Gkikas A., E.E. Houssos, C.J. Lolis, A. Bartzokas, N. Mihalopoulos and Hatzianastassiou N. (2011)
6th International Workshop on Sand/Duststorms and Associated Dustfall
Abstract
The Mediterranean basin (MB) is frequently affected by dust outflows, throughout the year, that are of great concern for the region’s weather and climate. The present study aims to portray the regime of dust episodes over the entire MB. This is achieved using daily aerosol optical properties measurements obtained by MODIS-Terra, Earth-Probe and OMI satellites, for the period 2000 – 2007. An objective and dynamic algorithm is set up to identify the dust episodes (DE) and to classify them to strong and extreme ones, according to their strength. The main features, namely the frequency, intensity and duration of DE are analyzed at pixel level through geographical distributions over the MB. The source regions and pathways of air masses leading to DE are determined, at different altitudes, by using the HYSPLIT model. The day-by-day evolution of specific atmospheric circulation types, in the lower troposphere, favouring the occurrence of intense dust outbreaks is studied based on NCEP/NCAR Reanalysis Project data and the implementation of multivariate statistical methods (S-Factor Analysis, Cluster Analysis). The perturbation of the Mediterranean surface and atmospheric radiation budget due to dust outflows is also computed for the episode days. The modification of the energy budget is found to be important and can modify the hydrological cycle and atmospheric dynamics of the region in the context of ongoing climate changes.