Chemical Characteristics of Wet and Dry Atmospheric Fallout in Northern California

Abstract

Abstract Wet and dry atmospheric fallout were monitored on an event basis at eight locations during the wet season, November 1978–May 1979. Nine different ionic species, plus conductivity and volume, were determined. Wet fallout was commonly acid (pH < 5.6) at all sites, although there was considerable variation between sites, and temporal variation within sites. At most sites H + was highly correlated with NO 3 − but not with SO 4 2− , and NO 3 − /SO 4 2− equivalent ratios exceeded 1.0, indicating that HNO 3 was predominant and H 2 SO 4 secondary. Dry fallout comprises a large proportion of total atmospheric fallout.