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.

China has made significant achievements on the applications of satellite ocean remote sensing since 1970s. Three series of Chinese ocean satellites including the ocean color satellites, marine dynamic environment satellites and ocean surveillance satellites have already been constructed, and a preliminary complementary operational application system of satellite ocean remote sensing has been found. In this paper, we review the important progresses of the application of ocean satellite remote sensing in China, focusing on the typical satellite remote sensing application demonstration systems in marine environment and resources monitoring, marine disasters monitoring, marine rights and interests maintaining, marine environment forecasting and safety assurance, as well as typical operational marine satellite monitoring applications. Finally, we give a prospect of the future development of ocean satellite remote sensing applications in China.

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.

Eco-dynamics of marine plankton are remarkably sensitive to changes in their environments. The Arctic Ocean is undergoing rapid environmental changes as the global climate change intensifies. Understanding the seasonal distribution and variation of low-trophic plankton is a prerequisite for exploring the response of ecosystem to changing environment in the Arctic Ocean, and is also an important basis for assessing the carbon sequestration capacity of the Arctic Ocean. Based on above, a coupled ocean-sea ice-biogeochemical cycling model was developed and applied to evaluate the temporal-spatial variations of chlorophyll a concentration and planktonic structures in the Arctic Ocean. The results suggested that: (1) surface chlorophyll a concentration mainly peaks in May, with the higher values on the Pacific side than the Atlantic; since stratification occurs, subsurface chlorophyll a maximums are found in areas having limited nutrients at surface, and the depth of subsurface chlorophyll a maximums gradually deepens from the shelf towards the basin; in September, the high chlorophyll a concentration returns to the upper layer from the subsurface, presenting a sub-peak of surface chlorophyll a concentration on the Pacific side. (2) Substantial regional differences in surface plankton communities exist in the Arctic Ocean due to the influences of the Pacific and Atlantic inflows with variations in nutrients concentrations and structures. Diatom and mesozooplankton are dominant species on the Pacific side where diatom biomass exhibits two peaks in May and September, meanwhile nanophytoplankton maintains relatively high biomass in March, May and June. Atlantic side experiences a seasonal succession from nanophytoplankton to diatom then to nanophytoplankton corresponding to early spring, late spring-early summer, and summer-autumn, respectively. Over the entire growth season, nanophytoplankton and microzooplankton dominate on the Atlantic side. Generally, the peak biomass of zooplankton has a lag for half a month to the peak of phytoplankton biomass in the Arctic Ocean.

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.

Coupled ocean and sea-ice models, developed based on Version 3.6 of the Nucleus for European Modelling of the Ocean (NEMO), with the sea-ice component being Version 3 of Louvain-la-Neuve Sea Ice Model (LIM), are applied for hindcast simulations covering the North Atlantic-North Pacific-Arctic Oceans (NAPA). The two model configurations, NAPA1/4 and NAPA1/12, have nominal horizontal resolutions of (1/4)° and (1/12)° in latitude/longitude, respectively. The model domains cover the Pacific Ocean north of 45°N, the whole Arctic, and the North Atlantic north of 26°N for NAPA1/4 and 7°N for NAPA1/12. A decade-long hindcast from 1993 to 2015 using NAPA1/4 has been completed. The hindcast results of sea-ice, circulation and hydrography variations in the Arctic Ocean are evaluated with available observational data and previously published results. The evaluation suggests that NAPA1/4 possesses reasonable skills in reproducing the key thermal and dynamic processes, and can be applied to study the seasonal and inter-annual variations of sea-ice, water masses, and Atlantic/Pacific inflows/outflows. Preliminary analysis of the NAPA1/12 hindcast during 1993-1996 suggests that increasing horizontal resolution simulates more details of the spatial structures of sea-ice, water-mass properties, and ocean circulation.

This thesis aimed to analyze the stable multimodal (3-peaked) particle size distributions (PSDs) of flocs in the Zhujiang River Estuary with the field observation data getting by LISST and the bottom boundary layer observation system during the dry season in 2010. The results show that the mean diameter of the basic building blocks of flocs, so-called primary particle, is about 8.3–9.0 μm; the mean diameter of microflocs in a range of 36–100 μm, and macroflocs have a size range of 180 μm to thousands of micrometers. In the neap tidal periods, the suspension sediment of halocline is dominated by the macroflocs with strong flocculation process; the mean diameter of flocs is increases and is controlled by flocs during the moderate and spring tide. The dynamic change of the tide has little impact on the multimodal PSDs and morphological parameters, with aggregation and breakage of the flocculation in the dynamic equilibrium. Study results further demonstrate the turbulent dynamic mechanism of flocculation by combining the turbulence data collected by the bottom tripod and the simplified Population Balance Equation (PBE). It is that, the high shear of the peak flow would enhance breakage of macroflocs to microflocs and decrease the mean diameter of flocs, on the contrary, aggregation is much stronger than breakage. It also shows that PSDs are in according with observation by solving PBE based on gaussian moment integral method. It turns out that PBE which containes the turbulent dynamic mechanism can be used to study the flocculation of cohesive sediment with turbulence and PSDs data.

Based on the 34th Chinese Antarctic scientific expedition "Xiangyanghong 01" cruise around the Antarctic Peninsula from January to February 2018, the properties and exchanges of water masses in the region of Antarctic Peninsula were analyzed. The main water masses are Antarctic Surface Water, Circumpolar Deep Water, Warm Deep Water, Antarctic Bottom Water, Bransfield Srait Bottom Water. Weddell Sea Warm Deep Water and Weddell Sea Deep Water flow into Scotia Sea through the Orkney Passage, the Bruce Passage on the east of the South Orkney Plateau and the Hesperides Gap on the west of the South Orkney Plateau. Among them, the deepest current velocity is 0.25 m/s in Orkney Passage, which allow denser Weddell Sea Deep Water to flow to Scotia Sea; the current velocity is 0.13 m/s in Bruce Passage, which allow warmer Warm Deep Water flows and the temperature of Warm Deep Water passing through this gap is the lowest, and the current velocity is 0.10 m/s in Hesperides Gap, only colder Warm Deep Water and lighter Weddell Sea Deep Water can pass. Southward currents and northward currents were observed on both sides of the South Orkney Plateau, but northward currents and water exchange are stronger. Water flow westward along the north side of the South Scotia Ridge after entering the Scotia Sea through the Passages on both sides of the South Orkney Plateau, with a velocity of 0.21 m/s. A branch of Antarctic Circumpolar Current in Drake Passage flow eastward to Scotia Sea, and influenced by Warm Deep Water and Weddell Sea Deep Water flowing westward, Circumpolar Deep Water in the Scotia Sea is obviously weaker than that in the Drake Passage. Affected by the eastward Antarctic Circumpolar Current, Weddell Sea Deep Water on the north side of the South Scotia Ridge is warmer than that on the south side. The water on the South Scotia Ridge may be affected by the Circumpolar Deep Water and Warm Deep Water in the north, Shelf Water in the West and Winter Water in the east, so the structure of the water on the South Scotia Ridge is much complex.

Core AMS01 dredged on the northwestern continental rise of the Amundsen Sea was used to reconstruct the history of ice sheet and paleoproductivity since MIS9 (about 34 ka BP) based on the analyses of color reflectance, grain size and geochemical proxies. The results show that: (1) Grain size and paleoproductivity proxies of the core exhibits evident glacial–interglacial cycles of Quaternary; (2) The interglacials such as MIS9, MIS7 and MIS5 have low sedimentation rates, brown sediments, low ice-rafted detritus (IRD) contents and high paleoproductivity, indicating warm climate, limited sea ice and large-scale retreat of the ice sheet in the Amundsen Sea sector; (3) Glacial ages such as MIS8c, MIS8a, MIS6 and MIS2 have relatively high sedimentation rates, gray sediments, high IRD and low biological components, which indicate the ice sheet expanded greatly to the edge of the continental shelf, and the continental rise became a proximal environment close to the grounded ice sheet and/or floating ice shelf with dense sea ice and icebergs, and significantly lowered marine productivity; (4) In the glacials and interglacials, ice sheet and paleoproductivity also have certain fluctuations, especially in MIS8b interstadial, the light brown sediments with low IRD and elevated marine productivity make it be like the environment of interglacial period, which indicates that the ice sheet and ocean in the Amundsen Sea sector are more sensitive to climate change than those in the East Antarctica.

To investigate the heat stress responding strategies of Antarctic ice algae, the characteristics of a catalase gene CiCAT from the transcriptome of Antarctic ice alga Chlamydomonas sp. ICE-L were analyzed. The length of CiCAT is 2 066 bp encoding a catalase of 492 amino acids. In the phylogenetic tree of catalase amino acid sequences, Antarctic ice alga is clustered with green algae. The amino acid sequence identities of CiCAT are about 80.5% and 78.9% to the catalase from Dunaliella salina and Haematococcus lacustris, respectively. The changes of CiCAT gene expression and catalase activity in Antarctic ice alga were also investigated. Under heat stress, both the relative expression state of CiCAT gene and catalase activity changed from up-regulation to down-regulation over time. After heat stress treatment for 24 h, the expression of CiCAT gene was almost unchanged, while the enzyme activity in the heat treatment group was significantly higher than that in the control group. After 72 h's heat stress treatment, both gene expression and enzyme activity reached the highest level. Our preliminary results show that antioxidase system plays an important role in Antarctic ice algae responding to heat stress, which is similar to that in temperate algae and higher plants.