The SMOKE-MOVES Integration tool prepares the meteorological data for use by MOVES and SMOKE, converts the MOVES lookup tables into the format needed by SMOKE, and processes the MOVES lookup tables (SMOKE formated) through the SMOKE modeling system to generate average/real-time hourly gridded meteorology data.
The approach for running MOVES for SMOKE relies on the concept of representative reference counties and reference fuel months, that are covered in Section 2.8.5.1, “Reference Counties” and Section 2.8.5.2, “Reference Fuel month”. The concept of reference county refers to running MOVES for a single county, which is the reference county, to represent itself and other counties that share the same MOVES input parameters and thus have the same emission rates for any given speed, temperature and humidity. A reference fuel month similarly refers to a representative fuel month's MOVES run that contains the temperatures that occur in neighboring months as well as the reference month. The mapping of calendar months to a reference month should be assigned on the basis of shared fuel parameters, because it is the interaction of fuel and temperature that is important. For example, an average-hourly temperature of 70°F may occur in some hour of any day in each of four months: May, June, July and August. If those four months share the same fuel properties (i.e. summer fuel) then an emission factor will be determined for just the reference month, reducing by a factor of four the number of calculations that MOVES needs to perform.
Unlike MOBILE6, MOVES differentiates between on-roadway emission processes and off-network emission processes. Figure 2.15, “MOVES mobile onroad processing steps” summarizes the approach used by MOVES for on-roadway mobile sources. The on-roadway emission process includes county-total VMT and average speed inventory as input. The on-roadway emission process does not require the meteorology processing step since MOVES reads real meteorology data from MCIP files. The off-network emission processes use the county-total vehicle population by vehicle type as input. Figure 2.16, “MOVES mobile off-network processing steps” summarizes the approach used by MOVES for off-network mobile sources.
In sections later in this chapter, we describe the SMOKE programs that are needed for each of the processing steps just described for MOVES processed mobile sources, and additional details about what activities are accomplished during each step. These sections are:
Processing mobile sources involves a number of concepts that are unique to mobile sources. These include a special classification of road types in MOVES, SMOKE and MOVES vehicle types, emissions processes, MOVES emission factors, reference counties, reference fuel months, and meteorological processing using Met4moves. The following subsections and section 2.17 explain these topics in more detail.
The approach for running MOVES for SMOKE relies on the concept of reference counties. These are counties that are used during the creation and use of emission rates to represent a set of similar counties (i.e., inventory counties) called a county group. The purpose of the reference county is to reduce the computational burden of running MOVES on every county in your modeling domain. By using a reference county, the user generates key emission rates for the single county in MOVES and then utilizes these factors to estimate emissions for all counties in the county group through SMOKE. The reference county is modeled at a range of speeds and temperatures to produce emission rate lookup tables (grams/mile or grams/vehicle/hour, depending on mobile emission process). The variables that are assumed to be constant across the county group members (and the reference county) are fuel parameters, fleet age distribution and inspection/maintenance (I/M) programs. The variables that can vary within the county group are vehicle miles traveled (VMT), source type vehicle population, roadway speed, and grid cell temperatures. Determining the reference counties and their respective county groups is a key aspect of utilizing the SMOKE-MOVES tool. It is ideal for the user to create each county group based on the similarity between the county characteristics (e.g., urban and rural) and the meteorological conditions (e.g., temperature and relative humidity). The user should avoid grouping counties that have significantly different meteorological conditions.
The concept of a fuel month is used to indicate when a particular set of fuel properties should be used in a MOVES simulation. Similar to the reference county, the fuel month reduces the computational time of MOVES by using a single month to represent a set of months. To determine the fuel month and which months it corresponds to, the user should review the State-provided fuel supply data in the MOVES database for each reference county. If the fuel supply data change throughout the year, then group the months by fuel parameters. For example, if the grams/mile exhaust emission rates in January are identical to February's rates for a given reference county, then use a single fuel month to represent January and February. In other words, only one of the months needs to be modeled through MOVES.
The meteorological data preprocessor program Met4moves prepares spatially and temporally averaged temperatures and relative humidity data to set up the meteorological input conditions for MOVES and SMOKE using the Meteorology-Chemistry Interface Processor (MCIP) output files.
Met4moves must be run after MCIP and before SMOKE and MOVES.
The following are the major processing steps that Met4moves performs:
-
Read the reference county cross-reference file
MCXREFthat contains a list of reference counties and the county groups that map to those reference counties. -
Read the surrogate description file
SRGDESCand a list of associated spatial surrogate(s) chosen for use in selecting grid cells. -
Determine a list of grid cells for each county. Only the selected grid cells are used to estimate the min/max temperatures, 24-hour temperature profiles, and RH over the user-specified modeling period.
-
Set the dates of the modeling episode in local time using the flags
STDATEandENDATE -
Determine the averaging method
AVERAGING_METHODchosen by the user to create 24-hour temperature profiles (i.e., MONTHLY). -
Determine the fuel month for the reference county using the
MFMREFinput file. -
Read the country/state/county
COSTCYfile to define the time zones for county groups. -
Read the meteorology data that have been processed by MCIP.
-
Calculate the min/max temperatures hourly and over the modeling period.
-
Calculate average RH for the specified hour range over the modeling period. The default hour range is from 6 AM to 6 PM local time).
-
Once min/max temperatures and averaged RH are estimated for all reference counties and all inventory counties in the county groups, estimate diurnal 24-hour temperature profiles for use by the MOVES driver script. The result is a normalized 24-hour shape profile over the user-specified period or fuel month.
When the MOVES model runs as a part of the SMOKE-MOVES integration tool, it runs for all emissions processes (or modes), including on-road and off-network emissions processes, for the selected pollutants. Off-network emission processes (e.g., parked engine-off, engine starts, and idling, and fuel vapor venting) in MOVES are hour-dependent due to vehicle activity assumptions built into the MOVES model; the emission rate depends on both hour of the day and temperature. On-roadway emission processes (e.g., running exhaust, crankcase running exhaust, brake wear, tire wear, and on-road evaporative), on the other hand, do not depend on hour. In MOVES, these emission processes are categorized into three major groups:
- RatePerDistance (RPD) - The emission rate of on-roadway vehicles (i.e., driving) from MOVES. The rate is expressed in grams/mile traveled.
- RatePerVehicle (RPV) - The emission rate of vehicles off-network (e.g., idling, starts, refueling, parked) from MOVES. The rate is given in grams/vehicle/hour.
- RatePerProfile (RPP) - The emission rate of vehicles off-network specifically, the evaporation from parked vehicles (vapor-venting emissions) from MOVES. The rate is expressed in grams/vehicle/hour.
MOVES emission rate tables are organized into three tables(RPD, RPV, RPP), depending on emission mode or process and whether the vehicle is parked or in motion. The approach to running MOVES for SMOKE is unique for each emission rate table listed in Table 2.6, “MOVES Organization of Emission Processes into Emission Rate Tables”. A complete inventory must use the emission rates from all three tables.
Table 2.6. MOVES Organization of Emission Processes into Emission Rate Tables
| Emission Rate Lookup Table | Units | smokeProcID | Emissions Process | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| RatePerDistance (RPD) | Grams/mile |
|
|
||||||||||||||
| RatePerVehicle (RPV) | Grams/vehicle/hour |
|
|
||||||||||||||
| RatePerProfile (RPP) | Grams/vehicle/hour | EVF | Off-network Evaporative Fuel Vapor Venting |
The Rate Per Distance (RPD) lookup table is used to provide estimates of on-roadway emissions processes from mobile sources, using a separate file for each reference county. The on-road running processes that appear in this table include running exhaust (EXR), crankcase running exhaust (CXR), brake wear (BRK), tire wear (TIR), on-road evaporative permeation (EVP), on-road evaporative fuel leaks (EFL), and on-road evaporative vapor venting (EFV). The units of the emission rates in this table are grams/mile. The lookup fields for the factors are temperature and average speed. There are 16 set speed bins defined in Table 2.7, “MOVES Default Speed Bins” (i.e., avgSpeedBinID 1=2.5mph, 2=5mph, 3=10mph, …16=75mph). The avgBinSpeed is used for interpolation in the RPD table.
The Rate Per Vehicle (RPV) lookup table is used to provide estimates of off-network emission processes (parked engine-off, engine starts, and idling), except for the evaporative off-network rts, and idling), except for the evaporative off-network vapor venting emissions process. A separate file is provided for each reference county. The off-network emission processes include start exhaust (EXS), crankcase start exhaust (CXS), off-network evaporative permeation (EVP), off-network evaporative fuel leaks (EFL), extended idle exhaust (EXT), and crankcase extended idle exhaust (CEI). Fuel month, temperature, and local hourID are the lookup fields in this table, and hours are in the local time of the countyID. The units of the emission rates are grams/vehicle/hour. Note: Although the units are grams/vehicle/hour, the number of vehicles (i.e., population) should not be temporally allocated to hours in SMOKE. Instead, a county total of vehicle population should be multiplied by emission rates at any given hour. The number of starts per vehicle by hour is already accounted for in the MOVES lookup table.
The Rate Per Profile (RPP) table is used only to estimate emissions for off-network fuel vapor venting (EFV) when the vehicle is parked. This process type includes diurnal (when the vehicle is parked during the day) and hot soak (immediately after a trip when the vehicle parks) emissions types. The process depends on the rate of rise in temperature and the maximum temperature achieved during the day for the diurnal emissions type, and on the hourly temperatures for the hot soak emission type. The lookup fields for this table are reference fuel month and hour of day. As with the RPV table, the units of the emission rates are grams/vehicle/hour. The estimated emissions rates need to be multiplied by the county vehicle population.
The reference county lookup tables contain 24-hour emission rates per hour per vehicle using a reference-county temperature profile with different minimum and maximum temperatures. The average day county emissions are determined by interpolating between the minimum and maximum temperatures for the county listed in the Met4moves output file for SMOKE.
Table 2.7. MOVES Default Speed Bins
| avgSpeedBinId | avgBinSpeed | AvgSpeedBinDesc |
|---|---|---|
| 1 | 2.5 | speed < 2.5mph |
| 2 | 5 | 2.5mph ≤ speed < 7.5mph |
| 3 | 10 | 7.5mph ≤ speed < 12.5mph |
| 4 | 15 | 12.5mph ≤ speed < 17.5mph |
| 5 | 20 | 17.5mph ≤ speed < 22.5mph |
| 6 | 25 | 22.5mph ≤ speed < 27.5mph |
| 7 | 30 | 27.5mph ≤ speed < 32.5mph |
| 8 | 35 | 32.5mph ≤ speed < 37.5mph |
| 9 | 40 | 37.5mph ≤ speed < 42.5mph |
| 10 | 45 | 42.5mph ≤ speed < 47.5mph |
| 11 | 50 | 47.5mph ≤ speed < 52.5mph |
| 12 | 55 | 52.5mph ≤ speed < 57.5mph |
| 13 | 60 | 57.5mph ≤ speed < 62.5mph |
| 14 | 65 | 62.5mph ≤ speed < 67.5mph |
| 15 | 70 | 67.5mph ≤ speed < 72.5mph |
| 16 | 75 | 72.5mph ≤ speed |
The following Table 2.8, “MOVES List of Pollutants associated with emissions processes SmokeProcIDs” gives the available MOVES pollutants and associates them with emission processes (smokeProcIDs) from the MOVES model. The
information is used to create the MEPROC input file that contains the list of MOVES emission processes and associated pollutants
for Spcmat.
Table 2.8. MOVES List of Pollutants associated with emissions processes SmokeProcIDs
| SMOKE Name | smokeProcIDs | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| EXR | EXS | CXR | CXS | CEI | EXT | EVP | EFV | EFL | BRK | TIR | RFV | RFS | |
| THC | x | x | x | x | x | x | x | x | x | x | x | ||
| NMHC | x | x | x | x | x | x | x | x | x | x | x | ||
| NMOG | x | x | x | x | x | x | x | x | x | x | x | ||
| TOG | x | x | x | x | x | x | x | x | x | x | x | ||
| VOC | x | x | x | x | x | x | x | x | x | x | x | ||
| CO | x | x | x | x | x | x | |||||||
| NOX | x | x | x | x | x | x | |||||||
| NH3 | x | x | x | x | x | x | |||||||
| NO | x | x | x | x | x | x | |||||||
| NO2 | x | x | x | x | x | x | |||||||
| SO2 | x | x | x | x | x | x | |||||||
| PM10OM | x | x | x | x | x | x | |||||||
| PM10EC | x | x | x | x | x | x | |||||||
| PM10SO4 | x | x | x | x | x | x | |||||||
| PM10BRAKE | x | ||||||||||||
| PM10TIRE | x | ||||||||||||
| PM25OM | x | x | x | x | x | x | |||||||
| PM25EC | x | x | x | x | x | x | |||||||
| PSO4 | x | x | x | x | x | x | |||||||
| PNO3 | x | x | x | x | x | x | |||||||
| NH4 | x | x | x | x | x | x | |||||||
| PMFINE | x | x | x | x | x | x | |||||||
| PMC | x | x | x | x | x | x | |||||||
| PM25BRAKE | x | ||||||||||||
| PM25TIRE | x | ||||||||||||
| CH4 | x | x | x | x | x | x | x | x | x | x | x | ||
| N2O | x | x | x | x | |||||||||
| Atmos. CO2 | x | x | x | ||||||||||
| CO2 Equivalent | x | x | x | ||||||||||
| BENZENE | x | x | x | x | x | x | x | x | x | x | x | ||
| Ethanol | x | x | x | x | x | x | x | x | x | x | x | ||
| MTBE | x | x | x | x | x | x | x | x | x | x | x | ||
| NAPHTH | x | x | x | x | x | x | x | x | x | x | x | ||
| BUTADIE | x | x | x | x | x | x | |||||||
| FORMALD | x | x | x | x | x | x | |||||||
| ACETALD | x | x | x | x | x | x | |||||||
| ACROLEI | x | x | x | x | x | x | |||||||