Data for: Multi-campaign ship and aircraft observations of marine cloud condensation nuclei, and droplet concentrations

In-situ marine cloud droplet number concentrations (CDNCs), cloud condensation nuclei (CCN), and CCN proxies, based on particle sizes and optical properties, are accumulated from seven field campaigns, ACTIVATE, NAAMES, CAMP2EX, ORACLES, SOCRATES, MARCUS, and CAPRICORN2. Each campaign involves aircraft measurements, ship-based measurements, or both. Measurements are collected over the North and Central Atlantic, Indo-Pacific, and Southern Oceans, representing a range of clean to polluted conditions in various climate regimes. With the large range of environmental conditions sampled, this collection of data is ideal for testing satellite remote detection methods of CDNC and CCN in marine environment. Remote measurement methods are key to expanding the available data, in these difficult to reach regions of the Earth, and improving our understanding of aerosol-cloud interactions. Additional particle composition and continental tracers are included to identify potential contributing CCN source. Several of these campaigns, include both High Spectral Resolution Lidar and polarimetric imaging measurements that will be the basis for the next generation of space-based remote sensors and, thus, can be utilized as satellite surrogates.

Methods
This is an aggregated dataset, consisting of timeseries with in-situ aircraft or ship campaign measurements from ACTIVATE, NAAMES, CAMP2EX, ORACLES, SOCRATES, MARCUS, and CAPRICORN2. CCN, CCN proxies and measurements necessary to identify particle physical and chemical properties and non-marine contributions to particle concentrations are included. All missing or invalid data flags are converted to ‘Na’. Some datasets have already been filtered for inlet shattering in-cloud, and measurement contamination from ship exhausts; however, methods of filtering ship exhaust vary by campaign. For the NAAMES ship campaigns, the research ship exhaust was identified and filtered out based on the wind direction relative to the ship exhaust and total particle counts. For CAPRICORN2, wind direction, total particle counts, black carbon particle concentration, and CO and CO2 measurements were also utilized in filtering ship exhaust. Finally, the MARCUS ship exhaust contamination periods are identified and filtered using total particle counts and CO measurements. The aggregated dataset is further filtered to eliminate measurements influenced by in-cloud inlet shattering and averaged at 10 second intervals for aircraft measurements and 5-minute intervals for ship measurements (except for CAPRICOR2 which is only publicly available at hourly averaged intervals).