An Observing System Simulation Experiment (OSSE) for Aerosol Optical Depth from Satellites

Abstract

Monitoring aerosols over wide areas is a scientific challenge with important applications for human health and the understanding of climate. Aerosol optical depth (AOD) measurements from satellites can improve the highly needed analyzed and forecasted distributions of ground-level aerosols in combination with models and ground-based measurements. To assess the benefit of future satellite AOD measurements, an observing system simulation experiment (OSSE) is developed. In this pilot study, the OSSE is applied to total AOD measurements from a flexible combined imager (FCI) proposed to fly on a geostationary satellite. OSSEs are widely used in the meteorological research community, but their use for air quality applications and specifically for aerosols is new. In this paper, the functionality and potential of the developed OSSE for evaluation of aerosol data from future satellite missions are demonstrated. The results show a positive impact of adding AOD observations next to in situ observations for the analysis of PM2.5 (particles smaller than 2.5 ?m in median diameter) distributions. However, the development of an OSSE for aerosols presents a number of further challenges, as discussed in this paper, which prohibits a detailed quantitative analysis of the results of this pilot study.