An investigation of the atmospheric HNO₃-NH₃-NH₄NO₃ equilibrium relationship in a cool, humid climate

Abstract

Simultaneous measurements of gaseous nitric acid and ammonia were made during summer. autumn and winter months in North-West England. Concentrations of HNO₃ and NH₃ lav within the ranges 0.03-0.36 ppb and 0.9-5.1 ppb respectively, gaseous HNO₃ accounting for only about 12% of total nitrate. Under the high humidity conditions prevalent during the work. the concentration data are consistent with the equilibrium of gaseous HNO₃ and NH₃ with solution droplets of NH₄NO₃.