With the proposal of “China maritime power strategy”, it has become an urgent necessity to accelerate the development of marine studies in China. Marine organism is an inalienable parts of the ocean, furthermore, this marine organism together with its environments are interact on and influence each other. As a part of marine studies, marine biological studies are more and more important. To commemorate the Chinese scientists in the field of marine biological studies, this paper reviews the major progress of marine biological studies since the founding of the new country, P. R. China. It summarizes and discusses the future directions of marine biological studies, and hope this will lead to a new thriving in the study of marine biological studied in China in near future.

Through 70 years of chemical oceanography research, China has entered a period of rapid development in synchronization with the world's advanced level in this field. The remarkable characteristics of marine chemistry study in China are as follows: (1) the study of marine chemistry has shifted from the study of geochemical distribution systems of elements to the study focused on revealing the deep-seated marine biogeochemical processes; (2) the study of chemical oceanography has achieved to become a comprehensive and interdisciplinary study of multi-fields and multi-viewpoints; (3) more attention has been paid to the study of the changes of marine ecological environment under the influence of both human activities and natural changes, and for offshore and coastal zones, more importance has been attached to analyzing the change process from the perspective of the integration of land and sea. In this paper, we summarized and analyzed the important progresses and developments status of marine chemistry research in China in the past 30 years, mainly from the perspectives of the marine biogeochemical processes of biogenic elements, the marine chemistry of trace elements and isotopes and the chemical oceanographic processes under the effect of biological processes. We hope this can provide references and illuminations for the further study of chemical oceanography.

This paper focusses on the three aspects including marine survey, oceanographic research, marine technology and equipment. It sorts out and summarizes the milestone achievements of scientific and technological developments with international and domestic influence in the marine field in the past 70 years since the founding of the People’s Republic of China. The substantial improvement of the marine scientific and technological strength serves as a crucial support for economic and social development and construction of a maritime power in China.

Aiming at the characteristics of SAR images on the ocean surface, the texture feature method based on gray level co-occurrence matrix is a common method for extracting oil spill information from the sea surface, but the complex information on the actual ocean surface makes the SAR image produce a dark spot area similar to the oil spill phenomenon. The false alarm rate is obtained when the oil feature information is extracted by the texture feature method, and the extraction precision of the oil spill information is reduced. Based on the RADARSAT-2 SAR quadratic polarization image, this paper proposes a texture feature recognition method based on SAR polarization ratio image to identify and extract the oil film on the sea surface. The results show that the texture feature recognition method based on SAR polarization ratio image can effectively and accurately extract the oil spill information on the sea surface. Compared with the texture feature recognition method of VV polarization image, the false alarm rate in the oil spill monitoring process is reduced by 17.96 %, the overall accuracy of oil spill monitoring reached 96.83%.

Based on the Okada model, nonlinear shallow water equation, and nested grid with high resolution, a real-time tsunami warning system of transoceanic-offshore-local is built for Wenzhou and Taizhou’s coastal region of Zhejiang Province. The grid resolution of the refined layer is 900 m. The tsunami warning system includes parallel numerical calculation module, visualization module based on Python 2D library (matplotlib), and product integration module which integrates all numerical graphical products on a web page by Python. Once an earthquake occurs, the system could complete the numerical calculation, visualization processing and graphic product integration within 10 minutes. Firstly, the system has been validated by the 2011 Japan tsunami with the magnitude of M _w 9.0. Then, the extreme potential tsunami from Nankai Trough and Okinawa Trough is simulated by the system in terms of tsunami amplitude and currents. The results show that the tsunami warning system can improve the efficiency and accuracy of tsunami early warning in the coastal region, and provide a scientific basis for tsunami early warning, disaster reduction and decision supporting.

The muddy coast has a large change in scouring and silting, and the beach profile is diverse. Firstly, according to the tidal range relationship between muti-temporal remote sensing watelines, the shape of the shoreline is automatically judged, and then the different functions are used to fit the profile. A new method of coastline remote sensing prediction based on self-adaptive profile morphology is constructed. The central muddy coast in Jiangsu has been empirically applied. The research shows that the concave-shaped erosion shore section, the slope-shaped gentle bank section and the upper convex-shaped siltation section use a three-exponential decay function, a linear function and a second-order polynomial function respectively to have a good profile fitting effect, using three waterlines. The absolute slope error of the profile obtained by data fitting is 0.20‰, –0.17‰, and 0.13‰, respectively, which is less than an order of magnitude than the measured average slope. When using the five waterlines data fitting to calculate the coastline, the error of the coastline plane position of the erosion shore section and gentle shore section are 6.5 m and –91.96 m, respectively, and the error is reduced by about 82.4% compared with the average slope method. Further consideration of seasonal changes in the beach, using the waterline data of the winter to calculate the coastline, has little effect on the erosion of the shore and the long section of the silt, but for the slope-shaped smooth section, the error is reduced by about 63.65%, so the use of winter waterline data has a higher shoreline projection accuracy than the season without distinction.

The statistical characteristics of rapid changes of different grade tropical cyclone intensity and path in the South China Sea are analyzed by the best track data set of tropical cyclones for 69 years from 1949 to 2017 compiled by Shanghai Typhoon Institute of China Meteorological Administrator. The results show that: (1) The change from a severe tropical storm to a typhoon, and from a typhoon to a severe typhoon, are the most frequent events of rapid intensity changes. Most tropical cyclones experience intensity change no more than twice. However, most of the rapid intensifying tropical cyclones occur mainly outside the South China Sea in the western Pacific, and the probability of rapid intensifying over the South China Sea is only 9.8%. (2) The duration of intensity maintenance has an important effect on rapid intensity changes for different grade tropical cyclones. It is the highest rapid change stage during the first 24 hours. Rapid intensity change to typhoon or above grade is easily to occur when the decreasing velocity of central pressure exceeds –12.0 hPa/(6 h). Moreover, the rapid intensifying of tropical cyclones is easily to occur in areas with high sea surface temperature. (3) The deflection of the tropical cyclone path in the South China Sea is mainly in the westbound path, in which the deflection of 5°–30° is the most common, accounting for 48.65% of the total number of tropical cyclones. However, According to the defined path mutation criterion, the probability of path sharp turning is only 15.13%. With the increase of tropical cyclone intensity, the frequency of path sharp turning in the South China Sea decreases rapidly, and the path sharp turning occurs mainly in the coastal area and the east-central region of the South China Sea. This work further refines and enriches the understanding of the intensity and path rapid changes of tropical cyclones in the South China Sea.

As a main carrier of nutrients and pollutants, total suspended matter (TSM) has a significant influence on water environment, especially on estuary water environment. The Ocean and Land Colour Instrument (OLCI) was onboard ESA Sentinel-3A satellite and launched in February 16, 2016, with fine spatial, temporal and spectral resolution. To find the best atmospheric correction method and TSM retrieval model for the application of OLCI in Hangzhou Bay (HZB), six atmospheric correction methods and eight TSM retrieval models were test based on in situ water color data collected from HZB on July 2017. In addition, the OLCI Level 2 product (e.g. TSM and inherent optical properties (IOP) data) was compared with in situ data to evaluate the accuracy and applicability of OLCI Level 2 product. The results show that the method of atmospheric correction based on ultraviolet wavelength (UVAC) and the TSM retrieval model based on band ratio have best performance. Specifically, the mean absolute percentage error (MAPE) of atmospheric correction in four match-up sites is 34.21%, 13.11%, 5.92% and 20.28%, respectively. In addition, the averaged MAPE of atmospheric correction in band Oa2 to Oa12 and Oa16 to Oa18 is 15.23%, and in band Oa4 to Oa10 is less than 8%. The band ratio (Oa16/Oa5) model has the best performance, with a MAPE of 16.49% and root mean square error (RMSE) of 50.92 mg/L in calibration stage, and a MAPE of 19.08% and RMSE of 19.29 mg/L in validation stage. However, the TSM and IOP product derived from C2RCC (case 2 regional coast colour) algorithm and the TSM product derived from OLCI Level 2 product has no linear relationship with in situ data. These results indicate that the above Level 2 product is unsuitable for HZB TSM and IOP remote estimation. Finally, the UVAC method and band ratio model are applied to OLCI imagery that is collected on July 23, 2017. Spatially, TSM shows a relative low value in the center of HZB and relative high value in the south and east part of HZB.

Mesoscale eddies are widely distributed in the ocean and play a significant role in the mixing and transporting of momentum and nutrients. Statistics suggest that more than 80% eddies’ lifetime are less than 1 month, belonging to the defined “short-life eddies” in this paper. This design adopt statistics and comparison, commit to having a earlier reasearch of global scale, short-life eddies. Results show that short-life eddies have a close correlation with ocean current. The most productive places for short-life eddies are those where warm and cold currents or two currents with opposite directions meet, and except in tropical areas of 30°S–30°N, the short-life eddies in other areas have a slight preference for cyclonic. Seasons with low temperature are favorable for short-life eddies in low latitudes, while seasons with high temperature are favorable in high latitudes. Short-life eddies tend to propagate westward in most of areas, however, they notable propagate eastward in eastward currents areas. Meridional deflection is quite messy, but with a tiny preference for equatorward and poleward deflections of cyclones and anticyclones, respectively. The distribution of average displacement and propagation velocity have similar regulation.

Sea ice is an important part of the global climate system. Landfast ice is commonly found in the Antarctic coastal area, which reached the thickest in the middle and late November around Zhongshan Station. Sea ice thickness is one of the important parameters of the sea ice. We presented measurements by taken 1 SIMBA (Snow and Ice Mass Balance Array) buoy and 3 TY buoys to monitor ice thickness based on the bias of different linear temperature gradient in air, snow, ice and sea water in three different landfast ice stations (S1, S2 and S3) in the Prydz Bay outside Zhongshan Station in 2016. The SIMBA measures vertical temperature profiles 4 times a day and TY measures vertical temperature per hour. Both SIMBA and TY buoys were set up in S3 station. Compared with borehole in situ measurements, the ice thickness derived by TY buoys had a mean bias and RMSE of 3.3 cm and 14.7 cm in S1 Station, 6.6 cm and 6.9 cm in S2 Station and 4.0 cm and 4.8 cm in S3 Station. And the mean bias and RMSE for the SIMBA buoys in S3 Station compared with borehole in situ measurements were 8.2 cm and 9.7 cm. The sea ice thickness derived by TY buoys were more agreement with the borehole in situ measurements compared with the sea ice thickness derives from SIMBA buoys in S3 Station. The result of Stefan’s law of ice growth model shows the sea ice growth process and the ice growth rate varied between 0.1 cm/d to 0.8 cm/d, which is faster than the result of TY buoys and is affected by the snow thickness. While compare with limited borehole in situ sea ice thickness measurements and the great uncertain in the sea ice thickness derived by remote sense data, the error for both the TY and SIMBA buoys are reasonable, which will benefit to the future sea ice thickness monitor near Zhongshan Station.