Data of cloud condensation nuclei number concentration and chemical compositions mass concentration

This dataset comprises cloud condensation nuclei number concentration (NCCN , cm-3) and chemical composition mass concentration (μg·m-3) from six sites, extracted from time-series plots in published studies using WebPlotDigitizer (https://automeris.io/). The digitized data points were averaged to hourly resolution, with NCCN samples below 10 cm-3 excluded. The extracted time series were carefully cross-compared with the original plots to verify reliability. However, perfect extraction of all data points was inherently challenging due to overlapping symbols or lines in some of the original figures, which may introduce uncertainties in the extracted values. Consequently, users are advised to exercise caution when utilizing this dataset for subsequent analyses. The authors disclaim any responsibility for potential errors, inaccuracies, or misinterpretations arising from the use of this dataset. Each CSV file is named following the convention "sitename_variable_df". Detailed site information and data sources are provided in the "0. Data description.xlsx" document.