Wan, Y.; Zhang, X.; Dai, Y.; Li, W.; Li, L., and Qu, X., 2020. Applicability of ERA-Interim high-resolution significant wave height data in global sea areas. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 1-8. Coconut Creek (Florida), ISSN 0749-0208.

In this paper, ERA-Interim high-resolution ocean wave reanalysis data provided by the European Center for Medium-range Weather Forecasts (ECMWF) are matched with time-space data from buoys in the China Sea, the United States East and West Coast, the Central Pacific Ocean and European seas. Taking the significant wave height (SWH) as an example, ERA-Interim wave field data are verified, and their applicabilities in sea areas around the world are analyzed. The results show that the means of the correlation coefficients (CCs) obtained by fitting in each sea area are greater than 0.7. Furthermore, in all areas except for the European waters, the root mean square errors (RMSEs) are less than 0.4 m. The linear regression method is used to correct the data in the European sea area, and the corrected results are significantly better than the uncorrected results. The corrected CC is reduced by 3.23% compared to the uncorrected CC. The corrected RMSE is increased by 24.24% compared to the uncorrected RMSE. This shows that corrected data better reflect the real situation of the ocean surface than uncorrected data.

Wan, Y.; Zheng, C.W.; Zhang, J.; Dai, Y.; Li, L.; Qu, X., and Zhang, X., 2020. The Study of Ocean Wave and Wave Power Observations by Synthetic Aperture Radar in Nearshore Waters. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.),Air-Sea Interaction and Coastal Environments of the Maritime Polar Silk Roads.Journal of Coastal Research, Special Issue No. 99, pp. 9-15. Coconut Creek (Florida), ISSN 0749-0208.

Based on 2 RADARSAT-2 SAR (Synthetic Aperture Radar) SLC (Single Look Complex) data and the cross-spectrum method, the distributions of significant wave heights and mean wave periods of ocean wave were inverted, and the distributions of the wave power density, which can represent the wave power, were calculated. Some comparisons between the results of the SAR and those of the ECMWF (European Center for Medium-Range Weather Forecasts) dataset were carried out, and the observation ability for the distribution characteristics of wave and wave power by the SAR was studied in detail. The results show that compared with buoys, which are single-point observations, and wave models, which are simulated observations, the SAR is an ideal tool for extensive wave observations in nearshore waters. The advantage of SAR observations is that some fine structure and microcosmic changes in wave and wave power can be found, which helps us understand the internal structure and transformation patterns of wave better. Therefore, the SAR showed extremely extensive application prospects in the field of wave observations. The contributions in this paper will provide some references for researchers aiming for ocean wave detection by remote sensing and promote the application level of SAR in the detection of wave and wave power.

Qi, Z.; Wang, B.; Qin, Y.; Shi, J., and Zhai, J., 2020. Planar path following control for wave glider and experimental study. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 16-20. Coconut Creek (Florida), ISSN 0749-0208.

This paper addresses a path following problem of Wave Glider along a predefined path in horizontal plane. The path following controller designing is challenging since Wave Glider is weak maneuvering, underactuated, inaccuracy mathematical model and large environmental disturbances. First, a planar curve path tracking error model is established in the Serret-Frenet coordinate frame. Based on the LOS guidance law and the virtual target method, a planar guidance controller for underactuated Wave Glider is presented to ensure the stability of the path following. And then, according to the classic feedback linearization PID controller and fuzzy controller, a fuzzy adaptive PID controller is developed. Fuzzy controller is used to achieve PID controller parameters online adaptive adjust, in order to improve the robustness of the control system under the influence of environmental disturbances and inaccuracy modeling parameters. Furthermore, analyzing the typical application scenarios of Wave Glider, we set two simulation path in horizontal plane named polyline path and circular path. Numerical simulation results illustrate the proposed control design is effective to deal with planar following problem of Wave Glider. Two sea trails show that the controller can achieve the path following task, however, the speed of Wave Glider is directly related to the accuracy of the path following.

Liu, Y.; Guo, F.; Zhai, X.; Li, Z.; Zhao, H., and Xue, G., 2020. Research on the operational stability and energy consumption of the profiling float. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 21-30. Coconut Creek (Florida), ISSN 0749-0208.

The profiling float is the crucial component of global ocean observation system. Considering the excessive change rate of motion speed and energy consumption issues during the ascending process of the float, this paper proposes two sets of the piecewise oil-pumping control strategies based on speed closed-loop (SCL) and speed-acceleration double closed-loop (SADCL) respectively. The kinematic model and energy consumption model of the 4000-meter profiling float during the ascending process are established, then the simulation and analysis were made to study the operational stability and energy consumption of the float. By comparing the influence of SCL and SADCL control strategies with that of traditional control strategy for pumping (TCS) on the performance of the float, the results are as follows: SCL and SADCL control strategies can effectively improve the float operational stability and lessen the energy consumption. The amplitude of velocity fluctuation decreased by 65.44% compared with the traditional strategy. When the setting value of feedback speed u_set is 1m/s, the SCL control strategy is more efficient, saving 18% energy than TCS. However, optimized control strategies will no longer have the advantage of energy saving at the speed u_set below 0.050 m/s. The conclusion drawn in this paper is beneficial for the further study of the profiling float oil-pumping control strategy.

Shi, W.; Dai, W.; Cheng, W.; Xiao, Z.; Li, S.; Gu, C., and Zhao, L., 2020. Variations in the establishment time and eastern boundary position of the Somali jet and correlations with summer rainfall in China. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads.Journal of Coastal Research, Special Issue No. 99, pp. 31-40. Coconut Creek (Florida), ISSN 0749-0208.

The establishment time index and eastern boundary position index were set up to describe the characteristics of the Somali jet (SMJ) activity, and relationships between the indices and Chinese summer rainfall were also explored used NCEP/NCAR reanalysis data. The Somali jet established in the 24th pentad and retreated in the 62nd pentad, and the eastern boundary position was maintained at 45-65°E. The establishment time sequence was characterized by an earlier tendency, and the eastern boundary position sequence exhibited the strong interannual variability. The intensity, establishment time and eastern boundary position indices were verified to describe the characteristics of the Somali jet activity from different angle and flank. The connection between these three indices and the Asian monsoon index seemed to be quite different. Both the intensity and establishment time were positively correlated with the third and second pattern of China summer rainfall, respectively. The eastern boundary position was negatively related to the first pattern of the summer rainfall in China. Additionally, the impact of the establishment time and eastern boundary position of the Somali jet on China summer precipitation were closely related to the Lake Baikal high and the western Pacific subtropical high as well as the equator warm wet airflow.

Zhang, R.; Yang, S.; Wang, Y., and Yin, Y., 2020. Regional ocean current field construction based on an empirical Bayesian kriging algorithm using multiple underwater gliders. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 41-47. Coconut Creek (Florida), ISSN 0749-0208.

The ocean current is an important component of the complex marine environment. Ocean current forecasting data mainly come from computational simulation, which merges satellite remote sensing data and in situ data measured from marine vehicles. Having a deep understanding of ocean currents is essential for ocean observation and path guidance of ships or other marine vehicles. In this paper, the regional depth-averaged flow is deduced according to the motion characteristics of underwater glider. Through virtual mooring observations of three underwater gliders in the northern South China Sea, sea trial data from June 25^th to July 11^th 2019 are obtained. After denoising and filtering, the depth-averaged flow data are used to construct the depth-averaged flow field with the spatial interpolation method. Then, the inverse distance weight (IDW) method, radial basis interpolation (RBI) method and empirical Bayesian kriging (EBK) method are adopted to construct the depth-averaged flow field. Thus, the results from the three constructed methods are compared with the real flow field data, demonstrating that the EBK method shows a better balance in interpolation accuracy and performance than the other methods. More specifically, for the EBK method, the mean error value is 0.00441, and the root-mean-square of error is 0.14977, which are lower than those of the other two methods. Furthermore, the evaluation results thoroughly verify the validity of the EBK method and prove that an underwater glider is a useful tool for observing ocean currents.

Xu, S.; He, X., and Li, X., 2020. An improved method on U-net near coastal areas. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads.Journal of Coastal Research, Special Issue No. 99, pp. 48-53. Coconut Creek (Florida), ISSN 0749-0208.

Object recognition near coastal area is the hotspot in recent years. However, the problems such as lack of precision, low efficiency and low fault tolerance of these traditional methods are an obstacle of hyperspectral image. This paper proposes an improved method on U-net deep learning model to identify these categories. Firstly, data enhancement processing is implemented on mini-batch×mini-batch×3 patches of cropped randomly images to improve the generalization ability of training network. Secondly, an improved U-net deep learning model is developed to extract the feature information automatically. Next, the improved model can be trained repeatedly by the cross-entropy loss function and INadam optimization algorithm to seek better results. Finally, obtained optimal model is used to extract the object information accurately. Simulation and experimental results show that the proposed method has better detection performance, higher training accuracy with lower loss fluctuation than state-of-the-art methods.

Wang, K.; Feng, X.; Zhang, H.; Li, Z.; Fan, G., and Yu, Z., 2020. Climate change characteristics and adaptation in the offshore East China Sea from 1979 to 2017. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 54-59. Coconut Creek (Florida), ISSN 0749-0208.

The climate change characteristics and adaptation abilities of the offshore East China Sea area are very important issues against the backdrop of the Maritime and Polar Silk Roads strategy. Based on meteorological observation data and reanalysis data, the spatial distribution and temporal variation characteristics of sea surface temperature (SST), sea surface salinity (SSS) and winds in the offshore East China Sea area were analyzed. From 1979 to 2017, the offshore average SST increased by 0.18°C/10 a as a whole. The average SSS showed an interdecadal cycle from 1980 to 2017 with a peak in 2005 (34.54 g/kg) and a trough in 1995 (34.26 g/kg). The lowest offshore SSS was 34.0 g/kg in the southern Korean Peninsula and the southern Taiwan Strait, while the highest offshore SSS was 34.8 g/kg in the low-latitude Pacific offshore area. The climatic characteristics annual accumulated gale days, annual local maximum wind speed, absolute maximum wind speed and average wind speed from 1971 to 2017 were analyzed, which showed that the influence of gales on Zhejiang was more serious than their influence on the other provinces in East China. In addition, decision-making strategies for climate change adaptation are discussed to provide a scientific reference for controlling the risks of climate change to the East China coastal zone and the Maritime Silk Road strategy.

Hu, J.; Li, Z., and Zhang, Y., 2020. Numerical study on initial laying process of submarine cables for wave energy booster station in real sea states. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 60-66. Coconut Creek (Florida), ISSN 0749-0208.

Based on real sea conditions of the national wave energy demonstration site in Wanshan sea area of Zhuhai City, China, some numerical experiments are carried out to simulate the submarine cables initial laying process of the Wave Energy Booster Station in this demonstration site. The numerical model is established with the Orcaflex software employed. The motion response of laying ship and the hydrodynamic characteristics of submarine cables are simulated here under three sea conditions, i.e. usual waves, waves with current combined and possible extreme waves. Research results show that the tension and curvature of the cable are large under the condition for wave direction perpendicular to the ship axial direction, which is a relatively bad sea condition. The current also has some influences on the submarine cable laying, and the maximum effective tension of cable produced by the combined wave-current action is 1.35 times that of cable with the wave action alone. When extreme waves appear, pitch, heave and heave acceleration of the laying ship and tension of the cable ends increases obviously. And the variation of effective tension at both cable ends can reach 1.67 times that of cable ends under usual random waves. The numerical model and research results in this paper can provide some guidance for the research and construction of the cable laying of booster stations for marine renewable energy power plants in real sea conditions.

Gong, J.; Jia, X.; Zhuge, W.; Guo, W., and Lee, D., 2020. Assessment of a parametric tropical cyclone model for typhoon wind modeling in the Yellow Sea. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads.Journal of Coastal Research, Special Issue No. 99, pp. 67-73. Coconut Creek (Florida), ISSN 0749-0208.

Tropical cyclones (TCs) pose one of the most dangerous threats to the lives and properties in coastal areas. Various parametric models have been developed to simulate TC wind fields and are critical for modeling and assessing the risk of storm surges and coastal inundations. The Holland parametric wind model (Holland, 1980) has been widely applied in the modeling of TC wind fields; however, systematic assessments of its performance in simulating typhoon wind fields in the Yellow Sea, where typhoons undergo extratropical transitions, are rare. Four typhoons that passed over the Yellow Sea were selected, and the wind measurements at 12 gauges and buoys along the Korean coast were used for model validation and assessment. The results showed that the Holland model is capable of producing satisfactory wind results for typhoons passing over the Yellow Sea given accurate TC parameters. The results also highlighted that the model-predicted typhoon winds were highly sensitive to R_max and that the shape coefficient B thus should be chosen carefully when the Holland model wind fields are used for TC-induced storm surge or wave modeling.

Li, J.; Fu, Y.; Tang, Q.; Feng, Y.; Zhou, X., and Liu, X., 2020. Accuracy assessment of a seamless depth datum model established on the basis of the global ocean tide model. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 74-78. Coconut Creek (Florida), ISSN 0749-0208.

Construction of a seamless depth datum model is important for the unification of the height datum of the land and chart datum of the ocean. Modern depth datum model is established based on the tide model, and its accuracy depends mainly on the accuracy of the tide model itself. In this paper, the global tide model FES2014 was adopted to construct a lowest normal low water (LNLW) and lowest astronomical tide (LAT) datum model, the resolution was 1/16° × 1/16° in Chinese Sea area (15 °N–42 °N, 105°E–128 °E). Statistical analysis was performed on the distribution of the datum values of LNLW and LAT in the study area, results ranged from -22.72 to -446.74 cm and -23.17 to -448.00 cm, respectively. The difference values between them were in the range of -29.92 to 36.45 cm. Furthermore, 94.0% of the differences were within ±10 cm and 66.4% were positive values, indicating that the surface of LNLW was above the LAT in the study area. Comparison with datum values calculated from 16 tide gauge stations with long-term observations showed that the standard deviation were 13.02 cm and 11.68 cm for LNLW and LAT, respectively.

Hao, X.; Zhang, X.; He, J., and Yan, X., 2020. An improved underwater acoustic positioning algorithm based on dithering technology. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads.Journal of Coastal Research, Special Issue No. 99, pp. 79-84. Coconut Creek (Florida), ISSN 0749-0208.

The sound source localization based on the microphone array to simulate the human ear has a wide application prospect. In the case of underwater environment of strong noise and vibration, the sound source localization technology based on the traditional generalized cross-correlation algorithm of the microphone array is difficult to achieve high precision. In order to improve the accuracy of underwater positioning, an improved GCC-IWF algorithm based on dithering technology is proposed in this paper. The noise removal ability of the algorithm is simulated by MATLAB, and the simulation results show that the GCC-IWF algorithm based on dithering technology has a good correlation sharp peak. Under the same positioning accuracy, the signal-to-noise ratio can be reduced by 5dB. In the case of signal to noise ratio, the positioning accuracy of the sound source can be increased by 49%. Finally, the actual verification is carried out through the five-element cross microphone array, which verifies the effectiveness of the algorithm and achieves the expected effect.

Ai, B.; Xia, Y.; Li, Z.; Yang, F., and Ji, M., 2020. Three-dimensional dynamic visualization of coastal zones for sea-land integration. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 85-91. Coconut Creek (Florida), ISSN 0749-0208.

The three-dimensional visualization of coastal zones for sea-land integration faces difficulties such as multisource terrain data fusion, tidal dynamic changes, and sea surface simulation. This paper proposes a method to convert the depth reference of water depth data into the 1985 national elevation benchmarks, which integrates multisource sea-land terrain data by vertical datums, converts rectangular coordinates and establishes a digital elevation model for sea-land terrain integration. Based on the dynamic characteristics of the sea surface with tides, this paper calculates the tidal level of the nearshore tide station using numerical tidal harmonic analysis and a prediction model. The dynamic sea surface height field away from the mainland is established by inverse distance weighted spatial interpolation. The paper simulates the sea surface by Phillips spectrum analysis and fast Fourier transform and achieves dynamic effects for the sea surface by concave-convex mapping and wave mapping, enhancing the reality of dynamic sea surface expression. In addition, this paper designs and develops the Coastal Zone Terrain Three-Dimensional Dynamic Visualization System, which realizes functions such as sea-land integrated three-dimensional terrain roaming, sea surface simulation visualization and the automatic generation of instantaneous coastlines at any time.

Li, H.; Wang, Y.; Chang, H.; Xiao, W.; Yu, Z., and Guo, S., 2020. Acoustic impedance and its application in seismo-acoustic landmines detection models. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads.Journal of Coastal Research, Special Issue No. 99, pp. 92-98. Coconut Creek (Florida), ISSN 0749-0208.

Acoustic-to-seismic (A/S) coupling method has been demonstrated to be an effective and accurate technique for the detection of non-metallic landmines buried in soils. However, the complexity and diversity of landed zones in different countries or areas make it difficult to design a practical landmine detection system used in different landed zones. Buried non-metallic mines induce very complex vibration characteristics, which depends on interaction between the soil and the mines as well as on their respective properties. Acoustic impedance is a simple and efficient parameter that can be used to describe A/S coupling and buried non-metallic mines impact on the coupling efficiency. In this paper, theoretical studies will be overviewed including the linear resonance, the non-linear resonance and the anti-resonance models. Relationships will be also discussed between the ground surface acoustic impedance and the buried mines. Finally, frequency response transfer function is proposed to study and summarize dynamics of the soil-mine resonance system.

Zhang, J.; Li, C.; Shu, X., and Chen, W., 2020. Research on waterway wireless propagation characteristics based on channel measurement: Ship moving across vs. moving through. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 99-104. Coconut Creek (Florida), ISSN 0749-0208.

The safety of ship traffic in inland waterway is crucial and relies on wireless communications. Yet previous wireless communication studies have focused on coastal and vehicles on land. This manuscript present measurement and analyses ship-to-boat pontoon campaign investigating the wireless propagation channel at 5.9 GHz in inland waterway. Research explore in particular the effect of ship motion transverse to and parallel to a fixed boat pontoon. And study analyze the effects of line-of-sight and non-line-of-sight conditions, which typify “inland intelligent waterway” scenarios. Beside different motion conditions like moving transverse to and parallel to boat pontoon, research also explore channel metrics such as path loss, small-scale fading, and correlations of signal with ship motion. The research results show that the relative motion of ships in inland intelligent waterway communication cannot be ignored.

Zhao, J.; Yan, Z.; Chen, X.; Pang, L., and Lu, Y., 2020. The calculation of extreme wind speed based on Bayesian method. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 105–114. Coconut Creek (Florida), ISSN 0749-0208.

Wind speed is one of the main factors to be considered in the design of offshore structures. However, due to the long period fluctuation of typhoons and climate change, the return levels of the wind speed derived using the samples of different years are considerably different, which can lead to unstable results. To solve this problem, in this study, the extreme wind speed is calculated based on the Bayesian method. In the Bayesian parameter estimation method, the parameters of the distribution are considered as random variables, and thus, the priori information can be fully exploited for parameter estimations. The data utilized in this study are deriveds from the best data set of the northwest Pacific tropical cyclone. A typical point in the South China Sea is selected as the calculation point. The samples are determined are determined using a parametric wind model developed by Cardone. Considering the influence of the difference samples of in different time instants, the samples are divided into early and recent samples, which are used as priori and posteriori information, respectively. The normal distribution is used as the priori distribution, and the estimator of the parameters is the expectation of the posteriori distribution, which is calculated using the Markov Chain Monte Carlo (MCMC) algorithm. By comparing the results pertaining to between Bayesian and maximum likelihood method, it can be observed that the former is more stable and reliable.

Li, J.; Sun, L.; Yang, Y.; Yan, H., and Liu, S., 2020. Upper ocean responses to binary typhoons in the nearshore and offshore areas of northern South China Sea: A comparison study. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 115–125. Coconut Creek (Florida), ISSN 0749-0208.

Changes in sea surface temperature (SST) and sea surface salinity (SSS) in response to the binary typhoons Sarika and Haima (2016) in the offshore and nearshore areas along the Guangdong Province Coast (GPC) and Hainan Island Coast (HIC) in the northern South China Sea are comprehensively investigated using multi-satellite observations and ocean reanalysis data. The results show that the maximum SST cooling was 2.5°C (average 1.5°C) and 6°C (average 2.5°C) after the passage of typhoon Sarika in the HIC nearshore and offshore, respectively. In contrast, the average SST cooling was 1°C in the GPC offshore and very marginal in the GPC nearshore after the passage of typhoon Haima. For SSS, typhoon Sarika induced changes of 0.1 psu and 0.35 psu in the HIC nearshore and offshore, respectively, while typhoon Haima caused changes of -0.1 psu and 0.3 psu in the GPC nearshore and offshore, respectively. The responses of both SST and SSS are similar in the offshores of both the GPC and the HIC. However, they are quite different in the nearshores of the GPC and the HIC. It is found that the nearshore responses to typhoon are quite different depending on the coast conditions: river discharge and advection of coastal current. In the GPC nearshore, the river discharge due to typhoon can lead to larger SSS decrease than that in the HIC nearshore. Besides, the advection of coastal high SSS water from the GPC to the HIC along coast made SSS decrease in the GPC but increase in the HIC. As a result, the SST and SSS responses are easily to be influenced, while they could exist much longer in the offshores.

Sun, W.; Shao, Z.; Liang, B., and Gao, H., 2020. Analysis of wave fields under tropical cyclones in the South China Sea. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 126–130. Coconut Creek (Florida), ISSN 0749-0208.

The study of wave fields under extreme weather conditions, such as tropical cyclones, is becoming increasingly important for ocean engineering. In this work, wave simulation under a tropical cyclone is carried out in the South China Sea (SCS). The SWAN model is driven by the blended wind field. In this model, the wind input term and whitecapping dissipation term are specifically studied to obtain a reliable model result. During tropical cyclones Doksuri and Kai-tak in 2012, the waves are simulated in the SCS, and the simulated significant wave heights are validated by the measured data at buoys B1, B2 and B3. The validation results show that the simulated values match the measured values well. By the simulated significant wave heights, the wave field is analyzed during the tropical cyclone. In the mean and maximal conditions, the wave fields are studied with the tropical cyclone track. The maximal significant wave heights at the buoy locations are associated with the corresponding spatial distribution of significant wave heights in the SCS, which can reflect the effect of the tropical cyclone on the wave at a specified point.

Li, B.; Chen, W.; Liu, J.; Li, J.; Wang, S., and Xing, H., 2020. Construction and application of nearshore hydrodynamic monitoring system for uninhabited islands. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 131–136. Coconut Creek (Florida), ISSN 0749-0208.

Real-time nearshore hydrodynamic information is important for the coastal engineering, resource development and environmental monitoring of remote undeveloped islands. This paper presents a nearshore hydrodynamic monitoring system applicable for uninhabited islands facing harsh natural conditions and unpredictable risks. The system integrates different functional units, such as an underwater observation unit, an island-based relay unit and a data receiving unit. The system is powered by solar energy. It measures and sends back hydrodynamic data in real-time. The system was deployed at the northeast shore of Dongluo Island in the northwestern South China Sea and has been in operation for more than nine months. The system has run stably with a high data receiving rate of 98%. Moreover, the obtained data are consistent with the basic hydrological characteristics of the region, which confirms the ability of the system to acquire hydrological data. The results show that the system has good potential in applications of future constructions and developments in remote islands.

Wang, Y.; Luo, C.; Yang, S.; Ma, W.; Niu, W., and Liu, H., 2020. Modified thermal lag correction of CTD data from underwater gliders. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 137–143. Coconut Creek (Florida), ISSN 0749-0208.

A real-time data quality control process and a modified thermal lag correction procedure are proposed in this paper. The data quality control process is designed for CTD sensors (conductivity, temperature and depth) installed on Petrel gliders. A modified thermal lag correction methodology, based on the hypothesis that CTD data sampled closer in time and space would be more similar, is also put forward in this paper. Therefore, in this method, each down profile and each up profile is split into two segments. The segments with closer temporal and spatial relationships are used to calibrate each other, which is the first time the limitation of using only one profile to correct the thermal lag effect in a glider-carried CTD has been overcome. Moreover, the data obtained in sea trials with a Petrel glider and a reference SBE 911 plus CTD are used to examine the modified method and the newly designed data quality control process. The excellent alignment with the reference data and significant calibrations indicate that the CTD data were successfully corrected.

Yuan, J. and Liu, Y., 2020. Evaluation of tourism efficiency in the coastal areas of China in the context of the happiness industry. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 144–150. Coconut Creek (Florida), ISSN 0749-0208.

As China's tourism industry enters a new era of the happiness industry, tourism livelihood efficiency has become an important basis for testing the development effect of tourism. Based on the perspective of the happiness industry, this paper takes Guangdong Province as an example to evaluate tourism livelihood efficiency in coastal areas. The DEA model and Malmquist model are used to measure tourism livelihood efficiency with the spatial and temporal evolution of 21 cities in Guangdong Province from 2010 to 2017. The results show that the tourism livelihood efficiency of Guangdong Province has reached a good state overall and that tourism development has entered a stage of intensive growth. The evolution of regional tourism efficiency has obvious regional characteristics, with the regional tourism efficiency of the Pearl River Delta being larger than that of eastern Guangdong, the mountainous area and western Guangdong. Based on the status of tourism livelihood efficiency over the years, cities are divided into four types: the strong type, growth type, steady type and stagnation type. Corresponding strategies are proposed based on the characteristics of different regional types.

Liu, X.; Wang, Q.; Liu, C.; He, C.; Wang, S.; Hou, P.; Zhu, X., and Wu, Z., 2020. Wind field reconstruction and analysis of super typhoon Mangkhut (1822). In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 151–157. Coconut Creek (Florida), ISSN 0749-0208.

This paper reports the research conducted on wind field reconstruction for super typhoon Mangkhut (1822), which occurred in 2018/09. The performances of two common methods, i.e., the parametric typhoon model and CCMP reanalysis data, for the hindcasting of typhoon wind fields are examined, and an improved method is then proposed, which avoids the radius effect in the traditional superposition method. The proposed method relies on a combination of CCMP reanalysis data and parametric wind field results and directly evaluates the maximum wind speed. Moreover, the central difference method is employed to smooth the transitional area. This method notably improves the hindcasting of typhoon wind fields, and its capability is calibrated by field data from buoy platforms in the Pearl River Estuary. Finally, certain typical parameters, such as the wind field, wind speed and wind stress curl, during super typhoon Mangkhut are determined and analyzed.

Guo, S.; Li, H.; Wu, B.; Zhou, J.; Su, C., and Guan, C., 2020. Combined optimization of neural network fault diagnosis methods for analog circuits on ships. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 158–164. Coconut Creek (Florida), ISSN 0749-0208.

With increasing automation, electronic systems are becoming more widely used on ships. When electronic systems fail, it will greatly affect the safety of ship operation or even cause catastrophic accidents. Therefore, it is necessary to diagnose a circuit fault in order to repair the equipment in time. In electronic systems, more than 80% of the faults come from analog circuits. To obtain better fault diagnosis accuracy for analog circuits, neural network classification algorithms are often combined with optimization steps, such as circuit feature collection, feature engineering, regularization and so on, significantly affecting the accuracy of the classification algorithm, such as circuit feature collection, feature engineering, and regularization. However, the accuracy of analog circuit fault diagnosis is often not high in practical applications because of the tolerance of analog circuit components and other factors. To solve the above problems, this paper proposes a neural network combination optimization method based on hypothesis testing and applies it this method to the fault diagnosis of analog circuits on ships. This method uses hypothesis testing to combine and sort the optimization methods of each step in a neural network classification algorithm to obtain a model ranking based on the accuracy rate with mathematical statistics rules, thereby obtaining the optimal combination method. Finally, the validity of the method is verified by experiments.

Wang, X.; Li, D.; Li, Y., and Wang, H., 2020. A study on the evaluation method of layout effectiveness of wave energy converter array - An example from point absorber wave energy converter. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 165–173. Coconut Creek (Florida), ISSN0749-0208.

A wave energy converter array can be formed by distributing multiple wave energy converters in a same sea area. This technology can meet the increased demand of total installed power by arranging more converters in case of a fixed installed power of a single converter, with vast prospects of application. It is required to analyze the motion characteristics and the interactions of array converters in wave field, as well as design and formulate a reasonable array layout plan to improve the energy capture efficiency of the array. Based on the existing evaluation indexes for wave energy converter array layout effectiveness, this paper proposes to use the array energy gain coefficient as a new evaluation index. By exemplifying a cylindrical point absorber converter, this paper starts from the theoretical analysis of array converter movement, studies the calculation method for the new index, and quantitatively evaluates the overall energy capture effectiveness of the wave energy converter array within a given interval of wave conditions. This paper applies the new index to calculate, analyze and evaluate the effectiveness of array layout in the example, and the theoretical method and relevant rules for the layout of wave energy converter array are summarized according to the calculated data. The new index enriches the evaluation method for the layout effectiveness of wave energy converter array, and can be applied to the design of array and related theoretical research.

Fan, F.; Zhu, Z.; Lu, Y.; Yang, B., and Zhao, C., 2020. Numerical investigation of the effect of suspended load on the morphology of a beach under the action of tsunamis. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 174–180. Coconut Creek (Florida), ISSN 0749-0208.

To study the morphology of a beach under the action of a tsunami, a beach evolution numerical model based on the open-source calculated fluid dynamics (CFD) code OpenFOAM is constructed. The bed load and suspended load models are fully coupled with the hydrodynamics model in the beach evolution model, and the moving mesh method is used to capture the change in bed morphology. Then, a laboratory experiment on the scour induced by solitary waves is adopted to validate the constructed numerical model, and the surface elevation, bed shear stress and bed profile of the model fit very well with the experimental observations. Finally, the effect of the suspended load on the evolution of beach morphology and the process of beach evolution under the action of a solitary wave are studied with a numerical model. The study results show that the beach evolution mainly occurred at the time the solitary wave ran down and that the suspended load played a major role in the beach evolution, contributing approximately 85% to the scour profile.

Liu, C.; Liang, Y.; Liu, X., and Zhang, X., 2020. Numerical investigation of irregular waves and induced currents in the Modaomen, Pearl River Estuary. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 181–188. Coconut Creek (Florida), ISSN 0749-0208.

The Modaomen Estuary has evolved from a runoff-dominated to runoff-and-wave-dominated estuary; thus, waves have become an important dynamic force. However, the nearshore irregular waves and wave-induced currents in the Modaomen Estuary have not been well studied. For the first time, a coupled wave-current model was developed in which the wave properties were calculated by the hyperbolic mild-slope equation, and the flow motion was simulated using a depth-averaged shallow water equation that was modified by introducing wave radiation stresses. The computational capability of this model was well calibrated by laboratory data from published references. Subsequently, the validated model was employed to analyze the wave height distributions, flow field characteristics and residual current under irregular waves, as well as to determine the differences in the above results with the scenarios under pure wave or pure tide. The results showed that the irregular wave heights reach 0.75 m near the sand bar and its surrounding shoals, reach 0.7 m in the main channel, and are approximately 0.3 m in the wave shadow area behind the Sisha shoal, which is more powerful than that under regular waves. The effect of waves on the current at the maximum ebb tide is greater than that at the maximum flood tide, especially in the estuarine shoal zone. Compared with the current velocity under pure tide, the residual current velocity is larger, and the vortex scale and the sediment transport route are all prominent under the combined wave and tide.

Liu, J.; Zhang, C., and Shu, D., 2020. A new strategy for GPS triple-frequency long-baseline ambiguity resolution. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 189–196. Coconut Creek (Florida), ISSN 0749-0208.

Over the last decades, several approaches for GPS phase ambiguity resolution haven been proposed and analysed. For triple-frequency long-baseline relative positioning, the most commonly used approach is LAMBDA, which can resolve all ambiguities in one step. However, the main limitation of LAMBDA is that it is difficult to validate the ambiguity results when it is in high dimension. To address this issue, in this research, a new strategy based on the sequential least squares estimation is proposed and the characteristics of this strategy are analysed. The performance of the new strategy and the commonly used one were assessed and compared using simulated triple-frequency GPS observations. Due to the fact that the two key quantities for the validation of GPS ambiguity are the ratio test and success rate, these two types of values were used to analyse the reliability of the integer ambiguity resolution in this study. The numerical results suggest that the success rates of the two approaches have no significant difference. However, the ratio value of the new approach can be significantly decreased in the case where the ambiguities are correctly fixed. This can smartly improve the reliability of long-baseline relative positioning, and then improve the operational efficiency of coastal surveying.

Xu, M.; Cui, B.; Lan, S.; Li, D.; Wang, Y., and Jiang, B., 2020. Exploring dynamic change of the tidal flat aquaculture area in the Shandong Peninsula (China) using multitemporal Landsat imagery (1990–2015). In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 197–202. Coconut Creek (Florida), ISSN 0749-0208.

In recent decades, the global distribution of tidal flat aquaculture has undergone great changes under climate change and economic development. In this study, the Shandong Peninsula in northeastern China was selected as the study area. Tidal flat aquaculture was extracted from multitemporal remote sensing data (TM and ETM+) between 1990 and 2015. The dynamic change of tidal flat aquaculture area and the reasons for spatial distribution variations were then analyzed. The results showed that: tidal flat aquaculture area in the Shandong Peninsula increased steadily by 1477.85 km² (from 638.50 km² to 2116.35 km²) between 1990 and 2015 at a rate of 59.70 km²•yr^-1. The tidal flat aquaculture area in the Yellow River Delta accounted for 27.06% of the tidal flat aquaculture area in the Shandong Peninsula in 1990, increasing to 72.27% in 2015. Due to the influence of sea reclamation, tourism development, and other anthropogenic activities, the aquaculture area in Jiaozhou Bay gradually decreased from 14.45% in 1990 to 2.42% in 2015 shifting the geometric center of gravity for aquaculture on the peninsula from the southeast to the northwest. The spatial distribution was mainly influenced by coastal geology, landforms, and geomorphology. The Yellow River Delta was a key area for tidal flat aquaculture development in the Shandong Peninsula. Effective planning and management are critical to promoting sustainable development of tidal flat aquaculture.

Sui, Y.; Shi, H.; You, Z.; Qiao, S., and Sun, J., 2020. Long-term trend and change point analysis on runoff and sediment flux into the sea from the Yellow River during the period of 1950-2018. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 203–207. Coconut Creek (Florida), ISSN 0749-0208.

Based on the observed runoff and sediment data from Lijin hydrological station during the period of 1950–2018, this paper addressed the long-term change characteristics of runoff and sediment fluxes into the sea from the Yellow River. The Mann-Kendall test was adopt to estimate the long-term trends in the runoff and sediment time series. The Mann-Whitney-Pettitt (MWP) test were used to determine the change points of runoff and sediment time series. It could be concluded that the annual runoff and the sediment fluxes decreased significantly at the rates of –6.17×10⁹ m³/a and –0.213×10⁹ t/a, respectively. The changes during the flood season were more dramatic than in the dry season, especially for the sediment flux. Different significant change points are detected in the runoff and sediment time series. The changing point for the runoff occurred in 1968, 1985, and 2002 and those of sediment flux in 1968, 1985, and 1996, respectively. The negative long-term change trend and the occurrence of change points are highly associated to natural variation and human activities in the Yellow River basin. The occurrence time of some change points accords even with man-made events.

Yu, X.; Li, B.; Wang, T.; Liu, Y.; Zhan, C., and Cui, B., 2020. The horizontal and vertical distribution of nutrients and the potential eutrophication assessment in the Yellow River estuary in dry season. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 208–213. Coconut Creek (Florida), ISSN 0749-0208.

Terrigenous nutrients discharged into seawater played an important role in controlling the marine primary productivity. Study on the horizontal and vertical distribution characteristics of nutrients was essential in eutrophication and sea-air exchange study. In this paper, the nutrient concentrations and their distribution in the surface microlayer and three sub-surface layers of the Yellow River estuary were measured. The horizontal and vertical distribution characteristic of nutrients was analyzed, so did the potential eutrophication assessment and the nutrient enrichment of the surface microlayer. The results showed that nutrient concentrations decreased from the estuary to the shore horizontally. NH₄⁺-N and NO₂^--N increased vertically. NO₃^--N and PO₄³-P decreased vertically. Eutrophication occurred in the micro-layer and the sub-surfaces. The Yellow River estuary suffered an eutrophication outbreak risk. The enrichment of NH₄⁺-N, NO₃^--N and NO₂^--N was significant in April 2018, nor did PO₄^3--P.

Li, X.; Sun, J.; You, Z.; Zhang, J.; Wang, L.; Zhang, Z.; Li, Q., and Xie, T., 2020. Numerical study on wave dissipation characteristics of open breakwater for erosion protection of muddy coasts. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 214–220. Coconut Creek (Florida), ISSN 0749-0208.

In the recent 60 years, accompanied by the remarkable decline of its sediment into the sea, The Yellow River Delta has been experiencing severe erosion. Based on this, this paper attempts to propose a new type of open breakwater with good wave-dissipating performance, which can be used to protect the Yellow River Delta from extensive erosion (Wang et al., 2016a). In this study, a numerical model for the interactions between waves and plate-type open breakwaters are constructed using the finite volume method, and their correctness is validated by experimental results. The numerical results show that, by comprehensively considering K_t, K_r, the double arc-shaped plate-type (DAPT) open breakwater is found to exhibit the highest wave-dissipating performance among the double flat plate-type (DFPT), single arc-shaped plate-type (SAPT) open breakwater and double arc-shaped plate-type (DAPT) open breakwater.

Zhan, C.; Dong, C.; Wang, T.; Li, B.; Liu, Y., and Yu, X., 2020. Remotely sensed retrieval of extreme high surface suspended sediment concentration in the Yellow River estuary from 1996 to 2017. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 221–226. Coconut Creek (Florida), ISSN 0749-0208.

Remotely sensed retrieval provides an alternative for surface suspended sediment concentration (SSC) monitoring with its advantages of wide area survey and real-time monitoring. In situ measurements were precise, however, they were inherently accidental, both in time and space. Extreme high SSC in shoal remains hard to be mapped. Moreover, in situ measurements were of a normal distribution but discontinuous. This paper tried to retrieval SSC in the Yellow River estuary, especially in the Yellow River Mouth characterized by extreme high SSC. The inherent optical property of SSC was precisely obtained based on a control experiment. A calibration model was then developed based on a band ratio (R(820)/R(490)), and was used in SSC mapping in the Yellow River estuary. The suspended sediment generally distributed in a strip pattern parallel to the coast in the northern part of the Yellow River Delta. SSC was high near the current Yellow River estuary. SSC contours in the southwest of Laizhou Bay were elliptical, with the highest SSC in the elliptical center and the northwest-southeast trend in the long axis.

Dong, C.; Zhan, C.; Lin, Z.; Yi, F.; Zhu, J.; Shi, H., and Wang, Q., 2020. Numerical study on the difference in geomorphic dynamics between current and abandoned estuarine coasts of the Yellow River Delta. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 227–235. Coconut Creek (Florida), ISSN 0749-0208.

Waves are the important driving factors that shape the estuary and coastal landscape of the Yellow River Delta (YRD). Changes in wave dynamics can affect the evolution of landforms, causing erosion or accumulation between coastal areas. In this study, the variation in suspended sediment concentration in the Yellow River under different seawater conditions is simulated based on the Delft3D. Quantitative study of the difference in ocean dynamics between the current estuary and abandoned estuary of the Qingshuigou channel in the YRD is conducted based on the difference in suspended sediment concentrations (Di), which revealed the shaping effect of tidal currents and waves in the evolution of the YRD during different periods. The results show that under multiple sediment and inflow conditions during different periods, the Di-value of the abandoned estuary and its nearshore area is generally high and positive, which indicates that the coastal dynamics of the abandoned estuary are dominated by waves. However, the distribution of Di-value in the current estuary is generally negative, indicating that the coastal dynamics of the current estuary are dominated by tidal currents. In the abandoned estuary, waves restarted and resuspended the deposited silt and clay, and they were moved away from the coast by tidal current, thus causing coastal erosion. However, due to the rapid input of a large amount of sediment in the current estuary, the tidal current could not move all of it; deposition occurred in the estuary and along both sides of the coast, extending the estuary into the sea. By comparison, the waves have a strong geomorphological effect on the abandoned estuary but are relatively weak in the current estuary. These findings have important theoretical value for understanding the evolutionary mechanism of dynamic geomorphology in the YRD.

Liu, Y.; Ji, L.; Zou, S.; Wu, Y., and Zhang, Y., 2020. Onboard fast retrieving of significant wave height from leading edge of altimeter waveforms. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 236–241. Coconut Creek (Florida), ISSN 0749-0208.

Satellite radar altimetry provides a unique perspective on ocean dynamic environment observation by measuring global sea surface height (SSH), significant wave height (SWH) and wind speed. As an important sea surface parameter, SWH is of significance in marine disaster prevention and mitigation, climate change studies, ocean energy survey, etc., and can be estimated by using an altimetry waveform retracking algorithm through satellite ground system. Given that ground processing could not respond to the disastrous ocean waves rapidly, it is inevitable to develop an onboard fast retrieval model to meet emergency demands. In this study, we proposed a linear model based on making use of leading edges of waveforms. The results show that root mean squared errors (RMSE) are from 0.165 m to 0.187 m between linear model and maximum likelihood retracker. Additionally, the time efficiency of the linear model is approximate 6000 times as fast as the on-ground maximum likelihood estimation procedure. Due to high accuracy, robustness and efficiency, the linear model provides a promising and practical solution for onboard quasi real-time wave height estimation.

Wu, Y.; Li, Q.; Liu, Y.; Xu, Y.; Wang, X., and Li, W., 2020. Study on dispersion of marine pollutants from islands in the southern section of Bohai Strait. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 242–249. Coconut Creek (Florida), ISSN 0749-0208.

The three-dimensional hydrodynamic model was established based on FVCOM, coupled with the Lagrangian particle tracking module to study the water exchange ability of 15 drain outlets of North and South Changshan Island. Meanwhile, the 30-day influence distance was introduced to quantify the water exchange ability. The drain outlets with a strong water exchange capacity are mainly located in the east of North and South Changshan Islands and the southwest corner of South Changshan Island, and those with a weak water exchange capacity are mainly located in the northwest corner of North Changshan Island, joint of South Changshan Island and the tombolo dyke and inside the Changdao Harbor. The 30-day influence range of the 15 drain outlets of North and South Changshan Islands is significantly affected by monsoon. East Asian monsoon accelerates the dispersion of the pollutants in the south sea areas of Bohai Strait.

Wang, Q.; Zhan, Q.; Wang, L.; Zhan, C.; Cui, B.; Liu, X.; Li, X.; Wang, X.; Yu, X., and Zhang, J., 2020. Morphodynamic evolution of the Huaihe River estuary during the Huanghe River invasion from 1128 AD to 1855 AD. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 250–256. Coconut Creek (Florida), ISSN 0749-0208.

Based on historical records, we investigated the dynamic conditions, geomorphological characteristics, and evolution mechanisms of the Huaihe River estuary during the period of Yellow River invasion. The results showed that the runoff and sediment discharge of the Huaihe River increased owing to a large quantity of sediment-laden runoff into the Yellow River from 1128 to 1855 CE. However, the sediment discharge in different periods is also affected by repeated siltation along the lower reaches of the Yellow River. Huaihe estuary is a tidal estuary with moderate intensity. Its reciprocating tidal current and coastal current system are favorable to the discharge of sediment into the sea. The shape of the Huaihe estuary is narrow on the upper side and wide on the lower side. Large-scale sandbar and underwater delta were developed in the inside and outside of the estuary, respectively. The channel of the estuary has a typical curved river type, and the width of the estuary has had an increasing trend since the 18th century. The evolution mechanism of the Huaihe estuary is that the tidal current limit continuously moves downstream, and the estuary continuously extends to the sea. In addition, the downstream movement distance of the tidal current limit is much longer than that of the outward extension of the estuary during the same period, resulting in a significant shortening of the estuary section. To satisfy the energy demand by runoff and tidal current, the river type of the estuary section becomes meandering and the entrance is widened. The ancient Huaihe River estuary and the modern Yellow River estuary have different dynamic geomorphological characteristics and evolution mechanisms, which cannot be simply analogized.

Liu, X.; Xu, Y., and Song, J., 2020. Geomorphologic characteristics of sandspit from the Yellow River estuary: Impact on land cover classification. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 257–262. Coconut Creek (Florida), ISSN 0749-0208.

It is of great importance to study the response of land cover classification to micro-geomorphic type, which is an important non-zonal environmental factor. In this study, digital elevation modeling and two pairs of synthetic aperture radar data captured by Landsat8 OLI in 2018 and Landsat5 TM in 2010 were used to interpret the relationship between the land cover classification and geomorphological type for sandspit from the Yellow River estuary, China. The results showed that water accounted for the largest proportion of the total study area (> 40%), followed by Tamarix–Suaeda (18.59%), naked tidal-flat (13.25%), Tamarix–Phragmites australis (9.70%), Suaeda (5.35%), Phragmites australis (4.34%), Spartina alterniflora (4.28%), and scattered manmade objects (1.74%). The vegetation communities of the sandspit in the Yellow River delta were affected by the dual effects of seawater and river water, and presented a concentric, annular distribution trend towards the sea. Plants such as Spartina alterniflora and Suaeda heteropera were affected by the ocean and were mostly distributed in the estuarine coastal area. Phragmites australis communities were greatly affected by the river, and were mostly distributed around the river banks and farther away from the coast.

Liang, X.; Tian, B.; Yu, P.; Ge, J.; Ning, Y., and Teng, L., 2020. Universal functions of relative humidity and temperature profiles in the South China Sea. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 263–269. Coconut Creek (Florida), ISSN 0749-0208.

Accurate prediction of evaporation duct is of great significance to improve the performance of some electronic equipment. And the universal function scheme of potential temperature and specific humidity is the key factor. To analyse the fitting effect of the universal function schemes in the South China Sea, five universal function schemes (BD74, SHEBA07, NWA, RSHMU and AT2005) were selected in this paper, and the actual data of a meteorological gradiometer from February to December 2018 were used. The results showed that: (1) under the stable condition, the standard deviation and gradient standard deviation of SHEBA07 scheme were the minimum, and AT2005 scheme were the minimum under the unstable condition, so it was suggested that SHEBA07 scheme be used under the stable condition and AT2005 scheme under the unstable condition; (2), RSHMU scheme was not suitable for the South China Sea under the unstable condition. And further study will be carried out to optimize the chosen schemes.

Ding, J.; Fei, J.; Huang, X.; Cheng, X.; He, H.; Yuan, B., and Liang, Z., 2020. Validation of evaporation duct model in coastal regions with ASIT data. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 270–281. Coconut Creek (Florida), ISSN 0749-0208.

This study aims to further verify the evaporation duct (ED) model in a coastal region as well as the need for model localization based on the measurements from the Air-Sea Interaction Tower (ASIT). The ducts tended to be more frequent and pronounced in coastal offshore winds than in onshore winds, especially in case of combining unstable conditions (100% and 9.5 m/8.7 m). They occurred with the lowest frequency (56.4%) and thickness (4.9 m/3.5 m) in stable onshore winds. The ED model with ψ functions of Edson04 (or Fairall03) and SHEBA07 delivered the best overall performance in terms of predicting local evaporation ducts. Its considerable advantages over the COARE 3.0 model and BYC model underscore the importance of localization to a given region. The overall performance of the localized ED model was encouraging but it encountered problems in case of extreme ducts under stable offshore conditions, when the available improvements to it failed. The reinforcement of a stable marine inner-boundary layer (MIBL) to a preexisting evaporation duct was considered the main reason for this and, hence, the future solution.

Wang, M. and Zhou, S., 2020. An adaptive visibility detection method based on a UAV-borne real-time panoramic camera. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 282–288. Coconut Creek (Florida), ISSN 0749-0208.

This paper presents an adaptive visibility detection method based on a UAV-borne real-time panoramic camera and designs a target board with strong absorption properties. One real-time panoramic camera and four target boards are carried by five UAVs. The horizontal visibility values in four vertical directions are measured with the brightness contrast method, and the visibility measurement errors are analysed for adaptation. The baseline length should be adjusted to the position where the minimum visibility error occurs to obtain high precision and refined atmospheric horizontal visibility results. This method uses UAV hovering in the near ground or half sky to measure the visibility, which can avoid the influence of background obstacles and uneven sky background, and even can be applied to the measurement of vertical visibility and slant visibility. Moreover, the inherent visual brightness ratio can be by improving the structure of the artificial target plate, the inherent visual brightness ratio can be increased by improving the structure of the artificial target board.

Fan, Q.; Liang, L.; Liang, F., and Sun, X., 2020. Research progress on coastline change in China. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 289–10. Coconut Creek (Florida), ISSN 0749-0208.

A coastline is an ecologically sensitive area at the land–water interface. Coastline change has an important impact on regional ecology, economy, and society. China has a long coastline and its coastal zone is among the fastest developing regions in the world. An effective understanding of Chinese coastline changes can aid sustainable development in China and surrounding areas. In this paper, we reviewed the literature of coastline changes in China through the end of 2018. Through literature analysis, the coastline change research in China can be divided into three stages: a start-up stage, an exploration period, and a developmental period. Ancient maps, traditional actual trace measurements, ancient sea level markers, remote-sensing images, and Light Detection and Ranging technology are the main data sources of coastline research. From the research content, the coastline change literature in China mainly focuses on the analysis of space–time changes and coastline driving forces. There is also limited literature on coastline change prediction, which mainly refers to the shape and location of coastline change. The next stage, the relationship between coastline change and the environment, is the focus of future research. This study provides a relatively comprehensive review of coastline changes in China that may have a certain significance for the study of these changes in China and perhaps the world. It can serve as a basis for developing scientific and reasonable policies for sustainable development in coastal zones.

Zhang, L.; Chen, W., and Liu, D., 2020. Uncertain effects of linear internal waves on convergence zone propagation in deep water. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 296–309. Coconut Creek (Florida), ISSN 0749-0208.

The use of the convergence zone effect is an important means of underwater long-range target detection. Many uncertain factors (ocean fronts, ocean eddies, etc.) can lead to uncertainties of the sound field in the convergence zone. Linear internal waves are usually produced in the deep ocean, causing fluctuations of the sound velocity which are otherwise stable. Over long distances, linear internal waves will have a great influence on the propagation of sound waves. In this paper, a model of sound velocity fluctuation caused by linear internal waves is established, and the sound velocity field within a certain depth and distance range is obtained. The transmission loss is calculated using the ray mode parabolic equation underwater sound propagation model. The Monte Carlo method is then used to simulate the uncertainty of the sound field in the generated convergence zone. The results shows that the loss of sound propagation varies greatly when an internal wave propagates through the convergence zone. The uncertainty of the sound field in different convergence zones varies, and the uncertainty of the sound field increases with convergence zone range.

Wang, X.; Gao, Y.; Wu, M.; Cai, F., and Liu, X., 2020. Freak wave prediction based on the nonlinear Schrödinger equation. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 310–318. Coconut Creek (Florida), ISSN 0749-0208.

To explore a prediction method for freak waves, a theoretical derivation is given to calculate the eigenvalue of the nonlinear Schrödinger (NLS) equation from measured wave height time history data based on the inverse scattering transform of the third-order nonlinear Schrödinger equation. The method further predicts the temporal and spatial evolution of the wave envelope. Based on the envelope prediction results, the spatiotemporal information for large wave occurrence can be obtained. The prediction results of this paper are compared with measured wave trains to verify the validity and accuracy of the method. This method gives a new technical approach for providing large-wave warnings for ships or offshore platforms, as well as for finding periods for offshore operations under large wave conditions.

Zhang, X.; Yang, B.; Sun, H., and Zhang, S., 2020. Prediction method of ocean wave spectrum based on an echo state network. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 319–323. Coconut Creek (Florida), ISSN 0749-0208.

In order to realize the prediction of ocean wave spectrum under strong nonlinear conditions, a new method combining the empirical mode decomposition (EMD) and an echo state neural network (ESN) is proposed based on ocean wave spectral data measured by shipborne X-band radar. The proposed method uses empirical mode decomposition to decompose the time series of the strongly nonlinear wavelet spectral density values so that the nonlinearity and nonstationarity of the obtained subsequence is greatly reduced compared with the original sequence, and the echo state neural network can be applied separately. By superimposing the prediction results, the predicted values of the wavelet spectral density can be obtained, and the entire ocean wave spectral information can be further combined. The results show that the method can effectively solve the problem of poor prediction effects under strong nonlinear conditions. The method can provide a certain basis for ships to obtain wave spectral information in real time and improve the practicability of shipborne wave radar systems.

Zhang, B.; Hou, J.; Huo, L., and Yao, K., 2020. Nonlinear evolution of waves based on radar wave measurements and the mNLS equation. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 324–331. Coconut Creek (Florida), ISSN 0749-0208.

Radar wave measurement is the only means of obtaining highly accurate wave information that can be carried by ship, reflecting the real-time and actual wave conditions of a ship's current navigation area. The nonlinear evolution of waves can simultaneously be effectively described by a model based on the mNLS equation. The purpose of this paper is to combine a radar wave measurement system with the mNLS equation by selecting the radar wave spectrum with application conditions of ε ≤ 0.3 and Δf/f₀ ≤ 0.2 to construct initial conditions and simulate the nonlinear evolution of waves.

Zhang, J.; Li, C., and Luo, X., 2020. Response of sea surface heat flux to the Kuroshio Extension ocean front for different background wind fields. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 332–339. Coconut Creek (Florida), ISSN 0749-0208.

The different sensible heat fluxes across KEF (Kuroshio Extension front) is the main reason for the formation of baroclinicity in lower atmosphere in northwest Pacific. In this study, several sets of numerical experiments are performed to study the similarities and differences in sensible in lower atmosphere and their causes for a given intensity and location of KEF but for different background wind fields. The results show that under the influence of winter wind field, the effects of the perturbed air–sea temperature difference and the perturbed friction velocity make obvious positive contributions to the difference in heat flux across the KEF, and play a certain role in maintaining the baroclinicity in the lower atmosphere. In contrast, advection of the air–sea temperature anomaly by the perturbed friction velocity weakens the difference in heat flux across the KEF, which can significantly weaken the baroclinicity in the lower atmosphere. Under the influence of summer wind field, the perturbed surface wind reduces the difference in heat flux across KEF, which weakens the baroclinicity. The effects of the perturbed air–sea temperature difference and the advection of the perturbed air–sea temperature anomaly by the perturbed friction velocity make positive contributions to the difference in heat flux on both sides of the KEF, which effectively maintains baroclinicity in the lower atmosphere. However, the perturbed friction velocity weakens the difference in heat flux across the KEF, which significantly weakens the baroclinicity in the lower atmosphere.

Cao, X.; Su, S.; Leng, H., and Liu, B., 2020. Global sensitivity analysis of parameters in the ENSO model based on Sobol' method. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 340–345. Coconut Creek (Florida), ISSN 0749-0208.

In this work, a global sensitivity analysis (GSA) is performed on physical parameters and initial values of a nonlinear El Niño Southern Oscillation (ENSO) model, to determine the influential parameters at different prediction times. The anomaly of sea surface temperature (SST) at each prediction time is viewed as the response quantity of interest in the sensitivity analysis by Sobol' method. And the Latin Hypercube Sampling technique is applied to all input parameters. Then, the first-order sensitivity indexes (FSI) and total sensitivity indexes (TSI) of physical parameters and initial values are calculated, respectively. The results of numerical simulations show that the proposed method is very effective and feasible for sensitivity analysis of nonlinear ENSO model. It is concluded that the sensitive parameters and relative ranking vary considerably at different prediction times. In the beginning period, initial values of the model have a great influence on the SST anomaly forecast, while for the long-term prediction, physical coefficients become main sensitive parameters, and the initial values have little effect on the output variable. In addition, the interaction between input parameters in the model increases with forecast time, which is indicated by that the difference between the TSI and FSI of each parameter becomes larger.

Zhou, J.; Wang, H., and Jiang, Z., 2020. Motion and whiplash effect of a floating crane model under wave load: Experiment. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 346–357. Coconut Creek (Florida), ISSN 0749-0208.

The top parts of tall terrestrial buildings are sometimes damaged or even destroyed during strong earthquakes because of the whiplash effect. Similarly, the marine floating high-rise multibody structure with a floating base may experience the whiplash effect even more easily, which means that marked motion of the upper part of the structure will occur accompanying minor motion of the floating base under the action of an external load induced by a wave or seismic load. The whiplash effect would threaten the operation and the survival of these offshore high-rise platform structures.

In this paper, a physical experiment involving a floating crane without a mooring system under wave loads was set up. The data and results were analyzed and discussed mainly in terms of the motion and the whiplash effect of the floating crane. The whiplash coefficient is defined to estimate the magnitude of the whiplash effect. Some factors, including wave amplitude, wave length, boom angle and boom length, are investigated to determine how they affect the motion and the whiplash effect of the floating crane. Some suggestions are given to control the whiplash effect, and those are useful for the operation of offshore floating platform structures, such as the oil-drill platform, the floating wind farm, the floating crane and some other high-rise marine floating structures.

Yang, Y.; Xue, X.; Gao, Y.; Zhang, H., and Du, X., 2020. Constructing sustainable coastal ecological environment: A hierarchical structure for sustainable smart ports. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 358–363. Coconut Creek (Florida), ISSN 0749-0208.

The sustainable smart ports can effectively promote the interconnection of important nodes among the Maritime Silk Road, effectively prevent Maritime risks and reduce the pollution of coastal ecological environment. However, few studies have discussed smart port from a sustainable perspective, while lack a systematic integration framework to guide the development of sustainable smart ports. This paper draws on the triple bottom line theory and creatively proposes three new dimensions of smart society, smart economy and smart environment, then attempts to use the combination of fuzzy set theory, DEMATEL, and ISM to evaluate the causal relationship between attributes and explore the interrelationship between levels so that a multilevel hierarchical structure model is established. The research results show that policy support, integration, knowledge and skills are the most important factors in the sustainable smart ports which provide a theoretical guidance for building a sustainable coastal ecological environment.

Li, X.; Xia, F.; Chen, X.; Shu, X.; Yang, M.; Li, L., and Wang, D., 2020. The interannual cycle features of the tropical Pacific-Indian Ocean associated mode and its mechanisms. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 364–372. Coconut Creek (Florida), ISSN 0749-0208.

Based on the SODA ocean analysis data, the interannual cycle features of the tropical Pacific-Indian Ocean associated mode (PIOAM) are studied by means of wavelet analysis and synthetic analysis. It is pointed out that PIOAM has a quasi-biennial cycle and a 3-4-year cycle. Furthermore, the dynamic and thermal mechanisms of the PIOAM interannual cycle are analyzed. The results show that the anomaly of Walker circulation over the two oceans is the key factor which forms the PIOAM. The propagation and reflection of ocean waves and the horizontal and vertical heat transfer of ocean circulation also play an important role in the cycle of PIOAM.

Cai, S.; Lu, S.; Zhao, L.; Wang, M.; Yu, R.; Cao, J.; Wu, M., and Xu, X., 2020. Improving strapdown airborne gravimetry by yaw tracking rotation modulation. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 373–381. Coconut Creek (Florida), ISSN 0749-0208.

Strapdown airborne gravimetry is a classical method to obtain the high quality gravity disturbance information. However, the horizontal components of the strapdown vector gravimetry are still potential for improvement. Residual error in navigation frame, originated from attitude error and accelerometer bias, is the main factor affecting the accuracy of the vector gravimetry. Theoretical analysis and actual repeat line data show that the variation of the flight direction would change the sign of the residual error, and this will create biases in the results of the survey lines in different direction. Therefore, keeping the yaw angle unchanged could eliminate the effect of residual error in strapdown gravimetry; this could be achieved by single axis rotation modulation. In this paper, strapdown vector gravimetry with yaw tracking rotation modulation technique is proposed to conquer the effect of residual bias. Simulation results show that the errors of horizontal gravity disturbance are reduced from 3.45 mGal and 4.59 mGal to 2.48 mGal and 1.77 mGal after using the improved gravimetry scheme.

Yu, R.; Xu, X.; Zhao, L.; Wang, M.; Cai, S.; Cao, J.; Wu, M., and Lu, S., 2020. Implementing marine gravimetry test using strapdown gravimeter in the South China Sea. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 382–388. Coconut Creek (Florida), ISSN 0749-0208.

As one of the major kinematic ways for surveying purpose in the sea region, shipborne marine gravimetry is important to get high accuracy and resolution gravity information. Until today, after decades of development and innovation, marine gravimetry is still a main and important mean of obtaining gravity data from the vast ocean areas. Based on the former generation gravimeter, SGA-WZ02 designed by NUDT has a further development. With this gravimeter, a marine test in the South China Sea was implemented for 40 days. The purpose was assessing feasibility and accuracy of this gravimeter for marine gravimetry. Surveying region was near the Xidutan area and the East Island in the South China Sea and total area of the measuring region is about 442.55 km² with a total of 884.7 km surveying distance. In this test, 15 east-west parallel lines separated by 1 km and 2 north-south inspection lines were measured. The average line distance is 14 km and the speed is about 10 kn. Since there were no repeated measurement lines, this paper used cross over differences among 17 lines to evaluate the performance. In marine gravity measurement experiments, it is particularly important to use GNSS precision point positioning (PPP) technology to measure the accurate position and velocity information of the carrier. Totally, 30 cross over points were obtained in the test and the average value of these points is -0.42 mGal using 300 s FIR filters which means the resolution was about 750 m. The root mean square value is 0.64 mGal that the result was at the same level of accuracy as the current mainstream marine gravimeters. It indicates that the SGA-WZ02 strapdown gravimeter can be used for marine gravimetry applications in geodesy and geophysical survey activities.

Jiao, Y.; Li, Z.; Zhu, J., and Zhang, B., 2020. Multi-strategy measurement of high-resolution ultrasonic TOF. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 389–395. Coconut Creek (Florida), ISSN 0749-0208.

Ultrasonic transducers are widely used in liquid sound velocity measurement. Acquisition of time-of-flight (TOF) is the key technology of high precision measurement of sound velocity.

In this paper, to measure TOF with high precision, a Multi-strategy Measurement technique is proposed, which is able to locate the region of interest of the signals received echo waveform, and the wavelet denoising is carried out. To evaluate the proposed method, in an identified environment, the experiments were performed under defined the distance between transmitter and receiver in pure water at 30°C. The experiments were performed that, in the sound velocity measurement, the method has a high adaptability, which can achieve the goal of removing noise and improving detection accuracy. Although this paper focus on sound velocity in pure water, the method described may also find application in air.

Gao, C.; Zheng, C.W.; Zhang, G.; Han, Y.; Tian, F.; Liu, X.; Wang, L.; Zhang, D., and Xiao, Z., 2020. Long-term projection of wind potential in the China seas. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 396–403. Coconut Creek (Florida), ISSN 0749-0208.

This study conducts the mid-long term predictions and assesses the multi-year average offshore wind energy in the China seas for the next five years based on CMIP5 wind data, in hope of providing reference for the long term prediction of wind energy. Results show that (1) large areas with multi-year average wind power densities (WPD) greater than 350 W/m2 are mainly found throughout the Ryukyu Islands and the Taiwan and Luzon Straits in the southeastern area of the Indo-China Peninsula. (2) From 2015-2019, the WPD in the Bohai Sea, Taiwan Strait and Beibu Gulf will be lower than the multi-year average level and thus will be similar to the multi-year average in the Yellow Sea and Gulf of Thailand but greater than the multi-year average in the East China Sea and South China Sea. (3) The predicted occurrences of exploitable wind speeds of the East China Sea and South China Sea are promising for the next five years, exceeding 60%. A value above 40% is predicted for the Yellow Sea, and a lower value is anticipated for the Bohai Sea. (4) The predicted occurrences of WPD > 50 W/m2 are more promising for the next five years.

Fan, L.; Zheng, C.W.; Zhou, H.; Tang, H.; Zhang, G.; Gao, C.; Lang, F., and Gao, Y., 2020. Gust characteristic analysis of wind energy resource in the western Pacific Ocean. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 404–410. Coconut Creek (Florida), ISSN 0749-0208.

As a key factor in the ocean energy development, particularly for preventing and reducing disaster, the analysis of gust characteristic is necessary. This study presents the characteristics of annual and seasonal wind speed, gust wind speed in the western Pacific region, using the CCMP wind data and ERA-interim gust data. Results show that, (1) There is a good consistency in annual variation between the averaged wind speed and averaged gust, while a great difference with the maximum gust. (2) The averaged wind speed for 35 years in the nearshore is smaller than that in the off-shore. There is a large value belt in Ryukyu Islands -- Taiwan Island -- the traditional South China Sea gale center, with two obvious large centers (about 7.5-8.0 m/s) located in the Taiwan Strait, the traditional South China Sea gale center. The large area of maximum annual mean gust (> 50 m/s) is mainly locates in the broad ocean of the east of Taiwan, (3) There is an obvious seasonal difference of the average wind speed, average gust and maximum gust. The average gust has noticeable monthly variation, the peak usually appears in November and the trough mainly appearing in summer. There is also a noticeable monthly variation for the maximum gust. In the middle and south of the South China Sea, the maximum gust is <16 m/s in each month. In the most part of the western Pacific region, the peak value of maximum gust appearing is in October and August, it is about 14-24 m/s in other months.

Wang, X. and Liu, Y., 2020. Validation of wave runup models in a New Zealand context. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 411–418. Coconut Creek (Florida), ISSN 0749-0208.

Runup is defined as the added water level above the still water level by waves. Accurate estimation of runup is essential for coastal protection, coastal management and hazard prediction. A video-based research was carried out in Gisborne and Mahia (New Zealand) to validate previously developed runup models in a New Zealand context and present locally adjusted models based on available models. A wave runup dataset containing 14 runup time series was produced. 5 previous models were tested with field observation. Among these models, the model proposed by Homan (1986) provides the most accurate predictions of R _2% . A locally adjusted model based on Homan (1986) yields improved results (R ² = 82%). For Gisborne and Mahia, R _2% is best parameterized by beach slope. A new model parameterized beach slope produces even better results (R ² = 83%). With information of beach slopes, it can be easily applicated to beaches around Gisborne and Mahia.

Wang, Y.; Deng, Q., and Zhang, Y., 2020. Research on the coupling and coordinated development of marine technological innovation and marine ecological economic development. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 419–427. Coconut Creek (Florida), ISSN 0749-0208.

The development of modern marine ecological economy relies heavily on scientific and technological progress. The level of development of marine scientific and technological innovation capabilities can to some extent reflect the level of marine ecological economic development in a certain region and future innovation directions and space. Fujian Province is selected as the research object to construct an evaluation index system for marine technological innovation capabilities and marine ecological economic development. Based on the sample of Fujian marine technological innovation capabilities and marine ecological economic data from 2007 to 2016, a coupling model is established to calculate the coupling coordinated development status and changing trend of marine technological innovation ability and ecological economy. The results show that the coordination of marine technological innovation and marine ecological economic development in Fujian has gradually improved in the past decade, marine technological innovation provides growth momentum for marine ecological economic development, marine ecological economic development provides basic guarantee for marine technological innovation. Through the joint development of the two, the coordination degree of the two is improved, and the healthy and sustainable development of marine economy is promoted.

Yu, K.; Yu, P.L.; Chen, Y.G.; Lu, Y., and Hao, W., 2020. A further investigation of the simulation of North Atlantic storm track activity in CMIP5 models. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads.Journal of Coastal Research, Special Issue No. 99, pp. 428-434.

By using the historical operation data of 12 Coupled Model Intercomparison Project phase 5 (CMIP5) model and NCEP reanalysis, the current study further evaluated the capacity of these models to simulate the climatology, seasonal variation and long-term trends of North Atlantic storm track (NAST) activity. It is found that all 12 models can effectively simulate the spatial pattern of NAST activity climatology but underestimate its intensity. The multimodel ensemble (MME) mean is better than any single model at reproducing NAST activity climatology. The differences in NAST activity climatology observed between the models are primarily concentrated in a region of 50°–60°N, 40°–20°W. These CMIP5 models basically capture the seasonal variation in the NAST intensity and latitudinal position but are relatively less effective at simulating the seasonal longitudinal migration of the NAST. Additionally, obvious discrepancies in long-term trend variations in the NAST strength and position are observed between most of the models and the NCEP reanalysis results. Only two models, CanESM2 and FGOALS-g2 (FGOALS-s2 and MRI-CGCM), are reasonably effective at simulating the long-term trend of NAST strengthening (northward-moving).

Zheng, C.W.; Liang, F.; Yao, J.L.; Dai, J.C.; Gao, Z.S.; Hou, T.T., and Xiao, Z.N., 2020. Seasonal extreme wind speed and gust wind speed: A case study of the China seas. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 435-438.

Previous researches have made great contribution to the evaluation of annual extreme wind speed and annual gust wind speed. However, the research on the extreme wind speed and gust wind speed of different season is extremely scarce, which is urgently needed in disaster prevention and reduction, navigation, ocean exploitation, etc. This study calculates the extreme wind speed with return period of 50-yr (U₅₀) and 100-yr (U₁₀₀) in each season and annual value by using the ERA-interim gust data and the Gumbel curve method, and the China seas were taken as case studies. The results show that, (1) Both the annual U₅₀ and U₁₀₀ have a good consistency with the multi-year average maximum gust as a whole, with the large area mainly located in the mid-low latitude (15°∼30°N) and the large center is located in the broad ocean surrounding the Volcano Islands (35-55 m/s in maximum gust, 50-75 m/s in U₅₀ and U₁₀₀). (2) The maximum gust, U₅₀ and U₁₀₀ exhibit noticeable seasonal difference. The large areas in January are located in the mid-high latitude, about north of 20°N, including the Japan Sea, south waters of Japan, Ryukyu Islands. The large areas in April are located in the mid-high latitude (north of 25°N) and the south of Volcano Islands, while in the broad ocean between 15°N and 30°N in both July and October.

Yang, S.; Li, L.; Li, X.; Liang, F.; Zhang, X., and Sun, W., 2020. Dynamics model of buoy unpowered heave considering seawater density. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 439-446.

The Deep-sea Autonomous Profile Buoys (DSAPB) are a new type of underwater buoys and they can dive to the deep sea below 4000m. Considering dynamic models of conventional underwater vehicle could not adequately satisfy the motion characteristic of DSAPB, a nonlinear dynamic model for the motion simulation of DSAPB is developed in this paper. In the model, the effect of sea water density change is taken into consideration and a viscous hydrodynamic calculation method satisfying the motion characteristic of DSAPB. The buoyancy variation is introduced into the standard hydrodynamic equation to simplify the DSAPB hydrodynamic equation, and the Motion of Planar Mechanisms (PMM) experiment is simulated by means of Computer Fluids Dynamics (CFD). The hydrodynamic coefficients in the equation are obtained and the DSAPB dynamic model is obtained which provides theoretical basis for effective control of DSAPB.