Evidence based on measurements for aerosol–PBL interaction (2018)


During the interaction process, aerosols affect the meteorology by absorbing solar radiation and blocking the sunlight reaching Earth's surface, causing upper-air heating and surface dimming. Previous works on aerosol–PBL interaction were mainly based on model simulations for short-term cases. Based on multiyear measurements and reanalysis meteorological data, Huang et al. (2018) provided long-term observational evidence for aerosol-PBL interaction and its impact on pollution aggravation. They found a significant heating in upper-PBL with a maximum temperature change of about 0.7℃ on average and a substantial dimming near the surface with a mean temperature drop of -2.2℃ under polluted conditions (Figure 1). Both observations and simulations using multiple models demonstrated the crucial role of light-absorbing aerosols like BC. BC-induced upper-air heating stabilizes the lower atmosphere and greatly weakens the diffusion and dilution of pollutants, which thereby worsens air quality.

Figure 1 Vertical profiles of temperature bias between radiosonde observation and ERA reanalysis in Beijing under polluted (a, PM2.5 concentrations greater than the 75th percentile) and clean (b, PM2.5 concentrations less than the 25th percentile) conditions in winter during 2010-2016. Solid lines, deep and light shadows represent average, 25-75th percentile and 10-90th percentile. Dash solid zero lines are shown for reference.

Huang, X., Wang, Z., Ding, A., Impact of Aerosol-PBL Interaction on Haze Pollution: Multi-Year Observational Evidences in North China, Geophys. Res. Lett., 45, 8596-8603, 2018.