Recent progress in understanding physical and chemical properties of African and Asian mineral dust

摘要

This paper presents a review of recently acquired knowledge on the physico-chemical properties of mineral dust from Africa and Asia based on data presented and discussed\udduring the Third International Dust Workshop, held\udin Leipzig (Germany) in September 2008. Various regional field experiments have been conducted in the last few years, mostly close to source regions or after short-range transport. Although significant progress has been made in characterising the regional variability of dust properties close to source regions, in particular the mineralogy of iron and the description of particle shape and mixing state, difficulties remain in estimating the range of variability of those properties within one given source region. As consequence,\udthe impact of these parameters on aerosol properties\udlike optical properties, solubility, hygroscopicity, etc. �\uddetermining the dust impact on climate � is only partly understood. Long-term datasets in remote regions such as the\uddust source regions remain a major desideratum.\udFuture work should also focus on the evolution of dust\udproperties during transport. In particular, the prediction of\udthe mineral dust size distribution at emission and their evolution during transport should be considered as a high-priority. From the methodological point of view, a critical assessment and standardisation of the experimental and analytical techniques is highly recommended. Techniques to characterize the internal state of mixing of dust particles, particularly with organic material, should be further developed.