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Persistence factors for mobile source (roadway) carbon monoxide modeling

Journal Article · · JAPCA, International Journal of Air Pollution Control and Waste Management; (USA)
 [1]
  1. Univ. of Central Florida, Orlando (USA)

A critical step in the modeling of the carbon monoxide (CO) impacts of mobile sources is predicting an 8-hour CO concentration given a modeled worst-case 1-hour concentration. Often, this is done by a multiplicative persistence factor. A meteorological persistence factor (MPF) accounts for the variability over 8 hours of wind speed, wind direction, stability class, and temperature. A vehicular persistence factor (VPF) reflects the lower traffic volumes during the off-peak hours. Hourly meteorological data for ten years for four cities in Florida were obtained from the National Climatic Data Center. The CALINE3 model was used to obtain hourly CO concentrations, which were combined to derive MPFs for each city. The mean VPF multiplied by the second highest MPF was defined as the worst-case total persistence factor (TPF). These worst-case TPFs increased significantly as more of nighttime were included in the 8-hour averaging time, but were fairly consistent from city to city. In general, the results suggest worst-case TPFs in the range of 0.4 to 0.5, lower than has been recommended by EPA in the past.

OSTI ID:
5136589
Journal Information:
JAPCA, International Journal of Air Pollution Control and Waste Management; (USA), Journal Name: JAPCA, International Journal of Air Pollution Control and Waste Management; (USA) Vol. 39:5; ISSN JIJME; ISSN 0894-0630
Country of Publication:
United States
Language:
English