Atmospheric dry deposition of water-soluble organic matter: An underestimated carbon source to the coastal waters in North China

Lei Xie; Xuelu Gao; Yongliang Liu; Bo Yang; Xiaoqing Lv; Jianmin Zhao; Qianguo Xing

doi:10.1016/j.scitotenv.2021.151772

Atmospheric dry deposition of water-soluble organic matter: An underestimated carbon source to the coastal waters in North China

Sci Total Environ. 2022 Apr 20:818:151772. doi: 10.1016/j.scitotenv.2021.151772. Epub 2021 Nov 19.

Authors

Lei Xie¹, Xuelu Gao², Yongliang Liu¹, Bo Yang³, Xiaoqing Lv¹, Jianmin Zhao³, Qianguo Xing³

Affiliations

¹ CAS Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² CAS Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong 266071, China. Electronic address: xlgao@yic.ac.cn.
³ CAS Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong 266071, China.

PMID: 34808180
DOI: 10.1016/j.scitotenv.2021.151772

Abstract

Water-soluble organic matter (WSOM) is a ubiquitous group of organic compounds in the atmosphere, which plays an important role in the biogeochemical cycle. To determine the quantity and chemical composition of the dry deposition of WSOM and assess its ecological effects on the coastal waters around the Yangma Island, North Yellow Sea, total suspended particulates (TSP) samples collected at a coastal site for one year from December 2019 to November 2020 were analyzed. The concentration of water-soluble organic carbon (WSOC) and the spectroscopy of chromophoric dissolvable organic matter (CDOM) and fluorescent dissolvable organic matter (FDOM) in the samples showed highly temporal variability with higher values in winter and spring than in summer and autumn. In addition, the correlation analysis revealed that the content of WSOM in the TSP as well as its chemical composition were greatly influenced by the sources and aging processes of aerosols. Moreover, the dry deposition flux of WSOC to the study area was calculated to be 0.79 ± 0.47 mg C m^-2 d^-1, namely 1.91 × 10⁸ g C yr^-1, which could increase the annual average concentration of dissolved organic carbon in surface seawater by 10.2 μmol L^-1, implying that the dry deposition could sustain the secondary production and affect the carbon cycle of the coastal waters. Besides, the complete decomposition of bioavailable WSOC of dry deposition could reduce the annual average concentration of dissolved oxygen in surface seawater by 4.8 μmol L^-1, which could contribute partly to the seawater deoxygenation in the coastal area around the Yangma Island.

Keywords: Air-sea process; Carbon cycle; Ecological effects; Fluorescent components; Optical properties.

MeSH terms

Aerosols / analysis
Atmosphere / analysis
Carbon* / analysis
China
Seawater / analysis
Water* / analysis

Substances

Aerosols
Water
Carbon