Unraveling the interaction of urban emission plumes and marine breezes involved in the formation of summertime coastal high ozone on Long Island

Abstract

The New York City (NYC) urban region and locations downwind (i.e., Long Island) are currently characterized as one of the critical regions for studying ozone pollution with special emphasis on...

Enhanced summertime PM2.5-suppression of O3 formation over the Eastern U.S. following the O3-sensitivity variations

“…1b). This can be attributed to urban plume transport, which has been discussed in some detail from recent and current studies based on the 2018 Long Island Sound Tropospheric Ozone Study (LISTOS), [22][23][24] and the formed O 3 and PM 2.5 and some unreacted precursors can be carried to downwind regions. Meanwhile, based on the fact that the averaging time period for MDA8 O 3 (8 hours) and DA24 PM 2.5 (24 hours) is generally much longer than the time scale of the photochemical reactions, it is reasonable to believe that the urban plume transport could result in the similar PM 2.5 -suppression factors for both urban and downwind sites.…”

“…These ve sites include (a) two urban sites: the IS52 site in Bronx County of NYC and the Queens College (QC) site in Queens County of NYC in New York State, and (b) three downwind sites: the Eisenhower Park (EP) site in western Long Island in New York State, the Holtsville (HOL) site in central Long Island, and the Criscuolo Park (CP) site in New Haven in Connecticut state, which was chosen because it is frequently inuenced by sea breezes that transport NYC urban outow plumes. [22][23][24] The IS52, QC, EP, and HOL sites belong to the New York State Department of Environmental Conservation (NYSDEC), and the CP site belongs to the Connecticut Department of Energy and Environmental Protection. In addition to these ve sites for NYC and downwind locations, another 11 major Eastern U.S. cities with the U.S. Environmental Protection Agency measurement sites for O 3 and PM 2.5 in the urban regions were chosen to investigate the spatial/temporal variation of the PM 2.5 -suppression factor.…”

“…7 To verify the connection between the PM 2.5 -suppression factors and the O 3sensitive regime existing over a larger region, major cities of the Eastern U.S. and their downwind regions are selected in this study, with a focus on the Long Island Sound and surrounding area located just downwind of NYC. [22][23][24] This study will focus on the spatial variation of the PM 2.5 -suppression factors over several major Eastern U.S. cities and also from urban to downwind regions (NYC as an example) and the temporal variation from 2004 to 2019 to explore the relationship between the PM 2.5 -suppression factors and the corresponding O 3 -sensitivity regimes over this regional scale.…”