SAFIRE ATR42: PMA/CDP-2 dataset

The CDP-2 cloud microphysics dataset contains microphysics in situ measurements gathered during EUREC4A field campaign with a CDP-2 installed on the SAFIRE ATR-42 (left-hand underwing pod). The CDP-2 is a cloud particle spectrometer that counts and sizes cloud droplets in the 2-50 micrometer range into 30 size classes with a resolution of 1 to 2 µm. The raw data (counts per second) is processed using DMT built-in sizing & counting algorithms. The probe sample volume is calculated using the true TAS (ATR-42 Core measurements) and calibrated sample area (measured at LaMP facility in 12/2019). The dataset contains one file per flight, 19 files in total. Measurements in the sub cloud layer reveal that the CDP-2 reponds to non-cloud droplet particles, e.g. large/ultra large aerosols. These particles may not satisfy the underlying assumption made in CDP-2 sizing algorithms (particles scatter light as spherical liquid water particles with an index of refraction of 1.33). In the CDP-2 files, a choice was made not to filter out the measurements taken in non-cloudy area so that further investigations on large aerosols may be conducted, at least qualitatively. However, the CDP-2 response to such aerosol particles is unknown, therefore data taken in non-cloudy area is prone to unquantified errors. Available parameters are Particle Size Distribution (PSD), Total concentration (NT) and Liquid Water Content (LWC, assuming particles are spherical with a density of 1g/cm3 ), given at a frequency of 1 Hz. Data acquisition was synchronized with the ATR-42 GPS synchronised clock and the data is geolocated using aircraft position.