大気エアロゾル中の反応性窒素の性状と動態

抄録

Anthropogenic activities such as fossil fuel combustion, fertilizer use, and biomass burning lead to significant Nr (reactive nitrogen) deposition following atmospheric transportation and transformation. Atmospheric Nr deposition can alter nutrient stoichiometry in ecosystems, contributing to changes in the nitrogen cycle. Once deposited to land or surface water, Nr may stimulate primary productivity, reduce the diversity of plant species, acidify aquatic and terrestrial ecosystems. The size distribution of particulate Nr plays a crucial role in processes of particle transformation, transport and deposition. This changes depending on meteorological conditions, the interparticle condensations and/ or volatile during the transport, and the levels of air pollution. Current monitoring of atmospheric Nr mainly focuses on the inorganic nitrogen fraction, while the observation of ON_ws (water soluble organic nitrogen) remains disproportionally insufficient. Regarding ON_ws, its concentration, proportion to total nitrogen, sources, behavior in the atmosphere vary depending on the previous studies. The proportion of ON_ws that can be utilized by organisms also remains unclear. While the emissions of SO₂ and NO_X are decreasing, whereas the emissions of NH₃ are increasing, continuous monitoring is necessary to understand the long-term changes in air quality resulting from variations in emissions of pollutants and social conditions.