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Aerosol acidity has broad significance in the atmosphere and ecosystems;
however, a reliable way to quantify its changes over long time is lacking.
Here, we propose a new approach calculating aerosol pH based on the
nitrogen stable isotope composition (δ15N) of aerosol ammonium (NH4+) and
for the first time reconstruct historical trajectory of aerosol pH over
the last two centuries via δ15N of NH4+ achieved in a Tibetan ice core. We
observed a significant decrease in δ15N of ice core NH4+ by 13‰ from the
preindustrial to modern era, corresponding to a decreased in aerosol pH by
0.75 units. The decline in pH demonstrates a dominant role of
anthropogenic emissions in acid gases over alkaline gases since Industrial
Revolution. Our study also suggests that spatiotemporal patterns of
aerosol acidity could be widely revealed by future nitrogen stable isotope
of aerosol or ice core ammonium measurement, which in turn will promote
the understanding in aerosol chemistry in the context of global
environmental changes.y in the context of global environmental changes.
140 views reported since publication in 2022.