Volume articles

The tropical Indian Ocean Sea Surface Temperature Anomaly (SSTA) and the Indian Ocean Dipole (IOD) indices are predicted, using the multiple linear regression model, the Markov model and the neural network model respectively. 63 years' hindcast experiments are set up to compare the differences between linear and nonlinear statistical models in detail. And the results reveal that the statistical models are little different from the complicated dynamic model. Their skillful prediction (correlation coefficients above 0.5) could reach 3 months for DMI, about 5-6 months for EIO index and 8-9 months for WIO. Since the IOD event has a strong seasonal phase lock, the DMI can be predicted previously for 4 months in fall. When the synchronistic ENSO index is added as a predictor, the prediction skill, especially the IOD peak, will be improved. The complicated neural network and the simple regression model are proved to be with a similar prediction skill.

The Complex EOF (CEOF) analysis of the upper abnormal circulation of the tropical Indian Ocean in May was carried out based on 52 years Carton data. The inter-annual and inter-decadal variation of Wyrtki Jet, and the relationship between the Jet and the Asian tropical summer monsoon were presented. The main results show that the first mode could be called as Wyrtki Jet mode which reflected the general intensity of Wyrtki Jet in May of every year. The first mode had obvious inter-annual variation in every 8 years, which was consistent with one of the inter-annual variations of Asian summer monsoon. It also had obvious inter-decadal variations in every 17 and 23 years. The latter was consistent with the PDO period of the main climate mode in North Pacific. When the intensity of Wyrtki Jet was weaker, the estabishment data of the summer monsoon in South China Sea and South Asia was usually earlier, and the summer monsoon in South China Sea was most likely stronger, and vice versa. The second mode reflected the non-uniformity of Wyrtki Jet in the east and west directions of equatorial Indian Ocean. It had very obvious inter-decadal variations in every 11 and 18-19 years. The former was consistent with the period of NPGO of the secondary climate mode in North Pacific. The second mode also had inter-annual variation in every 5 years.

The shelf slope and the Taiwan Strait are two main boundaries of the East China Sea, which obtain considerable heat and salinity as well as nutrients from the northwestern Pacific and the South China Sea. In this paper, based on the satellite drifter trajectories, a reliable method is established for estimating the cross-boundary exchanges by mapping the irregularly-distributed trajectories to the regular homogeneous grid. With this method, the calculated density of trajectories reveals the location of the Kuroshio main axis, and further indicates significant cross-slope exchanges. The statistical results reveal the remarkable region feature of water exchanges along the shelf slope of the East China Sea, showing seven dynamic exchange zones, i.e., three inflow (shoreward) zones and four outflow (offshore) zones. The study also shows that the cross-slope exchange has prominent seasonality. The most significant exchange and the most distinctive inflow occurs in autumn while the weakest in spring. The exchange through the Taiwan Strait is mainly northward and the most intense exchange occurs in the eastern side of the strait. The exchange through the Taiwan Strait reaches the strongest in summer but the weakest in spring and in winter.

Suspended particulate matter (SPM) plays an important role in determining the light field under water, which then affects the primary production and waters ecological environment. Therefore, SPM concentration is one of the important parameters for water quality and hydrographic environment monitoring.Based on a total of 89 in-situ SPM concentration and spectral data collected from June to July and from November to December 2011, the spectral characteristics of suspended matter in the Yellow River Estuary and its adjacent waters were analyzed. And an empirical inversion algorithms for SPM concentration with different combinations of bands or band ratios was established. The result showed that the algorithm with combining the R _rs655/ R _rs560 and R _rs865 was the best, the APD of algorithm was 25.65%, and the correlation was 0.95. Using the R _rs retrieved from Landsat 8 OLI data and the SPM algorithm, 7 maps of the SPM concentration in the Yellow River Estuary and its adjacent waters from 2014 to 2016 were obtained. The result indicated that the SPM concentration reduced gradually from the coastal to offshore waters, and the value of SPM concentration had significant changes during different periods.

With the rapid development of the eastern coastal harbor region and the continuous formation of man-made landforms, the geomorphic pattern of the harbor area has also changed accordingly. Quantitative study of the spatial and temporal pattern changes of coastal artificial constructed landform can be a comprehensive scientific and practical evaluation of human construction behavior, and it has a certain scientific and practical value. Four periods TM/OLI remote sensing images of 1990, 2000, 2010 and 2015 from Xiangshangang Bay were taken as the main data source, the changes of artificial constructed landform intensity during the last 25 years in Xiangshangang coastal zone were analyzed and its spatial pattern evolution was further explored. The research shows: (1) The development trend of artificial constructed landform in the coastal zone of Xiangshangang Bay appears a rapid growth in the early stage, a slow increase in the medium term and a strong follow-up, and its area growth has significant historical characteristics. (2) The number of punctate and surface topographic patches in each county (city) area rise in fluctuation as a whole, but its internal development level varies greatly. The rate and degree of geomorphic development in Ninghai County and Xiangshan County are in the lead. (3) The pattern evolution process can be divided into four important stages: point-like dispersion period, surface aggregation period, strip extension period and compound, update the diffusion period.

Two core sediment samples collected in the area of 16 ^th July 2010 split oil accident by box crab during April 2013. The biological dispersant were used during the split treatment in heavy pollution area. Site BQ050 and Site BQ007 located in the area where biological dispersant and chemical dispersant were used, respectively. The TOC content, soluble organic content (asphalt A), δ ¹³C _org value and ²¹⁰Pb _ex of sediments were analyzed for identifying the contaminated organic matters. The sediments of Site BQ050 have higher organic matter content (TOC: 0.58%~1.51%, mean: 1.15%; asphalt A: 0.061 5%~0.566 4%, mean: 0.174 9%, up to 0.566 4% in depth 10~12 cm), heavier δ ¹³C _org value(-22.2‰~-20.5‰PDB, mean: -21.74‰PDB), and higher asphalt A/TOC ratio (7.0%~34.8%, mean: 14.13%) indicating that the organic matter characterized by exotic. Meanwhile, the δ ¹³C _org values of sediments are similar, which shows the same organic input in the depth from 2 cm to 16 cm. The ²¹⁰Pb _ex of sediments has the similar distribution to the asphalt A. The sediments of Site BQ007 have much lower asphalt A content and asphalt A/TOC ratio compared to the sediments of Site BQ050, and the ²¹⁰Pb _ex distribution is normal. The content of ²¹⁰Pb _ex decreasing with depth shows the logarithmic correlation. The exotic organic matter is low in the Site BQ007. The split oil(characterized by asphalt A)has been migrated to about depth of 16 cm in the Site BQ050 until April 2013.

The water exchange capacity of the encircled harbor has an important influence on the water quality of the harbor basin, adding water exchange channel is an effective measure to improve it. Taking the seawall reconstruction project of Zhapo fishing port as an example, the irregular triangular mesh and finite volume method were employed, based on the research results of tidal current numerical simulation, a two-dimensional convection-diffusion model was established. The numerical simulation research of water exchange capacity before and after the expansion of Zhapo fishing port was carried out, and the half exchange period and water exchange rate of the harbor before and after the project were evaluated. The results show that the water exchange capacity of Zhapo fishing port is strong, the half-life time of water body is 129 hours before the engineering, and 104 hours after the project. After the project, the Zhouzaixia breakwater is changed into a culvert-type bridge, so that the water body exchange channel is formed between the fishing port and the offshore, the water body interaction and water body exchange capacity inside and outside the harbor basin are increased, and the corresponding water body exchange capacity is enhanced. As a comparison, two aquaculture areas outside the harbor basin have strong water exchange capacity as they are well connected with the sea, so the limit change in water exchange capacity caused by the project is reasonable.

The phenomenon of phytoplankton blooms in the northwest of Luzon Island is frequently observed in winter. In our study, using the multi-satellite merged ocean color remote sensing data from November 1999 to February 2015 in the northwestern region of Luzon Island, the spatial and temporal changes of Chl-a concentration in long time series were investigated by means of the empirical orthogonal function (EOF) decomposition method and multiple correlation analysis(MCA). Combined with physical environmental parameters such as wind speed(WS), sea surface temperature(SST) and sea level anomalies(SLA), the relationship between Chl-a and surrounding sea environments was then investigated in the study. The results show that centers of winter Chl-a blooms in northwest of Luzon Island appear often at the location of about (19°N, 119°E). Significant multiple correlation coefficient (R=0.782 6, P<0.05) from the multiple correlation analysis between Chl-a and oceanic conditions indicates that the wind parallel to the coastline and the wind stress curls enhance winter upwelling in the study area, increasing the input of the nutrients into the upper layer, which is probably the main mechanism of the formation of phytoplankton blooms in the area. At the same time, the advection effect of the background flow field is likely to induce the upwelling area to be inconsistent with the center of phytoplankton blooms, triggering the phenomenon that the centers of phytoplankton blooms shifted northward along with the water body in the area.

The pathogens causing mortality in Yesso scallop (Patinopecten yessoensisis) larvae in the hatchery of Zhangzidao Group Co. Ltd. were identified. A high mortality of the Yesso scallop larvae occurred during the seedling process: the larvae lost their ability to swim, their cilia fell off and their valves closed, they then sank to the bottom of the nursery pond and died. Vibrio has been reported as the primary pathogen for massive mortalities of different bivalves both in hatchery and in the field worldwide. Total viable vibrios counts in moribund larvae were 1.12×10 ⁴ CFU/g on Tryptone Citrate Bile Sucrose agar plates. Two dominant strains, named V1 and V2, accounted for 64.3% and 32.1% of total vibrios counts respectively. Blood agar plates were used to measure hemolysis of isolated strains. Strain V1 exhibited beta hemolysis, while strain V2 exhibited alpha hemolysis. A challenge test showed that the signs of infected larvae were identical to those of natural moribund larvae, the cumulative mortality caused by strains V1 and V2 was significantly higher than that of the control (P<0.05) and bacteria were re-isolated from the dead larvae. Strains V1 (GenBank Accession No: KR232924) and V2 (GenBank Accession No: KF232925) shared 99.9% and 99.2% identity with Vibrio splendidus ctt 31/5 and Vibrio tasmaniensis 007, respectively, by 16S rDNA sequencing. The presence of genes coding for virulence factors was examined by PCR analysis, showing that strain V1 possessed the extracellular metalloprotease (vsm) gene. Antibiotic susceptibility assays showed that both strains were sensitive to the rifampicin, florfenicol and sulfafurazole.

As one of the most important marine groups, zooplankton are very sensitive to climate change and anthropogenic activities. In this study, the structures and variations of zooplankton community were considered on the basis of monitoring data in Bohai Bay in the summer from 2004 to 2015, and the relationship between the zooplankton and environmental variables was examined. Results showed that species number and biodiversity indices of zooplankton appeared an increasing trend in Bohai Bay. Among 7 phyla identified, two major groups of Arthropoda and Coelenterata showed an increasing abundance in recent years. As a result, the zooplankton composition in the Bohai Bay had changed dramatically during 12 years: the number of large-sized copepods such as Calanus sinicus and Labidocera euchaeta had decreased gradually, while small copepods such as Acartia pacifica and Centropages dorsispinatus as well as gelatinous zooplankton such as Oikopleura dioica and Eirene ceylonensis had expanded. It was revealed that the zooplankton community variation mainly related with the environmental variables such as changes in temperature, salinity and nutrients concentration in Bohai Bay.

A study was carried out by “Dayang Yihao” from May 25 to June 17,2011. The meiofauna samples were collected from 7 stations in the south Mid-Atlantic Ridge. The results showed that 10 benthic groups were founded from the surveyed area. The average abundance and biomass of meiofauna were (60.63±54.77) ind/10 cm ² and (9.42±8.92) μg/10 cm ², respectively. Nematodes were present the great abundance (47.42±47.99) ind/10 cm ²,accounting for 78.21% of total abundance of meiofauna in study area. Besides,Sarcomastigophora and Copepod were also found to be the dominant taxa, constituting 16.63% and 3.91% of total abundance of meiofauna,respectively. Copepod had the most biomass in the 10 benthic groups,followed by Nematoda and Sarcomastigophora. The analysis of vertical distribution has shown that the abundance of meiofauna decreased with the depth in the sediment. About 73.55% of meiofauna live in the top 0-2 cm layer. In terms of body size,the range of 32-125 μm accounted for 75.32% of meiofauna.

Based on the method of the controlling factors analyses, a satellite remote sensing algorithm was developed to retrieve the aquatic pCO ₂ in the Pearl River Estuary in summer time. The end members of the Pearl River water and Kuroshio water were applied to quantify the pCO ₂ variations controlled by the water mass mixing and thermal dynamic effects, and a look-up table was generated to fulfill the calculation. Moreover, relationship between the a _CDM(443 nm) and surface layer water salinity was established to retrieve the salinity from ocean color satellite data. In addition, based on the underway measured pCO ₂ and matchup satellite Chl- a data, the model for the biological effect on the pCO ₂ was developed. Finally, the mixing and biological effects on the pCO ₂ were combined to retrieve the pCO ₂ from the satellite. Based on the established model, the comparisons between the retrieved pCO ₂ and underway measured pCO ₂ were carried out. The results show that if only considering the mixing and thermal dynamic effects it would overestimate the pCO ₂, while if considering the biological effect additionally it would much improve the results not only on the magnitudes, but also the variations. The satellite-retrieved pCO ₂ also reveals that in summer time, the coastal region in the Pearl River Estuary is a sink of the atmosphere CO ₂, while the outer shelf is a weak source of CO ₂.

A 3D temperature-salt numerical model of the sea area near Jinjiang was established,based on MIKE3, horizontal and vertical diffusion in different tide was simulated. The results show that brine distribution is affected by water level and current velocity,the higher the water level and velocity,the greater the effect of dilution and diffusion,and the smaller the vertical diffusion. The brine discharge from 200 000 t/d seawater desalination plant,the range of salt-rise is about hundreds of meters in horizontal and about 3 m in vertical. With the increasing of water level and current velocity,the salt-rise is spreading quickly. If there is no sensitive area nearby,it will not have a significant impact on the marine environment.

The sun glitter is caused by the direct reflection of the sun light from the rough sea surface, and its intensity is strongly affected by the sea surface roughness. The sea surface roughness is mainly affected by the sea surface wind field. Therefore, the remote sensing images containing sun glitter information are of great significance in ocean dynamic processes detection and sea surface wind speed estimation. In this study, 25 remote sensing images of MISR(Multi-angle Imaging Spectro Radiometer)sensor equipped with Terra Satellite acquired from February 2016 to March 2017 were used. The zenith angle, azimuth angle and sensor angles from the MISR images were obtained, then the normalized radiation intensities of sun glitter were corrected, while the sea surface roughness were further acquired, and the sea surface wind speed was estimated. Finally, the estimation results were compared to the model wind speed data of ECMWF(European Centre for Medium-Range Weather Forecasts).The results show that the correlation coefficients (0.745) are high, and the root mean square error and the mean absolute deviation error are 1.514 m·s ^-1 and 1.319 m·s ^-1, respectively. The preliminary experimental results show that it is feasible to extract the sea surface wind speed by using MISR multi-angle optical remote sensing images.

The influence of sediment turbidity on chlorophyll sensor determination of in vivo chlorophyll fluorescence was studied. The results show that turbidity can cause fluorescence effect and light shielding effect on the determination of chlorophyll fluorescence. In the range of 100 NTU turbidity, the fluorescence value of chlorophyll shows a good linear relationship with the turbidity of sediment suspension, which increases with the increase of turbidity. When actually measuring the in vivo chlorophyll fluorescence of diatoms in water, turbidity of sediment suspension causes light shielding effect that decreases in vivo chlorophyll fluorescence as turbidity increases. The concentration of microalgae in the water is higher, the light shielding effect is stronger. In 1 000 mV (including 10 μg/L), the highest concentration of microalgae, sediment suspension can reduce the chlorophyll fluorescence value by 20% at 100 NTU turbidity. Based on the experimental data, a correction method of turbidity effect of in vivo chlorophyll fluorescence detection is proposed. Within 100 NTU turbidity, the corrected deviation of chlorophyll fluorescence values is reduced to less than ±10% and the corrected fluorescence value is close to the true chlorophyll fluorescence.

Monitoring and recognizing the dynamic changes of coastline are vital for the protection of coastal zones and the rational exploitation of coastal resources. In this study, Canny edge detector was used to extract the coastline data of the Hainan Island in 1990, 2000, 2010 and 2015 from the data source of Landsat TM/OLI images. Then, the changes of coastline length and land area were obtained to analyze the characteristics of temporal and spatial variations regarding the coastline of the Hainan Island over the past 25 years. The results show that the total length of the island's coastline had increased by 33.58 km from 1990 to 2015, with the coastline expanding outwards and the offshore area increasing in size. The changes mainly happened in the north and the east coasts where the artificial coastline had evidently increased and natural coastline such as muddy coastline diminished. Largely affected by human factors, the coastal development was diversified in patterns, with pond farming, construction of cities and towns, ports and piers as the main forms.

The speckle noise of high resolution airborne MiniSAR image is serious, and in image the edge of the reclamation is fuzzy and messy. For more efficient extraction of reclamation information, a method of watershed segmentation was presented based on texture feature for SAR image of reclamation. First, the airborne MiniSAR image was filtered by the gray level co-occurrence matrix, and the texture feature image was obtained. Then the watershed algorithm was used to segment the texture feature image and to get the morphological reconstruction image, and finally, the threshold method was used to segment the morphological image, and to get the final results of the two values. On the one hand, this method suppresses the influence of speckle noise by adjusting the gray co-occurrence matrix texture filtering window size . On the other hand, it uses watershed algorithm of fuzzy edge clutter images to improve the accuracy of information extraction of sea reclamation. Test results show that this method is effective for the image segmentation of high resolution SAR image.

The spectral absorption characteristics of vegetation are not only closely related to the growth of vegetation, but also affected by soil moisture and other factors. In this study , Phragmites australis, Spartina anglica and Scirpus mariqueter were taken as the research objects, which are the typical vegetation in Nanhui Wetland of Yangtze River Estuary. Based on the calculation of spectral characteristic parameters, their spectrum of absorption and deformation of PSDI values were analyzed. Finally, combining with the measured soil moisture, the correlation between PSDI values of three kinds of vegetation and soil moisture values were analyzed. The results show that the PSDI value of Spartina anglica is maximum, the PSDI value of Scirpus mariqueter is minimum, and that of Phragmites australis is somewhere in between. It indicates that Spartina anglica is most affected by environment. The correlation between PSDI of Spartina anglica and soil moisture is maximum, the correlation between PSDI of Phragmites australis and soil moisture is minimum, while that of Scirpus mariqueter is somewhere in between.This points that Spartina anglica has stronger adaptability to wetland environment.

The geochemical characteristics and spatial distribution characteristics of 7 heavy metal elements in the surface sediments from the offshore area of eastern Sanya were studied, and the degree of pollution was assessed by using the index of geoaccumulation and the Nemerow comprehensive index methods. It is found that the content of heavy metals in the surface sediments from the offshore area of eastern Sanya are lower than the average value of elemental content in the neritic sediments of China,and the content of heavy metals conforms to the standard of Marine Sediment QualityⅠ, and the spatial distribution of the most heavy metal elements approximately follows the elemental particle-size control law. The provenances of heavy metals in this area are mainly from the terrigenous fine-grained sediments. The results of the index of geoaccumulation and the Nemerow comprehensive index methods all indicate that the heavy metals in the surface sediments of the study area are below pollution level and belong clean condition, the environment of surface sediments is fine.

Surface sediment samples were collected from Sanmen Bay in Zhejiang Province. The distribution of total concentration of five heavy metals (Zinc, Chromium, Cadmium, Copper, and Lead) was determined, and their speciation was investigated using BCR extraction method. The pollution level and ecological hazard of these heavy metals were evaluated with three methods: Potential Ecological Risk Index ( Eⁱ_r), Risk Assessment Code (RAC), Ratio of Secondary and Primary Phase (RSP). The distribution of five metals show that the total concentrations in inner bay are higher than those out of the bay. The results of metal speciation in surface sediment show that the residual fraction of four metals are predominated except for Pb, of which Zn accounts for 79.20%~84.25%, Cr accounts for 93.24%~96.16%, Cd accounts for 34.71%~57.58%, and Cu accounts for 66.06%~79.51%, respectively. The dominated fraction of Pb is the part bounded to amorphous Fe and Mn oxides and hydroxides, which accounts for 56.58%~76.44%. The evaluation results indicate that Cd is the primary element in the area according to Potential Ecological Risk Index, and which is consistent with that by the Risk Assessment Code method. However, Pb is evaluated to be the primary element with potential ecological threat according to the Ratio of Secondary and Primary Phase, and followed by Cd.

In order to meet the expanding applications of side-scan sonar and improvement of more users' requirement, some hydrography standards were published by International Hydrographic Organization and the world's developed countries one after another. For the purposes of improvement of Chinese specifications for side-scan sonar survey, the comparison of system detection capability, survey lines plan, data acquisition requirements, quality control and other measurements were studied in detail. And the problems and weakness of Chinese specifications for side-scan sonar survey were analyzed.It points out the weakness of China's specifications for side scan sonar in the measurement line layout, data acquisition requirements, etc., in order to promote the realization of China's measurement standards as soon as possible with international standards.

In order to investigate the effects of natural additive on Plectropomus Leopardus, 4 kinds of different contents of natural products (astaxanthin, xanthophyll, spirulina and corn gluten meal ) were selected to formulate the baits to feed the leopard coral grouper ( Plectropomus leopardus) in a recirculating aquaculture system for seventy-five days. The main growth index and the L^* value (Lightness), a^* value (red—green) and b^* value (yellow—blue) of body color in these fish's eight parts (head cheek, opercula, dorsal, abdomen, dorsal fin, pectoral fin, tail fin and caudal peduncle) were measured by scale, straightedge and colorimeter before and after the experiment. The results show that compared with control group, these four additives have no significant impact on the weight gain rate, specific growth rate, feed coefficient of leopard coral grouper ( P<0.05); all of these additives make the L^* value slightly smaller, and there are significance occurrings on some parts. Compared with the control group, all of the additives significantly lift the a^* value and b^* value of leopard coral grouper, among which the experimental feed with astaxanthin has the most significant effect.

In this study, residues, possible sources and ecological risk of 22 polychlorinated biphenyls (PCBs) in five mollusks from Zhoushan Fishing Ground (ZFG) were studied. The total concentration of PCBs in the collected samples ranged from 18.0 ng/g dry weight (dw) to 95.9 ng/g dw, with average of 51.9 ng/g dw. Compared with mollusks from other sea areas, the levels of PCBs in ZFG were at the median worldwide. The results of composition profiles show that penta- and di-PCBs are the most abundant. The health risk of PCBs calculated was far below 1, indicating low risk to human health.

The local typhoon refers to the tropical cyclone formed in the South China Sea. 1949-2014 CMA-STI compiled "best track dataset for tropical cyclone" was chosen in this study, the local typhoon intensity and intensity change characteristics on the scope of the study area (5°-22.5°N, 105°-120.5°E) were discussed. The results showed as follows: (1) The time curves of local typhoon intensity were similar to symmetric funnel-shape, that was changed from weak-strong-weak, intensity change was the most significant before and after 6 h in maximum intensity, and intensity change in summer was quickly than in winter. (2)The local typhoons had one intensified centers, located in the east of Hainan Island coastal area, but which decreased obviously near the south China coastal land area; further analysis showed that the typhoon intensified/weakened area moved with the changing seasons, in the summer it was mainly in the north offshore/nearshore area near 18°-23° N, while in the winter it was close to the west offshore/nearshore area near 10°-18° N, and the average decreased rate in winter was bigger than that in summer. (3) Furthermore, the eastward local typhoon intensity was generally stronger than that of westward, average intensity of summer eastward typhoon was the largest and that of winter westward typhoon intensity was the least; around the maximum intensity, the summer eastward typhoon intensity change was the fastest and winter westward typhoon was the slowest. Summer westward typhoon intensity distribution was stronger in the north, and eastward typhoon intensity distribution formed a northeast belt-shaped. In winter, westward and eastward typhoon intensity distribution was stronger in west. The difference of such spatial distribution was mainly due to the typhoon moving paths with the seasons. (4)The duration time of maritime activity with the intensity and variation in the range was proportional. The shorter maritime activity, the more westward paths, the average intensity was weaker, intensified/weakened centers was much smaller, intensified/weakened rate was slower; conversely, the longer maritime activity, the more eastward paths, the intensity distribution had multicenter, its average intensity was stronger, intensified/weakened center was more concentrated and broad, intensified/weakened rate was faster.

Equatorial Westerly Wind Bursts (WWBs) are characterized by sudden increase of surface westerlies over the equatorial region. Previous studies showed that the WWBs play a fundamental role in triggering and maintaining the El Niño event. In this thesis, we evaluate the simulation of WWBs in the state-of-the-art models from the Coupled Model Intercomparison Project phase5(CMIP5). Most of the models can reproduce the eastward propagation of WWBs in El Niño years, as occurrences of WWBs are strongly dependent on sea surface temperature in the tropical western-central Pacific. The WWBs generally occurs before the development of El Niño. Unlike what was proposed in previous studies, we found that MJO does not significantly increase the likelihood of WWBs in both observations and model simulations.

The sediments from 12.7 m to 17.4 m in the core QG01 which was taken from the west coast of Bohai Bay were analyzed with grain size analysis, XRD and OSL, the characteristics of clay mineral assemblages and used as paleoclimatic proxies were also investigated. The sediments are composed of sandy silt, silty sand, and clayey silt, with the rage 4.11~7.79 Φ. The results show that illite-chlorite-kaolinite-smectite is the main clay mineral assemblage. The KI and the ratio values of “(illite+chlorite)/(kaolinite+smectite)” are used as paleoclimate proxies. The results show that two proxies can reflect the feature of climate change when the trends of the two proxies are corresponding. On the contrary, when the trends of the two proxies do not correspond with each other, they cannot be used as paleoclimatic proxies since the source of sediments may change.

Multibeam sonar data can effectively reflect the features of seafloor topography and its substrates. The shipboard multibeam data were used to characterize the topography, geomorphology and the backscatter intensity characteristics of typical tectono-geographic units of the 60°-61°E segment in Carlsberg Ridge, Northwestern Indian Ocean, aiming to describe the strength of the magmatism and tectonism of the studied ridge segments. Basically, the 60°-61°E segment of Carlsberg Ridge showed symmetrical spreading with discontinuous zone. The Segment I was more influenced by tectonism, with more fractures occurred in the rift valley. The segment axis and nearby backscatter intensity reached -29 dB, with the rift wall height difference over 1 200 m. The segment also had deeper valley bottoms, higher rift valley walls, higher flank/width ratio (78.7-126.2) but less off-axial linear structures. In the rift flank, the normal fault plane was wider and the dip angle was smaller. Compared to the center of the segment, the volcanic activities in segment end had lower eruption frequency but larger eruption scale, and erupted volcanic edifices were larger in the aspect of number and volume. In contrast, the Segment II was dominated by magmatism with axial volcanic ridges and numerous symmetrically developed off-axial linear structures. The segment axis and nearby backscatter intensity reached -35 dB. The rift flank/width ratio was 77.6-116.8. The difference of the rift wall height was less than 500 m. The linear structures had relatively high aspect ratio, and were approximately symmetric on the flank of the rift. It is suggested that multibeam backscatter data combining with the topography analysis can provide quantitative evidence for the study of the strengths of the tectonism and magmatism of the mid-ocean ridge.

Icequakes on Laohugou Glacier No.12 were observed by operating a portable digital seismometer for 9 days in Oct. 2015. Lots of seismic signals relating to glacier dynamic characteristics were found. On the basis of signal frequency and duration time, two types of seismic event can be divided. Short-period icequakes have time duration less than 0.1 s, the frequency domains are among 20-100 Hz and the numbers are up to 6 600 per day. The majority of seismic events are short-period icequakes. Long-period icequakes have time duration from several minutes to several hours, the frequency domains are among 0.1-10 Hz and the numbers are up to 296 during the observation. Comparing the time distribution of short-period icequakes with local air temperature, it is found that once temperature drops, the numbers of short-period icequake increase rapidly. And once temperature rises, the numbers of short-period icequake decrease. The time distributions of short-period icequakes have a diurnal cycle. It is inferred that once air temperature decreases, temperature of glacier ice decreases and as a result, the fracture at the surface of glacier under tensile thermal stress was happened. Using Maxwell Model to calculate glacier stress change, the diurnal cycle of short-period icequakes can be explained.

Salt marsh is one of the major coastal wetland types in the world's temperate and subtropical regions. Taking Yancheng coastal area as an example and using 6 remote sensing satellite images of past 30 years, the temporal and spatial evolution of salt marsh in this area were analyzed by simple vegetation cover index (NDVI) crude extraction and visual interpretation. The influencing factors of these changes were also discussed. The results show that the area of salt marsh has risen and declined sharply at first and then risen slightly in the past 30 years, it has decreased about 18 km ² so far. The salt marsh continues to expand outward, the maximum expansion distance reaches 5.5 km. The width of the salt marsh has also changed over time, salt marsh vegetation types have also undergone different degrees of evolution. The landscape index shows that landscape fragmentation is getting worse. Mane, suaeda and reeds have decreased significantly, and plenty of spartina covers the wetland. Among the natural and human factors that affect the temporal and spatial changes of salt marshes, the effects of reclamation activities are the most pronounced.

Particulate biogenic silica (BSi) and chlorophyll a (Chl a) were determined at 61 stations in the Pearl River Estuary and adjacent coastal waters in summer, in order to evaluate spatial variability in biogenic silica and the interference of lithogenic silica (LSi) in the bulk silica leached from the alkaline solution. Our results showed that Chl a concentrations ranged from 0.06 to 8.64 μg·L ^-1. Particulate BSi concentrations varied from the detect limit to 14.3 μmol·L ^-1, LSi concentrations were 0.00-9.56 μmol·L ^-1 and the average ratio of LSi to LSi+BSi was 0.38 mol·mol ^-1. The average ratio of Si to Al was 2.42 mol·mol ^-1, comparable to the value reported by RAGUENEAU et al(2005). A significant correlation was found between particulate biogenic silica and Chl a, which indicated diatom and phytoplankton biomass in the water column. LSi concentrations varied spatially, with high BSi, LSi and low LSi/(LSi+BSi) ratios in the nearshore area, low BSi, LSi and high LSi/(LSi+BSi) ratios in the offshore waters, low BSi, high LSi and high LSi/(LSi+BSi) ratios in the estuary, high BSi, LSi and high LSi/(LSi+BSi) ratios in the upwelling region. LSi and LSi/(LSi+BSi) ratios in the bottom water were higher than those in the surface water. In addition, some limitations caused by other methodologies of BSi measurements had been discussed.

The potential pressure caused by sea use activities on marine eco-environment in Laizhou Bay was quantitatively evaluated based on GIS and geospatial modeling by combining the spatial distribution of marine ecological red line zone. We firstly identified the spatial distribution patterns of all anthropogenic pressures as well as their potential impact on key marine habitats. The general characteristic of spatial distribution of potential anthropogenic pressure on the eco-environment in Laizhou Bay can be described as that in the offshore area is higher than that in the far-shore area and the sequence from high to low is: the bay-head, the east area, the west area. Overall, the high pressure area is concentrated in the sea area within 10 km and the water depth within 5 m. It is worthy to note that a few of marine ecological red line zones, such as marine special protected areas, natural reserves, and important estuarine ecosystems, have already threatened by pressure caused by sea aquaculture and salt industry. The study reveals the spatial distribution pattern of the potential pressure of sea use activities on the marine ecological environment in Laizhou Bay. Accordingly, a few policy suggestions are also proposed at the end to implement the spatial planning of marine ecological red line zones and regulate utilization of sea area.

The design of compressive cabin which is used in the underwater vehicle requires that the design strength and stability can be improved to the maximum, and the weight can be reduced as much as possible to satisfy the requirements of the overall index. The Design Explorer Module in ANSYS Workbench was used for the fast optimization design of the compressive cabin, and a number of optimal candidate results were obtained at one time. The optimal design scheme was obtained by comparison and analysis. Then, contact analysis was carried out in the form of assembly to ensure that the structure would not fail under the condition of high pressure. Finally, the stability analysis of the cabin structure was carried out to ensure that the structure could not cause instability failure in a large depth environment. The result of this study provides the reference for rapid optimization design, strength and stability checking of the underwater vehicle's compressive cabin.

According to the comparative analysis result of historical heavy metals contents in the surface sediments from the Jiulong River Estuary and Xiamen Bay from 1980s, the average value of heavy metals contents in this sea area was established, and the overview of heavy metals distribution characteristic has been made. Besides, the background level of heavy metal element contents was determined according to the need of potential ecological risk index method, it provides the reference data of average value and background level for further research and evaluation. Combined with the survey data in August, 2016, the integrated risk evaluation results indicated an unoptimistic situation of this sea area, the eastern of Xiamen Sea Area mainly belonged to low ecological risk, Jiulong River Estuary mainly belonged to heavy ecological risk, and the rest of Xiamen Bay mainly belonged to moderate ecological risk.

To explore the effect of polyamines on the growth of diatoms, Chaetoceros sp., Phaeodactylum tricornutum Bohlin and Conticribra weissflogii were cultured indoor by adding spermine, spermidine, putrescine, cadaverine and phenylethylamine as exogenous polyamines. The results show that different polyamines reveal different specificity for the growth of different diatoms at the same temperature. Spermidine promotes the growth of Chaetoceros sp. And cadaverine promotes the growth of P. tricornutum, while spermine inhibit on the growth of P. tricornutum. The polyamines mainly promote the pre-growth of Conticribra weissflogii (before 13 d), and inhibit the growth (after 13 d). The timely and proper addition of polyamines can promote the growth of diatoms effectively and increase the reproductive efficiency of diatoms.

In order to study the effect of typhoon on the cultured Portunus trituberculatus, the changes of T-SOD, CAT, MDA, GSH, ACP and Na ⁺, K ⁺-ATPase in the hearts, gills and hepatopancreas were detected in 12 hours before and after typhoon “Canhong”(1509) at Xiangshan in July, 2015. The typhoon increased highly significantly the activity of the T-SOD enzyme ( p<0.01) and increased significantly CAT enzyme( p<0.05) in the gills. After typhoon, the MDA and GSH content in gills increased insignificantly ( p>0.05). T-SOD enzyme activity in the hepatopancreas showed an insignificant trend of decrease ( p>0.05) while the CAT enzyme activity showed an insignificant trend of increase ( p>0.05), MDA content increased significantly ( p<0.05) and the increase of the GSH content was highly significant ( p<0.01). In the hearts, the levels of T-SOD, CAT enzyme activity and GSH content increased and the MDA content decreased, but these changes were not significant( p>0.05). In addition, the ACP enzyme activity in the gills and the hearts increased insignificantly( p>0.05), which was reduced but not significantly in the hepatopancreas ( p>0.05). The Na ⁺, K ⁺-ATPase activity in the gills decreased highly significantly ( p<0.01), but increased highly significantly in the hepatopancreas ( p<0.01) and significantly in the heart ( p<0.05) . This study reveals that the typhoon can cause the cultured P. trituberculatus stress response in the short term and solutions are need to take to avoid typhoon damage to cultured P. trituberculatus.

Mesoscale eddies play an important role in energy transfer and material exchange in the ocean. Long-lived mesoscale eddies are frequently observed ocean processes at the shelf edge of the Black Sea. The researches about cross-shelf exchange are not enough, e.g., the seasonal characteristics of the exchange flux between shelf and basin induced by eddies, and the role of Rim Current in the cross-shelf exchange are not clear. Based on a three-dimensional circulation model output, combined with automatic eddies detection method, this study calculated cross-shelf exchange between the continental shelf and the deep sea in the northwestern Black Sea from 2002 to 2010. The contributions of Rim Current and eddies to the exchange process were comparatively investigated. The correlation coefficients between the intensities of Rim Current in the northwestern Black Sea region and the inward and outward transport across the continental shelf are 0.57 and 0.67 respectively, and the correlation coefficient between the Rim Current location and the cross-shelf exchange capacity is 0.52. Seasonal changes in intensity and location of the Rim Current lead to seasonal variations in the cross-shelf flux in the northwestern Black Sea. Eddies-induced cross-shelf exchange accounts for about 16% to 31% of the total cross-shelf exchange during March to August, in this research seasonality of cross-shelf flux has been confirmed. Even a single eddy is able to influence significantly the flux in the northwestern Black Sea. About volume of northwestern-shelf water was renewed by a single mesoscale eddy over the period 5 May to 20 July 2005, which is equivalent to 30.9% of the overall volume of shelf water.

Many studies pointed out that the North Atlantic Oscillation (NAO) is a physically meaningful mode but the Arctic Oscillation (AO) likes a statistical artifact mode from EOF analysis. To further explore their difference from a new perspective, here we applied a conditional maximum covariance analysis (CMCA) to capture the cross-seasonal teleconnection between preceding Arctic marginal sea ice concentration (MSIC) and the following wintertime NAO, from which the ENSO signals and the linear trends were removed. Statistically significant results showed that the dominant Ocean-Atmosphere interaction was the atmospheric effect on the MSIC anomalies, with a peak occurring when atmosphere leading MSCI by 0-1 month. However, the most eye-catching phenomenon was that the wintertime negative NAO could be significantly linked to the gradual evolution of preceding Arctic MSIC anomalies from high-summer to early-winter, with lead-times up to 6 months. However, according to previous studies, Arctic sea ice anomalies could only show significant precursory signals for winter AO about 4 months, suggesting that Arctic MSIC has a stronger impact on the following winter NAO than AO. And it also confirmed that there was a difference between AO and NAO from a new perspective. Further analysis showed that the gradual evolution of changes in Arctic MSIC was mainly driven by sea surface heat fluxes and surface temperature anomalies. Besides, we also re-investigated the effect of negative NAO on the boreal winter climate anomalies and the corresponding possible physical mechanisms.

The effective resolutions of six remotely sensed reanalysis products of sea surface salinity(SSS) from the soil moisture and ocean salinity (SMOS) and Aquarius/SAC-D missions were studied, in terms of the qualitative map, zonal wavenumber spectra, and root mean square (RMS) error. The mechanisms behind their differences also are studied. It suggests that the CATDS-0.25° reanalysis is unable to capture the small-scale structures in SSS and performs the worst in representing spatial variability in SSS. Its higher spectral energy is mostly a reflection of noises in the tropics while those in regions such as along the western boundary flows are signals. The BEC-L3-0.25° reanalysis, which has small RMS errors, clear salinity maps, and remarkable mesoscale energy, is the best fit for portraying mesoscale (25-100 km) SSS features. The SSS in the BEC-L4-0.25° reanalysis is overly attenuated by its singularity analysis remapping method. The Aquarius-V2-1.00° reanalysis, with an additional smoothing procedure, performs well in depicting large-scale (＞100 km) salinity phenomena. The Aquarius-CAP-1.00° reanalysis generates the smallest RMS errors benefiting from its combined active-passive (CAP) algorithm, however, and leads to a somewhat noisy, artificial pattern with unreasonable along-track strips. The CATDS-1.00° reanalysis is roughly equivalent to the Aquarius-V2-1.00° in terms of pattern, energy, and error features.

Airborne laser bathymetry gets a lot of attention because of its unique advantages. But its detection capability is limited at present. In order to solve the problem of its applicability, VIIRS data were used to evaluate the performance of laser bathymetry in the South Yellow Sea region. Firstly, the diffuse attenuation coefficients of 490 nm band in the South Yellow Sea region were retrieved by using field measured data and satellite images. Secondly, the linear relationship between diffuse attenuation coefficients of 490 nm band and 532 nm band was established. Finally, taking CZMIL system as an example, the ability of laser bathymetry in the South Yellow Sea region was evaluated, and the applicable range of CZMIL system along the coast of Jiangsu Province was estimated. The results show that the maximum sounding capability of the CZMIL system in the South Yellow Sea region is about 0.5-40 meters, and the applicable range of CZMIL system in the coastal waters of Jiangsu Province is about 4 700 m ² when the water surface is at the theoretical the lowest low water.

Inversion of shallow seawater depth using satellite multi-spectral data is an important measure of water depth measurement. The existing water depth inversion method is to establish an inversion model of unified mathematical parameters in the study area, without considering the problem of spatial non-stationarity caused by changes in sea floor sediment and water quality. In this study, the Geographically Weighted Regression (GWR) model was used to estimate the regression parameters in space. For the influence of the bandwidth of the GWR model on the inversion accuracy, a Cross Validation (CV) method was used to determine the best bandwidth, taking the sea areas of Woody Island and Ganquan Island in the South China Sea as experimental areas, the feasibility and accuracy of the GWR model were verified based on WordView-2 multi-spectral data. As a result of the experiment, the accuracy of the GWR model in the study area of Woody Island was improved by 36.05% compared with the linear regression model, and in the ranges of 0-5 m, 5-10 m, 10-15 m, and 15-20 m, the precision was increased by 49.46%, 39.97%, 12.36% and 49.68% respectively. The precision of GWR model in the study area of Ganquan Island was improved by 8.08%. In the ranges of 0-5 m, 5-10 m, 10-15 m, and 15-20 m, compared with the linear regression model, the precision was improved by 12.05%, 16.23%, 4.49% and 12.23% respectively, indicating that the GWR model has a better water depth inversion performance.