立山山麓における粒子状・ガス状成分の長期観測

抄録

Bi-weekly samples of aerosol particles, acidic gases and ammonia were collected using 4-stage filter-pack method from April 2004 to March 2017 at Tateyama Mountain area (Tateyama station, altitude: 1,180 m a.s.l.). The dominant ionic species in aerosol particles were non-sea-salt (nss) SO₄²⁻ and NH₄⁺. Long-term trends of nssSO₄²⁻ and NH₄⁺ during the period of 2005 to 2016 were −5.9 and −4.9 %/yr, respectively. NO₃⁻ concentrations were nearly unchanged. Factors contributing to seasonal variations and annual trends in these components were discussed, considering changes in emissions in Japan and China, in addition to air mass transport conditions. Observations at multiple remote sites would be useful for refining emission inventories, atmospheric chemical transport models, and further understanding of the atmospheric environment.