Vertical profiling of the electrical properties of charged desert dust during the pre-ASKOS campaign.

Numerous studies of the electrical properties in dusty environments, related to lofted particle charging, indicate that it is a rather complex mechanism which greatly affects the particle dynamics. The electrification of desert dust particles can differentiate their settling velocities and, therefore, can affect the removal of large particles from the atmospheric circulation. A systematic effort to orderly measure the electrical properties of elevated dust layers, with the subsequent monitoring of the respective parameters on a ground reference level, will be made in the major AEOLUS Cal/Val campaign of ASKOS in Cape Verde, in June/July 2021. The preparatory phase of the campaign was carried out in Cyprus, in November 2019, where the initial prototypes of disposable atmospheric electricity sensors were tested on-field. We report here, measurements of the vertical atmospheric electric field and atmospheric ion density through the launches of balloon-borne instrumentation under dust event conditions. We observed perturbations of the E-field within the dust layers which could be attributed to the stratification of charges within the layer, regardless of the layer structure, due to either gravitational settling or possible updraft mechanisms. To verify our findings, we plan to launch the complete instrumental suite in Cape Verde over Saharan dust elevated layers.

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