Ambient Ammonia Concentrations Across New York State

Ammonia (NH3) was monitored at four locations (two urban and two rural) across New York State from April 2016 to October 2017 using active and passive systems. The two rural sites were Pinnacle State Park (PIN) and the Village of Potsdam, and the two urban sites were the City of Rochester and Queens College in New York City. Active and passive concentrations were well correlated across all sites (r(2) = 0.866), but the active systems measured 6.2% higher NH3 concentrations. The mean (+/- SD) NH3 concentrations measured using active systems in Queens College, City of Rochester, Village of Potsdam, and PIN were 3.22 +/- 2.23, 2.84 +/- 1.91, 1.29 +/- 1.12, and 0.82 +/- 0.64 ppb, respectively. Ambient NH3 concentrations varied with diel vehicular and seasonal agricultural activities. NH3 concentrations at the urban sites had lower seasonal variability than the rural sites. NH3 concentrations were generally related to regional and in-state NH3 emissions although less regional influence was observed at the urban sites. Local NH3 source directions were identified using conditional bivariate probability function. The urban sites were affected by local NH3 sources such as vehicular emissions and urban population centers. Likely distant NH3 source locations affecting the four sites were identified using simplified quantitative transport bias analysis model. Rural sites were more highly affected by transported NH3. Midwestern and Atlantic were major NH3 source areas. NH3 emissions from the south of PIN were probably due to the use of diesel trucks and other diesel engines in the hydraulic fracturing industry in Pennsylvania near the New York State border.