Long term records of trace gas  atmospheric constituents (O₃, NO, NO₂, NO_Y, SO₂, CO), aerosol mass (PM2.5), and standard meteorological parameters have been collected by the Atmospheric Sciences Research Center (ASRC) of the University of Albany at two rural sites in New York State. In the Adirondack Park at 1483 m elevation, the Whiteface Mountain Observatory on Whiteface summit (44.37°N 73.90°W)  is near the 850 mb pressure level where long range transport of trace gasses from regional sources dominates. Pinnacle State Park near the Pennsylvania boarder in western New York hosts ASRC’s other rural site, Pinnacle Field Station (42.09°N 77.21°W) on the Allegheny Plateau at 504 m elevation. In addition to these ASRC sites, Queens College hosts an urban site (40.74°N 73.82°W) in a partnership with New York’s Department of Environmental Conservation and ASRC located in Queens, New York City less than a kilometer south of the Long Island Expressway. This suite of sites provides a rich data set that reveals long-term trends in trace gas and aerosol concentrations and is being used to examine current issues in atmospheric chemistry.

All trace gases have been continuously monitored at these three sites for 17 years or more. SO₂ at all three stations display a monotonic decrease of up to 90% reflecting policy driven emission controls. Oxides of nitrogen, both NO_X and NO_Y, are also decreasing over this time period although not as rapidly as SO₂ as their wider range of sources is more difficult to address with policy. CO at these three sites is trending downward with Whiteface reaching the lowest annual average of about 100 ppbv. Ozone is more complicated, with Whiteface seeing a modest decrease, Pinnacle remaining steady and Queens College experiencing an increase during 2001-2011 but remaining lower than both the rural sites. Work is underway to quantify summertime ozone production efficiency (OPE) at the rural sites where very low NO_x (<0.5 ppbv) sets the stage for OPE > 10 ppb/ppb at Pinnacle and >15 ppb/ppb at Whiteface.  PM2.5 measured at the three sites shows significant decreasing trends in total mass and in the major chemical components (SO₄, NO₃, NH₄ and TC).