Study of the spatial differentiation of antiquities' exposure to aerosols in Greece, using space - borne remote sensing

Abstract

In the present thesis, twenty-one archaeological sites in Greece were selected to be studied using space borne remote sensing, with respect to their exposure to air pollution and the potential impact on the structural materials of the monuments. Fourteen years (2002 – 2016) of observations of Aerosol Optical Depth (AOD) were retrieved via two satellite remote sensing instruments, MODIS and CALIPSO. The average levels of aerosols are greater in the north and north-eastern parts of Greece, while slightly lower levels of pollution are observed in southern areas. The presence of polluted dust and mineral dust is intense in the northern regions. Heading to the west, elevated levels of smoke are observed. In central and south Greece, mineral dust is observed and in the east, apart from dust, clean marine aerosols are frequently encountered as well (seaside areas). In the southern part of the country polluted dust, dust and polluted continental aerosols along with clean marine are noted. The presence of aerosols reveals a summer maximum for the northern regions and a spring maximum for the southern and western parts. The eastern side shows a moderately stable rate the whole year. A negative trend of aerosol optical depth is observed during the last ten years for all sites. The higher reduction is observed at the north and the lowest at the east parts of Greece. The above spatiotemporal characteristics of aerosols over Greece, determine the different exposure that monuments may be subjected in terms of location and season.