573 / 2024-09-18 14:17:57
Aerosol particle characterization and their immersion freezing properties in two coastal cities of China
Atmospheric particles,immersion freezing,ice nucleating,single particle analysis
Session 25 - IGAC-SOLAS: Chemistry and physics at surface ocean and lower atmosphere
Abstract Accepted
Jiemin Chen / Xiamen University;College of oceanic and earth
Jun Zhao / Xiamen University;College of Oceanic and earth
Bingbing Wang / Xiamen University;College of Oceanic and earth
Atmospheric aerosols exhibit complex and variable characteristics that can affect the air quality, cloud formation, and thus climate. Particle can serve as cloud condensation nuclei and ice nuclei. However, the connection between particle composition and ice formation ability is poorly understood. In this study, we investigate the physicochemical characteristics and ice nucleation properties of atmospheric particles in two coastal cities in the north east and south east part of China, Yangmeikweng (YMK) and Juehua Island (JHD), respectively. The results show that JHD particles were significantly impacted by marine emission from the Bohai Sea, with sea salt particles dominating the larger size, while YMK particles exhibited minimal marine influence. The proportions of sulfur-containing particles and carbonaceous particles increased as particle size decreases. The immersion freezing temperatures for all samples ranged from 235.0 K to 257.9 K. The ice nucleating particle (INP) concentrations varied from 0.0076 to 28 L⁻¹, which is classified as moderate to low compared to other urban regions. Notably, YMK exhibited significantly higher median freezing temperatures and INP concentrations compared to JHD. A significant positive correlation was observed between median freezing temperatures and the proportions of sulfur-containing particles, suggesting that these particles may serve as the primary INPs or promote the ice nucleating ability of other particles. Analysis of ice nucleation kinetics reveals that coastal urban aerosols in China outperform sea salt aerosols but are generally inferior to dust and bioaerosols in ice nucleation properties.