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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 m² 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.

Coastline is a fundamental element of the island and coastal zone research, which is of great significance to the exploitation and utilization of coastal resources. Remote sensing technology has become an important technical means for quickly extracting coastlines due to its macroscopic, multi-spectral and short cycle characteristics. In this study, the apparent reflectance of ground objects on both sides of the coastline was analyzed by using high-resolution remote sensing data WorldView-2, and the feature analysis was carried out to construct the coastline extraction index. On this basis, the shoreline of the Cotton Island, Malaysia was successfully extracted by further combining the texture feature extraction method. Then the accuracy of the extraction results was evaluated based on the lines matching method. The length error is -1.38%. When the buffer radius is 6 pixels, the integrity is 96.96% and the accuracy is 95.37%. The results show that this method could effectively extract the coastline and meet the demand for remote sensing survey.

A research on the sediments of DZ-1 borehole drilled from East China Sea near Zhoushan Islands was conducted for sediment grain-size analysis. The results indicate that the average grain size ranges 2.18-7.76 Φ, poorly sorted, mesokurtic, with skewness ranging -1.75-2.76. The coarse-fine changes of grain size can be correlated with sedimentary dynamics, which fine sediments indicate a relatively low dynamics, and coarse sediments indicate a high dynamics. The relationship among the sediment grain-size parameters of coarse sediments suggests the characters are close to continental sandy ridge of East China Sea, Yangtze Shoal, low-standings of tidal flats, and river in channels, indicating a high dynamics possible during a rapid transgression or erosional facies due to regression; and the one of fine sediments is similar to the modern sediments in muddy zone in East China Sea. The vertically quasi-cyclic changes of the sediment grain-size will be a potential indictor for cold-warm climate-related sediment dynamics.

Skipjack tuna (Katsuwonus pelamis) is widely distributed in the tropical and subtropical water of the worlds ocean, and has high abundance in the Western and Central Pacific Ocean. Evaluating the relationship between its abundance and environment factors using forecasting model is pivotal for sustainable exploration of this species. According to the catch data of skipjack tuna in the Western and Central Pacific during 1998-2013, we used catch per unit effort (CPUE) as an indicator of abundance and analyzed the grey correlation between each environmental factor and CPUE. The optimal model was constructed by choosing suitable environmental factor and comparing the prediction of multiple grey forecasting models with different environmental factors. The results showed that the catch of skipjack tuna gradually increased year after year, whereas CPUE fluctuate dramatically within years. The model M1 including four environmental factors, sea surface temperature, sea surface height, chlorophyll-a, and sea surface temperature anomaly in Nino3.4, was the best model among models with multiple environmental factors, the models mean relative error was 6.475 2 and correlation was 0.687 4 between fitting abundance sequence and predict abundance. The model S2 eliminating SST in November and containing that of May and June, was the best model among the models with single environmental factor, the models mean relative error was 7.419 2 and correlation was 0.791 0 between fitting abundance sequence and predict abundance. The model based on single environmental factor showed a stable and high correlation between actual and predict value, comparing with models based on multiple environmental factors. Therefore, the former forecasting model should be used as suitable model for the prediction of skipjack tuna abundance in the Western and Central Pacific Ocean.

Abrupt temperature drop in seawater could be caused by varied thermal effluents from coastal power plants, seasonal change, cold wave, etc., leading to different degrees of cold shock consequences on poikilotherm, like fish. In this study, we mimicked abrupt temperature drop events with several amplitudes to discuss the cold shock consequences on the incubation, mortality, abnormality rates of Larimichthys crocea eggs and larvae. As results, the three days old larvae were more sensitive to abrupt temperature drop than eggs. Within the optimal temperature, when temperatures decreased rapidly from 22 ℃ to 19 ℃ or to 16 ℃, the hatching success and mortality rates of eggs had no obvious change, but the embryonic and larval developments were slower, and the larval mortality rates were accelerated. When temperatures dropped acutely from 22 ℃ to 13 ℃ and 10 ℃, below the lower lethal temperatures, lethal consequences were caused on fish eggs and larvae, with high mortality rates (84.6%-100% and 72.1%-98.2%, respectively). Thus, we speculated that could shock would cause lethal consequences on the early stage of L. crocea and lead adverse impact on stock replacement and age structure of L. crocea when temperature dropped acutely below the lower lethal temperatures.

The hydrodynamic model and the water quality model of the sea near Sanmen Bay was established to study the effects of the huge water intake and drainage project on water exchange capability of the bay. According to the simulation results, the seawater exchange rate of 40 days in the Sanmen Bay changing from 51.60% to 51.06% after the water intake and drainage project was calculated, it was decreased by 0.54%. According to the sub-regional analysis of Sanmen Bay, the water exchange rate of the waterway near the drainage project decreased the most and it was decreased by 5.36%. The results show that the establishment of water intake and drainage project changes the water flow in the bay, and the water exchange rate varies greatly in different areas. Drainage works cut off the exchange of water from the nearby inlet and the sea,making the water exchange rate here decrease the most.