Submarine Groundwater Discharge in the Northern Bohai Sea, China: Implications for Coastal Carbon Budgets and Buffering Capacity

Zhang, Yan1; Zou, Changpei1,2; Wang, Zhaohui Aleck3; Wang, Xuejing4; Zeng, Zhenzhong4; Xiao, Kai4; Guo, Huaming1; Jiang, Xiaowei1; Li, Zhenyang1; Li, Hailong1,4

2022-08-01

10.1029/2022JG006810

Journal of Geophysical Research-Biogeosciences   Impact Factor & Quartile

2169-8953

2169-8961

Submarine groundwater discharge (SGD) has been widely recognized as an important source of dissolved nutrients in coastal waters and affects nutrient biogeochemistry. In contrast, little information is available on SGD impacts on coastal carbon budgets. Here, we assessed the SGD and associated carbon (dissolved inorganic carbon [DIC] and total alkalinity [TA]) fluxes in Liaodong Bay (the largest bay of the Bohai Sea, China) and discussed their border implications for coastal DIC budget and buffering capacity. Based on Ra-223 and Ra-228 mass balance models, the SGD flux was estimated to be (0.92-1.43) x 10(9) m(3) d(-1). SGD was the largest contributor of DIC, accounting for 55%-77% of the total DIC sources. The low ratio (<1) of SGD-derived TA to DIC fluxes and negative correlation between radium isotopes and pH in seawater implied that SGD would potentially reduce seawater pH in Liaodong Bay. Combining the groundwater carbon data in Liaodong Bay with literature data, we found that the SGD-derived DIC flux off China was 4-9 times greater than those from rivers. By analyzing the TA/DIC ratios in groundwater along the Chinese coast and related carbon fluxes, SGD was thought to partially reduce the CO2 buffer capacity in receiving seawater. These results obtained at the bay scale and national scale suggest that SGD is a significant component of carbon budget and may play a critical role in modulating coastal buffering capacity and atmospheric CO2 sequestration.

submarine groundwater discharge radium isotopes dissolved inorganic carbon total alkalinity carbon budgets buffering capacity

SCI

English

Corresponding

National Natural Science Foundation of China["42130703","42007170"] ; Science, Technology and Innovation Commission of Shenzhen[20200925174525002]

Environmental Sciences & Ecology ; Geology

Environmental Sciences ; Geosciences, Multidisciplinary

WOS:000842522800001

AMER GEOPHYSICAL UNION

Web of Science

1.China Univ Geosci Beijing, Sch Water Resources & Environm, MOE Key Lab Groundwater Circulat & Environm Evolu, Beijing, Peoples R China
2.Chinese Acad Geol Sci, Inst Karst Geol, Guilin, Peoples R China
3.Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA
4.Southern Univ Sci & Technol, Sch Environm Sci & Engn, State Environm Protect Key Lab Integrated Surface, Shenzhen, Peoples R China

Zhang, Yan,Zou, Changpei,Wang, Zhaohui Aleck,et al. Submarine Groundwater Discharge in the Northern Bohai Sea, China: Implications for Coastal Carbon Budgets and Buffering Capacity[J]. Journal of Geophysical Research-Biogeosciences,2022,127(8).

Zhang, Yan.,Zou, Changpei.,Wang, Zhaohui Aleck.,Wang, Xuejing.,Zeng, Zhenzhong.,...&Li, Hailong.(2022).Submarine Groundwater Discharge in the Northern Bohai Sea, China: Implications for Coastal Carbon Budgets and Buffering Capacity.Journal of Geophysical Research-Biogeosciences,127(8).

Zhang, Yan,et al."Submarine Groundwater Discharge in the Northern Bohai Sea, China: Implications for Coastal Carbon Budgets and Buffering Capacity".Journal of Geophysical Research-Biogeosciences 127.8(2022).