SAFIRE ATR42: UHSAS dataset

The UHSAS aerosol dataset contains microphysics in situ measurements gathered during EUREC4A field campaign with a UHSAS-A (airborne version) probe installed on the SAFIRE ATR-42 (lower left-hand pod on the fuselage section). The dataset contains one file per flight, 19 files in total. The UHSAS is an optical-scattering aerosol particle spectrometer commercialized by Droplet Measurement Technologies (DMT). It sizes and counts particles in the 0.06 – 1 µm range and sorts them into 99 size bins. The working principle is as follows: external air is drawn at a controled sample flow rate (about 50 sccm) through an inlet into the instrument body where it intersects a laser beam (Nd3+:Y LiF4 laser @ 1064 nm). The light scattered by each aerosol particle is collected by two pairs of Mangin collection optics and measured with a dual Avalanche photodiode/low-gain PIN photodiode detection system. The size of each particle is derived from the measured scattered intensity using the Rayleigh (40-300nm) or Mie (300-1000nm) scattering models. Available parameters are Particle Size Distribution (PSD), Total concentration (NT), 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.