Dataset abstract Cloud Condensation Nuclei (CCN) are a subclass of atmospheric aerosol particles, which can be activated to cloud droplets at a certain supersaturation, with respect to water. Due to their abundance, these particles can affect micro-physical properties of clouds, while acting as CCN. It was found that CCN are relevant for the Earth’s radiation budget, by affecting cloud albedo and lifetime. When giving a number concentration of CCN, also the supersaturation at which it was measured has to be given. With additional information on particle number size distribution, the hypothetical diameter of particle activation (critical diameter) was derived. Further, the particle hygroscopicity parameter (kappa) was calculated using the critical diameter. Values of kappa can be a proxy for bulk chemical composition of the sampled CCN population. Our dataset gives CCN number concentrations measured by a CCN counter (type CCN-100 by DMT, Boulder, US) operated at five different levels of supersaturation (0.15%, 0.2%, 0.3%, 0.5%, 1%) during the Antarctic Circumnavigation Expedition (ACE) cruise over the Southern Ocean, as part of the ACE-SPACE project. Temporal coverage is from December 20, 2016 to March 19, 2017. We give 5-minute averaged and quality controlled CCN number concentrations, critical diameter and kappa values. Dataset contents ACESPACE_cloud_condensation_nuclei_number_concentration_SS015.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_number_concentration_SS020.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_number_concentration_SS030.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_number_concentration_SS050.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_number_concentration_SS100.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_critical_diameter_SS015.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_critical_diameter_SS020.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_critical_diameter_SS030.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_critical_diameter_SS050.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_critical_diameter_SS100.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_hygroscopicity_parameter_SS015.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_hygroscopicity_parameter_SS020.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_hygroscopicity_parameter_SS030.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_hygroscopicity_parameter_SS050.csv, data file, comma-separated values ACESPACE_cloud_condensation_nuclei_hygroscopicity_parameter_SS100.csv, data file, comma-separated values data_file_header_number_concentration.txt, metadata, text data_file_header_critical_diameter.txt, metadata, text data_file_header_hygroscopicity_parameter.txt, metadata, text change_log.txt, metadata, text README.txt, metadata, text The files listed above contain Cloud Condensation Nuclei (CCN) number concentration (N_CCN), critical diameter (D_crit) and particle hygroscopicity parameter (KAPPA) values for the Antarctic Circumnavigation Expedition from in-situ measurements. Each file contains only N_CCN, D_crit or KAPPA values for one of the five measured levels of supersaturation (SS), e.g., N_CCN at SS=0.15% in ACESPACE_cloud_condensation_nuclei_number_concentration_SS015.csv or N_CCN at SS=0.2% in ACESPACE_cloud_condensation_nuclei_number_concentration_SS020.csv etc. In addition, for each N_CCN value the respective temperature of the CCNCs measurement column (T_col) is given. Values are from 1 Hz measurements and averaged to represent 5-minute intervals. For every given value of CCN number concentration, the respective supersaturation level is given, although files only contain values for one level only. Additionally, longitude and latitude for the ship’s position at the start time of the averaging period are given. For latitude and longitude nan values are given, in cases where positioning data was not available for the given time period. There are no nan values for CCN number concentration included, in a way that only quality assured data is given. Change log v1.1 - data files updated change dataset title to specify ACE cruise change time resolution to 5 minutes addition of critical diameter data addition of hygroscopicity parameter data create separate data_file_headers add change log v1.0 - initial release of dataset

{"references": ["Gysel, M. & Stratmann, F. (2014). WP3\u2010 NA3: In\u2010situ chemical, physical and optical properties of aerosols Deliverable D3.11: Standardized protocol for CCN measurements. http://www.actris.net/Portals/97/Publications/quality%20standards/aerosol%20insitu/WP3_D3.13_M24_CCNC_SOP_v130514.pdf", "David W H Walton, & Jenny Thomas. (2018, November 22). Cruise Report - Antarctic Circumnavigation Expedition (ACE) 20th December 2016 - 19th March 2017 (Version 1.0). Zenodo. http://doi.org/10.5281/zenodo.1443511", "Herenz, P., Wex, H., Henning, S., Kristensen, T. B., Rubach, F., Roth, A., Borrmann, S., Bozem, H., Schulz, H., and Stratmann, F.: Measurements of aerosol and CCN properties in the Mackenzie River delta (Canadian Arctic) during spring\u2013summer transition in May 2014, Atmos. Chem. Phys., 18, 4477\u20134496, https://doi.org/10.5194/acp-18-4477-2018, 2018.", "Khlystov, A., C. Stanier, and S. N. Pandis, 2004: An algorithm for combining electrical mobility and aerodynamic size distributions data when measuring ambient aerosol special issue of aerosol science and technology on findings from the fine particulate matter supersites program. Aerosol Science and Technology, 38, 229\u2013238, doi:10.1080/02786820390229543.", "Kristensen, T., T. M\u00fcller, K. Kandler, N. Benker, M. Hartmann, J. Prospero, A. Wiedensohler, and F. Stratmann, 2015: Properties of cloud condensa- tion nuclei (ccn) in the trade wind marine boundary layer of the eastern caribbean sea. Atmospheric Chemistry & Physics Discussions, 15.", "Modini, R. L., A. A. Frossard, L. Ahlm, L. M. Russell, C. E. Corrigan, G. C. Roberts, L. N. Hawkins, J. C. Schroder, A. K. Bertram, R. Zhao, A. K. Y. Lee, J. P. D. Abbatt, J. Lin, A. Nenes, Z. Wang, A. Wonasch\u00fctz, A. Sorooshian, K. J. Noone, H. Jonsson, J. H. Seinfeld, D. Toom-Sauntry, A. M. Macdonald, and W. R. Leaitch, 2015: Primary marine aerosol-cloud interactions off the coast of california. Journal of Geophysical Research: Atmospheres, 120, 4282\u20134303, doi:10.1002/2014JD022963. URL https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014JD022963", "P\u00e9rez, F., & Granger, B. E. (2007). IPython: a system for interactive scientific computing. Computing in Science & Engineering, 9(3), 21-29.", "Petters, M. and S. Kreidenweis, 2007: A single parameter representation of hygroscopic growth and cloud condensation nucleus activity. Atmospheric Chemistry and Physics, 7, 1961\u20131971.", "Schmale, J., Henning, S., Henzing, B. et al. Collocated observations of cloud condensation nuclei, particle size distributions, and chemical composition. Sci Data 4, 170003 (2017). https://doi.org/10.1038/sdata.2017.3", "Schmale, Julia, Henning, Silvia, Tummon, Fiona, Hartmann, Markus, Baccarini, Andrea, Welti, Andr\u00e9, \u2026 Gysel-Beer, Martin. (2019a). Sub-micron aerosol particle size distribution collected in the Southern Ocean in the austral summer of 2016/2017, during the Antarctic Circumnavigation Expedition. (Version 1.0) [Data set]. Zenodo. http://doi.org/10.5281/zenodo.2636700", "Schmale, Julia, Henning, Silvia, Tummon, Fiona, Hartmann, Markus, Baccarini, Andrea, Welti, Andr\u00e9, \u2026 Gysel-Beer, Martin. (2019b). Coarse mode aerosol particle size distribution collected in the Southern Ocean in the austral summer of 2016/2017, during the Antarctic Circumnavigation Expedition. (Version 1.0) [Data set]. Zenodo. http://doi.org/10.5281/zenodo.2636709", "Schmale, J., Baccarini, A., Thurnherr, I., Henning, S., Efraim, A., Regayre, L., Bolas, C., Hartmann, M., Welti, A., Lehtipalo, K., Aemisegger, F., Tatzelt, C., Landwehr, S., Modini, R. L., Tummon, F., Johnson, J. S., Harris, N., Schnaiter, M., Toffoli, A., Derkani, M., Bukowiecki, N., Stratmann, F., Dommen, J., Baltensperger, U., Wernli, H., Rosenfeld, D., Gysel-Beer, M., & Carslaw, K. S. (2019c). Overview of the Antarctic Circumnavigation Expedition: Study of Preindustrial-like Aerosols and Their Climate Effects (ACE-SPACE), Bulletin of the American Meteorological Society, 100(11), 2260-2283. https://doi.org/10.1175/BAMS-D-18-0187.1"]}

The Antarctic Circumnavigation Expedition was made possible by funding from the Swiss Polar Institute and Ferring Pharmaceuticals. We acknowledge funding from DFG within SPP 1158 (Grant no. STR 453/12-1). For more information about this dataset, please contact Christian Tatzelt (tatzelt@tropos.de) or Silvia Henning (henning@tropos.de).