Σχηματισμός και κλιματικές επιπτώσεις των αιωρούμενων σωματισδίων στην Ανατολική Μεσόγειο

• Main Authors: Sfakianaki, Maria, Σφακιανάκη, Μαρία
• Format: Doctoral or Postdoctoral Thesis
• Language: Greek
• Published: University of Crete (UOC) 2007
• Subjects: Αιωρούμενα σωματίδια; Οπτικό πάχος; Ανάκτηση δορυφορικών δεδομένων; Επεισόδια σκόνης; Επεισόδια πυρκαγιών; Ενεργειακό ισοζύγιο; Μεσόγειος Θάλασσα; Atmospheric aerosols; Optical thickness; Baer; Satellite remote sensing; Dust events; Fire plumes; Direct/indirect forcing; Mediterranean Sea; Φυσικές Επιστήμες; Χημεία; Natural Sciences; Chemical Sciences; Aerosol Robotic Network
• Online Access: http://hdl.handle.net/10442/hedi/15733; https://doi.org/10.12681/eadd/15733

Aerosols can affect human health and environment. They provide surfaces for heterogeneous reactions in the atmosphere and they also affect visibility and climate. The Mediterranean, as a crossroad of air masses from different origin is affected by different aerosol types; anthropogenic pollution, forest fire plumes, desert dust transports from Sahara as well as natural aerosol from the surrounding continents and ocean contribute to the aerosol loading over this region. Satellite remote sensing techniques provide a great opportunity for the observation and the understanding of the aerosol’s behaviour since they allow systematic and extended spatial and temporal sampling of the atmosphere. In the present study, the Bremen AErosol Retrieval algorithm (BAER) has been applied to MERIS (Medium Resolution Imaging Spectrometer) and SeaWiFS (Sea-viewing Wide Field-ofview Sensor) data over the Mediterranean during the years 2002 and 2003. The ability of BAER to retrieve aerosol optical thickness (AOT) over areas affected by various aerosol sources including dust and fire plumes has been evaluated by comparison with the AERONET (Aerosol Robotic NETwork) observations, ground based measurements and model (TM4) results. The comparison of the AOT’s retrieved with BAER from MERIS and from SeaWiFs data with the AERONET observations (AOT at 440 nm) at eight different stations in the Mediterranean and during four months of the year 2003 shows large day-to-day variability in the retrieved AOT as well as in the AERONET data and slight underestimation in the AOT retrievals from the sensors compared to the AERONET data. The retrieved AOTs indicate that dust and fire plumes episodes lead to 20% higher values of aerosol optical thickness than observed under background conditions. The seasonal variability of the derived AOT has been also studied based on the retrieved AOT from MERIS and SeaWiFS and on the MODIS available product version 5. The retrieved AOTs maximize in summer when the Mediterranean basins are subject to good weather ...