A048-02
Ozone Photochemistry in New York City – Long Island Sound: Results from Summer 2020 Aircraft Observations

Tuesday, 8 December 2020: 10:34
Virtual
Xinrong Ren1, Philip Stratton2, Hannah Daley2, Russell R Dickerson3, Brian C McDonald4, Jessica Gilman5, Aaron Lamplugh6, Ariel F Stein1, Joel Dreessen7 and George Allen8, (1)NOAA Air Resources Laboratory, College Park, MD, United States, (2)University of Maryland, College Park, MD, United States, (3)University of Maryland, AOSC and Chemistry, College Park, MD, United States, (4)Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, United States, (5)NOAA Earth System Research Laboratory, Chemical Sciences Laboratory, Boulder, CO, United States, (6)CIRES and NOAA ESRL, Chemical Sciences Laboratory, Boulder, CO, United States, (7)Maryland Department of the Environment, Air Monitoring Program, Baltimore, MD, United States, (8)NESCAUM, Boston, United States
Recorded Presentation
Abstract:
Aircraft observations of ozone, ozone precursors, and meteorological parameters were made over the New York City – long Island Sound (NYC-LIS) area during ozone exceedance events in summer 2020 when human activities partially recovered from the earlier COVID-19 pandemic lockdown. Despite the reduction in emissions due to COVID-19, ozone exceedance events still frequently occurred in this area. Ozone production efficiency, defined as the ratio of the ozone production rate to the NOx oxidation rate, was calculated using the observations and found to be about 14 ppb ozone produced per ppb NOx oxidized, which is about twice of what was found in Houston, TX during DISCOVER-AQ 2013. This high ozone production efficiency is likely causing the persistent ozone exceedance problem over the LIS and Connecticut coastal area, downwind of NYC under prevailing southwesterly winds. A box model constrained to observations was used to examine atmospheric photochemical oxidation processes. Ozone production and its sensitivity to nitrogen oxides (NOx) and volatile organic compounds (VOCs) were calculated based on the model results. In general ozone production is VOC sensitive near emission sources and NOx sensitive away from source regions. Preliminary results show controlling both NOx and VOCs is beneficial for reducing ozone production in the NYC-LIS area. Reducing VOCs can reduce ozone near emission sources while reducing NOx can reduce ozone production in areas downwind of the source regions. The results from this work strengthen our understanding of ozone photochemistry and provide scientific information for emission control strategies to reduce air pollution in ozone non-attainment areas.
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