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Presentation
Urban PM Estimation Based on MERIS/AATSR Synergy Derived AOT and MODIS Level-2 Atmospheric Parameters
3rd MERIS/(A)ATSR and OCLI-SLSTR (Sentinel-3) Preparatory Workshop (2012)
  • N. Benas
  • A. Beloconi
  • Nektarios Chrysoulakis
Abstract
In recent years, there has been a focus of the scientific community on urban air quality studies, aiming to improve the knowledge of the environmental factors that affect population health and well being, by providing more accurate air pollution exposure assessments. Important urban air quality indicators are both PM10 and PM2.5. Recent scientific efforts have concentrated on PM mapping using Earth Observation data, offering better spatial coverage and resolution compared to ground measurements (Gupta and Christopher 2009a,b, Lee at al. 2011). The most common approach of these studies has been the correlation of the in-situ measured near surface PM concentration with the satellite derived Aerosol Optical Thickness (AOT), constraint by ancillary meteorological parameters to estimate the overall AOT contribution at the surface PM level. Although several studies have shown promising results, a major drawback remains, regarding the spatial resolution of the available satellite derived AOT products, which reaches at best the 10 km x 10 km in both MODIS and the GlobAEROSOL products cases. This study aims at quantifying the surface PM concentration over the broader urban area of Athens, Greece, using high resolution satellite AOT spatial distributions derived by the MERIS/AATSR synergy algorithm for aerosol retrieval (North et al., 2009). Using this algorithm, AOT can be derived at 1 km x1 km and has been recently validated against AERONET station measurements globally (Benas et al., 2012). Using 3 years of PM2.5 and PM10 ground measurements, a multivariate regression technique was employed to estimate PM as function of the MERIS/AATSR derived AOT and some MODIS Level 2 atmospheric parameters (related to surface temperature and humidity, as well as to atmospheric static stability), spatially interpolated at the MERIS/AATSR AOT scale. Our results indicate that the inclusion of each one of these parameters improves significantly the correlation between AOT and PM. Furthermore, the use of the MERIS/AATSR synergy algorithm improves the spatial resolution of the derived PM concentrations by almost two orders of magnitude, when compared with the available AOT products. In conclusion, the proposed method offers new possibilities in exploiting the 10-year data record of the MERIS and AATSR instruments, for monitoring the PM spatial patterns in urban areas. Further investigation could be extended to Sentinel-3 OLCI/SLSTR synergy in the future.
Keywords
  • MERIS/AATSR Synergy; AOT; PM
Publication Date
October 19, 2012
Citation Information
Benas, N., Beloconi, A. and Chrysoulakis, N., 2012. Urban PM estimation based on MERIS/AATSR synergy derived AOT and MODIS Level-2 atmospheric parameters. In Proceedings of the 3rd MERIS/(A)ATSR and OCLI-SLSTR (Sentinel-3) Preparatory Workshop, held in ESA-ESRIN, Frascati, Italy, on 15 - 19 October, pp. 111 - 112.