SUNVEx 2021 Emissions

LA Emissions Inventory

The files provided here are a high-resolution (1.3km) fuel-based on-road emission inventory and total anthropogenic emissions inventory for June 2021 over southern California. Files are netCDF format and weekday, saturday, and sunday emissions are in separate folders, each split into two files with 12 hours of data in UTC. Emissions for gaseous species are in mol/km2/hr. The evaluation of this emission inventory is currently under review for publication.

The on-road emissions are a modified version of the Fuel-based Inventory for Vehicle Emissions (FIVE) (Harkins et al., 2021) with key modifications including gridding at 1.3km resolution and the inclusion of a light-/medium-duty diesel vehicle category. This vehicle category is distributed with the spatial pattern of light-duty gasoline vehicles, the temporal pattern of heavy-duty diesel vehicles, and accounts for 20% of on-road diesel fuel usage. In comparison to the existing FIVE inventory, this reapportionment results in higher on-road NOx emissions overall, especially on weekdays, and more emissions attributed to light-duty vehicle spatial patterns.

Emissions in the total anthropogenic emissions file include these on-road emissions, fuel-based off-road emissions from engines used in agricultural and construction equipment (Harkins et al., 2021), area and point sources scaled to 2021 from the National Emissions Inventory (NEI2017), oil and gas emissions from the Fuel-based Oil and Gas Inventory (Francoeur et al., 2021), and ocean-going vessels and Mexico emissions from the CAMS inventory (Granier et al., 2019). Emissions from these individual categories.

For more information or questions, contact Brian McDonald.

RACM2B_VCP Mechanism Development Inventory

The files provided here are for two chemical mechanisms in WRF-Chem, RACM_ESRL_VCP and RACM2B_VCP. Both are provided for May through September 2021 on two different domains. The "CA4km" domain covers California and Nevada at a resolution of 4km x 4km. The "CONUS12km" domain covers the continental United States at a coarser resolution of 12km x 12km.

Files are netCDF format and separated into representative days for each month of weekday, saturday, and Sunday. Each representative day is split into two files with 12 hours of data in UTC. The units of each species in the file are included in the variable attributes.

The emissions provided here are the total anthropogenic emissions, used for WRF-Chem model runs. The emissions include on-road emissions, fuel-based off-road emissions from engines used in agricultural and construction equipment (Harkins et al., 2021), area and point sources scaled to 2021 from the National Emissions Inventory (NEI2017), oil and gas emissions from the Fuel-based Oil and Gas Inventory (Francoeur et al., 2021), Volatile chemical products (McDonald et al., 2018; Coggon et al., 2021), and ocean-going vessels and Mexico and Canada emissions from the CAMS inventory (Granier et al., 2019). This emissions configuration is described in He et al. (2024).

For more information or questions, contact Brian McDonald.

RACM2B_VCP Mechanism Inventory with Cooking Emissions and Zero Emissions Vehicle Adoption Sensitivity Cases

The files provided here are for the RACM2B_VCP chemical mechanism in WRF-Chem. Both are provided for May through September 2021 on two different domains. The "CA4km" domain covers California and Nevada at a resolution of 4km x 4km. The "CONUS12km" domain covers the continental United States at a coarser resolution of 12km x 12km.

Files are netCDF format and separated into representative days for each month of weekday, saturday, and Sunday. Each representative day is split into two files with 12 hours of data in UTC. The units of each species in the file are included in the variable attributes.

The emissions configuration here is the same as described above in the "RACM2B_VCP Mechanism Development" section, with the addition of volatile organic compound (VOC) emissions from cooking. Cooking emissions included in this emissions configuration are derived from the estimates of cooking emissions in Las Vegas made by Coggon et al. (2024). In addition to the full anthropogenic emission files included here, emissions files for sensitivity cases which progressively remove mobile source sectors to estimate the impacts of vehicle electrification are also included.

For more information or questions, contact Brian McDonald.

LA Box Modeling Study Emissions

Emissions estimates here are provided in netCDF format and generally projected on the standard NEI continental US model grid. Emissions estimates for all reported species are in metric tons/hr, except for individual VOC species (those with names formatted as HC##) which are provided in moles/hr. Files are separated representative days of weekdays, Saturdays, and Sundays for each month. Emissions for a given day are provided as two separate 12-hour files in UTC time.

The exception to this is the biogenic emissions, which are provided at the same 4km x 4km resolution but for a domain centered over California and Nevada. Biogenic emissions are also provided specific to each hour during the study time period and have different units and species names, listed in the variable attributes.

The emissions provided here are for a variety of sectors and inventories and used for a box modeling study of the Los Angeles region for August 2021. The emissions include on-road emissions, fuel-based off-road emissions from engines used in agricultural and construction equipment (Harkins et al., 2021), area and point sources scaled to 2021 from the National Emissions Inventory (NEI2017), oil and gas emissions from the Fuel-based Oil and Gas Inventory (Francoeur et al., 2021), Volatile chemical products (McDonald et al., 2018; Coggon et al., 2021), and ocean-going vessels and Mexico and Canada emissions from the CAMS inventory (Granier et al., 2019). This emissions configuration is described in He et al. (2024). Volatile chemical product, on-road, and off-road emissions here are provided with additional sectoral granularity for use in this study. Further information can be found in the ReadMe file.

For more information or questions, contact Brian McDonald.

VCP Tracer Prior Emissions for Lagrangian Inversion

Emissions estimates here are provided in netCDF format and projected on the standard NEI continental US model grid. Emissions are only provided for 4 Volatile Chemical Product (VCP) tracer species (in moles/hour) and total non-methane VOC emissions (in metric tons/hour) from VCPs. The tracer species included are D4-Siloxane (HC54 in emission files), D5-Siloxane (HC55 in emission files), parachlorobenzotrifluoride (PCBTF, HC58 in emission files), and paradichlorobenzene (PDCBZ, HC58 in emission files). Files are separated into representative days of weekdays, Saturdays, and Sundays for each month. Emissions for a given day are provided as two separate 12-hour files in UTC time.

This inventory of VCP tracer emissions is updated from prior studies of VCP emissions (McDonald et al., 2018; Coggon et al., 2021) using VCP speciation profiles from the California Air Resources Board (CARB) for 2020.

The emissions are also provided in two different versions. The first is for VCP emissions using prior diel emissions profiles (VCP_emis_2021_regionalEF_CARB2020partialemis) and the second is for VCP emissions using a new optimized diel emissions profile developed in the Lagrangian inversion work (VCP_emis_2021_optimized_diurnal_regionalEF_CARB2020partialemis).

For more information or questions, contact Brian McDonald.