Article
Environmental Sciences
Wen Xu, Yeqiang Shu, Dongxiao Wang, Ju Chen, Jinghong Wang, Qiang Xie, Qiang Wang, Danian Liu, Tingting Zu, Yunkai He
Summary: This study reveals the strong intraseasonal variability (ISV) features of the upper-layer current in the northern South China Sea (NSCS) based on four long-time mooring observations and altimeter data. The ISV consists of two dominant periods of 10-65 days and 65-110 days, with spatial differences primarily due to baroclinic and barotropic instabilities. The spatial distribution of upper-layer ISV is closely associated with the mesoscale eddy radius of the NSCS, with the strength of ISV inversely proportional to the eddy radius of 10-65-day ISV and directly proportional to the eddy radius of 65-110-day ISV.
FRONTIERS IN MARINE SCIENCE
(2021)
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
Tongya Liu, Yinghui He, Xiaoming Zhai, Xiaohui Liu
Summary: This study examines the leakage of Eulerian eddies and quantifies the contribution of coherent eddy transport in the South China Sea (SCS) using Lagrangian approach. It is found that sea surface height (SSH) eddies are highly leaky during their lifetimes, with more than 80% of the original water leaking out of the eddy interior. The leaked water exhibits a spatial pattern of asymmetry relative to the eddy center. The contribution of coherent eddies to total eddy material transport is less than 5% in both zonal and meridional directions.
Article
Oceanography
Ruibin Ding, Jiliang Xuan, Tao Zhang, Lei Zhou, Feng Zhou, Qicheng Meng, In-Sik Kang
Summary: Research shows that significant eddy-induced heat transport occurs in specific regions of the South China Sea, with marked seasonality. The energy transfer in eddy-induced heat transport is influenced by both barotropic and baroclinic instabilities, resulting in a unique pattern of energy propagation.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2021)
Article
Environmental Sciences
Jinzheng Chen, Fenfen Liu
Summary: Based on satellite data and HYCOM-simulated results, the impact of mesoscale eddies on phytoplankton size and physiological level in the northern South China Sea from 2003 to 2018 is analyzed. The results show that there are higher nanophytoplankton levels for high and low nonlinearity in the center of cyclonic eddies. At the same time, the growth rate of phytoplankton increased, and the assimilation of phytoplankton decreased. Moreover, in the center of anticyclonic eddies, a lower nanophytoplankton level is observed in both high and low nonlinearity. At the same time, the growth rate of phytoplankton decreased, and the assimilation of phytoplankton increased. There is also a higher nanophytoplankton level in the mode-water eddy, while the growth rate of phytoplankton is increased, and the assimilation of phytoplankton is decreased.
Article
Engineering, Marine
Xiayan Lin, Guixi Wang, Guoqing Han, Yu Liu, Han Zhang, Xiaomei Liao, Qiyan Ji
Summary: Cross-slope eddies are crucial for the exchange of various biogeochemical elements between the basin and shelf in the South China Sea. This study used the ROMS model and satellite data to investigate the cross-slope transport process by a mesoscale anticyclonic eddy. The results showed different characteristics of the anticyclone at different locations on the slope, with enhanced on and off-slope transports during the cross-slope process.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Environmental Sciences
Taekyun Kim, Hyeong-Jun Jo, Jae-Hong Moon
Summary: This study explores the spatiotemporal variability of mesoscale phenomena in the northern part of the East Sea and identifies detailed structure and mechanism of occurrence and evolution. It highlights the importance of winter monsoon winds and thermohaline transport in regulating mesoscale features. The study also emphasizes the role of warm and fresh surface water intrusion in intensifying mesoscale activities in the East Sea.
Article
Engineering, Marine
Tao Zhang, Junyi Li, Lingling Xie, Quanan Zheng
Summary: The path type and temporal variability of eddies entering the continental shelf area of the northern South China Sea from 1993 to 2016 were analyzed using the AVISO mesoscale eddy trajectory atlas. Four types of eddies were identified, with differences in their characteristics and occurrence numbers. The direction and velocity of the background flow field influenced the path and seasonal distribution of the eddies.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Environmental Sciences
Zhanjiu Hao, Zhenhua Xu, Ming Feng, Qun Li, Baoshu Yin
Summary: This study investigates the spatiotemporal variations and generation mechanisms of mesoscale eddies across the whole Indonesian Seas for the first time. The Sulu Sea, Sulawesi Sea, Maluku Sea, and Banda Sea are identified as the main eddy generation regions, with over 80% of eddies having a short lifetime. Eddies exhibit high spatial inhomogeneity in their properties and different seasonal cycles in each basin.
Article
Oceanography
Ge Chen, Xiaoyan Chen, Baoxiang Huang
Summary: A methodology to expand eddy tracking capacity is proposed by utilizing altimetrically calibrated Argo measurements, aiming to tackle the issue of missed oceanic eddies due to inadequate spatiotemporal sampling by available altimeters. The independent identification scheme relates the surface signature of eddies to their interior property, effectively identifying additional eddies overlooked by altimeters and rectifying their ineffectiveness in certain regions. The approach demonstrates a highly complementary nature of combining altimetry and Argo profiling arrays for eddy identification.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Geosciences, Multidisciplinary
Angelina Cassianides, Camille Lique, Anton Korosov
Summary: A new method of ocean eddy detection based on sea ice vorticity signature from SAR images was developed to overcome the obstacle of sea ice presence, successfully identifying a mesoscale eddy in the Arctic Ocean. The method's robustness indicates the potential to detect more eddies as more SAR observations become available in the future.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Environmental Sciences
Junqiang Shen, Wendong Fang, Li Li, Yun Qiu, Zheng Xiao, Junpeng Zhang, Xiaogang Guo
Summary: This study reports the observation of a slope undercurrent beneath the winter western boundary current of the northwestern South China Sea, and discusses its spatiotemporal variation and possible underlying dynamics.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Oceanography
Chunhua Qiu, Zihao Yang, Dongxiao Wang, Ming Feng, Jingzhi Su
Summary: This study investigates the characteristics of submesoscale ageostrophic motion in the South China Sea using surface drifters and satellite altimeter data. The results show that this motion enhances the strength of mesoscale eddies and plays a significant role in their development.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Oceanography
A. A. Kubryakov, I. E. Kozlov, G. E. Manucharyan
Summary: Eddies in the Western Arctic play a crucial role in transporting heat, salt, and biogeochemical tracers across the continental shelf and deep basins. With increasing areas of the Arctic Ocean becoming ice-free due to global warming, satellite altimetry data has revealed the presence of numerous eddies with specific characteristics, aiding in statistical analysis and discussion of formation mechanisms in key regions.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Engineering, Aerospace
Cori Pegliasco, Alexis Chaigneau, Rosemary Morrow, Franck Dumas
Summary: This study compared Mediterranean Sea eddies detected and tracked using two altimetry products from 2000 to 2015. It was found that more individual eddies and trajectories are detected in the Sea Level Anomaly (SLA) data compared to the Absolute Dynamic Topography (ADT) data, with larger radius but lower Eddy Kinetic Energy. The spatial distribution of the mesoscale activity differs between the two data sets.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Mathematical & Computational Biology
Yong Fang, Yanhua Sun, Lu Zhang, Gengxin Chen, Mei Du, Yunxia Guo
Summary: This study improves the accuracy of typhoon track and intensity prediction in stochastic simulation using machine learning methods. By establishing a neural network model and conducting validation, it can effectively evaluate the risk of typhoon disasters.
COMPUTATIONAL INTELLIGENCE AND NEUROSCIENCE
(2022)
Article
Astronomy & Astrophysics
Shilin Tang, Xiaoqing Chu, Yongjun Jia, Junmin Li, Yiting Liu, Qiong Chen, Bo Li, Junliang Liu, Wuyang Chen
Summary: The China-France ocean satellite (CFOSAT) has obtained synchronized observations of sea winds and sea waves for the first time in the world, providing accurate data support for the study of swells. According to CFOSAT SWIM data analysis, the annual average significant wave height (SWH) of mixed waves in the South China Sea (SCS) is 1.47 m, with 80% of the waves ranging from 0.5 to 3 m, while the annual average SWH of swells is 0.93 m, with 99% of swells being less than 2 m.
EARTH AND SPACE SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Gengxin Chen, Weiqing Han, Tingting Zu, Xiaoqing Chu, Ju Chen
Summary: Using in-situ observation and reanalysis data, this study reports the detection of an eastward current beneath the westward-flowing South Equatorial Current in the South Indian Ocean, named the South Equatorial Undercurrent (SEUC). The SEUC, with unique characteristics, is a seasonal feature that contributes to our understanding of the current system and mass exchanges in the region.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Oceanography
Gengxin Chen, Rui Xin Huang, Qihua Peng, Xiaoqing Chu
Summary: The Sverdrup relation is essential for wind-driven circulation theory, describing the relationship between the meridional transport in the upper ocean and wind stress curl. This study introduces a time-dependent version of the Sverdrup relation and applies it to the equatorial circulation in the Indian Ocean.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Multidisciplinary Sciences
Qihua Peng, Shang-Ping Xie, Dongxiao Wang, Rui Xin Huang, Gengxin Chen, Yeqiang Shu, Jia-Rui Shi, Wei Liu
Summary: The changes in ocean circulation in a warming climate are poorly understood but important. Using a global ocean model, this study explores the distinct responses of ocean circulation to changes in sea surface temperature, salinity, and wind. The results reveal that the surface warming effect dominates and accelerates upper ocean currents globally, while wind stress and surface salinity changes affect regional current systems.
Article
Oceanography
Gayan Pathirana, Dongxiao Wang, Gengxin Chen, M. K. Abeyratne, Tilak Priyadarshana
Summary: This study investigates the effect of the seasonal barrier layer (BL) on the mixed-layer heat budget in the Bay of Bengal (BoB) using time series measurements from the Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction (RAMA) moorings. The results show an inverse relation between the BL thickness and the mixed-layer temperature (MLT), and the vertical heat flux at the base of the mixed layer (Q(h)) dominates during winter. The study suggests that BL exerts a significant influence on partial differential T/ partial differential t when the BL thickness is > 25 m.
ACTA OCEANOLOGICA SINICA
(2022)
Article
Meteorology & Atmospheric Sciences
Xiaoqing Chu, Weiqing Han, Lei Zhang, Gengxin Chen
Summary: This study examines the dynamics of interannual variability of equatorial currents in the Indian Ocean using reanalysis datasets and ocean model experiments. It finds that equatorial waves forced by equatorial winds dominate the interannual current anomalies. The study also quantifies the effects of El Nino-Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) climate modes on the currents. It concludes that ENSO and IOD have comparable effects on the currents in certain regions, but IOD has a larger role in others. The co-occurrence of ENSO and IOD enhances their respective impact on the currents, causing anomalies to last for several months.
Article
Geosciences, Multidisciplinary
Ke Huang, Dongxiao Wang, Gengxin Chen, Motoki Nagura, Weiqing Han, Michael J. McPhaden, Ming Feng, Ju Chen, Ying Wu, Xiaolin Zhang, Yuanlong Li, Qiang Xie, Weiqiang Wang, Feng Zhou
Summary: The anomalously strong westward Equatorial Undercurrent developed in 2016 and 1998 in the Indian Ocean coinciding with extreme Indian Ocean Dipole and El Nino events. The constructive interactions between directly wind-forced and boundary-reflected waves play a crucial role in driving the interannual variability of the Indian Ocean wEUC.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Oceanography
Gengxin Chen, Weiqing Han, Dongxiao Wang, Lei Zhang, Xiaoqing Chu, Yunkai He, Ju Chen
Summary: The South Equatorial Current in the south Indian Ocean plays an important role in the water exchange among the Pacific, Indian, and Atlantic Oceans. This study examines its seasonal structure and interannual variability using satellite and in situ observations. The results show that the current follows straight and meandering routes in different time periods and exhibits obvious interannual variability. The study also reveals that the abnormal routes are primarily caused by extreme positive Indian Ocean Dipole events.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Meteorology & Atmospheric Sciences
Lijing Cheng, John Abraham, Kevin E. Trenberth, John Fasullo, Tim Boyer, Michael E. Mann, Jiang Zhu, Fan Wang, Ricardo Locarnini, Yuanlong Li, Bin Zhang, Fujiang Yu, Liying Wan, Xingrong Chen, Licheng Feng, Xiangzhou Song, Yulong Liu, Franco Reseghetti, Simona Simoncelli, Viktor Gouretski, Gengxin Chen, Alexey Mishonov, Jim Reagan, Guancheng Li
Summary: Changes in ocean heat content, salinity, and stratification serve as critical indicators for Earth's energy and water cycles, which have been significantly impacted by human activities and greenhouse gas emissions. The year 2022 witnessed the highest ocean heat content on record, surpassing the previous maximum. The salinity-contrast index also reached a record high, indicating an intensification of the global hydrological cycle. Regional oceanic changes were driven by a strong La Nina event, and the global upper-ocean stratification continued to increase, ranking among the top seven in 2022.
ADVANCES IN ATMOSPHERIC SCIENCES
(2023)
Article
Oceanography
Xueying Ma, Gengxin Chen, Yuanlong Li, Lili Zeng
Summary: Phytoplankton play a crucial role in marine ecosystems and the global carbon cycle. This study investigates the characteristics and causes of the interannual variation of surface chlorophyll a (chl a) in the southern tropical Indian Ocean (STIO). The study finds that both the Seychelles-Chagos thermocline ridge (SCTR) upwelling zone and the southeastern tropical Indian Ocean (SETIO) exhibit large interannual variability. The study also identifies surface wind forcing anomalies and thermocline dynamics as the main factors driving the interannual chl a anomalies in these regions.
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS
(2022)
Article
Geosciences, Multidisciplinary
Gengxin Chen, Weiqing Han, Xueying Ma, Yuanlong Li, Tiecheng Zhang, Dongxiao Wang
Summary: Using observational-based data sets, this study reveals the notable impact of extreme positive IOD events on the three-dimensional freshwater content of the Southeast Indian Ocean. The wind changes induced the extension of the South Equatorial Current and intensified Sumatra-Java upwelling, leading to vertically opposite salinity anomalies in the surface and subsurface layers. The Equatorial Undercurrent plays a crucial role in water exchange between the equator and the Southeast Indian Ocean, highlighting a strong coupling within the framework of the IOD.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Oceanography
Guijing Yang, Xiayan Lin, Guoqing Han, Yu Liu, Gengxin Chen, Jianhui Wang
Summary: This study analyzes the three-dimensional characteristics of mesoscale eddies in two regions of the northwestern Pacific Ocean, revealing distinct properties and spatial distribution patterns.
ACTA OCEANOLOGICA SINICA
(2022)
Article
Oceanography
Qingwen Zhong, Gengxin Chen, Yuanlong Li, Qihua Peng, Xiaoqing Chu
Summary: Using observations and numerical simulations, this study examines the intraseasonal variability of the surface zonal current over the equatorial Indian Ocean. The study finds that atmospheric intraseasonal oscillations are the main driver of u ISV in the eastern basin, while both atmospheric ISOs and oceanic internal instabilities contribute to u ISV in the western basin. The study also highlights the seasonal differences, with eastern u ISV being stronger in boreal summer compared to boreal winter.
ACTA OCEANOLOGICA SINICA
(2022)
