Trends in wet precipitation, particulate, and gas-phase species in New York State

• Published in: Atmospheric pollution research 2017-11, Vol.8 (6), p.1090-1102
• Main Authors: Rattigan, O.V., Civerolo, K.L., Felton, H.D.
• Format: Article
• Language: English
• Subjects: Ammonium; Nitrate; Sulfate; Trends; Wet deposition
• ISSN: 1309-1042; 1309-1042
• DOI: 10.1016/j.apr.2017.04.007

Here we characterized wet deposition National Atmospheric Deposition Program (NADP) species and Clean Air Status and Trends Network (CASTNET) dry deposited particle and gas species across New York over the last 2-3 decades. In addition measurements of NH3 from the Ammonia Monitoring Network (AMoN) were analyzed. In general decreasing annual trends are observed for wet deposition SO42− and NO3− species and dry deposited particle SO42−, NO3− and NH4+ as well as gas phase SO2 and HNO3 consistent with reductions in SO2 and NOx emissions. Wet deposited NH4+ however does not show consistent trends with most sites showing little trend across the region and an indication that levels at some sites maybe increasing. NH3 concentrations also appear to be increasing although the data record is only 8 years. Base cations, Ca2+ and Mg2+ show some decreases in the 1980s but concentrations are relatively uniform since the mid-1990s. Na+ and K+ show large year to year variations, by more than an order of magnitude for Na+ due to influence of marine air at a near coastal site. In general there was a balance between the sum of cations and the sum of anions earlier in the record but the tendency has been for a cation excess in the more recent 5–10 years. Understanding the deposition of reduced nitrogen species is likely to be of concern for the foreseeable future. Such data are important in understanding acidification recovery in response to emission controls. •Over 2-3 decades of wet deposited, particulate and gas phase species are characterized.•Decreasing trends in wet deposited SO4 and NO3 and dry deposited SO4, NO3 and NH4 are consistent with SO2 and NOx emissions.•Little trend is observed for wet deposited NH4.•An 8 year record of NH3 concentrations indicate increasing trends.•Sum of cations is in balance with sum of anions at the beginning of the record but there is a cation excess in recent years.