The dynamic characteristics of biomass burning aerosol originated from South Asia are investigated in this research using nearly 9 years of POLDER/GRASP satellite aerosol dataset. The POLDER/GRASP remote sensing data can provide global, repeatable, various, and sufficient real-world aerosol information even in the remote ocean region, which can't be offered by the ground measurement, laboratory observation or model simulation. The MODIS thermal anomalies/fire dataset and HYSPLIT backward trajectory are applied to search the aerosol originated from South Asia biomass burning. The biomass burning aerosol originated from South Asia could transport to and influence the north part of Indian Ocean (including Bay of Bengal and Arabian Sea), the north part of Indo-China Peninsula, South China, and even far to the Pacific Ocean (including part of East China Sea and South China Sea). The chemical, physical and optical characteristics of biomass burning aerosol over land and over ocean show different features and evolution patterns. Such difference is caused by the different ambient environment and different mixed aerosol during the transport process (urban/industrial aerosol over land and sea salt over ocean). During the 48-hours aging process, the volume fraction of black carbon, AAOD and Angstrom Exponent decrease. Meanwhile, the aerosol sphere fraction and SSA increase. The biomass burning aerosol over land shows a more obvious evolution trend than that over ocean. The biomass burning aerosol over ocean generally have higher SSA and lower volume fraction of black carbon, aerosol sphere fraction, AAOD and Angstrom Exponent. The aerosol radiative forcing efficiency also varies between land and ocean, due to their different features of aerosol and surface properties. In general, a negative clear-sky aerosol radiative forcing efficiency (cooling effect) at the TOA is observed. The aerosol cooling effect at the TOA over ocean (-82 W/m(2) on average) is much stronger than that over land (-36 W/m(2) on average). During the 48-hours aging process, a significant enhancement of the negative radiative forcing efficiency at the TOA is found over land. Over ocean, the enhancement of the negative radiative forcing efficiency at the TOA is weaker.

Eighteen years of sun/sky photometer measurements at seven worldwide AErosol RObotic NETwork (AERONET) sites in typical biomass burning regions were used in this research. The AERONET measurements were analyzed with the help of Moderate-resolution Imaging Spectroradiometer (MODIS) fire products and the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. The variation in the physicochemical and optical properties of biomass burning aerosols (BBAs), as well as their shortwave radiative forcing, was revealed for different vegetation types in different aging periods. The result indicated that, with aerosol aging, the BBA characteristics have a non-negligible evolution trend with obvious clustering features for different burning vegetation types. During the aging process, the volume fraction of black carbon (BC) declined (with a maximum drop of 38%) accompanied by particle size growth (with a maximum increment of 0.017 mu m). Driven by the change in physicochemical properties, the Single Scattering Albedo (SSA) and the asymmetry factor increased as the aerosol aged (with maximum increments of 0.026 and 0.018 for the SSA and asymmetry factor respectively). The grass and shrub type had a higher volume fraction of BC (2.5 times higher than that in the forest and peat type) and a smaller fine mode volume median radius (with a difference of 0.037 mu m from that of the forest and peat type). Such a phenomenon results in a lower SSA (with a difference of 0.103) and asymmetry factor (with a difference of 0.035) in the grass and shrub type when compared to the forest and peat type. Negative (-74 to -30 W/m(2)) clear-sky top of atmosphere (TOA) shortwave radiative forcing, strengthened during the aging process, was generally found for BBA. The BBA in the forest and peat region usually had stronger negative radiative forcing efficiency.