Investigation Of Voc Reactivity Effects

Abstract

The CAMx grid model was used to assess ozone reactivity effects for Carbon Bond (CB4) VOC species and ethane using the CRC-NARSTO database for the July 12-15, 1995 NARSTO-NE episode in the Eastern United States. The ozone sensitivities to emissions changes in NO x , total VOCs, total anthropogenic VOCs, CO, ethane and the 8 CB4 species used to represent major anthropogenic VOC emissions were calculated using DDM sensitivity analysis. A number of different ozone reactivity scales were derived using various methods to quantify the ozone impacts of the VOC species on the regional scale. These were based on effects of VOCs on daily maximum 1-hour averages in four different episode days, on effects on daily maximum 8-hour averages in three different episode days, and on using six different methods or metrics to derive regional reactivity scales from the varying impacts throughout the modeling domain. The results were compared to relative reactivities calculated with the same chemical mechanism in an EKMA box model used previously to derive the Carter reactivity scales