Marine Engineering Research Articles

Comparative evaluation of machine learning models for assessment of seabed liquefaction using finite element data

Predicting wave-induced liquefaction around submarine pipelines is crucial for marine engineering safety. However, the complex of interactions between ocean dynamics and seabed sediments makes rapid and accurate assessments challenging with traditional numerical methods. Although machine learning approaches are increasingly applied to wave-induced liquefaction problems, the comparative accuracy of different models remains under-explored. We evaluate the predictive accuracy of four classical machine learning models: Gradient Boosting (GB), Support Vector Machine (SVM), Multi-Layer Perceptron (MLP), and Random Forest (RF). The results indicate that the GB model exhibits high stability and accuracy in predicting wave-induced liquefaction, due to its strong ability to handle complex nonlinear geological data. Prediction accuracy varies across output parameters, with higher accuracy for seabed predictions than for pipeline surroundings. The combination of different input parameters significantly influences model predictive accuracy. Compared to traditional finite element numerical methods, employing machine learning models significantly reduces computation time, offering an effective tool for rapid disaster assessment and early warning in marine engineering. This research contributes to the safety of marine pipeline protections and provides new insights into the intersection of marine geological engineering and artificial intelligence.

Application research on nonlinear partitioned analysis of soil-structure interaction method of seismic response for seawater-seabed-structure.

The analysis of seismic response in marine engineering structures is pivotal for guaranteeing their seismic safety. Such analyses are intricate due to the complexity of fluid-structure and soil-structure interactions. This paper introduces a unified computational framework for wave motion within a water-saturated seabed-bedrock system, employing the Davidenkov model and a modified Massing rule to characterize the nonlinear properties of the saturated seabed. A comparative analysis is conducted between the nonlinear responses of marine sites subjected to linear and nonlinear free-field inputs, with a specific focus on the seismic response of bridges under seawater-seabed-structure interaction. The study demonstrates that the modulus of a nonlinear saturated seabed diminishes, leading to a decrease in the wave impedance ratio between the saturated seabed and bedrock. Consequently, the reflection and transmission coefficients from the bedrock to the saturated seabed increase, amplifying the seismic response. For deepwater bridges, under harder site conditions, the abutment's bottom response is largely insensitive to increasing water depth, whereas the shear at the abutment's base diminishes with increasing water depth. The proposed method is validated through two case studies, with an examination of the impact of saturated sites on the analysis results.

Transient Sand Scour Dynamics Induced by Pulsed Submerged Water Jets: Simulation Analysis

Water jet scouring technology is extensively applied in marine engineering, harbor maintenance, river training, and various other fields, showcasing a broad spectrum of potential applications. However, achieving a comprehensive understanding of the transient sand scouring characteristics of water jets remains challenging due to the inherent complexity of the coupled flow structure involving submerged jets and environmental fluids, along with the intricate dynamics of two-phase flow. This study, rooted in numerical simulation and experimental validation, introduces pulse characteristics into a submerged jet. A thorough investigation is conducted to explore the transient sand scouring characteristics and sand transport laws of the submerged jet under diverse working conditions. The results of this study revealed that the main reason for the asymmetry of the sand pit morphology is not the non-uniform distribution of sand grains, but more likely caused by turbulence effects. Simultaneously, within the initial 0.25 s of the pulse cycle, suspended sediment resulting from the pulsed jet in the preceding cycle gradually transports to the dune and its surrounding areas. Subsequently, from 0.25 s to 0.5 s, sediment on both sides of the pit’s bottom undergoes movement and amalgamation with the sediment that remained unsettled during the previous cycle. The findings reveal that higher jet velocities significantly enhance sediment suspension, migration, and redeposition, leading to deeper erosion and the rapid formation of the sand pit’s outline within 2 s. Additionally, the jet velocity and the impact distance are identified as critical factors influencing erosion depth and sediment dynamics. These insights advance the understanding of erosion mechanisms driven by pulsed jets, highlighting their impact on sediment transport processes. The research findings provide important guidance for dredging and ocean engineering fields and offer a theoretical basis for improving the understanding of submerged jet scouring mechanisms.

Study on cavitation erosion mechanism of UHMWPE and PTFE

Polymer materials possess low density, high strength, corrosion resistance, and excellent cavitation erosion resistance. As a result, they are widely used in marine, water conservancy, and other engineering equipment as replacements for metal materials. However, polymer friction pairs working in a water environment for an extended period are easily damaged by cavitation erosion. In this work, the cavitation behavior of polytetrafluoroethylene (PTFE) and ultra-high molecular weight polyethylene (UHMWPE) in deionized water and seawater is investigated through experiments and computational fluid dynamics (CFD) simulations. The results indicate that the cavitation erosion resistance of UHMWPE is significantly better than that of PTFE, and the UHMWPE has four cavitation process stages, while the PTFE has only three cavitation stages. 316L counterparts in the seawater corrosion and cavitation coupling effect of a large number of metal particles off and wash polymer material surface, so that the cavitation erosion of PTFE and UHMWPE is more serious in seawater environment. CFD simulation demonstrates that the cavitation erosion zone under the radiator shows a semicircular distribution. Meanwhile, the formation of ring-shaped cavitation pit is related to the distribution of bubbles on the surface of the radiator. The cavitation rate of PTFE and UHMWPE is slowed down by the “water cushion effect”.

Training transfer validity of virtual reality simulator assessment

This study utilises computer-based simulations to explore the transfer effects of competency training in maritime education, addressing the current lack of research on their transferability to real-world scenarios.The research explores the accuracy of procedural knowledge assessment using virtual reality (VR), positing that head-mounted display (HMD) VR offers stronger concurrent validity through training transfer measures than 3D desktop VR. This is evaluated by regression on a training transfer condition. It also investigates motivation’s influence on training transfer and the regression model of this relationship.Fifteen marine engineering students were divided into two experimental groups using 3D desktop VR and HMD VR systems, with eight experts in the control group. The students had previously received traditional lecture-based instruction and were given practical training using a 2D desktop simulator in the same scenario as in the VR treatment and in the training transfer condition.The ANCOVA design experiment involved two levels of technical immersion before the operation of real-life equipment. Neither technical immersion nor expertise level as independent variables were found to have a significant effect in the relationship of the assessment predicting the training transfer. The direct relationship was significant (R2adj = 0.436) and further analysed with the influence of motivation, resulting in a moderation model with a decent effect size (R2 = 0.740). Based on these findings, we can infer that both types of VR simulations used for assessment demonstrate concurrent validity in predicting real-life performance before we discuss and define the characteristics of the observed transfer according to theory.

Multivariate risk assessment for offshore structures by Gaidai risk evaluation method under an accumulation of fatigue damage, utilizing novel deconvolution scheme

Current study presents a state-of-the-art structural spatiotemporal multimodal risk assessment methodology, that is particularly well-suited for multimodal structural dynamics, either recorded physically or numerically simulated over a representative timelapse. Offshore Jacket-type offshore platform, operating in Bohai Bay waters had been selected for the method’s verification. This investigation had shown that, in the presence of in-situ environmental stressors, it is possible to appropriately estimate dynamic structural system’s failure and damage risks. High dimensionality of engineering dynamic structural systems, alomg with nonlinear nonstationary inter-correlations between critical structural components, often present challenges for contemporary reliability methods, mostly limited to univariate and bivariate systems. Operating Jacket platform, subjected to in situ wave loads, had been chosen for this case study to benchmark advocated risk evaluation methodology. Number of hotspot stresses had been selected to represent multivariate structural system. Advocated multimodal method had been proven to be suitable for robust assessment of operational failure/damage risks, as well as for accurate structural life projection. Novel non-parametric deconvolution extrapolation scheme had been employed, providing enhanced numerical stability. Given increased safety concerns within offshore, naval, marine engineering, advocated multimodal reliability methodology may be utilized for safer and economically more viable structural design.

A baseline decomposition ultra-short baseline localization algorithm for arbitrary array structures.

With the rapid development of the marine economy, hydroacoustic positioning technology plays an increasingly important role in marine engineering. The ultra-short baseline (USBL) hydroacoustic positioning system has the advantages of small size, simple operation, and flexible use, and has been widely used. Aiming at the existing USBL acoustic positioning algorithm with low positioning accuracy and complex calculation, a baseline decomposition localization algorithm with arbitrary array structure is proposed. The algorithm is based on the theory of coordinate system transformation, establishes positioning observation equations for each baseline in the base array, and adopts the least squares method to obtain positioning results by selecting different combinations of baselines. The systematic errors of different positioning models themselves are simulated, and then the effects of the three parameter errors, namely, time delay, element coordinates, and sound speed, on the positioning results are analyzed, respectively. Finally, the simulation results and sea trial data show that, compared with the existing algorithms, this algorithm not only simplifies the complicated computation process, but also improves the positioning accuracy and robustness, and has a better application effect.

A novel bonding strategy of hydrogel on titanium alloy for marine antifouling engineering: multiple antifouling mechanisms and DFT calculations

Marine biofouling is one of the biggest problems for titanium alloys and rutile TiO2 coatings in marine engineering applications. Hydrogel materials are a novel and environmentally benign antifouling strategy, but they cannot be stabilized on alloy surfaces to provide long-term protection. Focusing on the challenges of bonding at the hydrogel-alloy interface, a PAA/PHEMA composite hydrogel containing Cu2O@PEG powder was strongly bonded to the titanium alloy by forming chemical bonds with APTES. The composite hydrogel still achieves an adhesion strength of 60-70 kPa after 7 days of immersion. The samples maintained a stable copper ion leaching rate of 2.61~3.76μg·cm-2·d-1 after 21 days of immersion. The coating-modified titanium alloys showed a 100% bactericidal rate within three hours of contact with different bacteria and exhibited a high anti-algal adhesion rate of up to 99%. In addition, the attachment mode of APTES on rutile TiO2 was clarified for the first time by Density Functional Theory (DFT) calculations. According to DFT calculations, the adsorption energy of APTES on Ti-TiO2 is -747.025kJ/mol, and the adsorption energy of acrylic acid on TiO2-APTES is -535.152kJ/mol. The chemical bonding connection between the hydrogel-alloy interface, as a novel interface bonding strategy, would be expected to broaden the application of titanium alloy in marine engineering.

High acetone soluble organosolv lignin extraction and its application towards green antifouling and wear-resistant coating

Marine fouling poses significant challenges to the efficiency and longevity of marine engineering equipment. To address this issue, developing effective marine antifouling coatings is critical to ensure the economic viability, environmental sustainability, and safety of offshore operations. In this study, we developed an innovative green antifouling and wear-resistant coating based on lignin, a renewable and sustainable resource. Lignin is considered environmentally friendly because it is abundant, biodegradable, and reduces reliance on petroleum-based materials. The coating was formulated with a controlled hydrophilic-to-hydrophobic ratio of 2:8, leveraging lignin's unique properties. Applying lignin increased the water contact angle by 14.5 %, improving surface hydrophobicity and contributing to the coating's antifouling efficacy. Moreover, the mechanical strength of the coating was enhanced by approximately 200 %, significantly boosting its durability in harsh marine environments. Additionally, the friction coefficient was reduced by about 85 %, further preventing organism adhesion. These results demonstrate that lignin-based coatings offer a greener alternative to traditional antifouling solutions. The results of this study not only help advance antifouling coating technology but are also consistent with the broader goal of promoting environmental responsibility in marine engineering practice.

Impact of PVA-coated aggregate on concrete impermeability and creep characteristics under hydraulic pressure and development of a creep model

In marine engineering projects such as sea dikes, concrete must exhibit both exceptional impermeability and plastic deformation to prevent cracking and subsequent internal corrosion due to synergistic deformation with the foundation. This study enhances the interface transition zone (ITZ) and plastic deformation of concrete by applying a PVA film to the aggregate surface. We use nuclear magnetic resonance to investigate the internal pore distribution and conduct permeability tests to assess its impermeability. Utilizing a self-developed triaxial hydraulic creep apparatus, we tests the concrete's creep performance under hydraulic pressure. Compared with conventional waterproof concrete, the findings reveal that the PVA film on the aggregate surface significantly increases the water penetration pressure of the concrete and markedly enhances the momentary deformation and creep deformation under hydraulic pressure, significantly extending the time to creep. Furthermore, the study proposes a creep model incorporating a fractional derivative-based dashpot model, combined with the Burgers model. This research offers a novel approach and theoretical support for developing impermeable and plastic concrete suitable for marine engineering applications.

Design and fabrication of multiphase TiVCrZrW films with superior wear resistance and corrosion resistance

High entropy alloys (HEAs) have the potential to overcome the conflict between hardness and toughness by incorporating dual-phase or multiphase structures. Under unbalanced magnetron sputtering, HEA films with large atomic size differences tend to form non-monophasic structures. In this study, based on a phase diagram calculation simulation, a multiphase TiVCrZrW film with deposition temperature-induced phase separation was successfully designed. Interestingly, the TiVCrZrW film deposited at 600 °C exhibited a multiphase structure including a double body-centered cubic (BCC) phase and Laves phase by spinodal decomposition, realizing a balance between hardness and toughness. The tribological experiments showed that the multiphase TiVCrZrW film provided superior wear resistance, with a minimum wear rate of 2.63 × 10−6 mm3/(N·m). The electrochemical experiment demonstrated the outstanding corrosion resistance of the multiphase TiVCrZrW film, and the corrosive solution was effectively inhibited by the ZrO2 and Cr2O3 oxides passive film formed on the surface. According to the results of this study, TiVCrZrW protective films have a wide range of potential applications in various fields of marine engineering.

Time-dependent corrosion behavior of EH36 steel caused by Pseudomonas aeruginosa based on big data monitoring technology

Marine microbial corrosion poses a significant threat to the safe service of marine engineering equipment. Previous studies have often failed to thoroughly analyze the continuous and prolonged microbial corrosion process, resulting in an incomplete understanding of microbial corrosion mechanisms involved at various stages and the development of ineffective control strategies. This study employed a corrosion big data online real-time monitoring technique to investigate the time-dependent corrosion behavior of EH36 steel caused by Pseudomonas aeruginosa in aerobic environments over a 30-d incubation period. It was found that P. aeruginosa accelerated the corrosion of EH36 steel in the early stages by enhancing the cathodic oxygen reduction process. As oxygen levels declined, P. aeruginosa transitioned from aerobic to anaerobic respiration, promoting corrosion through biocatalytic nitrate reduction. In the later stages, the reduction in sessile cell counts, extreme low oxygen concentration, and dense surface film increased the charge transfer and film resistances, ultimately leading to corrosion inhibition. The weight loss and electrochemical data confirmed the effectiveness of the big data monitoring technique in investigating microbial corrosion, which provides new approaches for diagnosing and preventing microbial corrosion.

An intelligence enhancement method for USV navigation visual measurement based on variable gradient soft-threshold correction

Maritime image enhancement is crucial in marine engineering for applications like unmanned surface vessels (USV) visual measurement and path planning. This paper proposes an image enhancement algorithm based on variable gradient soft-threshold correction (VGSC), tailored for USV intelligent navigation. By calculating the gradient of the two-dimensional difference quotient function of the pixels, we determine the pixel distribution and threshold. An innovative dynamic equalization function is applied to compress maximum pixel values and stretch minimum ones, allowing for adaptive adjustment of the threshold. The results indicate that the VGSC algorithm effectively suppresses background noise, thereby facilitating the extraction of target contour pixel information. When evaluated using four image assessment indicators, the VGSC algorithm enhances the image quality by 20.09 % and 28.92 % compared to bilateral filtering and Gamma correction, respectively. This method excels in enhancing image details and suppressing noise, promising robust application in multi-modal data fusion and precise maritime target detection.

Effects of Ta on the strengthening mechanism of microstructure and corrosion resistance of underwater wet laser cladding 17-4PH coating

Underwater wet laser cladding has gradually become the key technology for online repair of marine engineering materials. This work successfully prepared a Ta-reinforced 17-4PH coating on a 20Cr substrate using this technique. The study primarily examined how varying levels of tantalum (Ta) influence the microstructure, phase composition, microhardness, immersion corrosion, and electrochemical properties of underwater cladding coatings. Additionally, a detailed analysis of the corrosion mechanism was conducted. The experimental findings demonstrated that incorporating Ta can greatly enhance the forming quality and overall performance of coatings. When the Ta addition was 10 %, the forming quality was the best, and there were no porosity or depressions. The 10 % Ta coating had the best densification with a minimum porosity of 0.05 %. The average microhardness of the T10 coating was 594.1 ± 5.9 HV0.2, an increase of about 13 % over the original T0 coating. Additionally, when the Ta content reached 10 %, the formation of Ta2O5 on the surface played a crucial role in enhancing the coating's resistance to immersion corrosion. The T10 coating demonstrates the highest polarization resistance and superior corrosion resistance among the coatings tested. The corrosion mechanism of the original unadded Ta coating involved severe intergranular corrosion and pitting; The corrosion mechanism observed in the T10 coating involved local crevice corrosion and minor pitting. This study reveals the strengthening mechanism of Ta on the organizational properties of the underwater laser cladding layer, which can provide meaningful guidance for the future development of underwater laser cladding technology.

An Imine-Functionalized Silicone-Based Epoxy Coating with Stable Adhesion and Controllable Degradation for Enhanced Marine Antifouling and Anticorrosion Properties.

Biofouling and corrosion of submerged equipment caused by marine organisms severely restrict the rapid development of the marine industry. Traditional antifouling or anticorrosion coatings typically serve a sole purpose and exhibit limited degradability upon failure, rendering them inadequate for current demands. Herein, a novel imine-functionalized command-degradable bio-based epoxy coating (SAHPEP-DDM) with enhanced integrated antifouling and anticorrosion performances was synthesized utilizing 1,3-bis (3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and syringaldehyde. Compared with commercial epoxy resins (E51-DDM) and polydimethylsiloxanes (PDMS), the SAHPEP-DDM coating exhibits superior antifouling and anticorrosion properties due to the existence of -C=N- and Si-O-Si chain segments in the cross-linking network. The coating achieves resistance rates of 99.59 % and 99.20 % against E. coli and S. aureus, respectively, and shows promising resistance against algae and proteins, as well as excellent corrosion resistance in artificial seawater (with |Z|0.01 Hz and arc radius of about 1011 Ω and exceeding 1010 Ω respectively). The coating also exhibits excellent chemical resistance in organic solvents as well as neutral and alkaline environments. Moreover, its controlled degradation after coating failure can be achieved in acid aqueous solutions through temperature and acidity adjustments, facilitated by the presence of -C=N-. This work presents a novel degradable coating successfully coupled the dual functions of antifouling and anticorrosion coatings, avoiding the employment of intermediate coat, indicating vast potential for application in various marine engineering fields.

A New Deep Learning Methodology for Alarm Supervision in Marine Power Stations.

Marine engineering officers operate and maintain the ship's machinery during normal navigation. Most accidents on board are related to human factors which, at the same time, are associated with the workload of the crew members and the working environment. The number of alarms is so high that, most of the time, instead of helping to prevent accidents, it causes more stress for crew members, which can result in accidents. Convolutional Neural Networks (CNNs) are being employed in the recognition of images, which depends on the quality of the images, the image recognition algorithm, and the very complex configuration of the neural network. This research study aims to develop a user-friendly image recognition tool that may act as a visual sensor of alarms adjusted to the particular needs of the ship operator. To achieve this, a marine engineering simulator was employed to develop an image recognition tool that advises marine engineering officers when they are conducting their maintenance activities, with the aim to reduce their stress as a work risk prevention tool. Results showed adequate accuracy for three-layer Convolutional Neural Networks and balanced data, and the use of external cameras stands out for user-friendly applications.

Effect of deformation temperature on the microstructure and texture evolution of Ti-6Al-4Zr-2Mo-6V alloy

In this work, the effect of deformation temperature on the microstructure, texture, and tensile properties of a Ti-6Al-4Zr-2Mo-6V (wt. %) alloy was systematically investigated. The whole samples were composed of an equiaxed α phase, a strip α phase, and a β transformed microstructure. The recrystallization area fraction increased with the increase of deformation temperature. The orientation distribution of a retained β phase was {001}β⟨110⟩β texture regardless of deformation temperature. The textured microstructure of an α phase was {12¯10}α⟨101¯0⟩α under the 810 and 840 °C condition. Additional {112¯0}α⟨0001⟩α texture was observed as the rolling temperature increased to 870 °C. The yield strength and the tensile strength of a rolling direction were lower than that of a transverse direction. The yield strength of a rolling direction and a transverse direction were both above 990 MPa when the deformation temperature was 840 °C. In summary, the present study provided theoretical guidance for the high strength titanium alloy applied for the marine engineering field.

Progress in Corrosion and Protection Research in Offshore Petroleum Engineering

This paper summarizes the latest research progress on the corrosion of concrete structures in marine engineering and its protection technology. The article firstly emphasizes the influence of seawater on the performance of concrete engineering, and then discusses the application of composite corrosion inhibitors in the marine environment. The composite corrosion inhibitor significantly reduces the corrosion rate by simultaneously inhibiting the anodic and cathodic reactions and forming a protective hydrophobic film on the metal surface. The article describes in detail the classification of corrosion inhibitors, including adsorption or film-forming inhibitors with polar hydrophobic groups such as N, S, and -OH, as well as migratory corrosion inhibitors (MCIs) that diffuse through the pores of the concrete to the surface of the reinforcement bar to form a protective film. The article also discusses the performance evaluation criteria of corrosion inhibitors, including the electrochemical performance of saltwater impregnation, the performance of dry-wet cold-heat cycles, and the performance of resistance to Cl- penetration, etc., and lists the relevant national standards and test methods. Through a comprehensive analysis of relevant literature at home and abroad in recent years, the article points out that composite corrosion inhibitors show great potential in improving the durability of marine concrete structures, but the long-term stability and compatibility with different concrete types still need to be further studied. Future research should focus on developing more efficient and environmentally friendly corrosion inhibitors and expanding their application in marine engineering to meet the increasingly severe challenges of marine corrosion. At the same time, a comprehensive evaluation of the longevity, economy and environmental friendliness of corrosion inhibitors is also an important direction for future research.

Effect of chemical consolidation on physico-mechanical properties of porous coral reef limestone

Porous coral reef limestone (CRL) is characterized by the low strength and developed pore structure, so improving its physico-mechanical properties is important for marine engineering construction work. Chemically consolidated porous CRL was prepared by taking a non-granular chemical grout (sodium silicate) as the main consolidation material. Then, the chemical consolidation effect was evaluated from two aspects (both the physical and mechanical properties) by conducting computed tomography (CT) scanning and quasi-static uniaxial compression tests. The results indicate that the consolidation material can fill the pores in the CRL, which reduces the porosity of specimens by more than 50%. In addition, the peak strength under quasi-static compression is increased by about 20%. The fragments decrease at failure, and fracture plane slip and crack opening are inhibited. Finally, influences of the special banded shape of consolidation material retained in the specimens on the failure process and failure mode of specimens were investigated. The chemical consolidation mechanism of porous CRL was revealed by combining with the scanning electron microscope (SEM) images. Research results indicate that the non-granular chemical material (sodium silicate) improves the physico-mechanical properties of porous CRL. The research provides reference for the foundation treatment in coral reefs and the design of consolidation schemes for surrounding rocks of underground spaces in marine engineering operations.

Near-real-time atmospheric and oceanic science products of Himawari-8 and Himawari-9 geostationary satellites over the South China Sea

Abstract. The initial release of near-real-time (NRT) atmospheric and oceanic science products from Japanese Himawari-8 and Himawari-9 (H8/9) geostationary (GEO) satellites over the South China Sea (SCS) was unveiled in 2024. The primary objective behind crafting these NRT H8/9 satellite products is to facilitate weather and marine environment monitoring, enhance maritime security, and aid ocean navigation, among other purposes. As part of this investigation, a novel NRT data processing system was devised to generate a variety of regional H8/9 GEO satellite science products within a resolution of 10 min and a gridded resolution of 0.05° × 0.05° from 3 November 2022 to the present. This algorithm system was built upon the preceding Fengyun (FY) geostationary satellite algorithm test bed (FYGAT), which was the prototype of the FY-4 GEO meteorological satellite science product operational processing system. These regional H8/9 GEO satellite science products encompass a range of crucial data such as cloud mask, fraction, height, phase, optical, and microphysical properties; layered precipitable water; and sea surface temperature. We subjected these products to rigorous evaluations against high-quality analogous satellite products and reanalysis data spanning 1 year in 2023. The validations underscore a strong consistency between the H8/9 GEO satellite atmospheric and oceanic science products over the SCS and the referenced products. Nevertheless, slight discrepancies in these satellite science products were identified, primarily stemming from variations in sensor/dataset characteristics, retrieval algorithms, and geometric conditions. These outcomes demonstrate the suitability of the first edition of NRT atmospheric and oceanic science products of H8/9 satellites over the SCS in supporting the intended quantitative applications. This NRT GEO satellite data record is publicly accessible through the File Transfer Protocol (FTP) provided by the Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) in China. Free access to the dataset is possible via https://doi.org/10.6084/m9.figshare.25015853 (Liu et al., 2024).