Typhoon Rainbands over Southern China Cleanse Polluted Air and Sustain Marine-Like Warm-Rain Clouds
Description
Our hypothesis is that typhoon rainbands can cleanse continental aerosols via sustained warm rain, allowing marine‑like cloud microphysics to persist over land. We collected airborne data using cloud and aerosol probes on a King Air during three flights over southern China on 13–14 October 2020, supplemented by radar, surface PM₂.₅, and ERA5 back trajectories. After rainfall, PM₂.₅ fell by ~75–80% while low‑level trajectories remained continental, proving precipitation scavenging; aloft, marine trajectories also contributed. Clouds showed lower droplet concentrations, larger effective radii, and much earlier warm‑rain initiation. These observations support a positive feedback: rain removes aerosols, reduces droplet numbers, accelerates coalescence, and sustains warm rain over land. Data are available upon reasonable request.