Assessment and application of MODIS ocean and land algorithms for the characterization of aerosol properties over a Mediterranean coastal site

The aerosol optical depth (AOD) and Ångström exponent (α) obtained from MODIS Terra and Aqua over the coastal urban site of Burjassot (Spain) during the period 2002–2011 have been compared with retrievals from AERONET (AErosol RObotic NETwork) and ESR (European Skynet Radiometers) in order to investigate the performance of MODIS algorithms over land and ocean, respectively. The comparison of the MODIS aerosol products C051 over both land and ocean has been performed for a window size of 50km×50km centred on the monitoring site. The correlation coefficients obtained from the comparison of the AOD from MODIS with that from ground-based measurements are 0.85 and 0.87 over land for Terra and Aqua, respectively, and 0.90 over ocean for both satellites. For the comparison of α, the correlation coefficients are 0.25 and 0.30 over land and 0.73 and 0.66 over ocean for Terra and Aqua, respectively. Since our analysis shows that the MODIS algorithm over ocean characterizes better the aerosol parameters over the coastal urban site of Burjassot (Spain), this dataset has been used to perform a multi-year analysis of the aerosol properties in order to derive a local climatology over this site. The mean AOD at 550nm is 0.16, with percentiles 25 and 75 of 0.07 and 0.21. These results indicate a relatively clear atmosphere in the area in spite of local anthropogenic and remote dust sources.