The Xiamen Symposium on Marine Environmental Sciences (XMAS 2025)

Marine particles are key components of the global aerosols, severing as cloud condensation nuclei and ice nucleating particles. The atmospheric particles over the west coast of the Taiwan Strait are impacted by various sources including anthropogenic emission from the key ports and fishery ships and marine emission. In addition, the monsoon transition also significantly affects atmospheric composition. In this study, single particle characterization in Dongshan Island was performed by computer-controlled scanning electron microscope and energy dispersive X-ray spectroscopy. A significant large number of particles collected in different seasons were classified by K-means clustering method based on elemental composition. Sub-micrometer particles mainly consist of carbonaceous, sulfur-containing particles, sulfate, and K-rich compounds, while super-micrometer particles predominantly composed of sea salt. The prevailing wind in winter and spring is from the northeast. The particles in winter are most affected by anthropogenic sources, while the proportion of marine sources increases in spring. In summer, the prevailing wind shifts to the southwest, but both anthropogenic and marine sources affect atmospheric composition due to the alternating sea and land breezes during certain periods. Vertical distribution of particles is investigated. Sea salt particles predominantly found at lower altitudes, with the contribution increases with stronger winds. In contrast, carbonaceous and sulfate particles are in the smaller size and increase at higher altitudes, which is likely contributed to the oxidation of volatile organic compounds. The mixing state of particle population is investigated. The proportion of sea salt is positively correlated with the mixing state index, while carbonaceous and sulfate particles exhibit a negative correlation. The differences in the distribution of chemical components affect the mixing state of particle population, which may influence their chemical reactivity, optical properties, and cloud forming ability.