Article
Environmental Sciences
Yongfeng Qi, Huabin Mao, Yan Du, Xianpeng Li, Zhou Yang, Ke Xu, Ying Yang, Wanxuan Zhong, Fuchang Zhong, Linghui Yu, Huanlin Xing
Summary: This study reports an abnormal anticyclonic eddy with a lens-shaped structure and shallower mixed-layer depth, which may have potential implications for biogeochemistry, heat budget, and regional oceanic models in the northern South China Sea.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Oceanography
Wenjin Sun, Yu Liu, Gengxin Chen, Wei Tan, Xiayan Lin, Yuping Guan, Changming Dong
Summary: Abnormal mesoscale cyclonic and anticyclonic eddies with warm or cold cores have been found in the South China Sea. The highest incidence area of these abnormal eddies is in the northwest of Luzon Strait, with smaller sizes and shorter generation times compared to normal eddies. The intrusion of Kuroshio warm water is considered a key mechanism for the generation of these abnormal eddies near the northeastern SCS.
ACTA OCEANOLOGICA SINICA
(2021)
Article
Environmental Sciences
Bing Yang, Po Hu, Yijun Hou
Summary: Based on analysis of in situ observations, remote sensing, and data, the characteristics of near-inertial waves induced by tropical storm Noul in the South China Sea were studied. It was found that the near-inertial waves were influenced by a southwestward moving anticyclonic eddy and had comparable spectral density with internal tides. The downward propagation of near-inertial energy was concentrated in smaller wavenumber bands and influenced by mesoscale eddies.
Article
Environmental Sciences
Xinyu Zhang, Hua Zheng, Xiao-Hua Zhu, Ruixiang Zhao, Cong Xiao, Min Wang, Juntian Chen
Summary: The study investigates a supercharged cold eddy with strong temperature anomaly in the Kuroshio Extension region. The three-dimensional structure of the eddy is continuously observed for 83 days, showing stable characteristics in terms of radius, depth and speed. The analysis reveals that the eddy energy mainly originates from the Kuroshio and is enhanced by baroclinic and barotropic conversion.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Remote Sensing
Jia-Yi Lin, Zhe-Wen Zheng, Quanan Zheng, Ding-Rong Wu, Ganesh Gopalakrishnan, Chung-Ru Ho, Jiayi Pan, Yu-Chun Lin, Ling-Ling Xie
Summary: This study proposes a new mechanism of Kuroshio Intrusion passing through the Luzon Strait based on satellite observations. The statistical analysis shows that 82% of the observed cyclonic eddy impingement events led to consequential effects on the Luzon Strait. Further analysis reveals the detailed physical exchange processes and the role of planetary vorticity in influencing the Kuroshio.
INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION
(2022)
Article
Environmental Sciences
Yu Liu, Xuefeng Zhang, Hongli Fu, Zhiwen Qian
Summary: This study investigates the coupled effects of the Luzon cold eddy and tidal waves in the northern South China Sea using a 3D ocean-acoustic framework. The results show that the cold eddy shifts the location of the convergence zone forward and delays the arrival time of sound waves, while the tidal waves intensify these effects.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Geography, Physical
Guiyan Han, Fenglin Tian, Chunyong Ma, Ge Chen
Summary: The study of the average shape and orientation of eddies in the South China Sea reveals that the elliptical shape of eddies influences oceanic variables differently from global eddies, providing a new approach to explore the impact of air-sea interactions on oceanic eddies.
INTERNATIONAL JOURNAL OF DIGITAL EARTH
(2021)
Article
Environmental Sciences
Huarong Xie, Qing Xu, Yongcun Cheng, Xiaobin Yin, Kaiguo Fan
Summary: In this study, a deep learning model called Attention U-net network is proposed to reconstruct the salinity fields in the South China Sea. The model performs well in reconstructing the three-dimensional salinity field, with an average root mean square error of 0.051 psu and an overall correlation coefficient of 0.998.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Multidisciplinary Sciences
Jianfeng Wang, Fei Yu, Feng Nan, Qiang Ren, Zifei Chen, Tongtong Zheng
Summary: Ocean turbulence plays a crucial role in the transfer of heat, nutrients, momentum and sea level rise within the climate system. Research around the Luzon Strait revealed that turbulent kinetic energy dissipation rates are similar between the northeastern South China Sea and West Pacific, with notable enhancement near rough topography areas. The bottom diapycnal diffusivity in the South China Sea increases by a factor of three in the West Pacific, contrary to earlier indirect parameterization estimations.
SCIENTIFIC REPORTS
(2021)
Article
Acoustics
Yushen Wu, Jixing Qin, Zhenglin Li, Shuanglin Wu, Mengyuan Wang, Wen Li, Yonggang Guo
Summary: The spatial and temporal redistribution of sound energy caused by a warm eddy was measured in the South China Sea through a multiday experiment. The experiment utilized two vertical line arrays, a mooring source, and some wide-band explosive sources. The experiment analyzed and explained the influence of the warm eddy on sound propagation during its lifespan, showing that energy is redistributed both spatially and temporally due to the presence of the warm eddy.
Article
Environmental Sciences
Yikai Yang, Lili Zeng, Qiang Wang
Summary: Eddy-induced transport through the Luzon Strait significantly impacts the physical and biological properties of the South China Sea. Comprehensive evaluation of eddy-induced volume, heat, and salt transport highlights the non-negligible role of eddies in water exchange through the Luzon Strait.
Article
Environmental Sciences
Yan Gao, Jianping Li, Fuyuan Li, Ruwei Zhang, Yunsheng Zhao, Zhanxiang He
Summary: Studying the resistivity structure below an extinct mid-ocean ridge is crucial for understanding the evolution of a mid-ocean ridge. By using marine MT instruments, researchers discovered the presence of partial melt and low-resistivity anomalies below a stalled mid-ocean ridge. These findings contribute to understanding the current state beneath a ceased spreading mid-ocean ridge.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Oceanography
Xincheng Zhang, Zhiwei Zhang, James C. McWilliams, Zhongbin Sun, Wei Zhao, Jiwei Tian
Summary: This study focuses on two oppositely rotating submesoscale coherent vortices (SCVs) in the northeastern South China Sea, analyzing their core positions, rotation directions, velocities, etc. It suggests that SCVs may be generated through current-topography interaction and are common in the northeastern South China Sea, potentially providing a novel route for tracer exchange between this region and the western Pacific.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Engineering, Marine
Penghao Wang, Kefeng Mao, Xi Chen, Kefeng Liu
Summary: The study used observational and composite data to examine the three-dimensional structural characteristics of mesoscale cyclonic eddies in the Kuroshio Extension region. The findings suggest that the ARMOR 3D dataset underestimates velocity and the composite data from Argo exhibit weaker anomalies compared to observations.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Environmental Sciences
Jun Yu, Danling Tang, Sufen Wang, Lei He
Summary: This study investigates the spatial distribution, morphology, and chemical composition of microplastics in the surface seawater of the southwestern South China Sea. The results show low abundance and high diversity of microplastics, with significant differences observed between the Nansha Islands and the Xisha Islands, as well as between onshore and offshore areas.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Xiuli Yan, Jin-Yu Terence Yang, Min Nina Xu, Hongjie Wang, Minhan Dai, Shuh-Ji Kao
Summary: Information on the sources and transformations of particulate organic N (PN) and dissolved organic N (DON) at the coastal interface remains insufficient due to technological difficulties and complicated features of intensive physical mixing and rapid biological activities. The study investigated the spatial distribution of concentrations and isotopic compositions of PN and DON in the Changjiang plume during the summer flood period, revealing nonconservative DON behaviors and active transformations between the DON and PN pools.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Jin-Yu Terence Yang, Ting-Chang Hsu, Ehui Tan, Kitack Lee, Michael D. Krom, Sijing Kang, Minhan Dai, Silver Sung-Yun Hsiao, Xiuli Yan, Wenbin Zou, Li Tian, Shuh-Ji Kao
Summary: Coastal oceans are increasingly suffering from eutrophication and hypoxia, which significantly affect the nitrogen cycle. This study found that estuarine surface sediments are the major source of N2O production, while nitrification and denitrification have a minimal contribution. Furthermore, the coupling of nitrification and denitrification at the sediment-water interface, under the presence of abundant organic matter, is the main driver of N2O release in this region.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Multidisciplinary Sciences
Zuozhu Wen, Thomas J. Browning, Yihua Cai, Rongbo Dai, Ruifeng Zhang, Chuanjun Du, Ruotong Jiang, Wenfang Lin, Xin Liu, Zhimian Cao, Haizheng Hong, Minhan Dai, Dalin Shi
Summary: Nitrogen fixation is vital for ocean productivity, but the exact mechanisms controlling this process are still unclear. This study shows that the supply ratio of iron:nitrogen is the most important factor in regulating N-2 fixation distribution in the tropical ocean.
Review
Astronomy & Astrophysics
Minhan Dai, Jianzhong Su, Yangyang Zhao, Eileen E. Hofmann, Zhimian Cao, Wei-Jun Cai, Jianping Gan, Fabrice Lacroix, Goulven G. Laruelle, Feifei Meng, Jens Daniel Mueller, Pierre A. G. Regnier, Guizhi Wang, Zhixuan Wang
Summary: This review examines the current understanding of the global coastal ocean carbon cycle and provides a new quantitative synthesis of air-sea CO2 exchange. The study highlights the importance of coastal and open ocean carbon sinks in mitigating climate change and meeting the target set by the Paris Agreement. The review also identifies challenges and knowledge gaps in projecting future changes in the coastal ocean carbon cycle.
ANNUAL REVIEW OF EARTH AND PLANETARY SCIENCES
(2022)
Article
Oceanography
Jin-Yu Terence Yang, Jin-Ming Tang, Sijing Kang, Minhan Dai, Shuh-Ji Kao, Xiuli Yan, Min Nina Xu, Chuanjun Du
Summary: This study utilizes sedimentary N records in the South China Sea to reconstruct past changes in the oceanic nitrate inventory and provides insights into nitrate dynamics in the region. The findings suggest that the changes in nitrate isotopic ratios in the euphotic zone of the South China Sea are influenced by both nitrate assimilation and nitrification. In subsurface and thermocline waters, disproportional decreases in nitrate isotopes and elevated nitrate anomalies indicate the accumulation of external nitrogen. The study also reveals increased benthic denitrification at the western North Pacific Ocean margins, leading to consistent nitrate isotopic compositions but lower nitrate anomalies in the deep water of the South China Sea.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Environmental Sciences
Xianhui S. Wan, Hua Lin, Bess B. Ward, Shuh-Ji Kao, Minhan Dai
Summary: The coastal ocean and marginal sea are important sources of nitrous oxide (N2O) emissions into the atmosphere, but the spatial and temporal distribution of N2O in these regions is still uncertain due to lack of measurements. This study presents a large dataset of N2O concentrations and fluxes obtained from 10 cruises in the Northern South China Sea (NSCS). The results show that the NSCS is a net source of atmospheric N2O, with variations in fluxes across different regions and seasons. The study also highlights the influence of riverine discharge and the intrusion of the Kuroshio Current on N2O distribution in the NSCS.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Geosciences, Multidisciplinary
Wei Yang, Xianghui Guo, Zhimian Cao, Jianzhong Su, Liguo Guo, Lifang Wang, Yi Xu, Tao Huang, Yan Li, Yanping Xu, Zhe Wang, Guizhi Wang, Minhan Dai
Summary: This study investigated carbonate dynamics in the northwestern South China Sea, where upwelling, river plumes, and submarine groundwater discharge intersect. The study revealed complex spatial and year-to-year variations and demonstrated the joint modulations of upwelling, river plumes, and submarine groundwater discharge on the carbonate system.
SCIENCE CHINA-EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Xianhui S. S. Wan, Hua-Xia Sheng, Minhan Dai, Karen L. L. Casciotti, Matthew J. J. Church, Wenbin Zou, Li Liu, Hui Shen, Kuanbo Zhou, Bess B. B. Ward, Shuh-Ji Kao
Summary: The removal of carbon dioxide from the atmosphere by the marine biological pump is counteracted by the production of nitrous oxide in the subtropical ocean, which weakens the radiative benefit of carbon removal. Nitrous oxide production is promoted by enhanced biological activity, leading to substantial emissions that offset part of the greenhouse warming mitigation achieved by the biological pump.
Review
Geochemistry & Geophysics
Minhan Dai, Ya-Wei Luo, Eric P. Achterberg, Thomas J. Browning, Yihua Cai, Zhimian Cao, Fei Chai, Bingzhang Chen, Matthew J. Church, Dongjian Ci, Chuanjun Du, Kunshan Gao, Xianghui Guo, Zhendong Hu, Shuh-Ji Kao, Edward A. Laws, Zhongping Lee, Hongyang Lin, Qian Liu, Xin Liu, Weicheng Luo, Feifei Meng, Shaoling Shang, Dalin Shi, Hiroaki Saito, Luping Song, Xianhui Sean Wan, Yuntao Wang, Wei-Lei Wang, Zuozhu Wen, Peng Xiu, Jing Zhang, Ruifeng Zhang, Kuanbo Zhou
Summary: Subtropical gyres cover a significant portion of the world's ocean and are typically considered as ocean deserts due to their permanent stratification, depleted surface nutrients, and low biological productivity. Despite advancements in understanding biogeochemistry, subtropical gyres remain understudied. This review focuses on the North Pacific Subtropical Gyre and compares it with other subtropical gyres. It highlights the spatial variability and its impact on community structure and export production. The review also identifies knowledge gaps and research challenges in these unique systems that warrant future studies.
REVIEWS OF GEOPHYSICS
(2023)
Article
Limnology
Zhongwei Yuan, Thomas J. J. Browning, Ruifeng Zhang, Chengwang Wang, Chuanjun Du, Yanmin Wang, Ying Chen, Zhiyu Liu, Xin Liu, Dalin Shi, Minhan Dai
Summary: In nitrogen limited low latitude ocean regions, phosphate depletion can induce stress responses in marine microbes. This study associates a broad region of phosphate depletion in the subtropical North Pacific with different levels of phosphorus stress, and demonstrates the primary nitrogen limitation of the phytoplankton community with the relief provided by aerosol supply. Enhanced alkaline phosphatase activities indicate elevated phosphorus stress in northern sites with depleted phosphate. Increased aerosol deposition, likely stimulated by aerosol iron supply, can drive the regional enhancement in phosphate depletion through elevated nitrogen fixation. These findings are crucial for predicting future biogeochemical responses in the subtropical North Pacific to changes in aerosol supply.
LIMNOLOGY AND OCEANOGRAPHY LETTERS
(2023)
Editorial Material
Multidisciplinary Sciences
Wei-Lei Wang, Mar Fernandez-Mendez, Franziska Elmer, Guang Gao, Yangyang Zhao, Yuye Han, Jiandong Li, Fei Chai, Minhan Dai
NATURE COMMUNICATIONS
(2023)
Article
Oceanography
Xianghui Guo, Jianzhong Su, Liguo Guo, Zhiqiang Liu, Wei Yang, Yan Li, Zhentong Yao, Lifang Wang, Minhan Dai
Summary: A field survey in the Pearl River estuary showed that upwelling-induced high DIC, low pH, and low DO values led to acidification and hypoxia. The observed phenomena contradicted the predicted consumption of DIC and over-saturation of DO. Hypoxia, acidification, and DIC accumulation were observed in the bottom waters. The ventilation under the influence of downwelling winds during the second survey reduced hypoxia but enhanced acidification.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Ecology
Yifan Ma, Kuanbo Zhou, Weifang Chen, Junhui Chen, Jin-Yu Terence Yang, Minhan Dai
Summary: In this study, samplings were conducted in the South China Sea to examine the nutrient-dependent structures of export productivity. The results showed that nitrate concentrations sharply increased with depth in the nutrient-replete layer. By estimating POC export fluxes, it was found that the NDL could rapidly export POC, challenging the traditional view that it would not be a net exporter of POC.
Article
Geosciences, Multidisciplinary
Zhixuan Wang, Guizhi Wang, Xianghui Guo, Yan Bai, Yi Xu, Minhan Dai
Summary: This study reconstructed the monthly sea surface pCO2 in the South China Sea (SCS) using a machine-learning-based method. The results show that while the SCS is overall a weak source of atmospheric CO2, the northern SCS acts as a sink, with the strength of the sink increasing over the past 2 decades. This research is significant for understanding carbon cycling and climate change in the SCS.
EARTH SYSTEM SCIENCE DATA
(2023)
Article
Geochemistry & Geophysics
Zigeng Song, Shujie Yu, Yan Bai, Xianghui Guo, Xianqiang He, Weidong Zhai, Minhan Dai
Summary: The South China Sea is one of the largest marginal seas in the world, and estimating the air-sea CO2 flux in this region is challenging. In this study, a retrieval algorithm for sea surface pCO2 was developed using a combination of a mechanistic semianalytical method and machine learning. The algorithm was validated using independent cruise-based datasets and showed good accuracy and consistency.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2023)