立山有料道路沿いの桂台(標高660 m)~室堂平(標高2450 m)までの10カ所と,科学博物館屋上の合計11カ所で酸性雨調査を継続している.2017年調査の結果,(1)降水量は標高が高くなるほど増加する,(2)酸性雨の原因となる硝酸イオンや非海塩性硫酸イオンの濃度は標高が高くなるほど低下する(高度効果)ことがわかった.しかし,硝酸イオン濃度の方が非海塩性硫酸イオン濃度よりも標高の高まりによって早く減少した.アンモニウムイオン濃度は,9月,10月は硝酸イオンや非海塩性硫酸イオン濃度と同じく高度効果が見られたが,7月,8月は不規則に変化した.非海塩性カルシウムイオン濃度は科学博物館屋上で高く,立山では,所々で小さなピークが見られたが,標高によらずほぼ同様な濃度であった.
Acid rain observations were done at 10 observatories from Katsuradai (660 m a. s. l.) to Murodo-daira (2450 m a. s. l.) in Mt. Tateyama and Toyama Science Museum in Toyama city. Precipitations were increased with increase in altitude (altitude effect). Concentrations of nitrate ions and non-sea salt sulfate ions were decreased with increase in altitude (altitude effect). However, decreasing concentration with increasing altitude was higher in nitrate ion than in non-sea salt sulfate ion. Concentrations of ammonium ions at observatories of Mt. Tateyama were fluctuated in July and August though that concentrations showed altitude effect like as nitrate ion and non-sea salt sulfate ion in September and October. Concentrations of non-sea salt calcium ions were higher at Toyama city than at observatories of Mt. Tateyama and that concentration at observatories in Mt. Tateyama seemed almost same with some peeks at several observatories.