URBAN PM10 ESTIMATION BASED ON MERIS/AATSR SYNERGY DERIVED AOT AND MODIS LEVEL-2 ATMOSPHERIC PARAMETERS

摘要

In recent years, there has been a focus on urban air quality studies, aiming to improve the knowledge of the environmental factors that affect population health and well-being. 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 [1], [2]. 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 × 10 km in both MODIS and the GlobAEROSOL products cases. This study aims at quantifying the surface PM10 concentration over the broader urban area of Athens, Greece, using AOT spatial distributions derived by the MERIS/AATSR synergy algorithm [3]. Using this algorithm, AOT can be derived at 1 km × 1 km spatial resolution. Using 4 years of PM10 ground measurements, a multivariate regression technique was employed to estimate PM10 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), at 5 km × 5 km spatial resolution. Our approach can be easily extended to Sentnel3 observations since they will be capable of extracting information about all the above parameters.