
                                                                            705
                                                                          1,292
nonpt
                                                                            239
Total Road AADT
                                                                              0
                                                                             25
                                                                            551
                                                                              0
                                                                        274,266
nonpt
                                                                            240
Total Road Miles
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                         34,027
nonpt
                                                                            242
All Restricted AADT
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                          5,451
nonpt
                                                                            244
All Unrestricted AADT
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                         96,232
nonpt
                                                                            271
NTAD Class 1 2 3 Railroad Density
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                          2,252
nonpt
                                                                            300
NLCD Low Intensity Development
                                                                          5,198
                                                                         27,727
                                                                        104,108
                                                                          3,722
                                                                         71,770
nonpt
                                                                            306
NLCD Med + High
                                                                         27,518
                                                                        180,692
                                                                        207,536
                                                                         62,698
                                                                        950,022
nonpt
                                                                            307
NLCD All Development
                                                                             25
                                                                         46,331
                                                                        126,722
                                                                         14,185
                                                                        601,828
nonpt
                                                                            308
NLCD Low + Med + High
                                                                          1,027
                                                                        171,603
                                                                         16,096
                                                                         13,527
                                                                         65,123
nonpt
                                                                            310
NLCD Total Agriculture
                                                                              0
                                                                              0
                                                                             37
                                                                              0
                                                                        204,819
nonpt
                                                                            319
NLCD Crop Land
                                                                              0
                                                                              0
                                                                             95
                                                                             71
                                                                            293
nonpt
                                                                            320
NLCD Forest Land
                                                                             69
                                                                            378
                                                                          1,289
                                                                              9
                                                                            474
nonpt
                                                                            505
Industrial Land
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                            174
nonpt
                                                                            535
Residential + Commercial + Industrial + Institutional + Government
                                                                              5
                                                                              2
                                                                            130
                                                                              0
                                                                             39
nonpt
                                                                            560
Hospital (COM6)
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                              0
nonpt
                                                                            650
Refineries and Tank Farms
                                                                              0
                                                                             22
                                                                              0
                                                                              0
                                                                         99,564
nonpt
                                                                            711
Airport Areas
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                            271
nonpt
                                                                            801
Port Areas
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                          8,194
nonroad
                                                                            261
NTAD Total Railroad Density
                                                                              3
                                                                          2,154
                                                                            227
                                                                              2
                                                                            425
nonroad
                                                                            304
NLCD Open + Low
                                                                              4
                                                                          1,824
                                                                            159
                                                                              5
                                                                          2,727
nonroad
                                                                            305
NLCD Low + Med
                                                                             94
                                                                         15,985
                                                                          3,832
                                                                            126
                                                                        114,513
nonroad
                                                                            306
NLCD Med + High
                                                                            305
                                                                        183,591
                                                                         11,873
                                                                            421
                                                                         93,596
nonroad
                                                                            307
NLCD All Development
                                                                             99
                                                                         31,526
                                                                         15,340
                                                                            125
                                                                        169,943
nonroad
                                                                            308
NLCD Low + Med + High
                                                                            498
                                                                        338,083
                                                                         28,585
                                                                            487
                                                                         51,865
nonroad
                                                                            309
NLCD Open + Low + Med
                                                                            119
                                                                         21,334
                                                                          1,257
                                                                            162
                                                                         45,498
nonroad
                                                                            310
NLCD Total Agriculture
                                                                            422
                                                                        378,388
                                                                         28,387
                                                                            425
                                                                         40,707
nonroad
                                                                            320
NLCD Forest Land
                                                                             15
                                                                          5,910
                                                                            703
                                                                             15
                                                                          3,939
nonroad
                                                                            321
NLCD Recreational Land
                                                                             83
                                                                         11,616
                                                                          6,517
                                                                            104
                                                                        246,154
nonroad
                                                                            350
NLCD Water
                                                                            188
                                                                        115,175
                                                                          5,952
                                                                            240
                                                                        353,189
nonroad
                                                                            850
Golf Courses
                                                                             13
                                                                          2,001
                                                                            117
                                                                             18
                                                                          5,613
nonroad
                                                                            860
Mines
                                                                              2
                                                                          2,691
                                                                            281
                                                                              3
                                                                            521
np_oilgas
                                                                            670
Spud Count - CBM Wells
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                            112
np_oilgas
                                                                            671
Spud Count - Gas Wells
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                          6,284
np_oilgas
                                                                            674
Unconventional Well Completion Counts
                                                                             12
                                                                         18,802
                                                                            720
                                                                              9
                                                                          1,264
np_oilgas
                                                                            678
Completions at Gas Wells
                                                                              0
                                                                          5,315
                                                                            136
                                                                          2,488
                                                                         16,615
np_oilgas
                                                                            679
Completions at CBM Wells
                                                                              0
                                                                              3
                                                                              0
                                                                             80
                                                                            395
np_oilgas
                                                                            681
Spud Count - Oil Wells
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                         15,164
np_oilgas
                                                                            683
Produced Water at All Wells
                                                                              0
                                                                             11
                                                                              0
                                                                              0
                                                                         47,271
np_oilgas
                                                                            685
Completions at Oil Wells
                                                                              0
                                                                            255
                                                                              0
                                                                            769
                                                                         27,935
np_oilgas
                                                                            687
Feet Drilled at All Wells
                                                                              0
                                                                         36,162
                                                                          1,309
                                                                             22
                                                                          2,664
np_oilgas
                                                                            691
Well Counts -  CBM Wells
                                                                              0
                                                                         32,971
                                                                            490
                                                                             13
                                                                         27,566
np_oilgas
                                                                            693
Well Count - All Wells
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                            159
np_oilgas
                                                                            694
Oil Production at Oil Wells
                                                                              0
                                                                          4,165
                                                                              0
                                                                         15,385
                                                                      1,062,178
np_oilgas
                                                                            695
Well Count - Oil Wells
                                                                              0
                                                                        134,921
                                                                          2,953
                                                                             32
                                                                        566,235
np_oilgas
                                                                            696
Gas Production at Gas Wells
                                                                              0
                                                                         16,339
                                                                          1,847
                                                                            164
                                                                        428,206
np_oilgas
                                                                            698
Well Count - Gas Wells
                                                                              0
                                                                        320,688
                                                                          6,217
                                                                            258
                                                                        582,442
np_oilgas
                                                                            699
Gas Production at CBM Wells
                                                                              0
                                                                          2,413
                                                                            312
                                                                             25
                                                                          7,602
onroad
                                                                            205
Extended Idle Locations
                                                                            230
                                                                         78,126
                                                                            794
                                                                             36
                                                                         13,711
onroad
                                                                            239
Total Road AADT

                                                                          5,755
onroad
                                                                            242
All Restricted AADT
                                                                         34,545
                                                                      1,175,197
                                                                         38,140
                                                                          8,744
                                                                        194,836
onroad
                                                                            244
All Unrestricted AADT
                                                                         65,543
                                                                      1,773,993
                                                                         67,525
                                                                         17,788
                                                                        477,839
onroad
                                                                            258
Intercity Bus Terminals

                                                                            147
                                                                              2
                                                                              0
                                                                             34
onroad
                                                                            259
Transit Bus Terminals

                                                                             53
                                                                              3
                                                                              0
                                                                            149
onroad
                                                                            304
NLCD Open + Low

                                                                            829
                                                                             29
                                                                              1
                                                                          3,874
onroad
                                                                            306
NLCD Med + High

                                                                         15,209
                                                                            333
                                                                             17
                                                                         19,917
onroad
                                                                            307
NLCD All Development

                                                                        546,312
                                                                         10,195
                                                                            910
                                                                      1,073,380
onroad
                                                                            308
NLCD Low + Med + High

                                                                         40,054
                                                                            722
                                                                             62
                                                                         62,127
onroad
                                                                            506
Education

                                                                            629
                                                                             15
                                                                              1
                                                                            637
rail
                                                                            261
NTAD Total Railroad Density
                                                                             13
                                                                         33,389
                                                                            996
                                                                             15
                                                                          1,647
rail
                                                                            271
NTAD Class 1 2 3 Railroad Density
                                                                            313
                                                                        525,992
                                                                         14,823
                                                                            442
                                                                         24,435
rwc
                                                                            300
NLCD Low Intensity Development
                                                                         15,439
                                                                         31,282
                                                                        316,943
                                                                          7,703
                                                                        340,941

For 36US3 modeling in the 2016 platforms, most U.S. emissions sectors were processed using 36-km spatial surrogates, and if applicable, 36-km meteorology. Exceptions include:
 For the onroad and onroad_ca_adj sectors, 36US3 emissions were aggregated from 12US1 by summing emissions from a 3x3 group of 12-km cells into a single 36-km cell.  Differences in 12-km and 36-km meteorology can introduce differences in onroad emissions, and so this approach ensures that the 36-km and 12-km onroad emissions are consistent. However, this approach means that 36US3 onroad does not include emissions in Southeast Alaska; therefore, Alaska onroad emissions are included in a separate sector called onroad_nonconus that is processed for only the 36US3 domain. The 36US3 onroad_nonconus emissions are spatially allocated using 36-km surrogates and processed with 36-km meteorology.
 Similarly to onroad, because afdust emissions incorporate meteorologically-based adjustments, afdust_adj emissions for 36US3 were aggregated from 12US1 to ensure consistency in emissions between modeling domains. Again, similarly to onroad, this means 36US3 afdust does not include emissions in Southeast Alaska; therefore, Alaska afdust emissions are processed in a separate sector called afdust_ak_adj. The 36US3 afdust_ak_adj emissions are spatially allocated using 36-km surrogates and adjusted with 36-km meteorology.
 The ag and rwc sectors are processed using 36-km spatial surrogates, but using temporal profiles based on 12-km meteorology.

 Allocation method for airport-related sources in the U.S.
There are numerous airport-related emission sources in the NEI, such as aircraft, airport ground support equipment, and jet refueling.  The modeling platform includes the aircraft and airport ground support equipment emissions as point sources.  For the modeling platform, the EPA used the SMOKE "area-to-point" approach for only jet refueling in the nonpt sector.  The following SCCs use this approach:<PHONE_NUMBER> and<PHONE_NUMBER> (petroleum storage at airports), and<PHONE_NUMBER> (aircraft/rocket engine firing and testing).  The ARTOPNT approach is described in detail in the 2002 platform documentation:  http://www3.epa.gov/scram001/reports/Emissions%20TSD%20Vol1_02-28-08.pdf.  The ARTOPNT file that lists the nonpoint sources to locate using point data were unchanged from the 2005-based platform.
 Surrogates for Canada and Mexico emission inventories
Spatial surrogates for allocating Mexico municipio level emissions have been updated in the 2014v7.1 platform and carried forward into the 2016 alpha platform. For the 2016v7.2 platform, a new set of Canada shapefiles were provided by Environment Canada along with cross references spatially allocate the year 2015 Canadian emissions. Gridded surrogates were generated using the Surrogate Tool (previously referenced); Table 3-24 provides a list.  Due to computational reasons, total roads (1263) were used instead of the unpaved rural road surrogate provided.  The population surrogate was recently updated for Mexico; surrogate code 11, which uses 2015 population data at 1 km resolution, replaces the previous population surrogate code 10.  The other surrogates for Mexico are circa 1999 and 2000 and were based on data obtained from the Sistema Municipal de Bases de Datos (SIMBAD) de INEGI and the Bases de datos del Censo Economico 1999. Most of the CAPs allocated to the Mexico and Canada surrogates are shown in Table 3-25.
Table 3-24.  Canadian Spatial Surrogates
Code
Canadian Surrogate Description
Code
Description
100
                                  Population
                                      923
                      TOTAL INSTITUTIONAL AND GOVERNEMNT
101
                                total dwelling
                                      924
                               Primary Industry
104
                             capped total dwelling
                                      925
                          Manufacturing and Assembly
106
                                  ALL_INDUST
                                      926
                    Distribution and Retail (no petroleum)
113
                             Forestry and logging
                                      927
                              Commercial Services
200
                           Urban Primary Road Miles
                                      932
                                    CANRAIL
210
                           Rural Primary Road Miles
                                      940
                                PAVED ROADS NEW
211
                            Oil and Gas Extraction
                                      945
                           Commercial Marine Vessels
212
                           Mining except oil and gas
                                      946
                            Construction and mining
220
                          Urban Secondary Road Miles
                                      948
                                    Forest
221
                                 Total Mining
                                      951
                          Wood Consumption Percentage
222
                                   Utilities
                                      955
                           UNPAVED_ROADS_AND_TRAILS
230
                          Rural Secondary Road Miles
                                      960
                                    TOTBEEF
233
                            Total Land Development
                                      970
                                    TOTPOUL
240
                               capped population
                                      980
                                    TOTSWIN
308
                              Food manufacturing
                                      990
                                    TOTFERT
321
                          Wood product manufacturing
                                      996
                                  urban_area
323
                    Printing and related support activities
                                     1251
                                 OFFR_TOTFERT
324
                   Petroleum and coal products manufacturing
                                     1252
                                  OFFR_MINES
326
                  Plastics and rubber products manufacturing
                                     1253
                       OFFR Other Construction not Urban
327
                  Non-metallic mineral product manufacturing
                                     1254
                           OFFR Commercial Services
331
                          Primary Metal Manufacturing
                                     1255
                             OFFR Oil Sands Mines
350
                                     Water
                                     1256
                          OFFR Wood industries CANVEC
412
                   Petroleum product wholesaler-distributors
                                     1257
                           OFFR UNPAVED ROADS RURAL
448
                   clothing and clothing accessories stores
                                     1258
                                OFFR_Utilities
482
                              Rail transportation
                                     1259
                              OFFR total dwelling
562
                   Waste management and remediation services
                                     1260
                                  OFFR_water
901
                                    AIRPORT
                                     1261
                                OFFR_ALL_INDUST
902
                                 Military LTO
                                     1262
                          OFFR Oil and Gas Extraction
903
                                Commercial LTO
                                     1263
                                 OFFR_ALLROADS
904
                             General Aviation LTO
                                     1265
                                 OFFR_CANRAIL
921
                          Commercial Fuel Combustion
                                     9450
                        Commercial Marine Vessel Ports

Table 3-25. CAPs Allocated to Mexican and Canadian Spatial Surrogates (short tons in 36US3)
Sector
Code
Mexican or Canadian Surrogate Description
                                      NH3
                                      NOX
                                    PM 2_5
                                      SO2
                                      VOC
                                                                      othafdust
                                                                            106
CAN ALL_INDUST
                                                                             --
                                                                             --
                                                                          5,632
                                                                             --
                                                                             --
                                                                      othafdust
                                                                            212
CAN Mining except oil and gas
                                                                             --
                                                                             --
                                                                            684
                                                                             --
                                                                             --
                                                                      othafdust
                                                                            221
CAN Total Mining
                                                                             --
                                                                             --
                                                                        142,940
                                                                             --
                                                                             --
                                                                      othafdust
                                                                            222
CAN Utilities
                                                                             --
                                                                             --
                                                                         23,640
                                                                             --
                                                                             --
                                                                      othafdust
                                                                            940
CAN Paved Roads New
                                                                             --
                                                                             --
                                                                        210,336
                                                                             --
                                                                             --
                                                                      othafdust
                                                                            955
CAN UNPAVED_ROADS_AND_TRAILS
                                                                             --
                                                                             --
                                                                        389,775
                                                                             --
                                                                             --
                                                                      othafdust
                                                                            960
CAN TOTBEEF
                                                                             --
                                                                             --
                                                                          1,289
                                                                             --
                                                                             --
                                                                      othafdust
                                                                            970
CAN TOTPOUL
                                                                             --
                                                                             --
                                                                            184
                                                                             --
                                                                             --
                                                                      othafdust
                                                                            980
CAN TOTSWIN
                                                                             --
                                                                             --
                                                                            792
                                                                             --
                                                                             --
                                                                      othafdust
                                                                            990
CAN TOTFERT
                                                                             --
                                                                             --
                                                                            321
                                                                             --
                                                                             --
                                                                      othafdust
                                                                            996
CAN urban_area
                                                                             --
                                                                             --
                                                                            617
                                                                             --
                                                                             --
                                                                          othar
                                                                             11
MEX 2015 Population
                                                                        164,464
                                                                        168,447
                                                                         13,521
                                                                          1,164
                                                                        291,178
                                                                          othar
                                                                             14
MEX Residential Heating - Wood
                                                                              0
                                                                         23,842
                                                                        305,597
                                                                          3,658
                                                                      2,101,033
                                                                          othar
                                                                             16
MEX Residential Heating - Distillate Oil
                                                                              2
                                                                             58
                                                                              1
                                                                             16
                                                                              2
                                                                          othar
                                                                             20
MEX Residential Heating - LP Gas
                                                                              0
                                                                         26,526
                                                                            838
                                                                              0
                                                                            505
                                                                          othar
                                                                             22
MEX Total Road Miles
                                                                              1
                                                                          1,046
                                                                              2
                                                                              7
                                                                          2,308
                                                                          othar
                                                                             24
MEX Total Railroads Miles
                                                                              0
                                                                         63,136
                                                                          1,407
                                                                            551
                                                                          2,494
                                                                          othar
                                                                             26
MEX Total Agriculture
                                                                        713,253
                                                                        399,070
                                                                         80,458
                                                                         18,650
                                                                         33,742
                                                                          othar
                                                                             32
MEX Commercial Land
                                                                              0
                                                                            457
                                                                          7,719
                                                                              0
                                                                        106,077
                                                                          othar
                                                                             34
MEX Industrial Land
                                                                              8
                                                                          3,383
                                                                          4,833
                                                                              1
                                                                        563,953
                                                                          othar
                                                                             36
MEX Commercial plus Industrial Land
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                        272,155
                                                                          othar
                                                                             38
MEX Commercial plus Institutional Land
                                                                              3
                                                                          6,740
                                                                            235
                                                                              3
                                                                            148
                                                                          othar
                                                                             40
MEX Residential (RES1-4)+Commercial+ Industrial+Institutional+Government
                                                                              0
                                                                             16
                                                                             39
                                                                              0
                                                                        331,216
                                                                          othar
                                                                             42
MEX Personal Repair (COM3)
                                                                              0
                                                                              0
                                                                              0
                                                                              0
                                                                         26,261
                                                                          othar
                                                                             44
MEX Airports Area
                                                                              0
                                                                         13,429
                                                                            306
                                                                          1,561
                                                                          3,766
                                                                          othar
                                                                             50
MEX Mobile sources - Border Crossing
                                                                              5
                                                                            161
                                                                              1
                                                                              3
                                                                            293
                                                                          othar
                                                                            100
CAN Population
                                                                            761
                                                                             54
                                                                            669
                                                                             15
                                                                            241