Cite this article: Lin, C.C., Chen, W.N., Loftus, A.M., Lin, C.Y., Fu, Y.T., Peng, C.M. and Yen, M.C. (2017). Influences of the Long-Range Transport of Biomass-Burning Pollutants on Surface Air Quality during 7-SEAS Field Campaigns.
Aerosol Air Qual. Res.
17: 2595-2607. https://doi.org/10.4209/aaqr.2017.08.0273
The upper level short wave activities were significantly active during 2013 spring.
The sinking motion behind short wave trough enhanced the subsidence of cold surge.
The particle depolarization Lidar could directly observe this phenomena.
The 7-SEAS dual-field-experiments design contributes to this interesting finding.
The transport of aerosols relies primarily upon air flow for conveyance; however, the air flow pattern is dominated by large-scale circulation conditions. One mission of the 2013 7-SEAS/BASELInE (Seven SouthEast Asian Studies/Biomass-burning Aerosols & Stratocumulus Environment: Lifecycles and Interactions Experiment) was to capture/confirm the downwind effect on the surface air quality due to the long-range transport of Southeast Asia biomass-burning (SEA BB) pollutants. This phenomenon was first discovered during the 2010 Dongsha experiment and directly observed by a lidar system at Hengchun in southern Taiwan during 7-SEAS/BASELInE. Through three-dimensional structural analysis, it was found that the sinking motion behind the upper-level active short wave trough is the major mechanism that enhances subsidence along the cold surge leading edge. In turn, the enhanced subsidence could bring the long-range transport of the SEA BB pollutants down to the surface. Furthermore, the HYSPLIT backward air trajectories helped identify the SEA BB pollutants in the mid-troposphere, while the fine-resolution WRF model simulation combined with dual-polarization lidar observations demonstrated the evolution of the brought-down aerosols process. An additional significant finding of this study is that the upper-level ridge-trough short wave within 20°–35°N was very active during spring 2013, highlighting the inter-annual variability of the long-range transport of SEA BB pollutants.