Acoustic Doppler Current Profiler Data Research Articles

Dynamics of bubble plumes produced by breaking waves

Abstract Bubble plumes play a significant role in the air-sea interface by influencing processes such as air-sea gas exchange, aerosol production, modulation of oceanic carbon and nutrient cycles, and the vertical structure of the upper ocean. Using Acoustic Doppler Current Profiler (ADCP) data collected off the west coast of Ireland, we investigate the dynamics of bubble plumes and their relationship with sea state variables. In particular, we describe the patterns of bubble plumes vertical extension, duration and periodicity. We establish a power-law relationship between the average bubble penetration depth and wind speed, consistent with previous findings. Additionally, the study reveals a significant association between whitecapping coverage and observed acoustic volume backscatter intensity, underscoring the role of wave breaking in bubble plume generation. The shape of the probability distribution of bubble plume depths reveals a transition towards stronger and more organised bubble entrainment events during higher wind speeds. Furthermore, we show that deeper bubble plumes are associated with turbulent Langmuir number Lat∼ 0.3, highlighting the potential role of Langmuir circulation on the transport and deepening of bubble plumes. These results contribute to a better understanding of the complex interactions between ocean waves, wind, and bubble plumes, providing valuable insights for improving predictive models and enhancing our understanding of air-sea interactions.

Reconstruction of the currents structure in the Kuibyshev Reservoir using satellite data and field measurements

This paper is devoted to a series of the first field subsatellite experiments conducted in the waters of the Kuibyshev Reservoir (Kama estuary) in 2023. Simultaneously with ship-based measurements of current and wind fields, as well as chlorophyll-a concentration, two high-spatial-resolution satellite scanners surveyed the study area of the reservoir. From sequential images, current fields were reconstructed using the standard maximum cross-correlation (MCC) method, which were then compared with measurements from the Acoustic Doppler Current Profiler (ADCP). In certain parts of the water area, satisfactory agreement was obtained between the reconstructed currents and direct measurement current data. And in those parts of the water area where a significant discrepancy between the ADCP and MCC data was recorded, the possible reasons for the discrepancies were analyzed. Preliminary estimates of the parameters that have a significant impact on the possibility of reconstructing currents using the MCC method in inland eutrophicated water bodies have been made, and some limitations of the MCC method as a whole have been identified. Possible ways of further development of the method are analyzed.

Evaluating climate change impacts on reef environments via multibeam echosounder and Acoustic Doppler Current profiler technology

Crucial to the Earth's oceans, ocean currents dynamically react to various factors, including rotation, wind patterns, temperature fluctuations, alterations in salinity and the gravitational pull of the moon. Climate change impacts coastal ecosystems, emphasizing the need for understanding these currents. This study explores multibeam echosounder (MBES), specifically R2-Sonic 2020 instrument, offering detailed seabed information. Investigating coral reefs, rocky reefs and artificial reefs aimed to map seafloor currents movement and their climate change responses. MBES data viz. Bathymetry and backscatter were classified and acoustic doppler current profiler (ADCP) ground data were validated using random forest regression. Results indicated high precision in currents speed measurement i.e. coral reefs with 0.96, artificial reefs with 0.94 and rocky reefs with 0.97. Currents direction accuracy was notable in coral reefs with 0.85, slightly lower in rocky reefs with 0.72 and artificial reefs with 0.60. Random forest identified sediment and backscatter as key for speed prediction while direction relies on bathymetry, slope and aspect. The study emphasizes integrating sediment size, backscatter, bathymetry and ADCP data for seafloor current analysis. This multibeam data on sediments and currents support better marine spatial planning and determine biodiversity patterns planning in the reef area.

High-Frequency Surface Wave Radar Current Measurement Corrections via Machine Learning and Towed Acoustic Doppler Current Profiler Integration

High-Frequency Surface Wave Radar Current Measurement Corrections via Machine Learning and Towed Acoustic Doppler Current Profiler Integration

Grid Turbulence Measurements with an Acoustic Doppler Current Profiler

The motivation for this study is to investigate the abilities and limitations of a Nortek Signature1000 acoustic Doppler current profiler (ADCP) regarding fine-scale turbulence measurements. Current profilers offer the advantage of gaining more coherent measurement data than available with point acoustic measurements, and it is desirable to exploit this property in laboratory and field applications. The ADCP was tested in a towing tank, where turbulence was generated from a grid towed under controlled conditions. Grid-induced turbulence is a well-studied phenomenon and a good approximation for isotropic turbulence. Several previous experiments are available for comparison and there are developed theories within the topic. In the present experiments, a Nortek Vectrino acoustic Doppler velocimeter (ADV), which is an established instrument for turbulence measurements, was applied to validate the ADCP. It was found that the mean flow measured with the ADCP was accurate within 4% of the ADV. The turbulent variance was reasonably well resolved by the ADCP when large grid bars were towed at a high speed, but largely overestimated for lower towing speed and smaller grid bars. The effective cutoff frequency and turbulent eddy size were characterized experimentally, which provides detailed guidelines for when the ADCP data can be trusted and will allow future experimentalists to decide a priori if the Nortek Signature can be used in their setup. We conclude that the ADCP is not suitable for resolving turbulent spectra in a small-scale grid-induced flow due to the intrinsic Doppler noise and the low spatial and temporal sample resolution relative to the turbulent scales.

Exploring diel vertical migration and spatiotemporal variation of zooplankton backscattering strength using an acoustic Doppler current profiler instrument in the Halmahera Sea, Indonesia

Given its critical role in marine ecosystems, this study comprehensively examined zooplankton distribution and behavior in the Halmahera Sea. The temporal and spatial dynamics of zooplankton acoustic backscatter values were analyzed using a 153.6 kHz vessel-mounted acoustic Doppler current profiler (ADCP). Analysis was supplemented by biological sampling with a bongo plankton net. Further evaluation included the analysis of oceanographic and bathymetric data. The acoustic, oceanographic, and biological sampling data were obtained from the Jala Citra I ?Aurora? survey expedition in 2021, while the bathymetry data were obtained from the General Bathymetric Charts of the Ocean (GEBCO). The raw ADCP data, represented as digital counts, were transformed into mean volume backscattering strength (MVBS) expressed in decibels (dB) using sonar equations to yield a measure proportional to zooplankton biomass. Temporal observations revealed a diel vertical migration (DVM) pattern in zooplankton aggregation, characterized by movements responding to the daily solar cycle. Spatial observations indicated a higher zooplankton density in semi-enclosed waters than in open water. The high values of acoustic backscatter are not attributed to a single species of zooplankton. Biological sampling identified that Oncaea spp. and Oithona spp., a species from the Cyclopoida order, exhibit the highest abundance. The study concludes that the ADCP, based on acoustic backscatter measurements and data sampling, is an effective tool for detecting the presence and behavior of zooplankton.

Influence of a small submarine canyon on biogenic matter export flux in the lower St. Lawrence Estuary, eastern Canada

Abstract. Submarine canyons enhance shelf–slope sediment exchange and influence hydrodynamic processes, with consequences for biogeochemical cycles. This work documents variations in the vertical export of biogenic matter on the northern shore of the lower St. Lawrence Estuary (LSLE, Quebec, eastern Canada), which is characterized by the presence of an active submarine canyon system. A total of three moorings were deployed from November 2020 to September 2021. One nearshore mooring (PDMc) was deployed in the main axis of the Pointe-des-Monts (PDM) canyon system and was equipped with an acoustic Doppler current profiler (ADCP), and two moorings equipped with sediment traps were deployed in the distal PDM canyon system (PDM-154, PDM-224) and offshore Baie-Comeau (BC-133). The ADCP data revealed the occurrence of a minor sediment remobilization event (December 2020) and a small turbidity current (February 2021) in the canyon. Concurrent elevated fluxes of total particulate matter, particulate organic carbon, particulate nitrogen, and chloropigments showed that these events left a signature in sediment traps PDM-154 and PDM-224 located > 2.6 km further offshore by enhancing lateral dispersion of resuspended sediments. The composition of diatom and dinoflagellate assemblages was similar in the canyon system and offshore BC, but the diatom bloom occurred 2 weeks earlier (in mid-April) at the PDM site. A bloom of the potentially toxic diatom Pseudo-nitzschia seriata was also observed during the second half of September 2021 at the BC site. Annual diatom and dinoflagellate fluxes were almost 2 times lower at the PDM site than at the BC site, possibly due to differences in riverine input and the structure of the water column, as well as increased sediment input and resuspension at the PDM site, leading to limited light availability. This study notably helps identify the relationship between near-bed canyon processes and biogenic matter export in the water column, thereby directly influencing the ecosystem offshore PDM. The study period further covered an anomalously nearly ice-free winter, and thus, in the context of climate change, it provides valuable insight into future trends of biogenic matter export in the LSLE.

Upwellings and downwellings on the edge of the Gaspé Current: Observations and processes

The Gaspé Current carries the relatively fresh surface waters of the St. Lawrence estuary along the Gaspé peninsula to the Gulf of St. Lawrence. It presents complex dynamics including the development of meanders. A density front separates the fresher surface waters of the estuary from the saltier surface waters of the gulf. Over the past 40 years, upwellings and downwellings observed on the edge of this front have been the subject of several investigations. Tang (1982) proposed an analytical model featuring a permanent circulation consisting of an upwelling offshore of the front and a downwelling below the front. Using a unique set of in situ observations made with CTD (Conductivity Temperature Depth) profilers and ADCP (Acoustic Doppler Current Profiler) data collected between September 1991 and June 1993, upwellings and downwellings were inferred using a water masses analysis. Even if their presence is predominant (∼ 80% of the total number of sampled transects), they are not a permanent feature over the entire length of the Gaspé Current front, and their positions relative to the front vary. This data set also made it possible to determine via the ω equation that these vertical currents mostly result from frontogenesis and frontolysis (strengthening and weakening of the front). A new method to combine the ω equation with the nonlinear Ekman pumping shows that wind-driven vertical motions were generally weaker and much shallower than those due to frongenesis/frontolysis. This analysis shows that upwellings and downwellings are dependent on favorable conditions leading to the establishment of Gaspé Current instabilities and to frontogenesis or frontolysis.

Detection of suspended macroplastics using acoustic doppler current profiler (ADCP) echo

Plastic pollution has become an enormous environmental problem, endangering ecosystems, livelihoods, safety and human health. Large quantities of plastics are trapped in or transported by rivers. Monitoring methods mostly focus on plastics floating at the surface or deposited on riverbanks, while a substantial part of plastics may be transported below the water surface. Available underwater monitoring methods rely on nets and large equipment, making them labour-intensive, expensive and invasive. The measurements are, therefore, limited to occasional point measurements. In this paper, we explore the potential of echo sounding for the monitoring of suspended macroplastic (plastic items bigger than 5 mm). We performed tests in a controlled (basin), a semi-controlled (harbour) and an uncontrolled (river) environment using the high-end Acoustic Doppler Current Profiler (ADCP). This device is already in use for the estimation of flow velocity and suspended sediment concentrations using the wide network of ADCPs in the Netherlands and other countries. In the undisturbed controlled environment, 25 items varying in size, material, and orientation could be detected up to at least 4.6 m from the ADCP. The semi-controlled experiments showed that most of these items can also be detected among other naturally occurring scatterers, such as aquatic life, organic material and air bubbles. The field tests under natural conditions, combining ADCP and net measurements, showed that ADCP data can be calibrated towards a correct order of magnitude estimate of plastic transport. The coupling of the ADCP data to item characteristics such as size, material and orientation is still challenging, but more research into, for example, the signature of items may enable distinguishing item characteristics. This fundamental knowledge, combined with repetitions of validated field measurements under different flow conditions, is needed for the development of a robust monitoring method. Such a method may enable continuous or cross-sectional monitoring of suspended plastics and give insight into historic and plastic transport through 30-year long datasets. These insights can help improve and determine the effect of current mitigation and cleaning efforts.

Zonal circulation in the North Atlantic ocean at 52°W from WOCE-WHP and CLIVAR sections: 1997, 2003 and 2012

The A20 line is a meridional hydrographic section located at 52°W that cuts through the western North Atlantic Subtropical Gyre (NASG). It encloses the main paths of the Atlantic Meridional Overturning Circulation (AMOC). Using data from three A20 hydrographic cruises carried out in 1997, 2003 and 2012 together with Acoustic Doppler Current Profiler data and the velocities from an inverse box model, the circulation of the western NASG is estimated. The Gulf Stream is the main poleward path of the AMOC, carrying 155.3 ± 11.1, 102.7 ± 13.5 and 181.1 ± 14.9 Sv in 1997, 2003 and 2012, respectively (1 Sv = 106 m3/s ∼ 109 kg/s). In opposite direction, the Deep Western Boundary Current crosses the section at the northern/southern boundaries with a mass transport of −21.2 ± 8.9/29.0 ± 9.1, −14.4 ± 10.8/14.2 ± 8.1 and −37.9 ± 10.2/44.5 ± 9.8 Sv in 1997, 2003 and 2012, respectively. A net heat exchange from the ocean to the atmosphere is estimated to be −0.7 ± 0.1 PW and −0.6 ± 0.1 PW in 1997 and 2012, respectively, but is negligible in 2003 (0.1 ± 0.1 PW). The freshwater flux is significantly lower in 2003 (0.3 ± 0.1 Sv) than in 1997 (0.6 ± 0.1 Sv) and 2012 (0.6 ± 0.1 Sv). Ocean numerical models such as ECCO, GLORYS and MOM are used to address the interannual variability between the three surveys, but only the GLORYS output roughly agrees with the hydrographic data. GLORYS suggests a heat transport from the ocean to the atmosphere throughout the year and a net freshwater flux supported by precipitation plus river runoff higher than evaporation in all seasons except the spring.

Integrated path planning and control through proximal policy optimization for a marine current turbine

This paper presents an integrated path planning and tracking control framework for a marine current turbine (MCT), where the MCT is treated as an energy-harvesting autonomous underwater vehicle (AUV). Considering the ocean (space of action) is continuous, the proposed framework employs two modules to address path planning and path tracking enabled by the proximal policy optimization (PPO) algorithm, which is a policy gradient deep reinforcement learning (RL) method. To enable fully autonomous operation in a stochastic oceanic environment, the proposed path planning seeks a primary objective of maximizing the harvested energy; then, the path tracking module is designed to minimize the tracking error and avoid collisions with static and dynamic obstacles. Using field-collected acoustic Doppler current profiler (ADCP) data, the performance of the proposed framework is evaluated. Comparative studies with baseline algorithms in three different scenarios of path planning, path tracking without an obstacle, and path tracking with collision avoidance verify the effectiveness of our proposed approach.

Climatology of Transport in the Strait of Belle Isle

AbstractThe Strait of Belle Isle (SBI) is an important pathway for water mass exchanges between the Labrador Shelf and the Gulf of St. Lawrence (GSL), particularly for transport toward the GSL. Seasonal and inter‐annual variability of transport in the SBI are examined using 15 years of moored acoustic Doppler current profiler data. Tidal currents are largely along strait and homogeneous with depth. Transports are toward the GSL on average, lowest (−1.0 ± 0.8 dSv) from April to July, and highest (−4.0 ± 1.1 dSv) from September to January. Averaged seasonal transports are usually within one standard deviation of previously published modeled values. The volume of winter Labrador Shelf water (LShW) entering the GSL is computed by transport integration and compares well with integrated volumes that meet LShW temperature‐salinity criteria during an annual March survey of the GSL. Integrating over the whole year showed that on average 649 ± 397 km3 enters the GSL after the March surveys are conducted, independently of the volume that has entered up to March; this addition represents on average about a third of the total volume. Annual volumes of LShW calculated from transport suggest that flow through the SBI accounts for 12%–18% of the GSL winter surface mixed layer. Cross‐strait current shear may affect transport integration values, but sea surface temperature data suggests this bias is limited to the summer. Corrections are empirically derived to account for cross‐strait shear in our transport calculation. The corrected time series suggests that the average transport may be flowing toward the Labrador Shelf in July (0.6 ± 1.0 CI [0.1 1.1] dSv).

Characterizing the Marine Energy Test Area (META) in Wales, UK

With lack of convergence on any single wave or tidal technology, test centres have a unique role in the marine renewable energy industry. Test centres facilitate real testing at sea for devices and components at various TRLs (Technology Readiness Level), reducing the time, cost, and risks faced by marine energy developers. META (Marine Energy Test Area) is a £2.7M project managed by Marine Energy Wales (MEW), consisting of eight test areas in the Milford Haven Waterway and surrounding waters (Pembrokeshire, Wales). Although various datasets have been collected from the META test areas over the last decade, and some aspects of these data have been published in various reports, the data has not been gathered together, systematically analysed and critically assessed – the aim of this study. Here, we describe and interpret the various META datasets, including multibeam, ADCP (acoustic Doppler current profiler), and wave buoy data. We report the key parameters of relevance to testing at META, including bathymetry, the nature and magnitude of the tidal currents, turbulence, and wave climates. We make recommendations on future priorities for data collection at META, and discuss the future of the test areas, including expansion into floating wind and other evolving marine energy technologies.

Wavelet applications for turbulence characterisation of real tidal flows measured with an ADCP

Understanding turbulence is crucial to the design of tidal energy converters as it influences loads, fatigue life and power production. Acoustic Doppler Current Profilers (ADCPs) are normally employed in measurement campaigns to analyse turbulence at a particular location. Coherent turbulent structures are known to lead to the highest turbulence-induced stresses and are typically analysed by Fourier transform. However, this method can only yield parameters which are averaged over the signal length or the analysing window, and hence may not fully represent real flow turbulence, which is often non-stationary. This study applies wavelet time–frequency analysis to ADCP data from an active tidal test site to examine the turbulence spectrum and coherence characteristics of the flow, comparing these to Fourier methods. Results show that the average quantities from wavelet analysis agree favourably with Fourier analysis. Moreover, wavelet analysis yields instantaneous spectra and coherence, which show that at this site, high energy bursts occur at frequencies known to be significant for TEC loading and have turbulence intensities up to 80% higher than the average. We show that these intermittent, coherent bursts are obscured by the averages associated with Fourier analysis, highlighting the need for methods such as wavelets to understand interactions between fluid flow and TEC.

Validation of an Uncertainty Propagation Method for Moving‐Boat Acoustic Doppler Current Profiler Discharge Measurements

AbstractThe moving‐boat Acoustic Doppler Current Profiler (ADCP) gauging method is extensively used to measure the discharge of rivers and canals. Informed decisions related to water management require reliable estimates of the uncertainty of such measurements. The evaluation of the uncertainty is however a difficult task because of the complexity of the ADCP data workflow and the lack of reference discharges in rivers and canals. This study presents an evolution of the OURSIN method, which follows the framework of the Guide to the expression of Uncertainty in Measurement. The method has been implemented in the QRevInt software which provides an ADCP data quality review prior to the uncertainty analysis. As a computationally efficient alternative to the Monte Carlo approach, the uncertainty propagation combines elemental measurement uncertainty sources, transect‐to‐transect discharge variability, and estimation of the uncertainty of discharges in unmeasured areas by sensitivity analysis. The OURSIN uncertainty results are validated using empirical uncertainty estimates from two large‐scale repeated measures experiments with variable site and flow conditions. The mean and the 95% quantiles of the uncertainty differences are −0.4% [−4.4%; +2.5%]. The OURSIN method provides a comprehensive uncertainty budget that is helpful for understanding the relative impacts of error sources and defining strategies to minimize them. The method should be further evaluated with experiments in different conditions, and additional uncertainty components and options such as GPS reference for boat velocity could be implemented.

Towards Turbulent Stresses Estimates by Special Geometric Adjustment of Two ADCPs

The calculation of the turbulent stress matrix using acoustic Doppler current profiler (ADCP) data remains a challenging problem in the study of geophysical flows. One of the ways to overcome the problem is to use a system of two coupled ADCP with pairs of beams intersecting at a certain depth. When device configuration is symmetric in horizontal, this setting makes it possible to estimate the stresses only for a small range of depths, close to the depth of beam intersection point. To overcome this restriction, in this paper the modified setting is proposed, when both devices are symmetrically turned in the horizontal plane. The X axes of the devices are not collinear for such setting, and two pairs of beams intersect at two different depths, which depend on the distance between the emitters and devices’ rotation angle, and can be chosen in advance. At each of these depths, six beam velocity variances can be directly calculated, as well as the correlation of those velocity components, which correspond to the intersecting beams. As a result, an overdetermined system of equations is derived for unknown stresses, for both depths. The method was approbated during the processing of two series of field data obtained in lakes during open water and ice-covered periods. In most cases, calculations lead to physically consistent results; in particular, the stress matrix turns out to be positive definite. The method’s limitations and perspectives of its development are discussed.

Multi-layer flow field mapping in a small-scale shallow water reservoir by coastal acoustic tomography

Long-term, high-precision and spatiotemporal observation of current structure in small-scale waters is important for underwater research and water resources management. In this paper, a reciprocal sound transmission experiment was conducted using three Coastal Acoustic tomography (CAT) systems within 300 m spacing in Huangcai reservoir, Hunan, China from 14 to 16, Sep 2020. The multi-arrival reciprocal paths between each pair of stations were identified with the help of ray simulation. 3-D CAT data which penetrated the full depth of water were obtained. The flow field along vertical slice were mapped and showed consistency with Acoustic Doppler Current Profiler (ADCP) and Temperature Depth (TD) data. A standard deviation of 0.73 m/s at the bottom layer were observed, indicating strong bottom flows in the reservoir. Furthermore, to visualize the strong bottom flow, the horizontal flow fields in the bottom layer were mapped by 3-D inversion technique. The feasibility of the technique was validated by three measures: 1) comparison between range average current and horizontal flow field; 2) Uncertainty analysis; 3) Check net volume transport. This work proves the CAT combined with 3-D inversion technique has the potentials to provide real-time 3-D current data for water researches.

Imaging of Artificial Bubble Distribution Using a Multi-Sonar Array System

Bubble clusters present in seawater can cause acoustic interference and acoustic signal distortion during marine exploration. However, this interference can also be used as an acoustic masking technique, which has significant implications for military purposes. Therefore, characterizing the distribution of bubble clusters in water would allow for the development of anti-detection technologies. In this study, a sea experiment was performed using a multi-sonar array system and a bubble-generating material developed by our research group to obtain acoustic signals from an artificial bubble cluster and characterize its distribution. The acquired acoustic data were preprocessed, and reverse-time migration (RTM) was applied to the dataset. For effective RTM, an envelope waveform was used to decrease computation time and memory requirements. The envelope RTM results could be used to effectively image the distribution characteristics of the artificial bubble clusters. Compared with acoustic Doppler current profiler data, the backscattering strength of the boundary of the imaged artificial bubble cluster was estimated to range between −30 and −20 dB. Therefore, the three-dimensional distribution characteristics of bubble clusters in the open sea can be effectively determined through envelope RTM. Furthermore, the data obtained from this study can be used as a reference for future studies.

An investigation of tidal turbine performance and loads under various turbulence conditions using Blade Element Momentum theory and high-frequency field data acquired in two prospective tidal energy sites in Australia

Potential tidal energy sites are characterized by strong currents and high levels of shear, which is the main source of turbulent kinetic energy production. Enhanced turbulence levels are known to intensify fatigue loads acting on turbine blades, possibly causing premature device failure. Blade Element Momentum (BEM) numerical models allow for the investigation of device performance and loadings prior to device deployment and support turbine design optimization at low computational expenses. High-frequency novel Acoustic Doppler Current Profiler (AD2CP) data from two tidally energetic sites in Australia are used to feed a BEM model optimized to incorporate unsteady flow corrections. Power, thrust and bending moments coefficients as well as separation points are estimated to describe the performance of a turbine under various turbulence intensities and integral length scales. Results reveal that standard deviations were more sensitive than mean coefficients and turbulence intensities had a greater impact on performance coefficients than integral length scales. Periodic oscillations of separation points at two stations suggest the presence of weak dynamic stall but also that leading-edge vortex shedding is constrained to the blade roots. These findings highlight the need of assessing turbulence in tidal energy sites and support design improvements which can endure unsteady conditions.

Large-eddy simulations of the ice-shelf–ocean boundary layer near the ice front of Nansen Ice Shelf, Antarctica

Abstract. Ice melting beneath Antarctic ice shelves is caused by heat transfer through the ice-shelf–ocean boundary layer (IOBL). However, our understanding of the fluid dynamics and thermohaline physics of the IOBL flow is poor. In this study, we utilize a large-eddy simulation (LES) model to investigate ocean dynamics and the role of turbulence within the IOBL flow near the ice front. To simulate the varying turbulence intensities, we imposed different theoretical profiles of the velocity. Far-field ocean conditions for the melting at the ice-shelf base and freezing at the sea surface were derived based on in situ observations of temperature and salinity near the ice front of the Nansen Ice Shelf. In terms of overturning features near the ice front, we validated the LES simulation results by comparing them with the in situ observational data. In the comparison of the velocity profiles to shipborne lowered acoustic Doppler current profiler (LADCP) data, the LES-derived strength of the overturning cells is similar to that obtained from the observational data. Moreover, the vertical distribution of the simulated temperature and salinity, which were mainly determined by the positively buoyant meltwater and sea-ice formation, was also comparable to that of the observations. We conclude that the IOBL flow near the ice front and its contribution to the ocean dynamics can be realistically resolved using our proposed method. Based on validated 3D-LES results, we revealed that the main forces of ocean dynamics near the ice front are driven by positively buoyant meltwater, concentrated salinity at the sea surface, and outflowing momentum of the sub-ice-shelf plume. Moreover, in the strong-turbulence case, distinct features such as a higher basal melt rate (0.153 m yr−1), weak upwelling of the positively buoyant ice-shelf water, and a higher sea-ice formation were observed, suggesting a relatively high speed current within the IOBL because of highly turbulent mixing. The findings of this study will contribute toward a deeper understanding of the complex IOBL-flow physics and its impact on the ocean dynamics near the ice front.