Main Scientific questions to be answered

• Quantification of the relevant mechanisms, of the BVOC in the formation of tropospheric organic aerosols in typical Mediterranean conditions
• How anthropogenic emissions of reactive species affect the SOA from biogenic precursors
• Quantification of the origin and the fate of the biogenic aerosol
• Importance of biogenic aerosol component on urban air quality management
• Importance and variability of the biogenic component on particulate matter in the atmosphere
• Significance of OH in terms of aerosol formation in the ambient atmosphere
• Biogenic aerosols and radiation forcing

Scientific objectives and approach

• Quantification of the formation of SOA and individual products from the photochemical oxidation of selected anthropogenic and biogenic VOCs over the Mediterranean area
• Quantification of the biogenic fraction on aerosols
• Characterisation of the physical and chemical processes related to aerosols
• Development and validation of an advanced biogenic aerosol chemical module potentially suitable for integration to 3-D photochemical transport models
• Quantification and prediction of SOA budgets and radiative properties at regional scale as well as assessment of the potential climatic importance of SOA forcing mechanism and the change imposed on the energy balance

Needs for improvement of 3-D aerosol/photochemical models

• limited number of application and validation studies
• insufficient emission databases in the Mediterranean region
• lack of data on the evolution of the biogenic versus anthropogenic aerosol mass components
• insufficient data of 14C measurements (biogenic contribution)
• lack of understanding of physicochemical aerosol processes (especially on those of biogenic origin) and of secondary biogenic organic aerosol formation
• mismatch between model requirements and past measurement strategies and corresponding data