Facing the Future: Evidence from Joint Aspen FACE, SoyFACE and SFB 607 Meeting

摘要

Ground-level ozone (O_3) is a secondary atmospheric pollutant resulting from chemical reactions between anthropogenic and natural emissions of precursor oxides of nitrogen (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. Tropo-spheric O_3 production is more rapid under warm temperatures when air masses are stagnant. Meteorology exerts a significant role in the formation and transfer of O_3 to terrestrial surfaces such as forests and crops. Annual average background O_3 concentrations over mid-latitudes of the northern hemisphere range between 20 and 45 ppb and the annual cycle is characterized by a spring maximum that peaks during May (Vingarzan, 2004).