Wind Forcing Research Articles

Low-Temperature Annealing of Nanoscale Defects in Polycrystalline Graphite

Polycrystalline graphite contains multi-scale defects, which are difficult to anneal thermally because of the extremely high temperatures involved in the manufacturing process. In this study, we demonstrate annealing of nuclear graphite NBG-18 at temperatures below 28 °C, exploiting the electron wind force, a non-thermal stimulus. High current density pulses were passed through the specimens with a very low-duty cycle so that the electron momentum could mobilize the defects without heating the specimen. The effectiveness of this technique is presented with a significant decrease in electrical resistivity, defect counts from X-ray computed tomography, Raman spectroscopy, and nanoindentation-based mechanical characterization. Such multi-modal evidence highlights the feasibility of nanoscale defect control at temperatures about two orders of magnitude below the graphitization temperature.

Wheat Stripe Rust Inoculum from the Southwest Dispersed to the East Huang-Huai-Hai Region through Southern Anhui in China.

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is a continuous threat to global wheat production. In 2021, the epidemic of wheat stripe rust in China affected approximately 4.5 million hectares, resulting in severe yield losses. When confronted with the epidemic, tracing the sources of the pathogen can offer valuable insights for disease prevention and control. This study was conducted to analyze the genetic structure, aerodynamics, geographical features, and cultivation practices of the pathogen population in various wheat-producing regions, and to further reveal the spread patterns of the stripe rust pathogens in China. The findings indicated an overall trend of the pathogen dissemination from the west to the east. The pathogen was primarily spread from the northwestern region to the Huang-Huai-Hai region through the Guanzhong Plain and the NanXiang Plain. Meanwhile, the pathogen was also spread eastward from the southwestern region to the lower reaches of the Yangtze River, utilizing the Jianghan Plain as a bridge and the Yangtze River Valley in southwestern Anhui as the main pathway. Furthermore, the pathogen spread northward into Shandong under the driving force of the southeast winds. The findings of this study may provide valuable insights for the integrated management of wheat stripe rust in China.

Effects of athermal carrier injection on Co-60 gamma-ray damage in SiC merged-PiN Schottky diodes

Co-60 gamma irradiation of SiC merged-PiN Schottky (MPS) diodes up to fluences of 1 Mrad (Si) produces increases in both forward and reverse current, with less damage when the devices are biased during irradiation. Subsequent injection of minority carriers by forward biasing at 300 K can partially produce some damage recovery, but at high forward biases also can lead to further degradation of the devices, even in the absence of radiation damage. Recombination-enhanced annealing by carrier injection overall is not an effective technique for recovering gamma-induced damage in SiC MPS diodes, especially when compared to other near athermal methods like electron wind force annealing.

Thrust of a pulsed plasma jet measured from deviations of a ballistic pendulum

We measured the peak force of the plasma jet produced by a pulsed coaxial plasma gun operated at voltages up to 2 kV, using a home-made ballistic pendulum positioned in two locations, one in the proximity of the gun nozzle at 0.75 cm and the second at a distance of 9 cm from the gun nozzle. The force of the plasma wind is inferred and ranges from 11 to 60 N, which is almost an order of magnitude higher than that of typical ion-based thrusters. The results of various models of self-field magneto-plasmadynamic thrusters indicate that the magnetic component thrust tends to dominate over the thermal expansion, particularly at higher discharge voltages of 1.5 kV and 2 kV. The highest thrust of 60 N is obtained for a 2 kV discharging voltage. The plasma was ignited in CO2 at pressures between 1 and 5 Torr. The displacement of the pendulum pushed by the plasma wind force was measured using a high-speed camera.

The coupling of winds, ocean turbulence, and High Salinity Shelf Water in the Terra Nova Bay Polynya

The Terra Nova Bay (TNB) Polynya in the Western Ross Sea of Antarctica is a major producer of High Salinity Shelf Water (HSSW), a precursor to Antarctica Bottom Water (AABW). Processes occurring in and around the polynya can therefore effect change in the lower limb of overturning circulation in this region. Here, we use data from a densely-instrumented upper-ocean mooring, deployed for 1 year in a region of active HSSW formation within TNB, to examine the coupling of surface brine rejection and vertical mixing to katabatic wind forcing. We find a high correlation between salinity and winds during the wintertime HSSW production season at the mooring site, with a lag-response of 20 h in near-surface (∼47 m) salinity to winds measured at the nearby Automatic Weather Station (AWS) Manuela. Salinity and temperature measurements show a fully destratified water column by June, with a lag-response of near-seabed (∼360 m) salinity to near-surface salinity of just 5 h. Measurements of turbulent kinetic energy (TKE) dissipation rate (ɛ) from moored pulse-coherent acoustic Doppler current profilers (ADCPs) show general agreement with classic boundary layer scaling (BLS), and calculations of a vertical mixing timescale using the Obukhov length scale average to ∼2.5 h during austral winter, consistent with the 5-h lag time observed in the salinity data. Comparisons to data from concurrent mooring deployments along the southern boundary of TNB, as well as to previously published assessments of model simulations and data from Climatic Long-term Interaction for the Mass-balance in Antarctica (CLIMA) moorings, allow us to explore spatial variability in the coupling of winds and salinity across TNB and to speculate on possible HSSW circulation pathways.

Research on the mechanical performance of circular concrete‐filled steel tube columns under bending‐torsional coupling

AbstractUnder the influence of wind and horizontal seismic forces, structures such as piers in curved beam bridges, main arches of steel tube concrete arch bridges, and frame columns may experience combined bending‐torsion stress states, affecting the safe usage of the structure. To investigate the mechanical performance of circular concrete‐filled steel tube(CFST) columns under bending‐torsional coupling, a three‐dimensional solid‐shell finite element model of circular concrete‐filled steel tube columns under various bending and torsion ratios (k) was established using ABAQUS software, and validated with existing experiments on such columns under bending‐torsional loading. Parametric analysis was conducted to explore the trends of interface slip and the restraining effect in circular concrete‐filled steel tube columns under different bending and torsion ratios, analyzing the impact of parameters such as the yield strength of steel, concrete strength, steel content in the cross‐section, and shear–span ratio on the combined bearing capacity. The results of the parametric analysis show that: (1) with the increase of k, the relative slip at the interface between the core concrete and the outer steel tube first increases and then decreases, with interface slip leading to a reduction in the load‐bearing capacity; (2) the relative slip at the interface between the core concrete and the outer steel tube first increases and then decreases, with interface slip leading to a reduction in the load‐bearing capacity; (3) with the increase of k, the circumferential and axial stresses in the steel tube surface of the circular concrete‐filled steel tube columns increase, while the shear stress decreases, leading to a transition in the failure mode of the columns from combined bending‐torsional failure to bending‐shear failure. Based on these findings, a practical calculation formula for the bending‐torsional combined bearing capacity of circular concrete‐filled steel tube columns is proposed, offering high calculation accuracy and serving as a reference for the design of such components.

Disentangling the contributions of anthropogenic nutrient input and physical forcing to long-term deoxygenation off the Pearl River Estuary, China

Deoxygenation in estuarine and coastal waters worldwide has been largely attributed to the increasing anthropogenic nutrient input, whereas the contribution by long-term (decadal) changes in physical forcing is less investigated. This study aims to disentangle the impacts of three-decade changes in summer river nutrient concentration and physical forcing on the deoxygenation off a large eutrophic estuary, the Pearl River Estuary (PRE) in China. Using a coupled physical-biogeochemical model, we reproduce the observed summer oxygen conditions under the historical (the 1990s) and present (the 2020s) status of river nutrient concentration, freshwater discharge, and wind forcing. We show that the bottom hypoxic (dissolved oxygen < 2 mg/L) area off the PRE in the 2020s has increased by 73 % relative to the 1990s. The expansion is a result of the increased bottom water oxygen consumption outweighing the enhanced vertical oxygen supply, with the former driven by the sharp increase in inorganic nitrogen and phosphorus concentrations (160 %) and the latter caused by the decadal decline in both freshwater discharge (38 %) and wind speed (12.5 %) in summer. Model experiments suggest that if the observed changes in physical forcing had not occurred, the dramatic increase in anthropogenic nutrient concentrations from the 1990s to 2020s could have led to a much greater expansion of hypoxic area (249 %). On the contrary, the decadal decrease in summer freshwater discharge alone (while keeping the nutrient loading the same as in the 1990s) almost eliminates hypoxia off the PRE by weakening water column stratification and limiting the offshore spread of nutrients and organic matter, whereas the declined wind speed increases the hypoxic area by 247 % mainly through enhancing water column stability. Our results reveal that long-term changes in physical forcing are confounding the effects of anthropogenic nutrient input on deoxygenation, underlining the need to consider regional forcing changes in nutrient management to meet water quality goals.

Aerodynamic optimization of high-rise building with façade ribs through CFD-based multi-objective optimization algorithm

Façade appurtenances is an effective aerodynamic optimization measure for alleviating the wind loads on high-rise buildings in modern cities, while the optimized layout of façade ribs necessary for practical engineering remains unclear. The conventional method through numerical simulations and wind tunnel tests can only obtain limited optimal schemes of ribs, the optimization process is time-consuming and laborious, an optimization algorithm can be used to effectively evaluate the optimal arrangement of façade ribs. In present study, a multi-objective optimization procedure coupling large eddy simulation (LES), back propagation neural network (BPNN), and non-dominated sorting genetic algorithm (NSGA-II) is applied to evaluate the optimal arranged parameters of façade vertical ribs. The optimization procedure can quickly identify the optimal location parameter b and extensional depth d of façade ribs that producing minimum wind loads acting on building and ribs. The findings indicate that there are complex non-linear relationships between the ribs arrangement parameters and the objective wind loads. The mean drag C‾d and fluctuating lift C'l of models of windward ribs and upstream sidewall ribs have opposite trend. The relationships between wind forces and arranged parameters of the downstream sidewall and leeward ribs are relatively complicated due to the vortex shedding. Genetic algorithm NSGA-II can effectively evaluate the optimal trade-off solution among multi-objective wind loads. The ranges of optimal layout parameters b/D and d/D are 0.14–0.17, 0.073–0.077, the ratio of b/d is about 2, and the optimal arrangement of façade ribs well balances the total wind forces on the model and wind forces on the ribs. The 3D numerical simulations demonstrate that the optimal layout of the ribs can considerably improve the flow structure and wind load, the maximum reduction ratio of the C‾d and C'l are achieved 25 % and 56 %, respectively. The obtained optimized layout parameters can provide reference for engineers when actually using the facade ribs.

Unveiling the global influence of tropical cyclones on extreme waves approaching coastal areas

Tropical and extra-tropical storms generate extreme waves, impacting both nearby and remote regions through swell propagation. Despite their devastating effects in tropical areas, the contribution of tropical cyclones (TCs) to global wave-induced coastal risk remains unknown. Here, we enable a quantitative assessment of TC’s role in extreme waves approaching global coastlines, by designing twin oceanic wave simulations with and without realistic TC wind forcing. We find that TCs substantially contribute to extreme breaking heights in tropical regions (35-50% on average), reaching 100% in high-density TC areas like the North Pacific. TCs also impact remote TC-free regions, such as the equatorial Pacific experiencing in average 30% of its extreme wave events due to TCs. Interannual variability amplifies TC-induced wave hazards, notably during El Niño in the Central Pacific, and La Niña in the South China Sea, Caribbean Arc, and South Indian Ocean coastlines. This research offers critical insights for global risk management and preparedness.

PERANCANGAN STRUKTUR MENARA LATTICE UNTUK TURBIN ANGIN DARRIEUS TIPE-H DAYA KECIL

The structure of the lattice tower is designed to be able to withstand the loads that occur, namely the wind force, and the gravity that occurs in the H-type Darrieus wind turbine. Structural calculations can be carried out by considering all the maximum forces affecting and then analyzing them for each part or structural component. The tower is designed with dimensions t x l x p, namely 2500 mm x 500 mm × 500 mm, 5 angle iron rods, the dimensions of the steel plate are 500 mm long × 500 mm wide × 3 mm thick, with ASTM A36 carbon steel as the material. The stress from the simulation outcomes must be equal to or below the allowable stress value where the allowable stress is 83.3 MPa, the von misses stress is 0.110526 MPa, and the results of the simulation show that the stress value fulfills the design requirements. Angle iron specifications yield with the requirements of ASTM A36 carbon steel with a yield strength (250 MPa). Calculation of checking the von misses stress. Keywords: Tower, Stress, Materials.

Maintenance of the Zonal Momentum Balance of the Antarctic Circumpolar Current by Barotropic Dynamics

Abstract The vertically integrated zonal momentum balance of the Antarctic Circumpolar Current (ACC) is dominated by wind stress at the surface and topographic form stress (TFS) at the bottom. It has been argued that wind stress is transferred from the surface to the bottom by transient baroclinic eddies, via interfacial form stress, to establish the balance between wind stress and TFS. However, ocean models indicate TFS responds rapidly to changes in wind stress, suggesting that barotropic processes play a role in this balance. We investigate the dynamics governing the wind–TFS balance of the ACC and its response to wind using an idealized, wind- and buoyancy-driven channel model. We show that the balance is established and maintained at equilibrium by the barotropic dynamics. The balance results from the continuity of the flow, in which the Ekman transport at the surface, balanced by wind stress, is compensated by a return flow at depth, balanced by TFS. This leads to a match between wind stress and TFS which is independent of momentum stresses in the interior. Transient baroclinic eddies oppose the wind-driven isopycnal steepening via eddy buoyancy fluxes, which act to flatten the isopycnals. The eddy-driven isopycnal flattening corresponds to a reduction in the zonal geostrophic shear and thus a redistribution of the zonal momentum in the interior via eddy momentum stresses. The maintenance of the vertically integrated ACC momentum balance by the barotropic dynamics explains the fast response of the wind–TFS balance to changes in wind forcing.

Ocean Wave Directional Distribution from GPS Buoy Observations off the West Coast of Ireland: Assessment of a Wavelet-Based Method

Abstract Knowledge of the directional distribution of a wave field is crucial for a better understanding of complex air–sea interactions. However, the dynamic and unpredictable nature of ocean waves, combined with the limitations of existing measurement technologies and analysis techniques, makes it difficult to obtain precise directional information, leading to a poor understanding of this important quantity. This study investigates the potential use of a wavelet-based method applied to GPS buoy observations as an alternative approach to the conventional methods for estimating the directional distribution of ocean waves. The results indicate that the wavelet-based estimations are consistently good when compared to the framework of widely used parameterizations for the directional distribution. The wavelet-based method presents advantages in comparison with the conventional methods, including being purely data-driven and not requiring any assumptions about the shape of the distribution. In addition, it was found that the wave directional distribution is narrower at the spectral peak and broadens asymmetrically at higher and lower scales, particularly sharply for frequencies below the peak. The directional spreading appears to be independent of the wave age across the entire range of frequencies, implying that the angular width of the directional spectrum is primarily controlled by nonlinear wave–wave interactions rather than by wind forcing. These results support the use of the wavelet-based method as a practical alternative for the estimation of the wave directional distribution. In addition, this study highlights the need for continued innovation in the field of ocean wave measuring technologies and analysis techniques to improve our understanding of air–sea interactions. Significance Statement This study presents a wavelet-based technique for obtaining the directional distribution of ocean waves applied to GPS buoy. This method serves as an alternative to conventional methods and is relatively easy to implement, making it a practical option for researchers and engineers. The study was conducted in a highly energetic environment characterized by high wind speeds and large waves, providing a valuable dataset for understanding the dynamics of marine environment in extreme conditions. This research has implications for improving our understanding of directional characteristics of ocean waves, which is crucial for navigation, offshore engineering, weather forecasting, and coastal hazard mitigation. This study also highlights the challenges associated with understanding wave directionality and emphasizes a need for further observations.

Wind Forcing Controls on Antarctic Bottom Water Export From the Weddell Sea via Bottom Boundary Layer Processes

AbstractThe Antarctic Bottom Water (AABW) exported from the Weddell Sea has experienced warming and contraction in the past 30 yrs. Superposed on this decadal trend is substantial annual and interannual variability in the volume and properties of Weddell‐sourced AABW. Several mechanisms have been suggested to explain these variations, many of which highlight a role of wind stress, but the comparative importance and possible simultaneity of the different mechanisms remains unclear. Using data from two mooring sites within the Weddell Sea, we find a rapid intensification of the abyssal boundary current carrying AABW through Orkney Passage (OP), the most direct export pathway of AABW from the Weddell Sea, in response to periods of strong zonal wind stress and anomalous wind stress curl along the South Scotia Ridge upstream of OP. This acceleration is concomitant with a 40% reduction in northward AABW transport in late 2015. The changes in transport follow anomalous wind forcing by approximately 3 months, with the short timescale indicative of a barotropic response in the flow through OP. The bottom boundary layer over the OP's sloping topography is found to have a key role in regulating export on monthly to interannual timescales. Increased boundary current velocity leading up to the passage forms a thickened bottom boundary layer, resulting in reduced AABW thickness and density, and thus restricting northward transport of AABW through the passage. Whilst other processes are likely to dominate on longer (decadal) periods, the dynamics identified here can explain significant variability on timescales up to interannual.

Analysis of Tall Building by using Different Dimensions Under Wind Load Effects

Abstract: The expense of land is increasing day by day because of rapid increase in the population whereas vegetation is diminishing, due to diminished vegetation contamination is expanded. In this Research paper, we analyze the various types of the dimensions of the building considering them side ratios too and the effect of windward forces on the building in mainly X and Z direction. This paper is about the study of four-building models as Dimensions (30m*30m), (40m*25m), (55m*20m), (80m*15m) having their horizontal Aspect ratios viz. 1, 1.6, 2.75 &amp; 5.33 at an angle of 0 degrees. The height of the building is 90m. Therefore, the research is proceeding to balance out the structure from an increasingly affordable perspective. To find out the best performance and economical for the lateral wind-force resisting system of different models of 25 storey buildings are modelled in STAAD-PRO, assuming the site location as AGRA (Uttar Pradesh), India. For the different structural systems that are compared for minimum and maximum storey displacement, storey drift. The structural system used is prototype. The axial force, shear force, moment, and reactions at various windward sides are used to compare the best performance of the structure. Above all, wind forces in x- direction shows the adequate displacement and drift values when compared to z- direction but from the economic point of view Model-2 gives the satisfactory result from all the above.

Interference effect on super large twin cooling towers exposed to stationary tornado-like vortices

A comprehensive investigation was conducted aiming at the interference effects on wind pressure distribution, aerodynamics characteristics, structural stability and reinforcement areas of super large twin cooling towers exposed to tornado-like vortices, and the effects of swirl ratios of tornados, grouped tower layouts, and relative central distances between the towers and the tornado were analysed based on a tornado-like vortex simulator. Two types of rigid model wind tunnel experiments were constructed for base forces and wind pressure distribution measurements. The experimental results demonstrate that the interference effects on base forces and local wind pressures are significantly influenced by the swirl ratios, central distances, and grouped tower layouts, etc. Moreover, the layout with a tornado located on the side of tandem twin cooling towers (along with the tornado translation direction being perpendicular to the central axis of the tandem combined twin cooling towers) is the most unfavourable, resulting in obvious amplification effects on base forces and local wind pressures compared with an isolated tower, and the maximum of interference factors (IFs) is 1.68 and 1.41 for the along-wind total wind force coefficient and minimal net mean pressure coefficient respectively. Subsequently, local stability indices and time-variant dynamic reinforcement envelopes were selected as the other evaluation criteria for estimating the interference effects on the cooling towers exposed to the tornado-like vortices, and the interference effects result in enlargements of the structural responses with the maximal IF of 1.36 for the inside meridional reinforcement. Finally, the various interference criteria at aerodynamic loading and structural reinforcement aspects were contrastive analysed, showing that the criterion of time-variant dynamic reinforcement area envelopes is a more reasonable criterion for evaluating the interference effects on the super large cooling towers exposed to the tornado-like vortices. This investigation aims to contribute to a better understanding of the wind-related effects of the cooling towers exposed to extreme non-synoptic winds, particularly tornadic vortex impacts.

The impact of high rainfall events on the submesoscale salinity field in a coastal sea: Greater Cook Strait, New Zealand

ABSTRACT River inflow into the coastal oceanic environment can result in low salinity submesoscale features (LSMFs). The enhanced water column stability sustained within these coherent structures affects local biological productivity. With-event and seasonal variability of LSMFs were investigated in a coastal sea -- Greater Cook Strait -- that is characterised by strong tidal and wind forcing as well as being forced at the land-sea boundary by several major rivers. A combination of ocean glider and satellite observations revealed the existence of seasonal variability in temperature, chlorophyll and stratification in LSMFs. High rainfall from ex-cyclone enhanced production of LSMFs in seasons when they would otherwise be less frequent. Stronger stratification was observed at the end of spring, in summer and at the beginning of autumn both in ambient shelf conditions and within LSMFs. Subsurface chlorophyll-a maxima were found associated with summer and spring LSMFs, when temperature had a stronger contribution to vertical stratification. In the available samples, LSMFs were advected seawards when river discharges exceeded 600 m 3 s − 1 . When river flows were lower than this threshold, other drivers such as wind or currents were required to advect the observed LSMFs offshore.

Analysis and Research on Vibration of Hydraulic System at the Three Gorges Ship Lift Chamber

The hydraulic pump station at the lower head of the Three Gorges ship lift chamber primarily controls the opening and locking of the chamber gate, the lifting and locking of the anti-collision truss, the tensioning and release of the anti-collision buffer cylinder, and the extension and retraction of the sealing frame. The chamber gate is influenced by external forces such as water flow during the opening and closing process. The anti-collision truss, being in a single-arm suspended state, is affected by external wind forces during its lifting and lowering process. The operation of these mechanisms induces significant vibrations in the hydraulic system, which can lead to oil leakage at joints and other points. Leakage in the hydraulic system can affect the operation of the chamber gate, anti-collision truss, and sealing frame, and severe leakage can directly lead to the malfunction of these mechanisms. This paper utilizes accelerometers, data acquisition systems, and handheld spectrum analyzers to analyze the vibration of the hydraulic system, aiming to reduce system vibrations and decrease oil leakage occurrences.

Wind-Load Calculation Program for Rectangular Buildings Based on Wind Tunnel Experimental Data for Preliminary Structural Designs

In this study, we developed a wind load calculation program (WCP) capable of predicting wind loads with relative precision during the preliminary design phase. First, wind tunnel tests were conducted to identify the essential factors necessary for calculating wind loads and the variables influencing these factors. Square building shapes were considered, and the wind force coefficients and power spectral density were measured by combining four ground roughness values, eleven side ratios (D/B), four aspect ratios (H/BD), and wind directions ranging from 0° to 90°. The wind power coefficient and the spectral coefficient were formulated so that the wind load could be calculated according to various conditions. The WCP computations were based on the calculation of the load combination coefficient using the resonant wind load. Finally, the wind loads obtained from the wind tunnel tests were compared with those predicted by the WCP using an actual project model (inner-core (A) and outer-core (B) types). Building A yielded similar WCP and wind tunnel experimental responses when subjected to wind and laminar wind loads. Additionally, Building B yielded a larger error than that of Building A, but similar results were obtained when buildings were subjected to combination and laminar wind loads.

Numerical Study of the Ultra-High-Speed Aerodynamically Alleviated Marine Vehicle Motion Stability in Winds and Waves

The ultra-high-speed aerodynamically alleviated marine vehicle (AAMV) is a high-performance vessel that combines a hydrodynamic configuration and an aerodynamic wing to reduce wave-making resistance during the high-speed planing phase. The forces of the AAMV exhibit strong nonlinear and water–air coupling characteristics, resulting in particularly complex motion characteristics. This paper presents a longitudinal and lateral stability model of the AAMV, which considers the effects of aerodynamic alleviation. Additionally, a numerical model of wind and wave turbulence forces is established, which considers viscous correction based on the potential theory. Finally, the effect of wind and wave turbulence forces on the motion stability of the AAMV under regular and irregular waves is analyzed by numerical solution. The simulation results demonstrate the influence of these disturbance forces on the stability of the AAMV under different sea states. The motion parameters of the AAMV exhibit a pronounced response to changes in sea state level. The aerodynamically alleviated effect is enhanced as speed increases, and the influence of winds and waves on the AAMV is greatly weakened, reducing the possibility of instability. During the cruising phase under class V sea state, the pitch, roll, and heave response are 0.210°, 0.0229°, and 0.0734 m, respectively. This effect can effectively improve the motion stability of the AAMV in winds and waves.

Variability of saltwater flow in the Hoburg Channel, Baltic Sea: in situ measurements vs NEMO modelling

A half-year long time series of the bottom layer velocity measured in situ in the Hoburg Channel displayed seven-day oscillations of the saltwater flow. The flow was characterized by alterations of surges with the increase of northward velocity to approximately 0.2–0.3 m/s and blockages when the northward velocity vanishes or becomes small negative. The measured time series of the northward velocity component was surprisingly highly correlated with the simulation by NEMO reanalysis at the correlation coefficient of 0.82 and the 95 % confidence limits of 0.76–0.86. The seven-day oscillations were accompanied by almost synchronous oscillations of the southeast component of the wind vector. It can be considered convincing evidence that the seven-day oscillations in the saltwater flow were caused by wind forcing.