Physics and chemistry of acid precipitation

Studies were conducted on the sources of emissions having the potential to raise the acidity of precipitation, their transformation in the air and in hydro-meteors and droplets to strong acids, the transport mechanisms and the statistical nature of acid precipitation. Findings indicate that the acidity of precipitation has increased in the eastern United States over the past three decades; the larget percentage increase has occurred in the Southeast. Data on SO/sub 2/ and NO/sub x/ emissions in various regions of the US are presented. Information is presented under the following section headings: atmospheric chemistry; droplet chemistry; stack heights and acid rain; transport models of pollutants; comments on the use of statistics in acid precipitation analysis; possible observations and experiments in acid precipitation research; and partial bibliography on acid precipitation. (JGB)