Size distribution of neutral and charged particles smaller than 42 nm measured over the Southern Ocean in the austral summer of 2016/2017, during the Antarctic Circumnavigation Expedition (ACE).

The size distribution of neutral and charged particles was measured using a neutral cluster and air ion spectrometer (NAIS) instrument. The concentration was corrected for diffusional losses in the inlet.

The concentration and temporal dynamics of small particles is fundamental to characterize the first step of new particle formation (NPF) and growth. Moreover, naturally charged particles and ions can provide information about the role of ion induced nucleation. Newly formed particles can grow to larger sizes where they act as cloud condensation nuclei, directly affecting the Earth radiative budget and cloud properties.

Measurements were performed on the upper deck of icebreaker Akademik Tryoshnikov along the track of the Antarctic Circumnavigation expedition. Temporal coverage is from January 22, 2017 to April 11, 2017. The concentration is reported as dN/dlog(Dp) per cubic centimetre, where Dp indicates the corresponding diameter size bin. Data were collected with one-second time resolution and averaged automatically by the acquisition software to 120 seconds before January 31 2017 and to 90 seconds after that date. The instrument was calibrated before the campaign by the manufacturer and periodically cleaned during the campaign (one time per leg).

Pollution from the ship exhaust and other human activities (e.g. helicopter flights) was identified as described in Schmale et al., 2019 (https://doi.org/10.1175/BAMS-D-18-0187.1) and a corresponding flag was associated to the data (with 1 meaning clean data and 0 polluted data).

***** Dataset contents *****

- 01_neutral_particles_size_distribution.csv, data file, comma-separated values

- 02_negative_ions_size_distribution.csv, data file, comma-separated values

- 03_positive_ions_size_distribution.csv, data file, comma-separated values

- 04_neutral_particles_size_distribution_header.txt, metadata, text

- 05_negative_ions_size_distribution_header.txt, metadata, text

- 06_positive_ions_size_distribution_header.txt, metadata, text

- README.txt, metadata, text

Data that were missing or bad because of instrumental problems were simply removed from the file (no entry).