Chemical composition of waterfall-induced air ions : spectrometry vs. simulations
Tiia-Ene Parts, Aare Luts, Lauri Laakso, Anne Hirsikko, Tiia Grönholm, Markku Kulmala · Työväentutkimus Vuosikirja · 2024
Our measurements of ion size distributions near a waterfall provided new evidence for a waterfall-induced modification of air ion sizes.The ion size spectrum near a waterfall permanently differs from that in ordinary tropospheric air.In this paper we investigated the near-waterfall air ions chemical nature in detail.We carried out a simulation series of air small negative ion evolution, proposing that falling water, as a new environmental component, increases the concentration of OH -cluster ions.The produced OH -ions were employed as an extra input for our ion evolution model.The presence of additional OH -ions resulted in a decrease of typically model-provided NO 3 -and/or HSO 4 -cluster ion concentrations and an increase of the abundance of HCO 3 -cluster ions.Near the waterfall the latter ions became dominant in our simulations.