http://bolin.su.se/data/oden-ao-2018-aerosol-nais-1 Andrea Baccarini, Julia Schmale, Josef Dommen Bolin Centre Database 2020 Datafile Atmosphere Aerosols Aerosol physical properties Aerosols AO2018 Arctic Ocean Icebreaker Oden Atmosphere Arctic Ocean 2018 Atmospheric Science Atmospheric Chemistry Atmospheric Physics Clouds Aerosol Science Microbiology-Ocean-Cloud-Coupling in the High Arctic MOCCHA High Arctic North Pole Aerosol-Cloud-Interaction 2018 Neutral cluster and air ion spectrometer NAIS Ultrafine particles Ions Ion induced nucleation New particle formation Earth science > Atmosphere Julia Schmale 2020-09-23T10:00:09+00:00 English 1 Raw data were collected at 1 Hz frequency and then averaged for 90 s in order to improve the signal to noise ratio. The NAIS measures sequentially neutral and charged particles, the measurement sequence was set to 90 s for each of the two measurement modes plus 30 s for a background measurement. Hence, a full measurement cycle took 210 s. The datetime is reported in the UTC timezone as yyyy-mm-dd HH:MM:SS. Data are reported as dN/dlog(Dp), where dN is the particle number concentration per cubic centimeter per measured size bin normalized over the logarithm of the bin width. The bin width is defined as the distance between two diameters. They are spaced equally in log-space with 64 bins per decade. Charged particles were measured in a size range from 0.8 to 42 nm, whereas neutral particles were measured from 2 to 42 nm. The difference stem from the fact that corona charger ions had to be removed from the neutral particle measurements. The NAIS tends to overestimate particle concentration due to the NAIS background noise (coming from the electrometers and affecting only low number concentrations), the inversion algorithm and the fact that the NAIS is not a single particle instrument. During this campaign, the concentration measured by the NAIS was between 1.5 and 2 times higher compared to other particle counters as reported in the two figures attached, these results are in line with previous studies, which also reported similar higher concentrations from NAIS. The numeric column header corresponds to the starting size of each diameter bin. The last column in the dataset is a flag to separate between clean data and data that are potentially influenced by the ship exhaust: 1 indicates clean data and 2 contaminated data. Three different files are provided, containing the neutral, the positively and the negatively charged aerosol size distributions. The NAIS instrument was manufactured by Airel (Mirme and Mirme 2013). A characterization of the instruments when measuring neutral particles and ions is provided by Manninen et al. (2016) and by Wagner et al. (2016), respectively. The ship track with latitude and longitude information can be found in the [Navigation, meteorological and surface seawater data from the Arctic Ocean 2018 expedition](https://bolin.su.se/data/ao2018-navigation) data set. The data creator ORCIDs are the following: - Andrea Baccarini: https://orcid.org/0000-0003-4614-247X - Julia Schmale: https://orcid.org/0000-0002-1048-7962 - Josef Dommen: https://orcid.org/0000-0002-0006-0009 Data were collected during the Arctic Ocean 2018 expedition on board the Swedish icebreaker (I/B) Oden, which was organized by the [Swedish Polar Research Secretariat](https://polarforskningsportalen.se/en/arctic/expeditions/arctic-ocean-2018). The observations were part of the project 'Aerosol-cloud interactions in the High Arctic' (PI Paul Zieger, Department of Environmental Science, Stockholm University; see [MOCCHA project website](https://www.aces.su.se/research/projects/microbiology-ocean-cloud-coupling-in-the-high-arctic-moccha/) with updates).