A conceptual model for ambient volatile organic compounds over Staten Island, New York

The greater New York City area has failed to attain the National Ambient Air Quality Standard for ozone for more than 30 yr. Ozone is produced in the atmosphere by photochemical reactions involving volatile organic compounds (VOCs) and nitrogen oxides (NO_x). Analyses suggest that summertime ozone production in the urban core of the nonattainment area is often limited by VOCs or is in the transition regime between NO_x and VOC limitation. VOC monitoring at hourly time resolution was conducted for more than 1 yr on Staten Island, NY, to gain insights into VOC emission sources upwind of the New York City area. These data were analyzed using a suite of source apportionment tools. A petroleum refinery was identified as a major propylene source, while a spatial zone with numerous hydrocarbon storage tank farms and terminal operations was identified as a major source for several additional VOCs previously deemed influential in ozone production in the New York City urban core. VOC source regions along Newark Bay were also identified. This work demonstrates the use of highly time-resolved VOC data and source apportionment tools to support air quality management.<i>Implications</i>: This study developed a refined understanding of volatile organic compounds (VOCs) emission sources through hourly VOC monitoring on Staten Island, NY, and demonstrated the value of highly time-resolved VOC data to support air quality management. The study's results collectively suggest that targeted VOC control strategies within and immediately upwind of the dense NOx emissions area within the New York City urban core can help reduce ozone in the New York City urban region as a complement to regional NOx control strategies addressing high ozone formed farther downwind of the city.