Marine environmental data is an important strategic resource for mankind to understand, protect and exploit the ocean. With the rapid development of digital economy and science and technology, marine environmental data has become a new and important factor of production. As a new form of asset, how to value marine environmental data assets has become a new problem. Through the in-depth investigation and research of the value assessment of domestic marine data assets, it is concluded that the traditional cost method and the benefit method and their combination are the basis for the current valuation of marine environmental data, and it is found that the method of value assessment of marine environmental data in the new era has complexity, flexibility and multi-dimensional evaluation methods, which have very important economic value for the development of marine economy and the sustainability of marine scientific research.

Data sharing is an important task during the implementation of compilation project for the historical data reorganization of scientific investigation in the South China Sea and its affiliated islands and reefs. This study mainly introduces the design and construction of comprehensive database for scientific investigation in the South China Sea and the “Digital South China Sea” platform. First, the design and development focus of the “Digital South China Sea” will be elaborated to achieve the intensification of data management, sharing processes and efficient resource utilization. Then, the interactive analysis application of data and dynamic visualization application are introduced using the “Voyage Map” and “Island Reef Map” modules. The construction of the “Digital South China Sea” platform follows the project objectives, with unified planning and deployment, unified standard system, unified data platform, and unified achievement release. Data services run through the entire lifecycle of project implementation, promoting the formation of a new pattern of data work development that involves joint consultation, construction, sharing, and win-win results.

In the implementation process of the compilation project for the historical data reorganization of scientific investigation over the South China Sea and its affiliated islands and reefs, data management is an important task. From the perspective of data managers, this paper takes data as the research object and data governance as the research core content, discusses the scientific management of data, and builds a simple data governance model. This model includes six systems: security system, organization system, standard system, resource system, sharing system, and docking system. The model provides guidance for data governance of project data and the South China Sea ocean data. The article briefly discusses the security system, standard system, and resource system.

A large number of core sampling data were obtained from marine geological survey. Different kinds of measurement data have different sampling depths, resulting in irregularly scattered distribution of 3D geological sampling. The irregularly scattered data on the three dimensional were not able being clustered using traditional clustering algorithm especially in the case of big data analysis. The present study designs a clustering algorithm for irregular geological sampling data based on spatial interpolation. In this way, the 3D geological scatter data can be effectively reduced to 2D data, and the computational complexity can be reduced. This algorithm can better solve the classification and analysis of inequality measurement data in geological bodies, and provides a basic technical method for marine geological big data analysis.

In this paper, a new hybrid data assimilation method is designed based on particle filter and 3Dvar. The new method generates an ensemble deviation with background error information through an optimal estimation of particle filter, thus providing flow-dependent background error covariance for 3Dvar. Particle degeneracy has always been the main obstacle of particle filtering in data assimilation field. In order to make the hybrid method work better, an improved residual resampling method is proposed to solve the problem of particle degeneracy. By sampling particles in the normal distribution, the lack of particle diversity caused by degeneracy is solved. Data assimilation experiments were tested on the ideal lorenz-63 model. The results show that the new method is better than the ETKF-3Dvar method when the model error is large, and as the model error increases, the new method is also better than the traditional data assimilation method. In the comparison experiment with hierarchical resampling and general residual resampling, the improved residual resampling method can ensure the stability of the assimilation results within a given time window, while the other two methods have a large deviation in the assimilation results.

A comprehensive understanding of the geological characteristics of shallow strata of seabed is the basis for identifying and evaluating shallow marine geological hazards, which is of great significance to the development of marine resources and marine engineering construction. Multiple oil and gas fields are being explored and developed in northern Dongsha, South China Sea. However, there is a lack of systematic analysis of the fine geological characteristics of the shallow strata in this place. Based on the diverse data of AUV (autonomous underwater vehicle), multi-beam, AUV shallow stratum profile, 2D seismic data and sediment test, the factors of shallow strata geological hazards were identified and their risks were evaluated in the area of 100~400m water depth in northern Dongsha, South China Sea. The survey found that the seabed surface sediments in the study area were generally relatively stable, and several micro-geomorphologies of the seabed, such as sand waves, steep steps and gullies developed. Shallow gas below the seabed was not observed, and numerous paleovalleys are developed. Significant spatial differences are featured in the shape and distribution characteristics of seabed sand waves. The sand waves with wave height greater than 1m are mainly distributed in the depths of 134~143m, 168~187m and 205m, they can move positions under modern dynamic conditions. The observation results show that the development of seabed sand waves is related to the process of internal waves. The steep steps are more than 20°, which is considered to be related to the faults running through the shallow strata.

The survey of OBS2019-2 line was carried out across the continent-ocean transition zone (COT) near the Liyuexi Trough of the Nansha Block. This work is critical as it is able to reveal the crustal structure and study rifting-breakup mechanism of the southern continental margin of the South China Sea (SCS). The data of OBS2019-2 is also important to make a comparative study of conjugate continental margin of SCS. Compared with the northern continental margin, there is fewer Ocean Bottom Seismometer (OBS) survey lines and deep crustal structure study in the southern continental margin of SCS. Therefore, more work needs to be done on OBS2019-2. This paper focuses on the data processing workflow of OBS2019-2, including UKOOA file preparation, data format conversion, position relocation, single station seismic record section drawing, etc. Then different kinds of deep seismic phases (e.g. Pg, PcP, PmP, Pn) are identified and traced. These seismic phases are subsequently verified by the travel-time calculation using Rayinvr software. The results of data processing show that deep seismic phases in the seismic record profiles are distinct. The farthest seismic phase could be continuously traced up to 120 km away. Seismic data of OBS2019-2 are of high quality, which can provide a solid foundation for subsequent velocity modeling and structural interpretation.

Phytoplankton are the basis of the marine ecosystem food chain, and affect the variation of CO₂ flux through photosynthesis. In this study, an estimation system of phytoplankton biomass in the South China Sea was established based on an area indicator. We used the empirical orthogonal function decomposition interpolation method (DINEOF) to reconstruct the chlorophyll a concentration field in the South China Sea from long time series of remote sensing data. We studied the space-time distribution of the high biomass water area of the South China Sea and found that the changes of water area with high chlorophyll a concentration had significant seasonal characteristics. The area of waters with high chlorophyll concentration reached the maximum in winter, and the minimum in summer. Conversely, the chlorophyll concentration reached the minimum in winter, and maximum in summer. This feature may be due to the wind-driven dynamic processes that redistribute the chlorophyll concentration near the surface. Moreover, waters with high chlorophyll concentration were found near the coast year round, especially in coastal waters of China, along the coast of Vietnam, the Gulf of Thailand, and near Borneo Island. In the Sunda Shelf and the central basin east of the Mekong estuary, the area of high biomass water showed interannual variation. The East Asian monsoon modulated by the El Niño and Southern Oscillation led to different degrees of cold water invasion from the north to the southeast of the Mekong Estuary in different years, which may be the reason for the increase and decrease of local phytoplankton biomass.

The coral δ¹⁸O data can precisely record climate variation and change of the tropical ocean, making up the shortage of deficient instrumental observations and providing us with the possibility of retrieving long-term paleoclimate conditions. The climate modes of the tropical Indian Ocean influence the climate of the surrounding region and even the globe through ocean-atmosphere interaction; so they are of great significance in climate study. In the present study, coral δ¹⁸O data from 1880 to 1999 at four sites located in the tropical Indian Ocean (Kenya, Seychelles, Tanzania, Mentawai) are used to study their ability to reproduce past climate in the tropical Indian Ocean. First, coral δ¹⁸O and SST changes are consistent on the long-term trend. Second, coral δ¹⁸O coincides nicely with local SST in terms of seasonal cycle, and is more sensitive to SST variation in cold seasons. What is more, coral δ¹⁸O at the four sites can describe changes of IOBM (Indian Ocean Basin Mode) and IODM (Indian Ocean Dipole Mode), but the interannual variability of the tropical Indian Ocean recorded by coral δ¹⁸O is modulated by interdecadal variation. This study suggests that the δ¹⁸O data from coral is an essential indicator of paleoclimate in the tropical Indian Ocean. Different sites' information should be taken into account to reflect past climate change in the Indian Ocean.

The staff at the South China Sea and Adjacent Seas Data Center, which is a sub-center of the National Earth System Science Data Center, has developed South China Sea ocean database by combining the advantages of ecological environment research domain, the tropical marine environment research domain and the marginal sea and ocean geology research domain, to promote open access and effective utilization of ocean data. In this paper, we introduce our practice in the South China Sea and Adjacent Seas Data Center scientific data construction, which is arranged to share the multi-disciplinary, multi-element and multi-scale marine scientific data in the South China Sea and its adjacent water since 1985, including data of hydrology, meteorology, ecology, and geology. This center will provide high-quality data for research of the South China Sea. It will provide basic data for major national strategies, marine economic and social development and related decision making activities.

The development of marine sciences depends on observations. Satellite is one of the most important observation platforms for marine research. Satellite data are of great significance in marine research. Since the beginning of this century, China has successfully launched several satellites dedicated to ocean observations, and preliminarily established a global ocean satellite observation system. According to the basic situation of marine satellite resources at home and abroad, we study and analyze the current situation of the application and development of marine satellite data in China, especially in terms of receiving, processing, management and application of marine satellite data, put forward the scientific research demand for satellite data in China's marine research, and probe into the existing problems and development strategies of the scientific application of marine satellite data in China.

We compare four observations and reanalysis datasets (SSM/I&SSMIS, RSS V7R01, ERA5, and MERRA-2) in terms of climate states of global water vapor. The variation and long-term trend of total column water vapor (TCWV) of different scales are also explored. The results indicate that the spatial distribution, seasonal cycle and interannual variability of the four datasets are consistent. From 1988 to 2018, the TCWV had an increasing trend in the tropical oceans. The interannual changes of the TCWV are significant and highly correlated with the El Ni?o-Southern Oscillation (ENSO). The datasets of ERA5 and MERRA-2 should be used with caution when analyzing TCWV trend in a short period (e.g., 1991—1997). When studying the long-term water vapor trend in the tropical regions, MERRA-2 data should be used carefully because the long-term trend is different from other datasets.

The drag coefficient and aerodynamic roughness length of the sea surface are essential in calculating momentum, heat and water-vapor exchanges between the air and sea. With the observations collected by eddy covariance systems during typhoons Hagupit and Chanthu, we investigated parameterization relationships of 10-m wind speed with friction velocity, drag coefficient, and aerodynamic roughness length of the sea surface. Results show parabolic relationships between drag coefficient and friction velocity, and between drag coefficient and 10-m wind speed; results also show exponential relationships between aerodynamic roughness length and friction velocity, and between aerodynamic roughness and 10-m wind speed. We found that the critical friction velocity is 0.83 m·s^-1 and critical 10m wind speed is 23.69 m·s^-1.

Using the measured wave data in 2017 in the central Taiwan Strait, we analyze the basic features of wave, including spectral features, and their relationships with wind. The regression relationship among important characteristic wave parameters and the appropriate wave spectrum form are also investigated. The results are as follows. 1) The most frequently occurring wave direction is NE, and the strong wave direction is NNE. The monthly average significant wave height varies from 0.87 to 2.98 m. The wave height is the smallest in July and the highest in December. The wave period has similar inter-month change to wave height. 2) Mixed waves dominated by wind wave and single-peaked spectra make up the majority. The wave height is positively correlated with the wind speed as a whole. Strong wave is mainly generated by typhoons and strong northeast monsoon. 3) There are good linear correlations between mean wave period and most characteristic period parameters. The significant wave height and its corresponding wave period are strongly linearly related in the directions of NNE and NE. 4) Compared with the Jonswap spectrum, the Code spectrum 1 is more reasonable for the fitting of sea wave spectrum in this area. A spectrum in the form of Code spectrum 1 is given, which is fitted by significant wave height and spectral peak period. These results can provide references for ocean engineering design and numerical simulation of wave.

A new error-correction forecast model for sea surface temperature (SST) is proposed in this paper, where the SST errors are derived from the Group for High Resolution Sea Surface Temperature (GHRSST) data and operational numerical prediction SST product. First of all, the reliability of the GHRSST data was validated with the upper temperature data of Argo floats in the South China Sea. The results showed that the Root Mean Square Error (RMSE) between the two sets of data was about 0.3℃ while the correlation coefficient was 0.98; the GHRSST data could be used for the correction of operational numerical forecast model on SST in the South China Sea. After being corrected, the RMSEs of 24-hr, 48-hr and 72-hr SST forecast results were dropped from 0.8 ℃ to 0.5 ℃ compared with the upper temperature data of Argo floats. Meanwhile, the 24-hr, 48-hr and 72-hr SST forecast errors between the GHRSST data and model results were significantly reduced after the correction in the northern South China Sea (110°E -121°E, 13°N -23°N). During the influence of the cold air or the mesoscale eddy in the South China Sea, the effect of SST forecast correction was also quite significant. Therefore, this method should be considered to apply in the operational numerical forecast system on SST in the South China Sea.

Natural gas-hydrate is a new clean energy resource. The geological conditions in Shenhu area in the northern South China Sea (SCS) are conducive to the formation and storage of gas-hydrate. It is difficult to obtain accurate velocity information from traditional multi-channel seismic (MCS) data, and we can only judge the vertical distribution of geological bodies from the time domain. Ocean bottom seismometer (OBS) is a widely used active-source seismic instrument, which can receive clearer air gun signals. Compared with MCS data, refraction seismic data of OBS profiles can reveal velocity information from deeper layers. In this paper, combining the advantages of MCS and OBS, we determine the reflection interfaces on MCS profile, and then obtain the initial model. The OBS and MCS stacking profiles are merged to determine the reflection interface in the OBS profile. The reflection and refraction phases of OBS stations were picked up, and the two-dimensional velocity model of hydrate region was obtained by forward modeling using RayInvr, which solved the difficult time-depth conversion problem in MCS. The final model shows the depth, thickness and velocity of hydrate and free gas regions; it also shows the depth and velocity characteristics of the deeper interface below BSR.

In view of data security problem concerning ocean buoy data, such as hacker attack, illegal access, data leakage, etc., a data security management system based on multi-encryption is proposed and implemented. We introduce the system architecture, multi-encryption storage and key management scheme in this paper. In this system, the buoy data is encrypted and stored by using multi-encryption technology, and the confidentiality of data transmission is ensured by encrypted transmission in business application. The analytic results of system security indicate show that this system can ensure data security in the process of storage, transmission and application.

To obtain stable time series observations at low power consumption, a data acquisition system for water quality monitoring buoy was designed. It includes CPU module, control/protection module, communication positioning module, and interface expansion module. In this data acquisition system, a CF2 mainboard was used as the CPU module, with the assistant of a multi-functional board, which uses a single chip microcomputer as a control unit. All the following functions, such as collecting data, saving data and communication, and expanding the modules to realize counting, I/O control, AD (Analog to Digital) conversion, timing, and other functions can be accomplished. A double “watchdog” was designed for the control/protection module to achieve the entire process of independent work unattended in all-weather conditions. The water quality monitoring data system was designed for the purposes of remote receiving, storing and displaying of water quality monitoring data. It includes four key components: data acquisition module, data processing module, systematic early warning module, and data display module, which have the following advantage characters: easy operation, high degree of automation, and graphical display intuitively easy to read.

Marine geological survey is the strategic demand of our country to build a powerful marine nation. The survey data have important application values. With the rapidly developing technologies of computer, database and network, combining the ways of digital management, application and sharing of marine geological survey data has become an important indicator to measure the level of marine science and technology in China. In view of disadvantages of poor interactivity and low scalability in traditional WebGIS application, the sharing service platform of marine geological survey data in the South China Sea on the web was developed by Flex API and ArcGIS Flex Viewer, to develop widget for functional expansion based on the application framework. The users can browse and inquire these data easily. In this paper, the centralized management, display and service of the marine geological survey data in the South China Sea are illustrated. The results show that the platform can meet information service demands of marine users.

Based on the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) data in 2015, we analyzed the seasonal variation and genesis mechanisms of thermal fronts in Guangdong coastal zone. The Guangdong coastal thermal fronts are strong in winter and weak in summer. In the eastern Guangdong coastal zone, thermal fronts are seen all year round, while in the western Guangdong coastal zone, thermal fronts disappear in summer. In the Pearl River estuary zone, thermal fronts are associated with the Pearl River plumes, which extend east northward in summer and southward in autumn. We suggest wind speed play important roles in the genesis and disappearance of these thermal fronts. Using a simple model, we find that monsoon influences the front strength through air-sea turbulent heat fluxes. Under southwesterly (northeasterly) wind condition, warm and wet (cold and dry) air mass could decrease (increase) the latent heat release near the cold coastal zone, leading to a temperature increase in the cold zone, and finally the front disappears.

Gaofeng-4 products have become available since June 2016. GF-4 is the first geosynchronous orbit remote sensing satellite in China. The virtue of the satellite is its high spatial and temporal resolution. So, the satellite is useful for monitoring marine disasters. In this study, we established a model to retrieve the chlorophyll concentration from GF-4 satellite data based on the in situ measured data on 22th October 2009 (the coefficient of determination r²=0.90; root mean square error RMSE=0.1). The algorithm has been shown to have a relatively better applicability by comparing the result with Hydrolight (r²=0.92; RMSE=0.23). The model was further applied to analyze the harmful algal bloom in Guangxi in May 2016 by using GF-4 satellite data. The result showed a good agreement with the in situ survey data. This is the first time to retrieve chlorophyll concentration from the remote sensing reflectance, including the harmful algal bloom waters in Guangxi by using GF-4 products. The research can provide an effective technique for constructing marine civilization and marine disaster investigation.

This study was based on the raw eddy-covariance (EC) data measured in February 2016 from the observation tower on Yongxing Island. EddyPro software was used for data post-processing, and the influence on flux calculation was quantitatively analyzed before and after each processing step. Furthermore, flux data quality classification, footprint analysis and comparison with calculated results using easyflux_dl real time programme were conducted. The results showed that despiking, coordinate rotation, frequency response correction and density correction all influenced the flux calculation result to different degrees. The influences of coordinate rotation on momentum flux, latent heat flux and carbon dioxide flux were evident, which revealed increases of 11.28%, 7.36% and 18.53%, respectively. The density correction had a significant effect on the carbon dioxide flux calculation, which was reduced by 7.87% after density correction. Comprehensive quality evaluation results revealed that the ratios of high quality data (grades 1~3) of momentum flux, sensible heat flux, latent heat flux, and carbon dioxide flux were 90.29%, 90.22%, 88.46%, and 85.41%, respectively. Footprint analysis showed that 72.04% source area of the flux was scattered in the first interesting area (10~80°, the underlying surface is the ocean surface with an average water depth of more than 10 m). Comparison of flux calculation results between EddyPro and EasyFlux showed that the two flux time series were fundamentally consistent; the results obtained by EddyPro were smaller but more reliable and accurate due to more strict despiking adopted to get rid of outliers’ impacts.

Using offshore airguns and onshore explosions as seismic sources, along with portable seismic stations, permanent seismic stations and Ocean Bottom Seismometer (OBS) as a synchronously receiving array, a onshore-offshore 3D seismic exploration experiment was carried out for the first time in the Zhujiangkou area of the northern South China Sea. This paper introduces in detail the seismic data acquisition, observation system, data preprocessing method, and phase identification. A variety of seismic phases, including Pg, PcP, PmP, Pn, and Sg, can be clearly identified in most data collected by the permanent, portable seismic stations and OBS. Jointly using airgun and explosion sources, and dense stations receiving seismic signals simultaneously both on land and at sea, it can highly improve the ray coverage and cross overlap beneath the onshore-offshore transitional belt, which lays a foundation for obtaining fine crustal structure beneath such onshore-offshore area.

A two-dimensional ocean bottom seismometer (OBS) survey line (OBS2015-2) was carried out in 2015, which was an E-W trending and located in the front of the Manila Trench subduction zone. In this study, we take two OBS stations (OBS04 and OBS08) as examples to introduce the data processing flow for this short-period OBS type of data. The process includes data format transforming from original RAW data to SAC format and then to SEGY format; and it contains shot relocation and OBS position relocation. The preliminary results of data processing demonstrate that the OBS data are of high quality in this experiment. The seismic phases, such as PsP, Pg, PmP, etc. are very clear along the OBSs’ seismic record sections. They are further identified by the forward modeling using the Rayinvr software. Especially, the reflective seismic phases from the Moho interface are abundant and obvious in the incoming plate along the Manila Trench subduction zone, which will provide good constraints for the crustal bottom of the incoming plate.

It is of great significance to fully exploit the oceanic application potential of the GaoFen-1 data, which is the first domestic high-resolution satellite of Earth observation in China. In this study, a GaoFen-1 multi-spectral image is used to retrieve the island shallow water depth of Jinqing Island in Xisha sea area by adopting the dual-band linear model and log-ratio model, after serials of image processing including image geometric correction, atmospheric correction and sun-glint correction. The accuracy of the two models is evaluated by using actual water depth data. Meanwhile, possible influence factors of retrieval accuracy of island shallow water depth from satellite data are discussed. It is shown that the result from the dual-linear model is obviously better than that from the log-ratio model, and the dual-band linear model is more suitable for the retrieving shallow water depth of Jinqing Island. For water depth less than 20 m, the overall root mean square (RMS) error is 1.8 m with RMS error of 1.14 m within 5 m, which reaches the level of accuracy of water depth inversion by satellite remote sensing.

By regarding the moderate resolution imaging spectroradiometer (MODIS) remote sensing data as data sources and the southwest coastal waters of Hainan Island as the study area, the improved spilt-window algorithm is used to inverse the SST of the study area from 2005 to 2014. To verify the retrieval accuracy of the SST, we calculate the correlation coefficient between the inversion and measured results using the measured values of 12 observation points; the coefficient is 0.9. Based on the inversion results of SST, the data of four seasons in a year and a decade are analyzed to show the spatial and temporal variations of SST distribution, respectively. Results show that using the MODIS multi-channel improved spilt-window algorithm we can inverse Hainan Island offshore SST accurately. The spatial and temporal variations of SST distribution thus obtained can provide important reference values for marine fishery, change of marine environment and meteorological monitoring.

The dynamic characteristics of time-mean meridional overturning circulation in the Indian Ocean was examined using six reanalysis datasets. The results showed consistent time-mean features of the deep meridional overturning circulation, which is an anticlockwise overturning cell with inflows in the bottom and deep layers and outflows in the intermediate and upper layers. Dynamic decomposition of meridional overturning circulation was applied to examine the similarities and differences of every dynamic component. The structure of Ekman component is an anticlockwise overturning cell in the South Indian Ocean with maximum strength at ~10°S. In the region south of 10°S, geostrophic and external components show clockwise and anticlockwise overturning cells, respectively, they both reach maximum strengths at ~27°S. Based on different products of heat and momentum fluxes used, the dynamic components resulted from the six datasets show some inconsistent features as follows. The overall structures of Ekman component are similar since the wind fields of the six datasets have few differences. The discrepancies of the geostrophic component in the six datasets are due to the strength of the baroclinic flows in the interior ocean and the structure of the western boundary current: the greater the baroclinic flows in the interior ocean, the stronger the strength of the geostrophic component; the wider the western boundary current, the greater impact on the baroclinic flows in the interior ocean, and then on the strength of the geostrophic component. The strength of the external component is affected by the intensity of the western boundary current: the greater the western boundary current, the stronger the strength of the external component.

In this study, we conducted barotropic detiding of the summertime shipboard ADCP (SADCP) dataset in the southern Taiwan Strait (TWS) from June to September during 2004-2013, employing the widely used spatiotemporal fitting by the least squares method (STF-LSM). The results show that the mean flow derived from STF-LSM and that derived from averaged vectors by dataset gridding both flowed northeastward. Moreover, these two mean flows had similar spatial distribution patterns of strong and weak flows, but their maximum velocities were slightly different: 0.46 and 0.34 m·s^-1 for the former and the latter, respectively. Besides, the strong currents (about 0.3 m·s^-1) were characterized by the narrow mainstream confined around the depth of 30 m off the sea at Dongshan and Longhai as well as the Taiwan Bank (TWB) with drastic topographic change, whereas the weak currents (less than 0.1 m·s^-1) were mainly distributed in the central TWB. Estimation of the volume transport based on the above mentioned mean flows revealed similar results, up to (0.71±0.24) ×10⁶ m³·s^-1. The strong M₂ tidal currents derived from SADCP were near the TWB and extended to the offshore of Dongshan, with a maximum M₂ current amplitude as large as ~0.64 m·s^-1, which was located in the TWB. The cotidal chart for M₂ currents demonstrates the characteristics of progressive wave, which was delayed successively from the southwest to the northeast along the direction of the tidal wave as the wave propagated (about 2 h). Besides, there was a boundary line along northwestward to southeastward direction with ellipticity equal to zero at the offshore of Dongshan. The M₂ currents rotated counterclockwise in the southern region of this boundary line and clockwise in the northern region.

In this paper, sea surface salinity data of the equatorial Pacific Ocean in 2011~2012, acquired by the Soil Moisture and Ocean Salinity (SMOS) satellite, was processed for quality control and then analyzed for the first time in terms of dynamic process factors that may impact salinity retrieval. The neural network method was introduced to improve the quality-controlled salinity data of the same time period. It was found that precipitation and surface wave induced by precipitation can increase salinity error substantially in a negative trend. Sea surface roughness caused by wind also increased salinity errors. There was a weak positive correlation between wind speed and salinity error. Changes in sea surface temperature had little effect on salinity retrieval. Considering rainfall, wind speed and other major marine dynamic processes, the neural network method was used to revise sea surface salinity data of the equatorial Pacific in December 2011. The results showed that the RMS (root mean square) of salinity reduced from 0.383 7 to 0.244 1. It was found that not only was the salinity error caused by precipitation and other dynamic processes eliminated, but also the high salinity tongue in the equatorial Pacific was revealed, which the Level-3 data failed to.

According to the types of South China Sea marine datasets, especially the cruise data format, based on the marine data specifications at home and abroad, and on the references of a large number of relevant specifications, we designed “Collection and Management Guide of the South China Sea Data”, which is suitable for the South China Sea Ocean Database. It includes six data management specifications. In terms of data collection, the guide regulates data factor, data information, data classification, and data format, in terms of data management and guide proposes of data format conversion specification. This achieves various marine data collection and management effectively, promotes the specification system of the South China Sea marine data and improves the sharing of marine data and application services.