naa a22 4500 510750052 CHVBK 20180411083101.0 cr unu---uuuuu 180411e20130701xx s 000 0 eng 10.1007/s11270-013-1605-2 doi (NATIONALLICENCE)springer-10.1007/s11270-013-1605-2 Estimating Aerosol Optical Depth Over the Broader Greek Area from MODIS Satellite [Elektronische Daten] [G. Athanassiou, N. Hatzianastassiou, A. Gkikas, C. Papadimas] A first-to-date comprehensive climatological aspect of the regime of aerosol loading over the entire broader Greek region (19°E-30°E and 34°N-43°N) is obtained using pixel-level (50km × 50km) monthly aerosol optical depth (AOD) products derived from raw Level-2 (10km × 10km) MODIS-Terra AOD data at 550nm. The AOD climatology (for the 8-year period from March 2000 to February 2008) indicates that the study region is significantly loaded by aerosols (mean regional AOD equal to 0.196 ± 0.030 on an annual basis, with values ranging from 0.126 up to 0.382 at pixel level). It is also found that our high-resolution AOD data can reveal spatial patterns that are not evident in studies based on lower resolution data. There is a distinct longitudinal gradient of AODs, with higher values in the eastern than western part of the Greek peninsula. There is also a strong latitudinal gradient with decreasing values from south to north attributed to the presence of the Sahara Desert in northern Africa. The annual AOD cycle presents double maximum values, in spring and summer, and minimum ones in winter. There is also a remarkable year-by-year variability of AOD levels, especially as to their maxima, influenced by varying transport of desert dust, from the south, or biomass burning aerosols, from the north, to the region under prevailing favorable synoptic conditions. In this work, the processing, consisting in averaging over space and time, is done applying/testing five different criteria varying in their flexibility/severity in both spatial and temporal data availability. The criteria selection affects the magnitude of computed regional mean AOD value modifying it by up to 19%, although the patterns of geographical distribution of AOD and its intra-annual variability do not change drastically. Springer Science+Business Media Dordrecht, 2013 Aerosol optical depth nationallicence Air pollution nationallicence Climate nationallicence Satellites nationallicence Athanassiou G. Laboratory of Meteorology, Department of Physics, University of Ioannina, 45110, Ioannina, Greece aut Hatzianastassiou N. Laboratory of Meteorology, Department of Physics, University of Ioannina, 45110, Ioannina, Greece aut Gkikas A. Laboratory of Meteorology, Department of Physics, University of Ioannina, 45110, Ioannina, Greece aut Papadimas C. Laboratory of Meteorology, Department of Physics, University of Ioannina, 45110, Ioannina, Greece aut Water, Air, & Soil Pollution Springer Netherlands 224/7(2013-07-01), 1-14 0049-6979 224:7<1 2013 224 11270 https://doi.org/10.1007/s11270-013-1605-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11270-013-1605-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Athanassiou G. Laboratory of Meteorology, Department of Physics, University of Ioannina, 45110, Ioannina, Greece aut NATIONALLICENCE 700 1- Hatzianastassiou N. Laboratory of Meteorology, Department of Physics, University of Ioannina, 45110, Ioannina, Greece aut NATIONALLICENCE 700 1- Gkikas A. Laboratory of Meteorology, Department of Physics, University of Ioannina, 45110, Ioannina, Greece aut NATIONALLICENCE 700 1- Papadimas C. Laboratory of Meteorology, Department of Physics, University of Ioannina, 45110, Ioannina, Greece aut NATIONALLICENCE 773 0- Water, Air, & Soil Pollution Springer Netherlands 224/7(2013-07-01), 1-14 0049-6979 224:7<1 2013 224 11270 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer