Roles of Atmospheric Aerosols in Extreme Meteorological Events: a Systematic Review

Purpose of Review Atmospheric aerosol from both natural and anthropogenic activities has long been acknowledged as one of the important factors influencing regional and global climate change. Many regions around the globe experienced high aerosol loadings because of intensive emissions, yet the roles of atmospheric aerosols in extreme meteorological and air pollution events have not been well demonstrated due mainly to the complexity of atmospheric physical and chemical interaction at mesoscale and even microscale. Here, we present a comprehensive review of current understanding on the role of atmospheric aerosols in the development and evolution of extreme meteorological events, including monsoon circulation, heat waves, extreme rainfall, tornadoes, and severe air pollution. Recent Findings Aerosols could participate in the development of meteorological systems through direct and indirect effects. Large-scale precipitation from shallow stratiform clouds was found to be suppressed by aerosols, while invigoration effects contribute to deep convection and even catastrophic floods in local areas. The occurrence of high-impact weather such as tornadoes and tropical cyclone is also related to aerosol concentration and distribution. Moreover, a positive feedback between aerosols and boundary layer meteorology is proposed as an important factor conducive to heavy haze pollution over urban areas. The work underscores the great importance of aerosols' meteorological feedback in extreme weather events. Integrated observations and seamless coupling of meteorology and atmospheric chemistry in models are highlighted for future studies to fill the knowledge gap in current research.

Automated summary

This review presents a comprehensive understanding of the role of atmospheric aerosols in the development and evolution of extreme meteorological events. Aerosols can participate in the development of weather systems through direct and indirect effects, affecting precipitation and convection processes, and being related to high-impact weather events such as tornadoes and tropical cyclones. Furthermore, the positive feedback between aerosols and boundary layer meteorology is identified as an important factor contributing to heavy haze pollution over urban areas.