Source apportionment of cloud condensation nuclei in the China's marginal seas during the spring of 2021

Assessing the aerosol-cloud indirect climate influence requires determining the concentrations of cloud condensation nuclei (Nccn) and atmospheric particles (Ncn). Due to the rapid industrialization in East Asia, the concentration of pollutants in the atmosphere has significantly increased. Influenced by prevailing monsoon, these pollutants will be transported to the China's marginal seas, which are downwind of the East Asian continent. In this study, based on ship-based observations from the China's marginal seas during the spring of 2021, average Ncn was recorded as 4.4±1.1×103 cm-3 and Nccn values at 0.2%, 0.4%, and 0.6% SS were 1.8±0.4×103 cm-3, 2.4±0.8×103 cm-3, and 2.5±0.7×103 cm-3, respectively. Then, we used the Positive Matrix Factorization (PMF) analysis approach to allocate the sources of Nccn based on ship-based observations from China's marginal seas in the spring of 2021. There are five factors identified: continental emissions, different degrees of ship exhaust, and nucleation mode.