The Effect of Aerosols on Fog Lifetime: Observational Evidence and Model Simulations
Shuqi Yan, Bin Zhu, Tong Zhu, Chune Shi, Duanyang Liu, Hanqing Kang, Wen Lu, Chunsong Lu
Abstract
Abstract The aerosol–cloud interaction (ACI) and aerosol–radiation interaction (ARI) have notable influences on clouds, but their effects on fog are rarely analyzed before. Previous studies indicate that fog frequency in East China has been decreasing, and we further reveal that fog duration increases during 1960–2010. We hypothesize that this trend is related to the increase of aerosol pollution and perform WRF‐Chem simulations to study the ARI and ACI effects. Results show that ACI significantly advances fog formation, delays fog dissipation, and increases fog duration by about 1 h in a case study, while ARI has negligible effect. The more but smaller fog droplets produced in polluted conditions significantly inhibit droplet sedimentation and reduce solar radiation, therefore provide favorable conditions for the duration of fog. Under extremely polluted conditions, ACI effect also far overweighs ARI effect. To shorten the duration of dense fog, our findings suggest the necessity for mitigating emissions.