This study explores how smoke and volcanic ash particles, alter the way light is scattered in the atmosphere. By using a ground‑based HALO Doppler lidar system, we observed clear differences in the depolarization ratio, a shape-relevant optical parameter, between fresh smoke, aged smoke, and volcanic ash. These findings show that HALO Doppler lidars can help identify particle types in the air and even provide estimates of smoke mass concentrations, improving assessments of air quality.

With the reduction in inter-city distances, the wind carries heat downstream to neighboring cities. Focusing on the urban agglomeration area in China, we demonstrate the spatiotemporal variations of this heat transfer process, the moderating influence of meteorological factors, and quantify its effect on the intensity of the urban heat island in downstream cities. The results highlight the necessity of considering inter-city heat interactions in thermal risk management.

Using model simulations, we studied convective weather events to see how urban aerosol emissions influence cloud microphysics and precipitation. By tracing urban air volumes from convective clouds back to their emission sources, we could isolate the effects of emissions. The results show that urban emissions affect precipitation differently depending on the meteorological situation, highlighting the complex and case-dependent role of cities in shaping local rainfall.

Marine sulfur gases help form climate-cooling particles, but their controls over the Southern Ocean are unclear. During a summer research voyage we measured these gases and linked them to ocean and atmospheric conditions. Near Antarctica, coastal blooms drove sharp rises in dimethyl sulfide while methanethiol remained low. Over the open ocean, both gases varied together, mainly influenced by ocean mixing and temperature, suggesting models should treat coastal and open ocean regions separately.