Enhancement of Atmospheric Stability by Anomalous Elevated Aerosols During Winter in China

Abstract

Changes in anthropogenic aerosols with a low level of scientific cognition affect the atmospheric environment and radiative balance of the Earth. We determine anomalous elevated aerosol layers (EALs) and their source and effects on regional atmospheric stability in China by using 2007–2016 data from multiple satellite observations and models. Anomalous EALs occur during winter over Eastern China, and they are mainly distributed above 2 km and can even spread up to 4–5 km despite the disadvantageous atmospheric convection conditions during winter. Anthropogenic pollutants that mainly originate from local-range transport with enhanced atmospheric updraft play a dominant role (about 60%) in this situation. Furthermore, anomalous EALs result in considerable warming in the upper atmosphere (+0.32 K/day) and cooling on the surface (−0.04 K/day) over Eastern China. They decrease surface incident radiation by an average of 3.4 W/m2. The opposite heating rate change in the upper atmosphere and surface caused by anomalous EALs consequently increases the low atmospheric stability by an average of 0.39 K, and this increment weakens the dissipation of atmospheric dispersion. Related studies have indicated that increased atmospheric stability can severely exacerbate atmospheric pollution near the surface.