Acid Precipitation Patterns and Trends in Eastern North America, 1980–84

Abstract

Using data complied from seven nationwide precipitation chemistry networks in the United States and Canada, the spatial distribution of hydrogen, sulfate and nitrate ions in North America is discussed. Geographic patterns of concentration and deposition are characterized using isopleth maps which are presented and interpreted for the years 1980?84. The maps were developed using a geostatistical technique known as kriging. This method allows for the estimation of confidence limits on interpolated values. Using these limits, the significance of an observed decrease in the spatial patterns of deposition and concentration is assessed. Decreases of as large as 15?20% were observed in sulfate and nitrate concentrations between 1980 and 1983.