Simulated Effects of Hydrocarbon Emissions Controls on Seasonal Ozone Levels in the Northeastern United States: A Preliminary Study

摘要

The second generation Regional Oxidant Model (ROM2) was used to simulate ozone concentrations in the Northeastern United States over two week periods in each of three months: April, July and August 1980. In each period three separate model simulations were performed. The first of these, the base case, used the 1980 NAPAP 5.3 emissions inventory to specify anthropogenic hydrocarbon and NOx emissions. The second simulation, Control Strategy 1, assumed county-specific reductions of 5% to 50% in hydrocarbon emissions and the third simulation, Control Strategy 2, reduced VOC emissions from Control Strategy 1 an additional 22% across the board. In all three simulations the NOx emissions were the same and the hydrocarbon emissions from natural sources were identical. The predicted ozone changes that result from the emissions changes were extrapolated from the three, 2-week periods to the 'ozone season', which begins on 1 April and runs through 31 October. Three general conclusions were drawn: (1) reducing hydrocarbon emission rates generally reduces ozone levels; (2) the emissions changes proposed in control strategies 1 and 2 reduce peak O3 concentrations most -- they have virtually no effect on concentrations below about the 95-percentile level; (3) the impact of controls on ozone levels is sensitive to meteorological conditions.