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Acoustic Doppler Current Profiler (ADCP) is an effective way to monitor ocean internal waves. However, due to the influence of the instrument itself and complex ocean environment noise, there are a lot of noise and some abnormal velocity values in the velocity data recorded by ADCP. In order to further improve the extraction accuracy of internal solitary waves in the sea, the weight function factor of IGG3 method was introduced according to the characteristics of the shipboard ADCP velocity data, and the Robust Vondrak filter was designed. In order to verify the effectiveness and superiority of Robust Vondrak filtering method, it was compared with three traditional filtering methods: fast Fourier transform, wavelet transform and sliding average. The experimental results show that the Robust Vondrak filtering method can not only remove the flow velocity noise, but also effectively eliminate abnormal flow velocity values, so it has certain advantages compared with the traditional filtering methods. The Robust Vondrak filtering method can extract internal solitary waves accurately and the horizontal velocity of each layer is clear. It is a good method to extract internal solitary wave.

Diurnal cycle in two satellite-derived precipitation datasets(IMERG and TMPA) based on both Global Precipitation Measurement (GPM) and Tropical Rainfall Measuring Mission (TRMM) are compared with data obtained from 23 rain gauges mounted on floating buoys in the tropics for the period 1 April, 2014 to 30 April, 2018. The results show that both satellites underestimate the ranges of precipitation diurnal variations. In the Pacific Ocean and the Indian Ocean, both IMERG and TMPA observe the rainfall maximum in the early morning and the minimum in the evening, which are consistent with the rain gauge buoys. However, in the tropical Atlantic, both satellite datasets show quite different patterns of the diurnal cycle from the rain gauge buoys, which is due to little precipitations over the Atlantic Ocean leading to large biases in both satellites and rain gauge buoys.

From the continental shelf at the east of Hangzhou Bay, 28 sample columns were acquired. The thermal conductivities of soils at different depths (0.2 m,1.0 m and 1.8 m) from these cores were tested by thermal probe. Correspondingly, particle size of the soils were also tested. Through the comparison between six kinds of soils in the study area, It was found that those with higher sand content (>10%) have bigger thermal conductivities. Besides, water content and dry density have significant effect on thermal conductivities of certain type of soil. Average value of thermal conductivity for superficial soils in Hangzhou Bay area,mixed deposit area and shelf sandy area are respectively 1.25 W·m^-1·K^-1, 1.45 W·m^-1·K^-1 and 1.46 W·m^-1·K^-1, which indicates that thermal conductivities increase from the coast to open waters. On the other hand, vertical variation of thermal conductivities shows that spatial factors including water depth and buried depth have no direct effect on the thermophysical properties of seabed soils.

Based on the multi-beam bathymetric data of the Yap-Mariana Trench in the Western Pacific Ocean, the high-precision bathymetric topographic maps in the rectangular areas of 9.8°N-13.2°N and 132.2°E-145°E were obtained. Then the detailed geomorphologic analysis shows that there are large-scale horst-graben geomorphology on the slope of the southern part of Mariana Trench, obvious segmentation in the northern part of the Yap Trench, and large-scale ridge-trough geomorphology in different distribution directions in the Philippine Basin and the Parece Vela Basin. The results show that the complex topographic and geomorphological features are mainly controlled by plate motion, and the topographic and geomorphological features of the region are classified according to the published research results.

Underway sea surface pCO₂, sea surface temperature, sea surface salinity data, and discrete DO data in the East China Sea were obtained from August 23, 2017 to September 6, 2017. The distributions of pCO₂ in the Changjiang River Estuary and the adjacent sea areas were examined. Meanwhile, the effect of strong wind on air-sea CO₂ flux in this area was discussed based on data of a revisited section before and after a strong wind event. The results show that sea surface pCO₂ (145~929 μatm) in the study area was higher in the nearshore and lower in the offshore area. Biological production consumed dissolved inorganic carbon, and lowered sea surface pCO₂ of the Changjiang plume waters, which acted as carbon sink. The wind event (the maximum wind speed was 9.7 m·s^－1) triggered vertical mixing, enhanced carbon source significantly at nearshore area(from 0.2±1.9 to 55.0±12.4 mmol·m^－2·d^－1). While, the estimated CO₂ sink at offshore waters was stronger than that before the wind (from -12.7±2.3 to -16.8±2.5 mmol·m^－2·d^－1). Therefore, large bias in air-sea CO₂ flux estimation will be introduced if the influence of typhoon and cold-air events are not considered.

Using the WorldView-2 high-resolution satellite images, two models were studied: log transform model(Stumpf 2003) and dual bands linear regression model(Lyzenga 1985). Firstly, the correlation between water depth and each band was analyzed under different sediment conditions. Then the L-M(Levenberg-Marquardt) algorithm was used to solve the model parameters. Finally, the accuracy of the two models was compared and analyzed. The results show that for coral sediment, the determination coefficient and root mean square error of Lyzenga 1985 model are 0.902 and 1.651 respectively, which are better than those of Stumpf 2003 model(0.882, 6.421); For sandy sediment, the determination coefficient and root mean square error of Lyzenga 1985 model are 0.897 and 0.529 respectively, which are better than those of Stumpf 2003 model(0.779, 0.723). It can be seen that Lyzenga 1985 model is better than Stumpf 2003 model in the area of clear coral and sandy sediment, and Lyzenga 1985 model has stronger universality and can present relatively stable inversion effect.

The object-oriented classification method was utilized to interpret 4 time-series Landsat data of 1990,2000,2010 and 2015 to identify the aquaculture ponds in coastal area of Hainan Island. Based on the landscape indexes and centroid migrate model,the temporal and spatial characteristics of aquaculture ponds and its impact on the coastal ecological environment were explored. The results showed that the area of aquaculture ponds of Hainan Island continued to grow from 1990 to 2015 and the regional differences were obvious. The distribution position of aquaculture area moved to the northeast of Hainan Island and the landscape indexes showed that the landscape pattern of the aquaculture area tended to be fragmention. The expansion of aquaculture ponds invaded natural wetlands such as mangroves, causing damage to the coastal ecological environment. Therefore, reasonable planning and scientific upgrading are needed for the sustainable development of aquaculture.

Mangrove is a kind of biological coast composed of salt tolerant mangrove plant communities. Its growth status is of great significance to the coastal zone. Remote sensing technology has become one of the main means for mangrove monitoring. In this study, taking the mangrove in Shankou, Beihai of Guangxi as an example, using the coastal zone imager data of HY-1C satellite, combined with its texture parameters, the mangrove information was extracted, and the mangrove vegetation indexes were analyzed. The results showed that from October to November 2018, the RVI value of mangroves was greater than 1, and this in some areas was greater than 5; the NDVI value of mangroves varied from 0 to 0.01, and the average value was greater than 0.5; the EVI value of mangroves was mainly concentrated between 0.2 and 0.7. The results of different vegetation indexes showed that mangrove in Shankou grew well.

An Archiving Validation and Interpretation of Satellite Oceanographic(AVISO) mesoscale eddy tracking dataset from satellite altimeter during the period from 1993 to 2017 was used to classify the mesoscale eddies in the East China Sea(ECS) according to the path. The results show that 318 cyclones and 276 anticyclones were detected in the ECS during the 25-year period. These mesoscale eddies were classified into the following types according to the path: (1) Eddy generated on the continental shelf of the ECS intrudes into deep sea(148 cases); (2) Eddy generated in deep sea intrudes into the continental shelf of the ECS(35 cases); (3) Eddy spreads along the isobath(180 cases); (4) Eddy wanders around(121 cases); (5) Eddy generated in Pacific Ocean intrudes into the shelf area of the ECS(25 cases) and (6) Eddy generated in Pacific Ocean intrudes into the ECS(85 cases). There existed very obvious seasonality for these six types. And the seasonal distribution for cyclones and anticyclones is diverse. The quantity of eddies for the type 3 is higher in spring and summer, lower in autumn and winter. The distribution of eddies for the type 1 is more evenly. The quantity of cyclones for the type 1 is the lowest in summer, and higher in spring and winter. The seasonal distribution for mesoscale eddies is related to the variations of the Kuroshio. The mean lifetime of eddies for type 4 is the longest, about 44 days. The mean amplitudes of eddies for type 1 and 5 are the largest, about 13.2 cm. The maximum mean diameter of the eddies is for type 5, about 122 km. The mean lifetime, amplitude and diameter of eddies for type 6 are the smallest.

Marine survey is the basis for marine sciences. Survey components and demand have been developed with input from blooming new technology and research methods. Also, the related products gradually become highly professional, diversified and international. Thus it will be necessary to develop international standards for marine survey. Here we compare the differences of strategies, organizations, standard systems and the published marine survey standards among China, the United States and the European Union. It is suggested to bring China national marine survey standards into the international market by: (1) learning from the American standardization system which features free-competition; (2) learning from the European standardization system which has perfectly met the requirements of international community; (3) the better bridge of ISO/TC8/SC13 (Marine technology subcommittee of International Organization for Standardization).