Strong Currents Research Articles

Characterizing regional oceanography and bottom environmental conditions at two contrasting sponge grounds on the northern Labrador Shelf

Abstract. Deep-sea sponge grounds are distributed globally and are considered hotspots of biological diversity and biogeochemical cycling. To date, little is known about the environmental conditions that allow high sponge biomass to develop in the deep sea. Here, we characterize oceanographic conditions at two contrasting sites off the northern Labrador Shelf with respective high and low sponge biomass. Data were collected by year-long benthic lander deployments equipped with current meters, a turbidity and chlorophyll-a measuring device, and a sediment trap. Additionally, regional oceanography was described by analysing vertical conductivity–temperature–depth (CTD) casts, Argo float profiles, and surface buoy drifter data for the northern Labrador Shelf from 2005 to 2022. The stable isotopic composition of benthic fauna was determined to investigate food web structure at the sponge grounds. Our results revealed strong (0.26±0.14 m s−1; mean ± SD) semidiurnal tidal currents at the high-sponge-biomass site but 2-fold weaker currents (0.14±0.08 m s−1; mean ± SD) at the low-sponge-biomass site. Tidal analysis suggests that kinetic energy is dissipated from barotropic tide to baroclinic tide/turbulence at the high-sponge-biomass site, which could enhance food availability for benthic organisms. Bottom nutrient concentrations were elevated at the high-sponge-biomass site, which would benefit growth in deep-sea sponges. Organic matter flux to the seafloor was increased at the high-sponge-biomass site and consisted of fresher material. Finally, both sponge grounds demonstrated tight benthic–pelagic coupling prior to the onset of stratification. Stable isotope signatures indicated that soft corals (Primnoa resedaeformis) fed on suspended particulate organic matter, while massive sponges (Geodia spp.) likely utilized additional food sources. Our results imply that benthic fauna at the high-sponge-biomass site benefit from strong tidal currents, which increase the food supply, and favourable regional ocean currents, which increase the nutrient concentration in bottom waters.

Enhancing heat transfer efficiency in solar storage devices using eddy current structures and vibrations

This study introduces a novel phase change material (PCM)-based solar energy storage system integrating Tesla valve-inspired eddy current structures and mechanical vibrations to enhance thermal performance. By systematically optimizing the geometric design and vibration parameters, a 90°shunt angle was identified as the most effective configuration, achieving a significant 59.9% reduction in PCM melting time and completing the melting process in just 178 s. This superior performance was attributed to the generation of strong eddy currents, which disrupted the thermal boundary layer and enhanced heat transfer between the heat transfer fluid (HTF) and PCM. Mechanical vibrations (0.0003 m amplitude and 100 Hz frequency) further improved performance, particularly for shunt angles of 30°and 60°, where melting times were reduced by 13.4% and 13.36%, respectively, demonstrating the synergistic effects of geometry and vibration.The impact of natural convection was evaluated across a range of Rayleigh numbers (11,400 to 1,140,000), revealing that higher Rayleigh numbers enhanced heat transfer, especially for the 90°configuration. In contrast, shunt angles exceeding 90°showed reduced efficiency due to the thickening of boundary layers. Comparative analysis with existing heat transfer enhancement studies demonstrated the superior performance of the proposed system, which achieved greater reductions in melting time compared to designs using fin structures or optimized inclinations. This research provides valuable insights into the development of high-performance, scalable, and sustainable solar energy storage systems, bridging the gap between laboratory innovation and practical application.

Understanding Tidal Jet Vortices Over Complex Bathymetry via Numerical Modeling and Drone Observation: Match and Mismatch in the Vortex Dynamics Under Idealized and Realistic Topographic Settings

AbstractThe formation and evolution of tidal jet vortices over complex bathymetry were investigated using numerical modeling and in situ observation. Delft3D FM simulation on an unstructured grid system, complemented by field measurements using recreational drones captured tidal dynamics in the Uldolmok Strait, known for its strong tidal currents up to 6.0 m/s and turbulent whirlpool formation. This study particularly focused on temporal changes in whirlpools near their narrowest points. Modeling across the entire strait showed current velocity fields consistent with field observations, revealing significant temporal and spatial variability influenced by strait geometry and bathymetry. Whirlpools induced by tides were identified by setting a swirl strength threshold, with their centroids and equivalent spherical diameters pinpointed. It was observed that larger whirlpools, upon reaching critical size, were entrained and shifted with the tidal jet at about half its maximum velocity, while smaller vortices separated from the nearshore boundary layer remained nearly stationary. Focusing on the initiation of whirlpools and their relations with the coastline and bathymetry, a targeted field survey using a recreational drone measured surface flow fields in detail near the strait's narrowing region. During the ebb phase, shallow regions exhibited numerous smaller eddies due to increased energy dissipation, showing a dual power‐law scaling in the size distribution of eddies, contrasting with the single scaling exponent observed during the flood phase. The study underscored the role of coastline and bathymetry in developing whirlpools and shaping their dynamics, providing insights into complex tidal interactions in the natural coast.

Retinal direction of motion is reliably transmitted to visual cortex through highly selective thalamocortical connections.

Motion perception is crucial to animal survival and effective environmental interactions. In mammals, detection of movement begins in the retina. Directionally selective (DS) retinal ganglion cells were first discovered in the rabbit eye,1 and they have since been found in mouse,2,3 cat,4 and monkey.5,6 These DS retinal neurons contact a small population of neurons in the visual thalamus (dorsal lateral geniculate nucleus [LGN]) that are highly DS.7,8,9,10 The primary visual cortex (V1) also contains DS neurons, but whether directional selectivity in V1 emerges de novo11,12,13 or is inherited from DS thalamic inputs14,15,16 remains unclear. We previously found that LGN-DS neurons generate strong and focal synaptic currents in rabbit V1, similar to those generated by LGN concentric cells.17 Thus, the synaptic drive generated by LGN-DS neurons in V1 is spatially well situated to influence the firing of layer 4 (L4) simple cells, most of which show strong directional selectivity.18 However, two important questions remain: do LGN-DS neurons synaptically target DS simple cells in L4, and, if so, do they contribute to the directional preferences of these V1 DS neurons? We used spike-train cross-correlation analysis of pairs of LGN-DS and L4 simple cells to address these questions. We found that LGN-DS neurons do target L4 DS simple cells and that the targeting is highly selective, largely following a simple set of "connectivity rules." We conclude that this highly selective thalamocortical connectivity of LGN-DS neurons contributes to the sharp directional selectivity of cortical simple cells.

Flow characterization and turbulence in the eastern section of the Strait of Magellan, Southern Chile

The Strait of Magellan connects the Pacific and Atlantic oceans in South America’s southern region, and it has been recognized for centuries as an important transoceanic navigation route as well as a unique marine environment with a rich ecological diversity. Evaluations of the impact of human activities in the channel and multiple potential future developments require a better understanding of the physical environment to design sustainable strategies aimed at preserving these characteristics. In this investigation, we study the flow near the Atlantic inlet of the Strait where the dynamics is characterized by the interactions of the tide propagation within two narrows, which are the predominant features of the channel morphology. Tides amplified by the Patagonian shelf generate strong currents through these narrows and control the exchange between the Atlantic and central regions of the Strait. We employ bottom-mounted and vessel-mounted Acoustic Doppler Current Profilers (ADCPs) with tide gauges to analyze the mean flow, tidal propagation, and turbulence, complementing the data with previous available measurements. The analysis reveals residual flows directed toward ebb flow at the channel center and flood near the edges, showing a significant spring-neap variation. Turbulence statistics in the second narrows exhibit a significant variability between ebb and flood, with a balance between production and dissipation observed only during ebb phases.

Demokrasi dalam Era Globalisasi: Menjaga Kearifan Lokal di Tengah Arus Global pada Kalangan Remaja

Democracy essentially provides space for individual freedom, including the freedom to choose one's way of life. In the era of globalization, democracy presents significant challenges and opportunities, particularly for the younger generation, in preserving local wisdom amidst the increasingly strong currents of global influence. Globalization itself is evidence of the world's ongoing progress and interconnectedness in various aspects. The application of local wisdom values is an effort to minimize the negative impacts of globalization in this modern era. However, the impact of globalization can become a boomerang that threatens the younger generation if it is not grounded in awareness and the importance of preserving the values upheld within their community. The method used in this research involves quantitative data analysis through the use of Google Forms containing a mix of open and closed-ended questions for data collection. The findings of the study reveal that young people face pressure to conform to global culture through social media and technology, which often erodes their understanding of local wisdom. Thus, democracy provides space to accommodate cultural plurality and build collective awareness of the importance of preserving local traditions amidst the global currents.

Optimal Attitude Determination for the CR200 Underwater Walking Robot

The Crabster CR200 is an underwater walking robot inspired by crabs and lobsters, designed for precise seabed inspection and manipulation. It maintains stability and position on the seafloor, even in strong currents, by adjusting its posture through six legs, each with four degrees of freedom. The key advantage of the CR200 lies in its ability to resist drifting in strong currents by adapting its posture to maintain its position on the seafloor. However, information is still lacking on which specific posture generates the maximum downforce to ensure optimal stability in the presence of currents and the seabed. This study aims to determine the fluid forces acting on the CR200 in various postures using Computational Fluid Dynamics (CFD) and identify the posture that generates the maximum downforce. The posture is defined by two parameters: angle of attack and seafloor clearance, represented by the combination of the robot’s pitch angle and distance to the seabed. By varying these parameters, we identified the posture that produces the greatest downforce. Through a series of analyses, we identified two main fluid dynamic principles affecting the downforce on a robot close to the seabed. First, an optimal pitch angle exists that generates the maximum downward lift on the robot’s body. Secondly, there is an ideal distance from the seabed that produces maximum suction on the bottom surface, thereby creating a strong Venturi effect. Based on these principles, we determined the optimal robot posture to achieve maximum downforce in strong current conditions. The optimal underwater robot posture identified in this study could be applied to similar robots operating on the seafloor. Furthermore, the methodology adopted in this study for determining the optimal posture can serve as a reference for establishing operational postures for similar underwater robots.

Monitoring and Disaster Assessment of Glacier Lake Outburst in High Mountains Asian Using Multi-Satellites and HEC-RAS: A Case of Kyagar in 2018

The glaciers in the High Mountain Asia (HMA) region are highly vulnerable to global warming, posing significant threats to downstream populations and infrastructure through glacier lake outburst floods (GLOFs). The monitoring and early warnings of these events are challenging due to sparse observations in these remote regions. To explore reproducing the evolution of GLOFs with sparse observations in situ, this study focuses on the outburst event and corresponding GLOFs in August 2018 caused by the Kyagar Glacier lake, a typical glacier lake of the HMA in the Karakoram, which is known for its frequent outburst events, using a combination of multi-satellite remote sensing data (Sentinel-1 and Sentinel-2) and the HEC-RAS hydrodynamic model. The water depth of the glacier lake and downstream was extracted from satellite data adapted by the Floodwater Depth Elevation Tool (FwDET) as a baseline to compare them with simulations. The elevation-water volume curve was obtained by extrapolation and was applied to calculate the water surface elevation (WSE). The inundation of the downstream of the lake outburst was obtained through flood modeling by incorporating a load elevation-water volume curve and the Digital Elevation Model (DEM) into the hydrodynamic model HEC-RAS. The results showed that the Kyagar glacial lake outburst was rapid and destructive, accompanied by strong currents at the end of each downstream storage ladder. A series of meteorological evaluation indicators showed that HEC-RAS reproduced the medium and low streamflow rates well. This study demonstrated the value of integrating remote sensing and hydrodynamic modeling into GLOF assessments in data-scarce regions, providing insights for disaster risk management and mitigation.

Bering Strait gateway currents and their implications for sediment distribution, shelf conceptual models and economic potential

This paper addresses a gap in our knowledge about strong geostrophic current control of epicontinental shelf deposits. The northward current that accelerates towards the Bering Strait gateway affects sediment distribution in the northern Bering Sea leading to the Strait, in the Strait and in the Chukchi Sea where currents slack. Leeside sand bodies develop when the northward geostrophic current shears and accelerates against topographic projections into the current. When currents slack downstream, leeside sand bodies deposit. Yearly 1 m and decadal catastrophic up to 5 m storm surges resuspend the Yukon sediment. Most of this sediment is then entrained by strong northward currents and transported up to 1000 km north, bypassing Chirikov Basin and the Bering Strait gateway, to deposit in the Chukchi Sea. Northern Bering Sea depositional patterns reinforce evidence that epicontinental shelf sedimentary sequences are different from more regular proximal to distal offshore sequences on marginal shelves. Compared with marginal shelves, strong currents, Coriolis force and topographic constrictions result in sediment bodies detached from the shoreline and large areas of sediment bypass on epicontinental shelves. The Bering Sea currents prevent Holocene sediment from covering both relict gravel with the world's largest offshore gold deposits and large areas of surficial sediment with heavy-mineral concentrations >16% that contain scarce rare earth metals.

Effect of Calcium on the Characteristics of Action Potential Under Different Electrical Stimuli

This study investigates the role of calcium ions in the release of action potentials by comparing two models based on the framework: the standard HH model and a HH + Ca model that incorporates calcium ion channels. Purkinje cells’ responses to four types of electrical current stimuli—constant direct current, step current, square wave current, and sine current—were simulated to analyze the impact of calcium on action potential characteristics. The results indicate that, under the constant direct current stimulation, the action potential firing frequency of both models increased with the escalating current intensity, while the delay time of the first action potential decreased. However, when the current intensity exceeded a specific threshold, the peak amplitude of the action potential gradually diminished. The HH + Ca model exhibited a longer delay in the first action potential compared to the HH model but maintained an action potential release under stronger currents. In response to the step current, both models showed an increased action potential frequency with a higher current, but the HH + Ca model generated subthreshold oscillations under weak currents. With the square wave current, the action potential frequency increased, though the HH + Ca model experienced suppression under high-frequency weak currents. Under the sine current, the action potential frequency rose, with the HH + Ca model showing less depression near the sine peak due to calcium’s role in modulating membrane potential. These findings suggest that calcium ions contribute to a more stable action potential release under varying stimuli.

Behaviours of Sea Turtles in Shipwrecks in Northeast Brazil

ABSTRACT Shipwrecks are one of the most common types of artificial reefs. They are home to several sea creatures, including sea turtles. Here, we aim to understand the relationship between sea turtles and shipwrecks by investigating species occurrence, behaviours and food availability in artificial reefs in Pernambuco, Northeast Brazil. To map sea turtle occurrence in shipwrecks, we considered data from the literature, and we inspected 54,145 photos resulting from 867 recreational dives performed in 19 shipwrecks. We then selected four wrecks for systematic behavioural observations through 97 h and 56 min of passive video recordings. We also investigated potential food resources for turtles in these shipwrecks. We identified three turtle species (i.e., Chelonia mydas, Eretmochelys imbricata and Caretta caretta), but most records were juvenile Chelonia mydas individuals using conserved wrecks. We recorded nine behaviours. ‘Resting’ was the predominant activity for all three species, representing over 60% of the records for all species. Their overall activity pattern varied. The wrecks were predominantly encrusted with ascidia, octocoral, sponge and algae—organisms that are part of sea turtles' diet. We highlight the ecological role of the shipwrecks for sea turtles since they may serve as shelter (especially for the juveniles of Chelonia mydas), potentially protecting them against predators and strong currents. The wrecks may also serve as potential feeding areas for sea turtles. We reinforce the need to establish appropriate regulations for recreational dive tourism in shipwrecks in Brazil to avoid disturbing sea turtles in this ecologically important artificial reef.

Exploring morphometry, hydrodynamics, and surface sediment composition in Khenifiss lagoon: Insights from a shallow coastal environment in Southern Morocco

Coastal lagoons are widely recognized as highly dynamic and intricate ecosystems within coastal environments, playing a crucial role in supporting both human communities and biodiversity. However, these coastal ecosystems are confronted with a multitude of challenges stemming from both natural phenomena and human activities. Hence, acquiring a comprehensive understanding of coastal lagoon dynamics is imperative for safeguarding and ensuring the sustainability of these ecosystems, relying on discerning the intricate interplay between hydrodynamic and sedimentological factors and processes. In Morocco, the Khenifiss lagoon is recognized as the largest lagoon and the most significant wetland along the Atlantic coast, designated as a protected area under the Ramsar Convention since 1980. However, the lagoon is confronted with the challenge of inlet and channel narrowing due to heightened sediment transport and accumulation toward its interior, along with dune advancement. This paper aims to establish correlations between morphometry, hydrodynamic conditions, and surface sediment composition to categorize the main channel of Khenifiss lagoon according to sedimentary environmental conditions. This categorization aims to delineate zones characterized by high, moderate, and low energy levels. Such classification will offer valuable insights into the dynamic interactions governing the lagoon’s ecosystem by identifying areas prone to resuspension and deposition. The study categorized the main channel of the Khenifiss lagoon into distinct zones based on hydrodynamic conditions. Areas with high energy levels, including the entrance zone and the narrowest central section, featured the highest current velocities, fostering conditions favoring the resuspension of fine materials. Zones with moderate energy levels, such as the downstream main channel and sinuous sections, exhibited moderate current velocities and a predominance of fine sand over medium sand fractions, along with observed reductions in current velocity. Areas characterized by low energy levels, encompassing the upstream main channel, are marked by slower current velocities and shallow depths, facilitating the deposition of fine and very fine sediment. Finally, areas with very low energy and calm conditions, well-protected from strong currents, prevent the reworking of sediments and facilitate their accumulation. This study highlights the importance of integrating sedimentological, hydrodynamic, and morphometric analyses as a valuable approach for monitoring coastal ecosystems and understanding the morphodynamics of coastal lagoons. This approach guides ecosystem management, such as targeted conservation efforts, erosion control, and habitat protection, while also supporting informed coastal development and adaptive management strategies to ensure the long-term sustainability and protection of the Khenifiss lagoon.

Investigating the Trip of a Transformer in Sweden During the 24 April 2023 Storm

AbstractGeomagnetically Induced Currents are unwanted currents that flow in large ground‐based conductive infrastructure and are a significant threat to bulk power grids. This susceptibility is increased at high latitudes due to the larger amplitude geomagnetic disturbances caused by the strong and dynamic auroral electrojet currents. In Sweden, there has been a record of disturbances connected to geomagnetically induced currents; the most documented was a blackout in Malmö, a city in southern Sweden, on 30 October 2003. However, on 24 April 2023, there was a transformer trip in the Bandsjö substation (near Sundsvall) around the time of enhanced space weather. In this paper, we investigate this event by studying the solar wind properties as well as geomagnetic disturbances. The study shows evidence that the transformer trip was caused by a strong geomagnetic disturbance in the morning sector. This was triggered by a high‐pressure sub‐structure within the interplanetary coronal mass ejection cloud, preceded by 2 hr of strong southward interplanetary magnetic field. Additionally, analysis of multiple ground magnetometers shows that the geomagnetic impact was highly spatially structured.

Decadal Changes in the Pathways of the Atlantic Water Core in the Arctic Ocean Inferred From Transient Tracers

AbstractThe Atlantic Water plays a major and increasing role in the heat budget of the Arctic Ocean (Atlantification). The pathways of Atlantic Water within the Arctic Ocean, and in particular their sensitivities to large‐scale atmospheric patterns such as the Arctic Oscillation, remain unclear. In this study, we used the trace gases CFC‐12 and to investigate the Atlantic Water pathways during different phases of the Arctic Oscillation. We calculated tracer ages for the temperature maximum of the Atlantic Water, focusing on repeated transects (1994, 2005, 2015) in the Amerasian Basin of the Arctic Ocean. During a positive phase of the Arctic Oscillation in 1994, tracer ages were low along the Chukchi shelf due to a strong coherent boundary current. In contrast, the ages were up to 10 years higher in 2015 without this coherent current during a mixed phase of the Arctic Oscillation. Further, we identified a discontinuity in the inflow between the Makarov Basin and the Canada Basin during this phase. Tracer ages were 10 years higher in the Canada Basin, suggesting a closed circulation without direct inflow in this region. Our tracer ages generally align with previously proposed circulation schemes and water ages, with major exceptions in 2015. We have shown that the tracer ages are applicable to identify decadal changes in the Atlantic Water core pathways in the central Arctic Ocean.

The calculated voyage: benchmarking optimal strategies and consumptions in the Japanese eel’s spawning migration

Eels migrate along largely unknown routes to their spawning ground. By coupling Zermelo’s navigation solution and data from the Japan Coastal Ocean Predictability Experiment 2 (JCOPE2M), we simulated a range of seasonal scenarios, swimming speeds, and swimming depths to predict paths that minimize migration duration and energy cost. Our simulations predict a trade-off between migration duration and energy cost. Given that eels do not refuel during their migration, our simulations suggest eels should travel at speeds of 0.4–0.6 body-length per second to retain enough energy reserves for reproduction. For real eels without full information of the ocean currents, they cannot optimize their migration in strong surface currents, thus when swimming at slow swimming speeds, they should swim at depths of 200 m or greater. Eels swimming near the surface are also influenced by seasonal factors, however, migrating at greater depths mitigates these effects. While greater depths present more favorable flow conditions, water temperature may become increasingly unfavorable, dropping near or below 5 °C. Our results serve as a benchmark, demonstrating the complex interplay between swimming speed, depth, seasonal factors, migration time, and energy consumption, to comprehend the migratory behaviors of Japanese eels and other migratory fish.

The hovering pontoon trap: The tougher, younger sibling in the pontoon trap family

Trap nets are a large, stationary, and fixed type of passive fishing gear that has traditionally been used for catching fish in shallow coastal environments. Despite their large size, catches are often retrieved using small boats, making them less energy demanding compared to active gear types. This, along with the stationary nature of the trap, allows for fishing with relatively low environmental impact due to minimal disturbance of the benthic community. The combination of minimal benthic impact, live catch, low fuel, and selectivity offers great potential for the development of sustainable coastal fisheries.Here, we describe the development of the hovering pontoon trap, a fishing gear with a robust design to resist strong waves and currents, and usable in both shallow and deep waters to catch both pelagic and benthic species. We present results from early case studies targeting benthic Baltic Sea species, including perch (Percha fluventaliis), Atlantic cod (Gadus morhua) and vendace (Coregonus albula), showing similar or improved catches in relation to earlier studies. Further, we show that the hovering pontoon trap was able to withstand harsher conditions than previous bottom-set models, making it a possible solution for the targeting of benthic fish communities in coastal environments.

The relative effects of bottom trawling, organic enrichment, and natural environmental factors on coastal seabed communities

Coastal regions are under intense and growing pressure from human activities. Here, we examine how human and natural drivers interact with benthic communities, species, and life-history traits across four distinct coastal areas. Sediment organic content was a key driver of seabed community characteristics, with positive (increased benthic biomass) and strongly adverse (depauperate communities) effects observed. Similarly, environmental factors such as bottom currents were highly influential. In contrast, bottom trawling impacts varied by location. Beam trawling in areas of low organic enrichment was most damaging to seabed fauna, even in the presence of strong bottom currents. However, we did not observe any faunal impacts of trawling under chronic enrichment, despite the fishery using relatively heavy gears (e.g. otter trawls) at high intensities. Lastly, we discuss how human and natural factors interact and shape seabed ecosystems under different conditions, and how management measures can be adapted to improve coastal seabed health.

Optimal policies for autonomous navigation in strong currents using fast marching trees

Optimal policies for autonomous navigation in strong currents using fast marching trees

Plastic recovery and strength enhancement of pre-deformed AZ31B magnesium alloy using transient strong pulse current

Magnesium alloy components are mainly used in aerospace and automotive fields, but poor deformation ability at room temperature restricts their application in other industries. To address this issue, electrically-assisted technology is employed to enhance plasticity of alloys. However, conventional method weaken strength and intensify surface oxidation of such alloys because of prolonged action of current. In view of the above, pre-deformation (PF) treatment in combination with transient induced pulse current treatment (TIPCT) is proposed in the present work so as to balance between plasticity recovery and strength of AZ31B alloy. The results show that the total elongation of PF sample and the corresponding TIPCT specimen first increases and then decreases with the increase in PF percentage under the same voltage. At the same PF percentage, the total elongation of PF and TIPCT specimens also presents the same trend as the voltage increases. At the same time, the total elongation in PF and TIPCT specimens is greater than that of the as-received sample. The maximum total elongation is achieved at the PF percentage of 16 % and the voltage of 6 kV, being 35 % higher than that in the as-received sample. The improvement in total elongation is due to activation of more non-basal dislocations induced by TIPCT and the appropriate amount of microcracks generated by PF. In addition, the TIPCT process also improves the yield strength even if the PF percentage and voltage are changed. Besides that, the work hardening induced by PF treatment and instantaneous action of TIPCT process are the key factors enhancing yield strength. Moreover, comprehensive mechanical properties of TIPCT sample are found to outperform those after direct pulse current treatment (DPCT) under the same PF percentage. Therefore, the proposed composite process provides a feasible scheme to enhance strength and elongation of Mg sheets.

Seasonal impacts of Kuroshio intrusion on pico-phytoplankton dynamics near the Changjiang River estuary

The strong western Pacific boundary current of the Kuroshio significantly affects the oceanographic and ecological processes of the East China Sea through its branches. To understand the seasonal variation of Kuroshio intrusion and its ecological effects, 10 cruises were conducted from February 2015 to January 2016 in the waters adjacent to the Changjiang River estuary to collect hydrological data and abundances of phytoplankton assemblages of Prochlorococcus (Pro), Synechococcus (Syn) and picoeukaryotes. High salinity bottom water representing the Nearshore Kuroshio Branch Current (NKBC) appeared in the spring, peaked in the summer, and then almost disappeared at the end of the autumn. During this period, the seasonal variations of Pro and Syn subgroup with lower orange fluorescence (dim type Syn) abundances correlated and synchronized with the intensity of the NKBC intrusion. Water masses analysis further illustrated that the spring was the critical season for NKBC to influence and transport phytoplankton along the pathway to coastal waters. NKBC will further impact the phytoplankton dynamics and ecological processes in this sea area.