Frontiers in Physical Oceanography

A special issue of Journal of Marine Science and Engineering (ISSN 2077-1312). This special issue belongs to the section "Physical Oceanography".

Deadline for manuscript submissions: closed (5 May 2023) | Viewed by 19794

Special Issue Editors

State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
Interests: ocean circulation, air–sea interaction, and climate change; tropical ocean dynamics and mixed-layer and thermocline dynamics; teleconnection and feedback in the Indo-Western Pacific; tropics and extra-tropics interaction

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Guest Editor
State Key Laboratory of Tropical Oceanography (LTO), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
Interests: ocean observation; mesoscale and submesoscale dynamic processes
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Special Issue Information

Dear Colleagues,

Physical oceanography focuses on describing and understanding the physical properties and dynamic processes of the oceans, including surface and internal waves, ocean circulation, air–sea interactions, mesoscale eddies, density fronts, submesoscale processes, turbulent mixing, etc. These dynamic processes and their interactions over a wide range of space and time scales sustainably contribute to the mass transport and energy cycle in the ocean, as well as their impacts on climate change, the marine ecological environment, and offshore engineering. Benefiting from the developments of observational and computing technologies, the understanding of physical processes and their climatic and ecological effects have achieved a great progress in the last several decades. Not limited to the aspects mentioned above, the Physical Oceanography Section of this JMSE welcomes the submission of papers on a wide range of topics associated with the latest advances in descriptive or dynamical oceanography, indicating new insights, problems, methods or products, etc. to this Special Issue.

Prof. Dr. Yan Du
Prof. Dr. Zhiyou Jing
Guest Editors

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Keywords

  • ocean circulation
  • air–sea interactions
  • density fronts
  • submesoscale processes
  • surface and internal waves
  • turbulent mixing
  • impact on climate and ecosystem
  • ocean hazards
  • field observations
  • numerical modeling

Published Papers (13 papers)

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Research

13 pages, 3145 KiB  
Article
Laboratory Study on the Entrainment Process in Overflow
by Qiyue Hu, Jiahui Yu, Yong Cao, Xu Chen, Jing Meng and Xianqing Lv
J. Mar. Sci. Eng. 2023, 11(7), 1383; https://doi.org/10.3390/jmse11071383 - 06 Jul 2023
Viewed by 832
Abstract
During the sinking process, overflow generates an entrainment phenomenon, accompanied by the occurrence, development, and dissipation of vortices. In this paper, particle image velocimetry (PIV) technology is used to measure the flow fields of overflow sinking, invasion, and mixing. In order to quantitatively [...] Read more.
During the sinking process, overflow generates an entrainment phenomenon, accompanied by the occurrence, development, and dissipation of vortices. In this paper, particle image velocimetry (PIV) technology is used to measure the flow fields of overflow sinking, invasion, and mixing. In order to quantitatively analyze the mixing and flow processes during the sinking of the overflow, vorticity, turbulence dissipation, Froude number, local Richardson number, and entrainment coefficient are calculated. In a stratified environment, the overflow entrains the environment fluid of lower density to reach a terminal height where their density equals that of their surroundings and then spread out horizontally. The experimental results show the terminal depth is related to the density of the overflow. The lower the density, the smaller the terminal depth. The turbulent dissipation mainly occurs in the area along the slope and during the process of invading flow to the surrounding. The extreme of the turbulent dissipation is corresponding to the maximum velocity shear and vorticity. At the point where the overflow crosses the sill and at the front end of the overflow, there will be a more obvious phenomenon of entrainment. The entrainment parameter is positively correlated with the density of overflow. These preliminary results would require additional experimental validation and data observation in order to assess their relevance for realistic flow regimes. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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14 pages, 4882 KiB  
Article
Experimental Study on the Effects of Waves and Current on Ice Melting
by Tianyi He, Huijie Hu, Ding Tang, Xu Chen, Jing Meng, Yong Cao and Xianqing Lv
J. Mar. Sci. Eng. 2023, 11(6), 1209; https://doi.org/10.3390/jmse11061209 - 10 Jun 2023
Cited by 1 | Viewed by 1591
Abstract
Ice melting plays a crucial role in ocean circulation and global climate. Laboratory experiments were used to study the dynamic mechanisms of the influence of waves and currents on ice melting. The results showed that under near stable air temperature and water temperature [...] Read more.
Ice melting plays a crucial role in ocean circulation and global climate. Laboratory experiments were used to study the dynamic mechanisms of the influence of waves and currents on ice melting. The results showed that under near stable air temperature and water temperature conditions, the ice melting rate was significantly greater with waves than that without waves, as well as the higher the wave height, the greater the melting rate. This is related to the increase in the contact area between ice and water by waves. Further research was carried out to observe the flow field at different locations on the ice bottom, ice sides, and behind the ice by particle image velocimetry (PIV) and dyeing experiments. At different flow velocities, the changes in the side melting rate and bottom melting rate were not the same. Meltwater is attached to the bottom in the form of plume at low background flow velocity, which leads to the slowness of the heat exchange between the ice with a higher ambient temperature. Therefore, the melting of the ice bottom and the ice side were slower at low flow velocity. At high background flow velocity, there is strong shear instability and vortex at the ice bottom and behind the ice. The dissipation and mixing effects caused by vortices accelerate the melting of the ice bottom and the ice back. The thermodynamic factors, such as air temperature and water temperature, had significant impacts in the experiments. Further research needs to improve the accuracy of temperature control of experimental equipment. Computational fluid dynamics and sensitive tests of numerical simulation may also be carried out on ice melting. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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11 pages, 2026 KiB  
Article
Evaluating Changes in the Multiyear Predictability of the Pacific Decadal Oscillation Using Model Analogs since 1900
by Yanling Wu and Xiaoqin Yan
J. Mar. Sci. Eng. 2023, 11(5), 980; https://doi.org/10.3390/jmse11050980 - 04 May 2023
Cited by 1 | Viewed by 1127
Abstract
In this study, we investigate the changes in the multiyear predictability of the Pacific decadal oscillation (PDO) since 1900. A newly developed method, the model-analog method, is used to hindcast the PDO from 1900 to 2015. Model-analog hindcast provides comparable PDO prediction skills [...] Read more.
In this study, we investigate the changes in the multiyear predictability of the Pacific decadal oscillation (PDO) since 1900. A newly developed method, the model-analog method, is used to hindcast the PDO from 1900 to 2015. Model-analog hindcast provides comparable PDO prediction skills with the traditional assimilation-initialized forecast but with much lower computational costs. Our results show that PDO prediction skills have significantly changed over time. Specifically, the PDO could skillfully be predicted up to 5 years in advance in 1910–1960, but it can only be predicted 2–3 years in advance after 1960. We attribute these changes to the strength of the re-emergence process, where deep oceanic mixed layer temperature anomalies from one winter reappear in the following winters. In the high-prediction-skill period, the stronger re-emergence process provides more predictable information, leading to enhanced multiyear prediction skills. Our study offers new insights into the multiyear predictability of the PDO over a long-time frame and sheds light on the reasons behind the low prediction skill of the PDO. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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22 pages, 9638 KiB  
Article
How Efficient Is Model-to-Model Data Assimilation at Mitigating Atmospheric Forcing Errors in a Regional Ocean Model?
by Georgy I. Shapiro and Mohammed Salim
J. Mar. Sci. Eng. 2023, 11(5), 935; https://doi.org/10.3390/jmse11050935 - 27 Apr 2023
Cited by 2 | Viewed by 899
Abstract
This paper examines the efficiency of a recently developed Nesting with Data Assimilation (NDA) method at mitigating errors in heat and momentum fluxes at the ocean surface coming from external forcing. The analysis uses a set of 19 numerical simulations, all using the [...] Read more.
This paper examines the efficiency of a recently developed Nesting with Data Assimilation (NDA) method at mitigating errors in heat and momentum fluxes at the ocean surface coming from external forcing. The analysis uses a set of 19 numerical simulations, all using the same ocean model and exactly the same NDA process. One simulation (the reference) uses the original atmospheric data, and the other eighteen simulations are performed with intentionally introduced perturbations in the atmospheric forcing. The NDA algorithm uses model-to-model data assimilation instead of assimilating observations directly. Therefore, it requires a good quality, although a coarser resolution data assimilating parent model. All experiments are carried out in the South East Arabian Sea. The variables under study are sea surface temperature, kinetic energy, relative vorticity and enstrophy. The results show significant improvement in bias, root-mean-square-error, and correlation coefficients between the reference and the perturbed models when they are run in the data assimilating configurations. Residual post-assimilation uncertainties are similar or lower than uncertainties of satellite based observations. Different length of DA cycle within a range from 1 to 8 days has little effect on the accuracy of results. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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20 pages, 63936 KiB  
Article
Assessing the Spatio-Temporal Features and Mechanisms of Symmetric Instability Activity Probability in the Central Part of the South China Sea Based on a Regional Ocean Model
by Yifei Jiang, Weimin Zhang, Huizan Wang and Xiaojiang Zhang
J. Mar. Sci. Eng. 2023, 11(2), 431; https://doi.org/10.3390/jmse11020431 - 16 Feb 2023
Cited by 3 | Viewed by 1228
Abstract
Symmetric instability (SI) is credited with one of the important submesoscale instabilities. However, due to its small scales, it is challenging to capture using current observational measurements and ocean models. Estimates of SI activity are useful for assessing whether SI should be parameterized. [...] Read more.
Symmetric instability (SI) is credited with one of the important submesoscale instabilities. However, due to its small scales, it is challenging to capture using current observational measurements and ocean models. Estimates of SI activity are useful for assessing whether SI should be parameterized. Based on a high-resolution ocean model, we use a criterion to assess the spatio-temporal features of SI activity without directly solving SI in the Xisha–Zhongsha waters. An Ertel potential vorticity (PV) analysis is performed, and the negative PV injection and frontal tendency are calculated to analyze the generation mechanisms. The results show that the activity of SI is strongly seasonal. In comparison, SI is active in winter, but it is inactive in summer. In addition, it is mainly found within the ocean surface mixed layer (SML), and it almost disappears in the base of the surface mixed layer (BML). Moreover, the vertical component of the Ertel PV leads to the vertical spatial difference of SI activity, and both the vertical component of the Ertel PV and the sea surface buoyancy flux play an important role in the seasonality of SI activity. The stronger frontogenesis around the Xisha Islands partially accounts for the horizontal distribution difference of SI. This work implies that the parameterization of SI may have potential value in practical application in this region in winter due to the high probability of SI activity. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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19 pages, 6743 KiB  
Article
Laboratory Studies of Internal Solitary Waves Propagating and Breaking over Submarine Canyons
by Ying-Tien Lin, Ling Liu, Biyun Sheng, Yeping Yuan and Keke Hu
J. Mar. Sci. Eng. 2023, 11(2), 355; https://doi.org/10.3390/jmse11020355 - 05 Feb 2023
Viewed by 1344
Abstract
This paper carried out laboratory experiments to study evolution of internal solitary waves (ISWs) over submarine canyons with a combination of PIV (particle image velocimetry) and PLIF (planar laser-induced fluorescence) techniques. Taking canyon angle θ and collapse height ∆H as variables, Froude [...] Read more.
This paper carried out laboratory experiments to study evolution of internal solitary waves (ISWs) over submarine canyons with a combination of PIV (particle image velocimetry) and PLIF (planar laser-induced fluorescence) techniques. Taking canyon angle θ and collapse height ∆H as variables, Froude number Fr, head position, energy loss, vorticity field and turbulence intensity when ISWs propagate to the canyon were analyzed. According to the Froude number Fr values, the study cases can be divided into three types: Fr > 1.7 means complete internal hydraulic jump (IHJ); 1 < Fr < 1.7 denotes wavy IHJ and Fr < 1 represents no IHJ. The greater canyon angle, collapse depth and amplitude of the incident wave more easily generate IHJs, which can lead to more energy loss, greater vorticity and turbulence intensity in the canyon area. Among all canyon cases, vorticity and turbulence intensity of the no IHJ case showing an obvious bimodal distribution are smaller than IHJ cases. For wavy IHJ, the energy dissipation is not obvious, and the average turbulent intensity performs a “sharp unimodal distribution”. Complete IHJ cases last for a long time and cause violent mixing, the average turbulent intensity is the largest and its distribution presents a “gentle single peak” pattern. For the 180° conditions (no canyon cases), less energy is delivered to the reflected wave and more energy is dissipated near the terrain, so the energy loss is the largest in comparison to other conditions. These findings will deepen our understanding of the evolution mechanisms of ISWs propagating over submarine canyons. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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11 pages, 2636 KiB  
Article
Marine Heatwaves in the Indonesian Fisheries Management Areas
by Ahmad Dhuha Habibullah, Ayi Tarya, Nining Sari Ningsih and Mutiara Rachmat Putri
J. Mar. Sci. Eng. 2023, 11(1), 161; https://doi.org/10.3390/jmse11010161 - 09 Jan 2023
Cited by 3 | Viewed by 1519
Abstract
Ocean temperatures increased during the 20th century and are predicted to continue to rise during the 21st century. Simultaneously, the extreme phenomena of shorter time ocean warming, known as Marine Heatwaves (MHWs), are also taking place. The present study used the Daily Optimum [...] Read more.
Ocean temperatures increased during the 20th century and are predicted to continue to rise during the 21st century. Simultaneously, the extreme phenomena of shorter time ocean warming, known as Marine Heatwaves (MHWs), are also taking place. The present study used the Daily Optimum Interpolation Sea Surface Temperature (DOISST) v2.1 with a spatial resolution of 0.25˚. The time period of the DOISST data used in this study was from January 1, 1982 to December 31, 2020, and the region was 90° E–150° E and 16° S–16° N, which is divided into 11 Fishing Management Areas (FMAs). MHWs have a set of metrics derived from the SST data to describe the statistical characteristics of each event. To examine and quantify the influence of the Pacific Ocean and the Indian Ocean, we used the Niño 3.4 SST index and the Dipole Mode Index (DMI), respectively. Based on the data analysis, there has been an increase in the duration and frequency of the occurrence of MHWs in the study area, with the highest increase occurring in FMA 573, FMA 716, and FMA 711. Based on the severity, MHWs in Indonesia are dominated by category I, which is dominantly located in FMA 716, category II in FMA 573, category III with the center of events in FMA 771, and category IV with irregular spatial patterns. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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12 pages, 8090 KiB  
Article
SAR Observation of Waves under Ice in the Marginal Ice Zone
by Ziyue Dai, Huimin Li, Dongbo Liu, Chen Wang, Lijian Shi and Yijun He
J. Mar. Sci. Eng. 2022, 10(12), 1836; https://doi.org/10.3390/jmse10121836 - 29 Nov 2022
Cited by 2 | Viewed by 1673
Abstract
The marginal ice zone (MIZ) connects the open ocean and the pack ice, playing significant roles in shaping the ice edge and wave–ice interaction. Spaceborne synthetic aperture radar (SAR) has been demonstrated to be one of the most advantageous sensors for MIZ exploration [...] Read more.
The marginal ice zone (MIZ) connects the open ocean and the pack ice, playing significant roles in shaping the ice edge and wave–ice interaction. Spaceborne synthetic aperture radar (SAR) has been demonstrated to be one of the most advantageous sensors for MIZ exploration given its capability to collect images under all weather conditions during day and night. In this study, we take advantage of the Sentinel-1 wave mode vignettes acquired around the Antarctic to quantify the image properties over MIZ. A data set of SAR images covering the ice edge with both open water and sea ice present in the same scene was created by manual inspection. It is found that the radar return over sea ice decreases by an average of approximately 1.78 dB in comparison to its adjacent open water, which is roughly independent of the polarizations and incidence angles. The long ocean waves are barely attenuated right across the ice edge in terms of their comparable azimuth cutoff. Further inside the ice from the edge, the waves are gradually dampened out at distances associated with their wavelengths. The results obtained in this study shall help interpret the radar scattering model validation as well as the wave–ice interaction. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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23 pages, 11690 KiB  
Article
The Three-Dimensional Structure of the Mesoscale Eddy in the Kuroshio Extension Region Obtained from Three Datasets
by Penghao Wang, Kefeng Mao, Xi Chen and Kefeng Liu
J. Mar. Sci. Eng. 2022, 10(11), 1754; https://doi.org/10.3390/jmse10111754 - 15 Nov 2022
Cited by 2 | Viewed by 1331
Abstract
The high-resolution observation data from June 2019, Argo data from 1997 to 2019, and the multi-observation ARMOR 3D dataset from 1993 to 2019 were used to study the three-dimensional (3D) structural characteristics of the mesoscale cyclonic eddy (CE) in the Kuroshio Extension region [...] Read more.
The high-resolution observation data from June 2019, Argo data from 1997 to 2019, and the multi-observation ARMOR 3D dataset from 1993 to 2019 were used to study the three-dimensional (3D) structural characteristics of the mesoscale cyclonic eddy (CE) in the Kuroshio Extension region (KER). The observed eddy has a typical 3D structure of the KER CE, which was a longer lifespan eddy in this KER. The maximum anomalies of temperature and salinity were −7.69 °C and −0.71 PSU, which were located at the 350 m depth. In the vertical, the observed and composite eddy had a dipole structure, while ARMOR 3D had a monopole. The study of the velocity fields indicate that ARMOR 3D underestimates the velocity below 500 m. The 3D structures of the CE composite eddy of Argo were comparable to the observations, whereas the temperature and salinity anomalies were weaker than the observation. The surface of the Argo composite eddy shows a positive temperature anomaly within 50 m, which used to be opposite to the observation. This phenomenon was due to the limited Argo data of the composite eddy, and most of them were the observed profiles of winter CE in the weak years of EKE in the KER. We tried using ARMOR 3D to explore the reliability of ARMOR 3D composite eddy and compared the seasonal variations of temperature/salinity anomalies of the cyclonic and anticyclonic eddy. The anomalies of temperature and salinity caused by CE have seasonal variations: the anomalies have been strong in summer and weak in winter. This is consistent with the variant of eddy kinetic energy (EKE), but AE has no seasonal variation. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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13 pages, 6745 KiB  
Article
The Roles of Off-Equatorial Subsurface Cold-Water Incursions in Triggering the Second-Year Cooling of the La Niña Event in 2021
by Chunyang Song, Xuefeng Zhang, Fei Zheng, Xingrong Chen and Hua Jiang
J. Mar. Sci. Eng. 2022, 10(11), 1667; https://doi.org/10.3390/jmse10111667 - 05 Nov 2022
Cited by 5 | Viewed by 1156
Abstract
During 2020–2022, a consecutive two-year La Niña event occurred in the tropical Pacific. This work analyzes the evolution of atmospheric and oceanic anomalies in the equatorial Pacific between 2020 and 2022 to describe and illustrate the processes that led to the second-year cooling [...] Read more.
During 2020–2022, a consecutive two-year La Niña event occurred in the tropical Pacific. This work analyzes the evolution of atmospheric and oceanic anomalies in the equatorial Pacific between 2020 and 2022 to describe and illustrate the processes that led to the second-year cooling of the La Niña event in 2021/22. After the first year of the La Niña event in 2020/21, neutral SST conditions resumed in the eastern equatorial Pacific prior to June 2021. However, in the first half of 2021, significant cold water persisted at the surface and thermocline depth in the off-equatorial areas, which were more noticeable in the tropical South Pacific. The turning point of the second-year cooling event occurred in June 2021 when the subsurface cold water from the off-equatorial regions intruded into the equatorial regions between approximately 115°–125° W. This interrupted the eastward propagation of warm water along the thermocline. Negative SST anomalies and positive SLP anomalies occupied the tropical southeast Pacific, which strengthened southeasterly wind stress anomalies from the tropical South Pacific, driving them northward across the equator. Subsequently, the subsurface ocean current that originated from the tropical southeast Pacific began to prominently propagate to the northwest. This transported cold water across the equator, which then mixed with the cold subsurface waters in the tropical north Pacific. Finally, negative ocean temperature anomalies gradually intensified from the subsurface to the surface throughout the tropical central-eastern Pacific, which initiated a local air–sea coupling process that led to the second-year cooling of the La Niña event through autumn 2021. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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14 pages, 12296 KiB  
Article
Relationship of the Warming of Red Sea Surface Water over 140 Years with External Heat Elements
by Xuehai Liu and Fengchao Yao
J. Mar. Sci. Eng. 2022, 10(7), 846; https://doi.org/10.3390/jmse10070846 - 22 Jun 2022
Cited by 2 | Viewed by 2279
Abstract
Using historic data, variations in the sea surface temperature (SST), sea surface air temperature, and air–sea heat flux of the Red Sea and its adjacent seas over 140 years (1876–2019) as well as correlations of these variations were statistically analyzed. The results show [...] Read more.
Using historic data, variations in the sea surface temperature (SST), sea surface air temperature, and air–sea heat flux of the Red Sea and its adjacent seas over 140 years (1876–2019) as well as correlations of these variations were statistically analyzed. The results show that the SST of the Red Sea increased at a mean rate of 0.043 °C/decade in these years with an accelerated rate in recent decades, and the SST anomalies of the sea had significant positive correlations and high synchronisms with those of adjacent seas as well as air temperature anomalies. In this period, the Red Sea lost more heat to the air via evaporation due to water warming and gained more heat from the Gulf of Aden. The analysis revealed that the temperature rise in the Red Sea surface water was directly caused by the horizontal heat input from the upper warming water of the Gulf of Aden under the circumstance of global ocean warming, rather than by the rise in local air temperature. However, in recent decades, the accelerated rise in air temperature over the sea has decreased the sensible heat flux, which might contribute to the Red Sea warming. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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15 pages, 14850 KiB  
Article
Synoptic Flow Variability in a River-Influenced Inner Shelf off Central Chile
by Marcus Sobarzo, Camila Soto-Riquelme, Raúl P. Flores and Gonzalo S. Saldías
J. Mar. Sci. Eng. 2022, 10(4), 501; https://doi.org/10.3390/jmse10040501 - 05 Apr 2022
Cited by 1 | Viewed by 1721
Abstract
The response of inner shelf circulation and bottom temperature variability to synoptic wind forcing and freshwater outflow is evaluated in an area with a wide continental shelf off central Chile. This forced circulation, with a strong seasonal evolution from upwelling- to downwelling-favorable conditions, [...] Read more.
The response of inner shelf circulation and bottom temperature variability to synoptic wind forcing and freshwater outflow is evaluated in an area with a wide continental shelf off central Chile. This forced circulation, with a strong seasonal evolution from upwelling- to downwelling-favorable conditions, is a key process modulating the exchange of water properties in a coastal zone characterized by multiple river outflows and high biological productivity. Ocean currents on the inner shelf (34 m depth) off the Itata River mouth were obtained and analyzed for a nine-month record (December 2008 to September 2009). The synoptic wind and current variability was defined between 2 and 16 days (0.02 to 0.0026 cph). The subinertial coastal circulation within the inner shelf off Itata River was dominated by the along-shelf flow, while cross-shelf flows driven by along-shelf winds were substantially reduced. The alongshore synoptic currents showed two distinct modal structures: (i) A mean two-layer flow field during upwelling-favorable wind stress with northward (southward) flow at the surface (bottom), and (ii) a mean southward flow through the entire water column during downwelling-favorable wind stress periods, which were intensified during peak river discharge events in winter. Calculations of the wind index clarified the relative importance of wind versus buoyancy forcing on the alongshore flow. The wind forcing dominated during summer when the river discharge was minimum, whereas the relative importance of the freshwater outflow from the Itata River became dominant in winter (May-August) when the buoyancy forcing, in conjunction with southward wind events, modulated strong barotropic southward flows. The change in the long-term regime of coastal winds and river discharges, with a dominance of upwelling winds and reduced river outflows in the last decade, is discussed in the context of observations of thinner river plumes under frequent upwelling conditions off central Chile. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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15 pages, 5982 KiB  
Article
Statistical Analysis of Mesoscale Eddies Entering the Continental Shelf of the Northern South China Sea
by Tao Zhang, Junyi Li, Lingling Xie and Quanan Zheng
J. Mar. Sci. Eng. 2022, 10(2), 206; https://doi.org/10.3390/jmse10020206 - 02 Feb 2022
Cited by 3 | Viewed by 1677
Abstract
An Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO) mesoscale eddy trajectory atlas product is used to analyze the path type and temporal variability of the eddies that entered the continental shelf area of the northern South China Sea (SCS) from 1993 [...] Read more.
An Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO) mesoscale eddy trajectory atlas product is used to analyze the path type and temporal variability of the eddies that entered the continental shelf area of the northern South China Sea (SCS) from 1993 to 2016. A total of 184 mesoscale eddies entered the continental shelf area of the northern SCS during a 24-year period. We classify the mesoscale eddies into four types according to the motion trajectories: along-the-isobath type, intrusion-of-continental-shelf type, local wandering type, and shelf-internal-generation type. The occurrence numbers of these four types were 87, 38, 23, and 36, respectively. The mean amplitude and radius of the along-the-isobath type are the largest, about 18 cm and 153 km, respectively; furthermore, their average lifetime is also the longest, about 93 days. The mean amplitude, radius, and lifetime are the smallest for the shelf-internal-generation type, about 16 cm, 146 km, and 74 days, respectively. The direction and velocity of the background flow field affects the intrusion path of the mesoscale eddies onto the continental shelf of the northern SCS. The seasonal distribution of the mesoscale eddies quantity is also related to the direction and velocity of the corresponding background flow field. Full article
(This article belongs to the Special Issue Frontiers in Physical Oceanography)
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