Seasonal source identification and formation processes of marine particulate water soluble organic nitrogen over an offshore island in the East China Sea

Mengke Tian; Hao Li; Guochen Wang; Mengxin Fu; Xiaofei Qin; Da Lu; Chengfeng Liu; Yucheng Zhu; Xingzhang Luo; Congrui Deng; Sabur F Abdullaev; Kan Huang

doi:10.1016/j.scitotenv.2022.160895

Seasonal source identification and formation processes of marine particulate water soluble organic nitrogen over an offshore island in the East China Sea

Sci Total Environ. 2023 Mar 10:863:160895. doi: 10.1016/j.scitotenv.2022.160895. Epub 2022 Dec 17.

Authors

Affiliations

¹ Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
² Physical Technical Institute of the Academy of Sciences of Tajikistan, Dushanbe, Tajikistan.
³ Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; Institute of Eco-Chongming, No.20 Cuiniao Road, Chen Jiazhen, Shanghai 202162, China; IRDR ICoE on Risk Interconnectivity and Governance on Weather/Climate Extremes Impact and Public Health, Fudan University, Shanghai 200433, China. Electronic address: huangkan@fudan.edu.cn.

PMID: 36539088
DOI: 10.1016/j.scitotenv.2022.160895

Abstract

Water soluble organic nitrogen (WSON) had great influences on the aerosol chemistry, hygroscopicity, marine primary productivity, as well as nitrogen biogeochemical cycles. Aerosol sampling was conducted over an offshore island in the East China Sea in four seasons of 2019, aiming to reveal the seasonal sources and secondary formation processes of marine WSON. The annual mean WSON concentration reached 1.05 ± 1.72 μg/m³ with a mean WSON/WSTN fraction of 27 %. In spring, WSON was associated with combustion emissions. The liquid-phase reaction of NH₃/NH₄⁺ with VOCs was a potential secondary formation process of WSON. In summer, WSON was mainly formed through the gaseous phase oxidation of marine biogenic precursors. In autumn, WSON showed miscellaneous sources from agricultural activities, biomass burning, and fossil fuel combustion. In addition to the contribution from primary urea, WSON could be also affected by the oxidation of biological proteinaceous matters. This explained the highest WSON concentrations and WSON/WSOC ratios in autumn. In winter, WSON was probably emitted from sea spray aerosols via the bubble-bursting processes. This study indicated that the sources of WSON over the coastal waters in the East China Sea were quite diverse, highlighting the need of more detailed characterization of marine WSON at the molecular level.