Causes of Large Increases in Atmospheric Ammonia in the Last Decade across North America.

ABSTRACT: Decadal trends of atmospheric ammonia (NH₃) and their potential causes were explored through the analysis of monitored data collected at 15 sites in the United States and 7 sites in Canada. Large percentage increases in the annual average concentration of atmospheric NH₃, for example, >100% at 6 sites and 40-100% at 10 sites, were observed over the most recent 8-13 year period. In contrast, a decrease or a narrow variation in NH₃ emissions was reported at the state or provincial level in both countries during the same period. Decreased emissions of SO₂ and NO _x across North America in the past decade would have reduced the chemical loss of atmospheric NH₃ to form particulate NH₄ ⁺. Such a chemica

SUBMITTER: Yao X 

PROVIDER: S-EPMC6933799 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature