Aerosol levels at Mediterranean Basin are significantly affected by desert dust that is eroded in North Africa and is transported northwards. This study aims to assess the performance of the Dust REgional Atmospheric Model (BSC-DREAM8b) in the prediction of dust outbreaks near the surface in Eastern Mediterranean. For this purpose, model PM10 predictions covering a 7-year period and PM10 observations at five surface monitoring sites in Greece are used. A quantitative criterion is set to select the significant dust outbreaks defined as those when the predicted PM10 surface concentration exceeds 12？μg/m3. The analysis reveals that significant dust transport is usually observed for 1–3 consecutive days. Dust outbreak seasons are spring and summer, while some events are also forecasted in autumn. The seasonal variability of dust transport events is different at Finokalia, where the majority of events are observed in spring and winter. Dust contributes by 19–25% to the near surface observed PM10 levels, which can be increased to more than 50？μg/m3 during dust outbreaks, inducing violations of the air quality standards. Dust regional modeling can be regarded as a useful tool for air quality managers when assessing compliance with air quality limit values. 1. Introduction A large portion of atmospheric Particulate Matter (PM) is derived from arid regions of the Earth (North Africa, Arabian Peninsula, central Asia, Australia, etc.) and is distributed all over the globe. Saharan desert is responsible for up to half of the global mineral dust emissions, thus it is considered as the most important dust source worldwide [1]. Once in the atmosphere, dust aerosols induce serious environmental and health effects [2]. They influence the Earth’s radiation balance as they interact with solar and thermal radiation, causing large uncertainties in assessing climate forcing by atmospheric aerosols [3], they impact on photololysis rates and ozone chemistry by modifying UV radiation [4], and they contribute to the increase of PM levels over populated areas. Therefore, the estimation of the dust load over an area as well as its contribution to aerosols surface concentration is crucial for the implementation of air quality and generally environmental management policies. The North African desert dust cycle depends on the synoptic circulations, which control the frequency and extent of transport and on the washout by precipitation which influences the residences time of dust particles in the atmosphere. The bulk of the dust is transported westward into the Atlantic Ocean and an
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