The Jordan Wind erosion And Dust Investigation (J-WADI)

Knowledge about the particle-size distribution and mineralogical composition of mineral dust at emission are fundamental to advance our understanding and quantification of dust climate effects, yet comprehensive measurements are still largely lacking, especially of super-coarse and giant particles and particle composition. Here, we introduce the Jordan Wind erosion And Dust Investigation (J-WADI), an intensive field measurement campaign conducted in September 2022 north of Wadi Rum in Jordan. The aim of J-WADI is to improve our fundamental understanding of the emission of mineral dust, in particular its full-range size distribution (from fine to giant dust particles) and mineralogical composition. For this purpose, in-situ and ground-based remote sensing instrumentation was installed to measure aerosol properties, e.g. particle numbers and sizes up to about 100 μm, optical  properties, and aerosol distributions; collect soil and aerosol samples for laboratory analysis and experimentation; and to measure meteorological parameters including wind cross sections at high temporal and spatial resolutions and near-surface turbulence. In this contribution, we will present an overview of the J-WADI measurement setup and campaign conditions, together with preliminary results of observed dust events. In the future, J-WADI measurements will serve as a basis to investigate, e.g., (a) the mechanisms leading to the emission and continued suspension of super-coarse and giant dust particles and the possible variability of the emitted dust particle-size distribution; (b) the size-resolved mineralogy of dust at emission, its relationship with the parent soil, and spectroscopic measurement, and (c) dust-radiation and dust-cloud interactions.