Disentangling dust transport pathways to western Crete using aerosol measurements and HYSPLIT trajectories

Abstract. Mineral dust transported to the eastern Mediterranean affects atmospheric conditions, radiation balance, soil development processes, and ecosystem functioning in deposition areas. While the dominant source regions of deposited dust can be roughly identified with the help of sediment fingerprinting approaches, different methodological challenges hamper the exact identification of aeolian sediment sources and their potential temporal and spatial shifts. This study evaluates whether the combination of ground-based aerosol concentration measurements and backward-trajectory modelling can provide a temporally more resolved perspective on dust-source variability in western Crete. With this aim, aerosol concentrations from a monitoring network in and around the Lefka Ori mountains were used to identify days with elevated surface-near dust loads between October 2023 and September 2025. For these days, air-mass pathways were reconstructed using the atmospheric transport and dispersion modelling system HYSPLIT, and grouped into recurring transport patterns. The resulting clusters show that elevated aerosol concentrations were primarily associated with transport from southern directions representing North Africa, especially Libya and Egypt, but also with frequent northerly pathways connecting Crete to the Balkan, the Black Sea region and eastern Europe. Clusters summarising southerly transport patterns showed the strongest seasonal relevance during the main dust season in spring and were associated with higher aerosol concentrations, whereas clusters associated with northerly transport patterns occurred frequently but were generally associated with lower aerosol concentrations. The applied method enabled a temporally high resolved assessment of dust source regions, thereby revealing subordinate but nevertheless relevant source areas. Future work should combine longer observation periods with chemical, mineralogical, and isotopic analyses to quantify the relative contribution of these source regions to the deposited dust.