In-situ Saharan dust observations over the Eastern Mediterranean with an uncrewed aircraft system

The Saharan desert is the main source of mineral dust in the atmosphere, and its presence in the air can have a significant impact on the solar radiation budget. In evaluating the radiative effect of airborne mineral dust, aerosol charge may be a critical factor. This space charge and its relationship to particle concentrations is not taken into account by current model simulations, and such in-situ measurements are hardly available. In this work, a novel sensor network equipped on an uncrewed aircraft system (UAS) of type MASC-3 was employed for vertical profiling of Saharan dust particle concentrations, meteorological (temperature, relative humidity and wind field) parameters and turbulent kinetic energy (TKE), during a dust event that occurred in Orounda, Cyprus in April 2022. The MASC-3 performed profiles up to 3000 m altitude, and identified the vertical extent of the dust cloud, which was located between 1900 and 2500 m. We were able to capture the evolution of the event over several days, and additional numerical simulation and remote sensing observations verify the results. During the first day of measurements, when dust load was the highest, charge data from the MASC-3 also allowed for investigation of aerosol concentrations and dust electrification. For the first time, this innovative sensor system provided in-situ UAS measurements of the aforementioned quantities and described the dust event in detail, and with high resolution. Considerations on aircraft charging, the effect of turbulent levels and local meteorology, on the space charge / aerosol data collected by the MASC-3, as well as probing Saharan dust events more generally, are elaborated for further related research.