Long-Range Transport of Anthropogenically and Naturally Produced PM in the Mediterranean and North Atlantic: Present Status of Knowledge

During the past 20 years, organized experimental campaigns and continuous development and implementation of air pollution modeling has lead to the gain of significant knowledge on the paths and scales of pollutant transport and transformation in the Greater Mediterranean Region (GMR). Research results showed that the climatic conditions in the GMR have significant regional scale characteristics capable of long-range transport. The climatic patterns and the physiographic characteristics of the Mediterranean Region define air quality patterns with remarkable spatiotemporal variability. In addition, concentrations of various pollutants (primary and/or secondary) are found to be significant in remote locations as well as in multiple-layer structure up to a few kilometers above the surface. The characteristic transport and transformation scales have been identified. During the last years, there is a great concern about the important role of aerosols on the air quality of a specific area, due to the potential impact on human health and ecosystems. Aerosols of natural origin such as desert dust and aerosols of anthropogenic origin such as particulate sulfates and nitrates are the key for the investigation of the prospective air quality degradation in the GMR. Longer paths of transport of air pollutants from other areas (e.g. Indian Ocean and Central Africa) towards the Mediterranean as well as from the Mediterranean towards the Atlantic Ocean are under investigation. In addition to this analysis there is a need to better understand the convoluted effects of both the anthropogenic and naturally produced air pollution and especially PM in the atmosphere. Due to these facts the aerosol concentration and deposition patterns are of great interest, along with ozone and its precursors, especially the effort for predicting air quality degradation episodes. In order to investigate these longer paths and scales of processes in the GMR and North Atlantic a major effort has been devoted recently at University of Athens to develop various modeling tools. In this presentation, the present status of knowledge on these complicated processes is discussed wile some new results from such modeling analysis is presented.