The Gentpro program estimates emissions temporal profiles for residential wood combustion (RWC), agricultural ammonia (RC_NH3), livestock ammonia (BASH_NH3) or generic area sources by relating meteorology to air emission fluxes. Gentpro reads in hourly gridded meteorology data from the Meteorology-Chemistry Interface Processor (MCIP) and a gridded spatial surrogate (commonly used in SMOKE) to produce temporal profiles and cross-reference data in a comma separated value (CSV) format and/or a temporal data binary netCDF file. Annual MCIP input data are required to calculate temporal profiles with Gentpro. Spatial surrogate(s) are used to identify the grid cells for computing county averaged meteorology variables.

Gentpro provides an option to specify a profile method [PROFILE_METHOD], which can be set to generate RWC, BASH_NH3, RC_HNH3, or generic meteorology-based temporal profiles. the RWC, BASH_NH3 and RC_NH3 temporal profiles are based on algorithms described by Adelman (2009 and 2010), Mansell et al. (2000), and Bash et al. (2012) respectively, while the MET profiles can ben generated from any user-selected meteorology variable. The RWC profile method produces county-specific daily temporal profiles to convert annual or monthly inventories to daily emissions estimates. Diurnal profiles must then be applied to estimate hourly RWC emissions from the daily estimates. Gentpro provides the option to aggregate the daily RWC profiles to month-of-year profiles as well, which can be used to compute monthly inventory estimates from annual inventory data. The BASH_NH3 and RC_NH3 profile methods produce county-specific hourly temporal profiles to convert annual, monthly, or daily inventories to hourly emissions estimates. Gentpro provides the option to aggregate the hourly profiles to day-of-year or month-of-year profiles as well. The MET profile method represents time series of a selected meteorology variable as a temporal profile and can be used to convert annual, monthly, or daily inventories to hourly emissions estimates. Gentpro also provides the option to aggregate the hourly MET profiles to day-of-year or month-of-year profiles. All of the Gentpro profile options create temporal cross-reference files that associate county FIPS codes in a modeling domain to the new profiles.

[1] RWC

A regression equation relating observed daily minimum temperatures and chemical tracers of wood combustion was developed using data from sites in the Pacific Northwest of the United States (Adelman, 2009; Adelman, 2010). The sites selected to develop the algorithm were screened to be representative of RWC activities. Equation (1) uses estimates of daily PM2.5 emissions to build either annual-to-daily or annual-to-monthly emission profiles for application to RWC sources. The algorithm uses county average daily or monthly minimum temperatures to estimate the percentage of RWC emissions allocated to each day or month of the year. Gentpro includes a temperature threshold setting to limit RWC emissions from allocated to days too warm to have much (if any) RWC emissions. A temperature threshold (T_t) variable is implemented in Gentpro to allow users to set a maximum temperature cutoff by either state or county. By default, Gentpro estimates RWC emissions at temperatures below 50°F. If the temperature threshold variable is set in the Gentpro script, RWC emissions will be activated below T_t. A look-up table of state/county FIPs codes and temperatures (°F) can be input to Gentpro to set several different temperature thresholds across a modeling domain. The purpose of using the temperature threshold override is to control when RWC emissions are activated in regions where the 50°F cutoff may not be appropriate. For example, counties in southern Florida may only experience one or two days in an entire year when the minimum temperature dips below 50°F. Without using the threshold override, all of the RWC emissions for these counties will be allocated to these one or two days, producing large emissions spikes that may not be realistic. By increasing the temperature threshold, these spikes can be avoided by activating the RWC algorithm on other days. The outputs from this algorithm are temporal profiles that convert annual or monthly RWC inventories to daily emissions for every county in the modeling domain.

Two alternative RWC temporal profile algorithms are implemented in Gentpro. Equation 1 below shows the algorithm developed from the Pacific Northwest Sites described by Adelman (2009; 2010).

The second RWC temporal algorithm is an ad hoc approximation of the original equation that broadens its application by removing the intercept term. By removing the intercept term, Equation 2 below will not produce negative emissions when the temperature threshold is increased above 53.3°F.

The alternate RWC algorithms can be selected using RWC_ALT_EQ_YN listed below. When RWC_ALT_EQ_YN = N, Equation 1 will be used to calculate RWC temporal profiles.

where

[2] NH3

Two NH3 profile methods are implemented in Gentpro to estimate hourly temporal allocation factors, which are output as temporal profiles to convert annual, monthly, or daily livestock ammonia inventories to hourly emissions for every county in the modeling domain. Gentpro can output hour-of-month and hour-of-year temporal profiles that can be input to the Temporal. The recommended application of the BASH_NH3 and RC_NH3 profile methods are to convert monthly agricultural ammonia inventories to hourly emissions.

where

[3] MET: Generic Meteorology Profile Algorithm

This is a simple algorithm that computes the percentage of emissions to allocate to each hour based on the hourly fractional contribution of a selected meteorology variable relative to the annual, monthly, and daily sum of all hourly values for that variable. While the fractional contribution of county-average wind speed for each hour of the year is somewhat meaningless, it does provide a way to build a time series that can be applied to an annual/monthly inventory to estimate hourly values using monthly, daily and/or hourly MET profiles.

where

[Reference]

Adelman, Z. (2010) 'Proposal: Estimating Temporal Profiles for Residential Wood Combustion Emissions', Prepared for U.S. EPA, OAQPS, Research Triangle Park, NC under Contract No. EP-D-07-102 Assignment No. 3-07 (M. Houyoux, WAM) by UNC, Chapel Hill, NC.

Adelman, Z. (2009) 'Technical Memo: Emissions Modeling Improvements Task 2 – Temporal Allocation for Residential Wood Combustion', Prepared for U.S. EPA, OAQPS, Research Triangle Park, NC under Contract No. EP-D-07-102 Assignment No. 2-13 (M. Houyoux, WAM) by UNC, Chapel Hill, NC.

Mansell, G, S. Kemball-Cook, L. Ma (2009) 'Draft Report: Temporal Allocation of Agricultural Ammonia Emissions', Prepared for U.S. EPA, OAQPS, Research Triangle Park, NC under Contract No. EP-D-07-102 Assignment No. 2-13 (M. Houyoux, WAM) by ENVIRON, Novato, CA.

Muck, R.E., and T.S. Steenhuis (1982) 'Nitrogen Losses from Manure', Agricultural Wastes, 4: 41-54.

Russell, A.G. and G.R. Cass (1986) 'Verification of a Mathematical Model for Aerosol Nitrate and Nitric Acid Formation and Its Use for Control Measure Evaluation', Atmospheric Environment, 20: 2011-2025.

Zue, Henze, et al (2013) 'Constraining U.S. Ammonia Emissions using TES Remote Sensing Observations and the GEOS-Chem adjoint model', Journal of Geophysical Research: Atmospheres, 118: 1-14.

This optional program must run prior to Temporal.