Abundance of ice-nucleating particles and cloud condensation nuclei measured at the Southern Great Plains and Eastern North Atlantic observatories in autumn 2019 and 2020

The ambient concentration data of ice-nucleating particles and cloud condensation nuclei was collected at two contrasting sites, one in the Southern Great Plains region of the United States with a substantial terrestrially influenced aerosol population, and one in the Eastern North Atlantic area with a primarily marine-influenced aerosol population. The 6-hour time-averaged data was collected from each site, the first from October 1 – November 15, 2019, in Oklahoma, USA, and the second from October 1, 2020 – November 30, 2020, on Graciosa Island, Azores. These datasets were collected to comprehensively understand the difference or similarity in the particle source(s) as well as aerosol-cloud interactions in the atmosphere in association with other ambient observations at these sites. For both sites, the abundance data was taken with online monitors and complementary measurements of ice-nucleating particles by means of offline droplet freezing assay. A total of 14 tabular datasets is provided (the metadata and data matrices are separated). An individual method-oriented data abstract is available in each metadata.