Make BEAM Vehicles emit Black Carbon and Road Dust #3911
Description
Update BEAM’s emission modules to incorporate both Black Carbon (BC) and Road Dust emissions using new emission rate estimates generated by @arielgatech.
Black Carbon Emissions (Three sets of BC emission rates are introduced)
- BC-V1: Derived from EMFAC PM2.5 emission rates adjusted with an empirical BC fraction (from MOVES).
- BC-V2: Based on measurement data provided by Chelsea Preble and Tom Kirchstetter.
- BC-V3: Primarily measurement-based, with lower speed emissions imputed using BC-V1 values.
- The methodology involves calculating vehicle model–specific proportions from EMFAC-based BC-V1 and then applying these proportions to adjust BC-V2 and BC-V3, ensuring consistent estimates across different vehicle models and operating conditions.
Road Dust Emissions
- It is estimated using AP-42 method and CA-specific parameters that accounts for vehicle weight, roadway-specific silt loading, and vehicle miles traveled across various road types.
https://www.epa.gov/air-emissions-factors-and-quantification/ap-42-compilation-air-emissions-factors-stationary-sources#:~:text=AP%2D42%2C%20Compilation%20of%20Air,200%20air%20pollution%20source%20categories
General Background
This update is part of a broader initiative to accurately estimate traffic-related air pollutant emissions (e.g., NOx, HC, PM, PM2.5, SOx, NH3, CO) using BEAM CORE vehicle activity data combined with emission rates from multiple sources (EMFAC, NREL Cambium datasets, etc.). While the BC component uses both empirical speciation and measurement-based approaches (to capture variations across vehicle classes, fuel types, and emission control technologies), the road dust component leverages established regression techniques to quantify fugitive dust emissions.