Ten-year operational dust forecasting – Recent model development and future plans

Abstract

The Sahara desert is one of the major sources of mineral dust on Earth, producing up to 2x10 8 t yr -1 . A combined effort has been devoted during the last ten years at the University of Athens (UOA) from the Atmospheric Modeling and Weather Forecasting Group (AM&WFG) to the development of an analysis and forecasting tool that will provide early warning of Saharan dust outbreaks. The developed tool is the SKIRON limited-area forecasting system, based on the Eta limited area modeling system with embedded algorithms describing the dust cycle. A new version of the model is currently available, with extra features like eight-size particle bins, radiative transfer corrections, new dust source identification and utilization of rocky soil characterization and incorporation of more accurate deposition schemes. The new version of SKIRON modeling system is coupled with the photochemical model CAMx in order to study processes like the shading effect of dust particles on photochemical processes and the production of second and third generation of aerosols. Moreover, another new development in the AM&WFG is based on the RAMS model, with the incorporation of processes like dust and sea-salt production, gas and aqueous phase chemistry and particle formation. In this study, the major characteristics of the developed (and under development) modeling systems are presented, as well as the spatiotemporal distribution of the transported dust amounts, the interaction with anthropogenically-produced particles and the potential implications on radiative transfer. 1. Ten-Year Operational Dust Forecasting Saharan desert is known as the most important source of soil particles in the atmosphere. Saharan dust particles have been associated with changes in the earth's radiation balance, more frequent precipitation events at the affected areas, modifications in photolysis rates, air quality degradation and reduction of visibility. Large concentrations of mineral dust can be found in the tropical Atlantic, reaching the Caribbean due to specific wind patterns. Episodic transport of dust particles to the Mediterranean region, as well as northern Europe has been also observed. The production, transport and deposition cycle of Saharan dust is rather complicated and the complexity of these processes becomes more enhanced by taking into account their mixture with anthropogenically-produced air pollutants. Advanced modeling techniques, as complementary tools to observations, are implemented world-wide for the identification of production, transport, transformation and deposition patterns, as well as for the understanding of the aerosol cycle in the