cc-by-4.0Beck, LisaSchobesberger, SiegfriedJunninen, HeikkiLampilahti, JanneManninen, AnttiDada, LubnaLeino, KatriHe, Xu-ChengPullinen, IidaQuéléver, LaurianeFranck, AnnaPoutanen, PyryWimmer, DanielaKorhonen, FransSipilä, MikkoEhn, MikaelWorsnop, DouglasKerminen, Veli-MattiPetäjä, TuukkaKulmala, MarkkuDuplissy, Jonathan2025-03-242021-11-302021-11-30https://hydatakatalogi-test-24.it.helsinki.fi/handle/123456789/10570The data used in the publication is available for download. The unit of the data can be found in the header of the csv files. Please note, that the mass spectrometer data is in UTC+3 time, the rest of the data in UTC+2 time.OpenDiurnal evolution of negative atmospheric ions above the boreal forest: From ground level to the free tropospheredataset