MODIS AEROSOL OPTICAL PROPERTIES OVER NORTH ITALY FOR ESTIMATING SURFACE-LEVEL PM2.5

During the last years, attention has been devoted to the possibility to monitor surface Particulate Matter (PM) concentrations using satellite observations. The capability of NASA sensors MODIS - on board Terra and Aqua platforms - to retrieve tropospheric Aerosol Optical Depth (AOD) has been exploited to verify the degree of correlation between satellite AOD at 550 nm and surface-level PM2.5. However, several factors affect the relationship between columnar AOD and PM. Among these, two of the most important are the aerosol vertical distribution and the relative humidity. In our analysis, concerning 2004 data over Northern Italy, we discuss how the employment of mixing layer height and relative humidity at satellite overpassing time can increase the degree of cited correlation