Anthropogenic emissions dominate ozone production in a high-elevation
and highly forested region in central China: implications on forest
ecosystems and regional air quality
One-month continuous ozone (O3) measurement at a high-elevation and
highly forested site discovered elevated O3 levels in the free
troposphere (FT) over central China. O3 injuries to the old-growth
forest in the study region were expected. Local emissions in central
China overwhelmed regional impacts in building up the concentrations of
most air pollutants, same for the ozone formation potential of VOCs.
Nitrogen dioxide dominated the in-situ O3 production. It facilitated the
transformation of peroxyl radicals to hydroxyl radical (OH), instead of
consuming OH. VOCs showed little impact on in-situ O3 production, and
accounted for net consumption of OH, with isoprene as the most
predominant OH depleting species. This study fills the gaps in FT O3
observation and photochemistry in central China, and provides hints that
O3 pollution in central China was more attributed to local emissions.