Radiative impact of biomass burning events: the October 2010 smoke episode in South-East Asia

Over the past two decades, the Asia and South-Asia region has experienced a dramatic economic, industrial and population grow. Big cities are becoming large emission sources of anthropogenic aerosols resulting from the incessant industrial activity. In rural areas, clearance of large forested areas, via the method of burning, has resulted in severe smoke emission episodes during the 1996-2006 decade and has become an annual phenomenon specially in the South-East-Asia region. Large emission episodes can occur during periods of severe draught and exacerbated by the inter- annual El Ninõ events. Depending on weather patterns, smoke events can evolve into a persistent trans-boundary smoke with aerosol concentrations high enough to significantly reduce visibility and become a health hazard for local populations. During the month of October 2010, elevated levels of fire activity was detected by remote sensing satellites as well as by local in-situ measurements of fine particulate matter. In this work, we investigate the radiative impact of this smoke episode by firstly, analyzing the physical and optical properties of smoke particles with the aid of passive (Sun-photometer, AERONET), active and in-situ sampling of fine particulate (PM2.5) at our Singapore receptor site. Secondly, inversions of particle size distribution as well as single scattering albedo were used to evaluate the radiative impact of this biomass burning episode.