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Intraseasonal variabilities (ISVs) are important factors in tropical climate. The ISVs like sea surface temperature (SST) and sea surface height (SSH) from oceanic reanalysis ECCO2, SODA3 and CORA were compared with the satellite observations during boreal summer and winter. Intraseasonal SST anomalies were also further compared during MJO and CIO cases. Results show that the ISVs from reanalysis data have the same clear variabilities nearshore as the observations, while within the ocean, the ISVs standard deviation (STD) of reanalysis data is weaker than that of the observation data for at least 20%, SODA3 even faces the differences up to 60%. During the eastward propagation of MJO and northward propagation of CIO, the SST anomalies induced by thermal force is well simulated by the reanalysis data, only ECCO2 and CORA encounter a phase lag of 5-10 days. During the westward propagation of SST anomalies at CIO, reanalysis data have an awful simulation for this dynamic forced ISVs. ECCO2 and CORA propagate to the west in a small area from 85°E-95°E feebly, and even that in SODA3 doesn’t show its westward signals. Temperature in all reanalysis data is a half weaker than the observations at eastern Indian Ocean (90°E-100°E). Through comparison in intraseasonal velocity anomalies, the STD of reanalysis data is far less than RAMA (51.42%), the averages among the peaks of velocity are also weaker than observations for 65.16%. This suggests that improper simulation of dynamically-forcing ISVs may lead to the weaker variabilities within Indian Ocean. Therefore, in order to upgrade the ISVs in reanalysis, it is necessary to modify the heat forcing as well as dynamic forcing in atmospheric modeling and, more importantly, add up the oceanic assimilation. Equatorial Indian Ocean, as the prevalent area for ISV events and the area with clear difference in STD, is surely a region for more observation plans with oceanic variabilities like currents.

Geostationary Ocean Color Imager (GOCI) provides ocean water color data with time resolutions up to the hour, making it possible to monitor the marine environment in a time-varying manner. However, due to the influence of clouds, fog and haze over the ocean, the continuous high-missing rate or even complete loss of data makes the data use value greatly reduced. Based on the Data INterpolating Empirical Orthogonal Functions, highlighting the position of time elements in reconstruction, a reconstruction method using abnormal pixel detection, Laplacian smoothing and temporal coefficient twice decomposition interpolation was proposed for geostationary satellite ocean color data (DINEOF-G). This method is used to reconstruct the total suspended matter data of Hangzhou Bay in 2017. The results show that the proposed method improves the reconstruction accuracy by 8% and the data reconstruction rate by 36% compared with the classical method. The reconstructed data reflects the seasonal variation and spatial distribution characteristics of the total suspended matter in Hangzhou Bay.

A set of monthly mean global ocean(0~1 500 m)Argo data sets (1°× 1°) from 2004 to 2017 was constructed by using “Gradient-dependent Correlation Scale Method”. And based on the comparative test of the data set, we have initially applied the data set to the fisheries analysis of yellowfin tuna in the Central and Western Pacific Ocean. The results show that the temperature and salinity deviations between the Argo data set and the WOA13 historical data set were slightly larger in the upper surface layer of the ocean about 0.5 ℃ and 0.1 respectively, and the two deviations both decreases gradually with the increase of depth. The temperature deviations between the Argo data set and time series of the TAO buoy were less than 1 °C in 2004-2017, and the maximum salinity deviations were less than 0.5 while most of those in the sea areas were close to 0. In the Central and Western Pacific Ocean, the central fishing ground of yellowfin tuna mostly concentrated at the isotherm of the range of 28 ~ 29 ℃, and in the sea areas where temperature below 22 ℃, the catch per unit effort (CPUE) value was very small. In the central fishery area, the upper boundary depth of the thermocline was in the range of 20 m and 120 m, and the frequency of formation of the center fishing ground at each depth was generally normal distribution. When the upper boundary depth of the thermocline was 90 m, the possibility of forming the center fishing ground was the greatest. While further verifying the reliability of the data set, it is also shown that the data set constructed in our study has certain application value in hydrologic environment analysis and resource assessment.

In order to understand the impact of marine environment and terrestrial environment on GPS multipath effect, Anubis software was used to analyze the multipath error in the marine environment and terrestrial environment based on the observation data of two stations at the seaside. The differences were compared and analyzed. The results show that: (1) When the satellite elevation is low, the multipath error in the marine environment and the terrestrial environment increases gradually with the decrease of the satellite elevation angle, and the multipath error increase in the marine environment is significantly greater than that in the terrestrial environment. (2) When the satellite elevation angle is less than 20°, the multipath error in the marine environment is greater than the multipath error in the terrestrial environment; when the elevation angle is greater than 20°, the difference in the multipath error between the sea surface direction and the land direction is small.

Based on the theoretical analysis, wave flume experiments were carried out employing vegetation models with quantifiable root, stem and canopy. The attenuation characteristics of irregular wave height within the vegetation filed was investigated by a combination of water depth, incident wave height and vegetation distribution density. Variation of wave spectra associated with vegetation was studied using FFT. The results show that the vegetation models in this experiment have good wave-absorbing effect, but the boundary effect of vegetation wave attenuation is rare. The variation of irregular wave height along the flora is inconsistent with Mendez's theoretical curve most of the time. At the same time, there is no fixed variation of wave energy loss within different sections of the vegetation filed. In addition, the attenuation of wave energy is concentrated at the peak frequency, and increasing incident wave height result in a bigger difference between spectra values of transmitted wave and incident wave at peak frequency, while spectra of both transmitted wave and incident wave show similar bands. This study can provide a theoretical basis for using coastal vegetation to reduce shoreline erosion by surface waves.

In this study, the content of bio-silicon and organic matter in the surface sediments were analyzed, which were collected by the Ocean 40 voyage in the mountain basin of the Marcus-Wick Sea area in the western Pacific, and the preliminary research on its distribution characteristics and sources were also conducted. The results show that the content of bio-silicon in the deep sea surface sediments near the Marcus-Wicker Sea area is generally low, ranging from 0.88% to 12.41%, with an average content of 2.19%. The distribution shows a high content in the southwest and a diminishing trend toward the northeast. The content of organic carbon in the surface sediments is low, and the distribution of δ¹³C is the same as that of bio-silicon. Sediment core studies show that the primary production of siliceous organisms in the surface waters of the study area during the past 100-200 ka is gradually increasing.

The sustainable development of island resources is an important issue in marine development and management. In order to optimize the allocation of island resources and promote the coordinated development as well as ecological environment protection of island, in view of the particularity of island ecosystem, and based on the related researches, the concept, connotation and characteristics of island ecosystem vulnerability(IEV) were describes. The islands in Liaoning were paid more emphasis on, and a large number of typical cases of islands were analyzed to establish the impact mechanism framework and analyze the causes and manifestations of IEV. On this basis, the assessment system and methods of IEV were discussed. Finally, the research prospect was put forward. The study shows that the IEV is the sensitive response and self-recovery ability of island ecosystem when the island is interacted with the natural environment and in the process of island development under the background of certain natural factors and human factors. The IEV is objective, sensitive and difficult to recover. It has the characteristics of long-term, difference and controllability. The IEV varies with different types and degrees of natural disturbance and human disturbance, and the establishment of its driving mechanism and evaluation system can provide ideas for further research. The results of the study can provide scientific basis for island ecological environment protection and have important practical significance for promoting sustainable development of the island.

The classification and grading of sea area is the making collecting standard for the sea area using charge, and it is also the premise and basis for carrying out the appraisal of sea area asset price. Based on the technical guidelines for sea area grading (Trial implementation) and following the principles of resource endowment difference, income difference, economical utilization and ecological sea use, we selected two grading factors of sea natural conditions and sea area location conditions, and 10 assessment factors, such as seawater quality, marine natural disasters, et al., and then established the index quality assessment system of Shenzhen bathing beaches grading. Using the comprehensive index assessment method, we could get the scores of 207 assessment units, and use cluster analysis method and coefficient of variation (CV) to check the level. Finally, the bathing beaches are divided into three levels: level-Ⅰ(22.22%), level-Ⅱ(33.82%) and level-Ⅲ(43.96%). The research results provide a basis to evaluate the reference price of different levels bathing beaches for the marine management department in Shenzhen.

On December 8th and 15th, 2018, sampling survey was conducted in the sea area near the second petrochemical sewage pipeline discharge outlet in Daya Bay. Content of pollution factor in seawater and sediments in the sea area near the sewage outlet was analyzed and factors were evaluated by the single-factor pollution index method. The results indicate that the single factor indexes of pollutants causing eutrophication are low while the heavy metal pollution is serious in the seawater, mainly due to the high background value of heavy metal concentrations in the seawater of Daya Bay. All pollution factor indexes in sediments are low, and the main pollution factors of heavy metals are Cr, Pb and Zn. Since the second petrochemical sewage pipeline was put into use, the impact on the surrounding area is still within a small range.