Seasonal Changes of Organic Carbon Mixing, Degradation and Deposition in Yangtze River Dominated Margin Related to Intrinsic Molecular and External Environmental Factors

Han, Lulu1,2; Wang, Yinghui1; Xiao, Wenjie1,3,4; Wu, Jianqiang1,5; Guo, Lixia1; Wang, Yasong1; Ge, Huangmin1; Xu, Yunping1,2

2021-12-01

10.1029/2021JG006637

Journal of Geophysical Research-Biogeosciences   影响因子和分区

2169-8953

2169-8961

The East Asian monsoon is characterized by warm, humid summer and cool, dry winter that results in seasonal changes in fluvial sediment and organic carbon (OC) discharge. Here, we report measurements of elemental, isotopic, and optical compositions of OC in surface waters and sediments that were collected along the lower Yangtze River, Estuary, and East China Sea continuum in March and July 2019. The principal component analysis separates samples into three groups that correspond to fresh water area, mixing area, and seawater area. The terrigenous signal in the mixing area, indicated by water salinity and delta C-13, is stronger in July. The applications of binary mixing models based on water salinity, dissolved OC (DOC) concentration and specific terrigenous fluorescence component suggest: (a) net removal of DOC from waters in July, but net addition of DOC into waters in March, attributed to more extensive degradation and larger deposition of OC in summer; and (b) more conservative behaviors of terrigenous OC compared to marine or mixed OC, suggesting an important role of intrinsic molecular characteristics on the persistence of DOC. The estimated monthly OC burial flux in the estuary and continent shelf is 0.48 x 10(12) g in July and 0.081 x 10(12) g of OC in March, equal to 15.5% and 2.6% of the annual OC discharge by the Yangtze River, respectively. Our study suggests that the burial of OC mainly occurs in the summer monsoon due to the larger sediment load of the Yangtze River, prevailing southeastern wind, and intensified Kuroshio Current.

Yangtze River East China Sea organic carbon (OC) dissolved organic carbon (DOC) monsoon

SCI

英语

其他

National Natural Science Foundation of China[41676058] ; NSFC Shiptime Sharing Project[NORC2019-03-02]

Environmental Sciences & Ecology ; Geology

Environmental Sciences ; Geosciences, Multidisciplinary

WOS:000734472100013

AMER GEOPHYSICAL UNION

Web of Science

1.Shanghai Ocean Univ, Coll Marine Sci, Shanghai, Peoples R China
2.Shanghai Ocean Univ, Minist Educ, Key Lab Sustainable Exploitat Ocean Fisher Re, Shanghai, Peoples R China
3.Southern Univ Sci & Technol, Dept Ocean Sci & Engn, Shenzhen, Peoples R China
4.Southern Univ Sci & Technol, Shenzhen Key Lab Marine Archaea Geo Om, Shenzhen, Peoples R China
5.Shanghai Acad Environm Sci, Shanghai, Peoples R China

Han, Lulu,Wang, Yinghui,Xiao, Wenjie,et al. Seasonal Changes of Organic Carbon Mixing, Degradation and Deposition in Yangtze River Dominated Margin Related to Intrinsic Molecular and External Environmental Factors[J]. Journal of Geophysical Research-Biogeosciences,2021,126(12).

Han, Lulu.,Wang, Yinghui.,Xiao, Wenjie.,Wu, Jianqiang.,Guo, Lixia.,...&Xu, Yunping.(2021).Seasonal Changes of Organic Carbon Mixing, Degradation and Deposition in Yangtze River Dominated Margin Related to Intrinsic Molecular and External Environmental Factors.Journal of Geophysical Research-Biogeosciences,126(12).

Han, Lulu,et al."Seasonal Changes of Organic Carbon Mixing, Degradation and Deposition in Yangtze River Dominated Margin Related to Intrinsic Molecular and External Environmental Factors".Journal of Geophysical Research-Biogeosciences 126.12(2021).