Article
Mechanics
E. A. Ryzhov, P. Berloff
Summary: Parameterizing mesoscale eddies in ocean circulation models remains a challenging problem. Dynamically filtered eddies can address this issue by not requiring explicit spatio-temporal filters and enhancing the model's ability to reproduce the reference circulation. We uncovered the physical properties of these eddies and found that both the diffusive and advective parts of the transport tensor are significant, with the filamentation component dominating.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Geosciences, Multidisciplinary
Jiangbo Jin, Run Guo, Minghua Zhang, Guangqing Zhou, Qingcun Zeng
Summary: This study proposes a new explicit tidal scheme and evaluates its performance in a global ocean model. The new scheme improves the simulation of tidal characteristics and reduces errors, leading to better dynamic sea level (DSL) simulation in the North Atlantic.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)
Article
Mechanics
A. F. Wienkers, L. N. Thomas, J. R. Taylor
Summary: This study investigates the linear growth and saturation of symmetric instability in a model representing a broad frontal zone, revealing the significant impact of front strength on the mixing down of balanced thermal wind and the primary source of energy. Nonlinear numerical simulations show that the adjustment process and induced inertial oscillations depend on front strength, with weak fronts developing narrow frontlets and small-amplitude sheared oscillations, while stronger fronts generate large inertial oscillations and bore-like gravity currents.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Oceanography
Hui Zhou, Hengchang Liu, Shuwen Tan, Wenlong Yang, Yao Li, Xueqi Liu, Qiang Ren, William K. Dewar
Summary: This study investigated the structure and variations of the North Equatorial Countercurrent (NECC) in the far western Pacific Ocean during 2014-16, finding that the impact of the 2015/16 El Nino on the NECC was comparable to that of the extreme 1997/98 El Nino, showing baroclinic instability during the developing phase. This differs from traditional understanding and highlights the diverse eddy-mean flow interactions associated with various states of the El Nino-Southern Oscillation (ENSO).
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2021)
Article
Oceanography
Tsushi Kubokawa
Summary: Under no-slip boundary conditions, Western boundary currents tend to prematurely separate from the coast and form eastward jets. This study examines the meridional structure and location of a prematurely separated WBC extension jet using a two-layer quasigeostrophic model. It is found that the meridional structure can be determined based on the strength of the PV front, the value of the stream-function at the jet's center, and the meridional profile of the Sverdrup zonal flow.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2023)
Article
Meteorology & Atmospheric Sciences
Hengling Leng, Hailun He, Michael A. Spall
Summary: The Chukchi Slope Current is a westward-flowing current along the Chukchi slope, which has a significant impact on the hydrographic structure and ecosystem of the region. This study uses numerical modeling to investigate the energetics of the slope current during the ice-covered period. The results show that ice friction plays a crucial role in suppressing the growth of surface eddies and driving Ekman pumping to decrease the available potential energy and kinetic energy of the mean flow and mesoscale eddies.
Article
Mechanics
W. Coenen, A. L. Sanchez, R. Felez, K. A. Davis, G. Pawlak
Summary: The article presents an analytical study of two-dimensional flow in a wedge driven by a time-dependent surface heat flux, focusing on the principles and effects of cross-shore flow, as well as the parameters and properties of the solution.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Oceanography
Antoine Hochet, William Llovel, Florian Sevellec, Thierry Huck
Summary: Understanding the mechanisms of regional steric sea level variability is crucial for interpreting satellite altimetry data and improving climate models. A novel method based on steric sea level variance budget is developed to identify the sources and sinks of variability. The study finds that interannual steric sea level variability is mainly driven by interannual fluctuating winds through Ekman transport, with the effects of atmospheric heat fluxes and eddies also playing a role.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Meteorology & Atmospheric Sciences
Abdullah A. Fahad, Natalie J. Burls, Erik T. Swenson, David M. Straus
Summary: Subtropical anticyclones and midlatitude storm tracks play key roles in the large-scale atmospheric circulation. In the Southern Hemisphere, the seasonality of subtropical anticyclones over the South Pacific, South Atlantic, and south Indian Ocean basins has significant impacts on local weather and climate. The study investigates the strength of the South Pacific subtropical anticyclone in austral summer, attributing it to heating over the South Pacific convergence zone triggering a propagating Rossby wave train.
JOURNAL OF CLIMATE
(2021)
Article
Mechanics
Bo Zhao, Zhenhua Xu, Qun Li, Yang Wang, Baoshu Yin
Summary: Three-dimensional numerical modeling is used to investigate the emission of inertia-gravity waves (IGWs) from an exact geostrophic vortex in a rotating and stratified fluid. The generation of spiral IGWs with clockwise rotation is likely due to an instability mechanism occurring within a short transient time period.
Article
Meteorology & Atmospheric Sciences
Vigan Mensah, Yoshihiro Nakayama, Masakazu Fujii, Yoshifumi Nogi, Kay I. Ohshima
Summary: Understanding the formation and descent of Dense Shelf Water (DSW) and Antarctic Bottom Water (AABW) in the Southern Ocean requires high horizontal resolution and relatively coarse vertical resolution. By simulating and comparing with observational data, it was found that realistic simulation of AABW production and descent process requires fine horizontal grid resolutions equal to or higher than 2 km.
Article
Oceanography
A. Pirro, E. Mauri, R. Gerin, R. Martellucci, P. Zuppelli, P. M. Poulain
Summary: The deepwater formation in the northern part of the South Adriatic Pit was investigated using oceanographic data. The results showed the breaking up of a convective area after two weeks of mixing, due to a baroclinic instability process. These observed features differ from previous studies.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Geosciences, Multidisciplinary
B. D. Dushaw, D. Menemenlis
Summary: An unconstrained global ocean simulation in 2020 confirms previous observations of diurnal internal tides by acoustic tomography in the Western North Atlantic. The simulation accurately reproduces the characteristics of K1 and O1 internal-tide standing waves, but shows deviations from observations in terms of barotropic and internal tides. The tomographic data provide a benchmark for improving the representation of tides, internal tides, and dissipation in models.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Oceanography
Ken X. Zhao, Andrew L. Stewart, James C. McWilliams
Summary: This study used idealized numerical simulations to investigate the controlling parameters of overturning and horizontal recirculation, finding that sill height, wind direction/strength, subglacial discharge strength, and depth of offshore warm water are crucial for overturning circulation, while fjord width is important for horizontal recirculation. Based on developed dynamical predictions and vorticity budget, improved estimates of ocean-driven melting of the Greenland and Antarctic ice sheets can be achieved.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2021)
Article
Meteorology & Atmospheric Sciences
Jiangbo Jin, Hailong Liu, Xiao Dong, Juanxiong He, Xin Gao, Yi Yu, He Zhang, Minghua Zhang, Qingcun Zeng
Summary: The study focuses on investigating the impact of redistributed heat flux on ocean heat uptake and the Atlantic Meridional Circulation, while also evaluating how well different heat flux anomaly experiments in the FAFMIP project capture the ocean's response to prescribed surface heat flux. The findings suggest that the faf-heat-NA50pct experiment, where the redistribution-feedback nearly equals the initial perturbation, provides better results in simulating the ocean's response, compared to the faf-heat-NA0pct experiment, which results in significant reduction in ocean heat uptake with minimal impact on AMOC intensity.
Article
Environmental Sciences
Xiaokun Ding, Jie Shi, Xinyu Guo, Huiwang Gao, Sumei Liu, Wei Guo
Summary: There is growing concern about the impact of human activities on the coastal nutrient cycle, but the interannual variations in response to anthropogenic nutrient input have been rarely studied. This study used a hydrodynamic-ecological model to analyze the interannual variations in the nutrient cycle in the central Bohai Sea. The results showed increasing trends in nitrogen levels, but no noticeable interannual variations in phosphorus levels. Atmospheric nitrogen deposition played a significant role in the nitrogen cycle, and sedimentation processes were responsible for removing most of the anthropogenic nitrogen inputs.
Article
Oceanography
Zheng Guo, Shuya Wang, Anzhou Cao, Jieshuo Xie, Jinbao Song, Xinyu Guo
Summary: This study examines the role of anticyclonic and cyclonic eddies in modulating the M2 internal tides in the northern South China Sea. The results show that the anticyclonic eddy causes northward refraction of the M2 internal tides, while the cyclonic eddy causes southward refraction. The most significant impacts occur on the continental slope in the northern South China Sea.
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS
(2023)
Article
Oceanography
Su Mei Liu, Wen Liang, Xinyu Guo, Nian Wu, Wuchang Zhang, Xiujuan Shan, Hua-De Zhao, Juying Wang, Jin Huang
Summary: Chinese continental margins are undergoing significant environmental changes due to anthropogenic activities and climate change. This study focuses on the Bohai as a case study and examines the impacts of multiple stressors on ecosystems and social interactions. The Bohai ecosystem has been extensively modified, with changes in the coastline, nutrient concentrations, and fishery resources. It is important to implement strict policies for coastline protection and pollution control, as well as measures like fishing bans and stock enhancement to mitigate these impacts.
Review
Oceanography
Shuya Wang, Qun Li, Anzhou Cao, Xinyu Guo
Summary: This study investigates seven burst events of near-inertial waves (NIWs) based on moored observations from the Beaufort Gyre Exploration Project. The NIW events are divided into two groups. Four events in group I are dominated by downgoing components associated with near-inertial currents. The other three events in group II have comparable downgoing and upgoing components and may be related to eddy events.
PROGRESS IN OCEANOGRAPHY
(2023)
Article
Environmental Sciences
Junying Zhu, Quanyi Zhou, Qianqing Zhou, Xinxing Geng, Jie Shi, Xinyu Guo, Yang Yu, Ziwei Yang, Renfu Fan
Summary: Coastal upwelling around Hainan Island has a significant impact on the physical environment, ecological environment, and fishery resources of the surrounding waters. The study analyzed the interannual variations of sea surface temperature (SST) around Hainan Island based on satellite observations from 2003 to 2021, focusing on the upwelling regions in Qiongdong and Qiongxi. The results showed warming trends in the upwelling regions, and the SST variations were influenced by factors such as wind stress curl, stratification, and bottom cold water in the Gulf of Tonkin.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Geosciences, Multidisciplinary
Junyong Zheng, Xinyu Guo, Haiyan Yang, Kailun Du, Xinyan Mao, Wensheng Jiang, Takuya Sagawa, Yasumasa Miyazawa, Sergey M. Varlamov, Ayako Abe-Ouchi, Wing-Le Chan
Summary: By using a simple box model, researchers reconstructed the sea surface salinity in the Japan Sea over the past 35 kyr and found that the sea experienced a low salinity event during the Last Glacial Maximum, with the minimum value occurring at 20 kyr BP. It was concluded that both the inflow transport and the sea surface freshwater flux determine the exact value and timing of minimum salinity.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2023)
Article
Oceanography
Yu-Lin K. Chang, Sergey M. Varlamov, Xinyu Guo, Toru Miyama, Yasumasa Miyazawa
Summary: In July 2020, a stationary atmospheric front over Japan resulted in persistent heavy rainfall, causing extreme river discharge, floods, and landslides. Existing models failed to accurately represent the river discharge, but new experiments using real-time river discharge information improved the model simulation. The inclusion of real-time river discharge had a significant impact on coastal salinity distribution, offshore currents, and cross-shelf exchange.
Article
Oceanography
Yifei Luo, Jie Shi, Xinyu Guo, Xinyan Mao, Peng Yao, Bin Zhao, Lin Chen, Yucheng Wang
Summary: The intensity of Zhejiang coastal upwelling (ZCU) is the principal factor influencing the coastal primary productivity of the East China Sea (ECS) in summer, while the Kuroshio intrusion (KI) has a relatively smaller impact. Strong ZCU leads to higher nutrient concentrations and greater nutrient supplies in nearshore areas. The years 2013 and 2018 were identified as strong and weak ZCU years, respectively, with significant differences in nutrient concentrations and phytoplankton biomass.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Geosciences, Multidisciplinary
Shoichiro Kido, Masami Nonaka, Yasumasa Miyazawa
Summary: Through experiments, it has been discovered that the intensities of the Kuroshio and Gulf Stream warm ocean currents can be accurately predicted up to 2 years in advance. The predictability mainly depends on initial ocean memories, while variations in local atmospheric conditions have a secondary role. These results indicate that the multiyear variations in ocean currents and eddies in these regions can be operationally predictable with properly initialized ocean models of sufficient spatial resolution.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Oceanography
Hakase Hayashida, Andrew E. Kiss, Toru Miyama, Yasumasa Miyazawa, Sayaka Yasunaka
Summary: The large meander of the Kuroshio western boundary current influences the local climate, fisheries, and aquaculture. It determines the extent of the shallow nutricline region and triggers offshore phytoplankton blooms during the LM phase. The LM also modulates the spatial distributions of primary production, air-sea carbon flux, and export production.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Engineering, Civil
Tsubasa Kodaira, Tomotaka Katsuno, Takehiko Nose, Motoyo Itoh, Jean Rabault, Mario Hoppmann, Masafumi Kimizuka, Takuji Waseda
Summary: The interaction between waves and ice plays a crucial role in the seasonal change of sea ice extent. However, a lack of observations limits our understanding of this phenomenon. In this study, a novel design concept for a wave buoy is proposed, using 3D printing technology for customization. Preliminary field tests in the Pacific and Arctic Oceans show promising results, with comparable accuracy to more expensive instruments.
COASTAL ENGINEERING JOURNAL
(2023)
