When winds are strong, large amounts of sand and dust can be lifted from bare dry soils and transported downwind in the atmosphere, affecting regions hundreds to thousands of kilometres away. For countries in and downwind of deserts, the airborne sand and dust represents a serious risk to the environment, property and human health. Due to a semi-permanent existence of the dust aerosol in the atmosphere and because of its direct (radiational) and indirect (clouds, precipitation) impacts, dust also represents an important climate controlling factor.
The first part of the presentation addresses the recently established WMO Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS) project. An increased interest for predicting and better understanding of the mineral aerosol processes, and accumulated experience in dust modeling and observing, has motivated WMO to coordinate and support activities in modelling and monitoring sand and dust storms (SDS). The project’s goal is to integrate activities of the modelling and observation communities, and also to provide users with dust-related products. Recent developments and implementation plans will be presented.
In the second part of the lecture, developments of the Dust Regional Atmospheric Model (DREAM) will be reviewed. The DREAM is embedded in the NCEP Eta and NMM regional models as an online component. It simulates/forecasts all major phases of the atmospheric dust cycle, including dust emission, mixing, long-range transport and deposition. Based on this model, the first ever operational dust predictions were preformed in early nineties. The most recent DREAM developments that will be presented include the atmosphere-dust interaction modeling and simulation of the atmospheric cycle of iron (the major marine nutrient) carried by dust.