Investigation of Saharan dust plumes in Western Europe by remote sensing, in situ measurements, and transport modelling

Atmospheric dust has significant impact on the Earth’s climate system but different aspects of the impact remain highly uncertain. These uncertainties can be attributed to the larger spatial-temporal variability of aerosol dust and its complex interaction with other atmospheric constituents, radiation, and clouds.  To investigate Saharan dust plumes in Western Europe, we collected a comprehensive set of observational data and compared it with global transport model simulations to achieve a better understanding of the distribution, evolution, and potential impact of dust plumes in southwest Germany for four characteristic cases during April 2018, February 2021, June 2021, and March 2022. Remote sensing methods including lidars and sunphotometers were used to study the dust events employing different retrieval methods and comparing these retrievals with ICON-ART simulations. In situ measurements (e.g. Optical Particle Counters (OPC), Aerodynamic Particle Sizer (APS), and Scanning Mobility Particle Sizer (SMPS)) were used to determine e.g. size distributions and particle number concentrations of dust particles, which were compared for suitable cases with remote sensing measurements and ICON-ART simulations. One major objective was to quantify the uncertainties of the different measurements and retrieval methods including a demonstration how useful scanning lidar measurements can be in addition to vertical lidar and sun photometer data and what kind of understanding of the aerosol properties can be achieved by combining the different measurement techniques. Furthermore, we compared these observational data with predictions by the state-of-the-art transport model, ICON-ART, to evaluate the quality of its predictions for different meteorological conditions. In this contribution, we will discuss the systematic comparison between observational data and ICON-ART model results.