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A two-dimensional coupled tide-surge model was used to investigate the effects of tide-surge interactions on storm surges along the coast of the Bohai Sea, Yellow Sea, and East China Sea. In order to estimate the impacts of tide-surge interactions on storm surge elevations, Typhoon 7203 was assumed to arrive at 12 different times, with all other conditions remaining constant. This allowed simulation of tide and total water levels for 12 separate cases. Numerical simulation results for Yingkou, Huludao, Shijiusuo, and Lianyungang tidal stations were analyzed. Model results showed wide variations in storm surge elevations across the 12 cases. The largest difference between 12 extreme storm surge elevation values was of up to 58 cm and occurred at Yingkou tidal station. The results indicate that the effects of tide-surge interactions on storm surge elevations are very significant. It is therefore essential that these are taken into account when predicting storm surge elevations.

Oceanic eddies may cause local sea surface temperature （SST）, height, and salinity anomalies in remote sensing （RS） images. Remote sensed SST imagery has proven to be an effective technique in oceanic eddy detection, because of its high temporal and spatial resolution. Various techniques have been used to identify eddies from SST images. However, mainly owing to the strong morphological variation of oceanic eddies, there is arguably no uniquely correct eddy detection method. A scheme of algorithm based on quasi-contour tracing and clustering of eddy detection from SST dataset is presented. The method does not impose fixed restrictions or limitations during the course of ＂suspected＂ eddy detection, and any eddy-like structures can be detected as ＂suspected＂ eddies. Then, ＂true＂ eddies can be identified based on the combination of intensity and spatial/temporal scale criteria. This approach has been applied to detect eddies in the East China Sea by using Operational SST ＆ Sea Ice Analysis （OSTIA） dataset. Experiments proved that oceanic eddies ranging in diameter from tens to hundreds of kilometers can be detected. Through investigation of the 2007-2011 OSTIA daily SST dataset from the Kuroshio region in the East China Sea, we found that the most active regions for oceanic eddies are those along the Kuroshio path, northeast of Taiwan Island, the Yangtze Estuary and the Ryukyu Islands. About 86% of the cyclonic eddies and 87% of the anticyclonic eddies have the size of 50-100 km in diameter. Only 25% of the anticyclonic eddy and 26% of the cyclonic eddy have the strength more than 0.4℃ in the sea surface layer.

The Kuroshio inflow northeast of Taiwan Island plays an important role in the heat and nutrient balances over the East China Sea （ECS）. Based on merged satellite altimeter data and the PCM-1 mooring observation at the East Taiwan Channel （ETC）, the study employs a correlation iteration scheme to find the optimal transport index for the Kuroshio inflow. The sea level dif- ference with the highest correlation to the ETC transport is across the ECS shelf break rather than along the PCM-1 line. The counter-intuitive result is caused by large signal noise and poor track coverage of altimeters near the Taiwan coast. The opti- mal altimetric index is highly correlated with the two-year in-situ measurements as well as the ten-year output of the global as- similation model. It serves as a better estimator of Kuroshio inflow than those using tidal gauge data, and helps pinpoint a 5 cm mismatch of mean sea level in the Keelung tidal record. The mean transport of Kuroshio inflow based on the twenty-year alti- metric index is 20.55 Sv with a standard deviation of 3.05 Sv. Wavelet spectrum of the index reveals that semi-annual period dominates the Kuroshio variation northeast of Taiwan Island.

We reconstruct the environmental evolution of the East China Sea in the past 14 kyr based on glycerol dialkyl glycerol tetraethers（GDGTs） in a sediment core from the subaqueous Yangtze River Delta. Two primary phases are recognized. Phase I（13.8–8 cal kyr BP） reflects a predominantly continental influence, showing distinctly higher concentrations of branched GDGTs（averaged 143 ng/g dry sediment weight, dsw） than isoprenoid GDGTs（averaged 36 ng/g dsw）, high BIT index（branched vs. isoprenoid tetraethers） values（〉0.78） and a fluctuating GDGT-0/crenarchaeol ratio（R_（0/5）, varied from 0.52 to 3.81）. Within this interval, temporal increases of terrestrial and marine influence are attributed to Younger Dryas（YD）（ca. 12.9–12.2 cal kyr BP） cold event and melt-water pulse（MWP）-1B（11.5–11.1 cal kyr BP）, respectively. The prominent transition from 8 to 7.9 cal kyr BP shows a sharp decrease in BIT index value（〈0.4） and increase in crenarchaeol, which marks the beginning of phase II. Afterwards, the proxies remain relatively constant, which indicates that phase II（7.9 cal kyr BP-present） is a shelf sedimentary environment with high stand of sea level. Overall, the BIT index in our record serves as a good marker for terrestrial influence at the site, and likely reflects the flooding history of the region. The TEX_（86）（Tetra Ether Index of tetraethers consisting of 86 carbons） proxy is not applicable in phase I because of an excess terrestrial influence; but it seems to be valid for revealing the annual SST in phase II（21.6±0.9°C, n=49）. In contrast, the MBT＇/CBT（Methylation of Branched Tetraethers and Cyclization of Branched Tetraethers） proxy appears to faithfully record the annual mean air temperature（MAT）（14.3±0.63°C, n=68） and presents an integrated signal over the middle and lower Yangtze River drainage basin.

Anaerobic oxidation of methane and sulfate reduction was studied in the pore waters of four cores at two stations of the middle Okinawa Trough. Pore water vertical distributions of sulfate, methane, sulfide, total alkalinity, ammonium, and phosphate were determined in this study. Our results show strong linear sulfate concentration gradients of 6.83 mmol/L m-1 in Core A and 5.96 mmol/L m-1 in Core C, which were collected from two stations. Concurrent variations of methane, total alkalinity and hydro- gen sulfide all exhibit steep increases with depth at both cores, which indicate active methane seep activities around two sta- tions. Pore water ammonium and phosphate concentrations reveal minor influences of organic matter degradation on sulfate reduction at two stations. Sulfate methane interface （SMI） was extrapolated from linear sulfate profiles in methane seep cores. Shallower SMI depths （A： 4.9 mbsf; C： 5.4 mbsf） indicate strong methane fluxes and active anaerobic oxidation of methane in the underlying sediments.

Atmospheric Intercomparison Project simulations of the summertime diurnal cycle of precipitation and low-level winds over subtropical China by Intergovernmental Panel on Climate Change Fifth Assessment Report models were evaluated. By analyzing the diurnal variation of convective and stratiform components, results confirmed that major biases in rainfall diurnal cycles over subtropical China are due to convection parameterization and further pointed to the diurnal variation of convective rainfall being closely related to the closure of the convective scheme. All models captured the early-morning peak of total rainfall over the East China Sea, but most models had problems in simulating diurnal rainfall variations over land areas of subtropical China. When total rainfall was divided into stratiform and convective rainfall, all models successfully simulated the diurnal variation of stratiform rainfall with a maximum in the early morning. The models, overestimating noon-time （nocturnal） total rainfall over land, generally simulated too much convective rainfall, which peaked close to noon （midnight）, sharing some similarities in the closures of their deep convection schemes. The better performance of the Meteorological Research Institute atmospherer. ocean coupled global climate model version 3 （MRI-CGCM3） is attributed to the well captured ratio of the two kinds of rainfall, but not diurnal variations of the two components. Therefore, a proper ratio of convective and stratiform rainfall to total rainfall is also important to improve simulated diurnal rainfall variation.

Wave energy resources assessment is a very important process before the exploitation and utilization of the wave energy. At present, the existing wave energy assessment is focused on theoretical wave energy conditions for interesting areas. While the evaluation for exploitable wave energy conditions is scarcely ever performed. Generally speaking, the wave energy are non-exploitable under a high sea state and a lower sea state which must be ignored when assessing wave energy. Aiming at this situation, a case study of the East China Sea and the South China Sea is performed. First, a division basis between the theoretical wave energy and the exploitable wave energy is studied. Next, based on recent 20 a ERA-Interim wave field data, some indexes including the spatial and temporal distribution of wave power density, a wave energy exploitable ratio, a wave energy level, a wave energy stability, a total wave energy density, the seasonal variation of the total wave energy and a high sea condition frequency are calculated. And then the theoretical wave energy and the exploitable wave energy are compared each other; the distributions of the exploitable wave energy are assessed and a regional division for exploitable wave energy resources is carried out; the influence of the high sea state is evaluated. The results show that considering collapsing force of the high sea state and the utilization efficiency for wave energy, it is determined that the energy by wave with a significant wave height being not less 1 m or not greater than 4 m is the exploitable wave energy. Compared with the theoretical wave energy, the average wave power density, energy level, total wave energy density and total wave energy of the exploitable wave energy decrease obviously and the stability enhances somewhat. Pronounced differences between the theoretical wave energy and the exploitable wave energy are present. In the East China Sea and the South China Sea, the areas of an abundant and stable exploitable wave energy are primarily located in the north-central part of the South China Sea, the Luzon Strait, east of Taiwan, China and north of Ryukyu Islands; annual average exploitable wave power density values in these areas are approximately 10-15 kW/m; the exploitable coefficient of variation （COV） and seasonal variation （SV） values in these areas are less than 1.2 and 1, respectively. Some coastal areas of the Beibu Gulf, the Changjiang Estuary, the Hangzhou Bay and the Zhujiang Estuary are the poor areas of the wave energy. The areas of the high wave energy exploitable ratio is primarily in nearshore waters. The influence of the high sea state for the wave energy in nearshore waters is less than that in offshore waters. In the areas of the abundant wave energy, the influence of the high sea state for the wave energy is prominent and the utilization of wave energy is relatively difficult. The developed evaluation method may give some references for an exploitable wave energy assessment and is valuable for practical applications.

The pelagic species is closely related to the marine environmental factors, and establishment of forecasting model of fishing ground with high accuracy is an important content for pelagic fishery. The chub mackerel（Scomber japonicus） in the Yellow Sea and East China Sea is an important fishing target for Chinese lighting purse seine fishery. Based on the fishery data from China＇s mainland large-type lighting purse seine fishery for chub mackerel during the period of 2003 to 2010 and the environmental data including sea surface temperature（SST）, gradient of the sea surface temperature（GSST）, sea surface height（SSH） and geostrophic velocity（GV）, we attempt to establish one new forecasting model of fishing ground based on boosted regression trees. In this study, the fishing areas with fishing effort is considered as one fishing ground, and the areas with no fishing ground are randomly selected from a background field, in which the fishing areas have no records in the logbooks. The performance of the forecasting model of fishing ground is evaluated with the testing data from the actual fishing data in 2011. The results show that the forecasting model of fishing ground has a high prediction performance, and the area under receiver operating curve（AUC） attains 0.897. The predicted fishing grounds are coincided with the actual fishing locations in 2011, and the movement route is also the same as the shift of fishing vessels, which indicates that this forecasting model based on the boosted regression trees can be used to effectively forecast the fishing ground of chub mackerel in the Yellow Sea and East China Sea.

The seasonal variations of several main water masses in the southern Yellow Sea （SYS） and East China Sea （ECS） in 2011 were analyzed using the in-situ data collected on four cruises. There was something special in the observations for the Yellow Sea Warm Current （YSWC）, the Yellow Sea Cold Water Mass （YSCWM） and the Changjiang Diluted Water （CDW） during that year. The YSWC was confirmed to be a seasonal current and its source was closely associated with the Kuroshio onshore intrusion and the northerly wind. It was also found that the YSCWM in the summer of 2011 occupied a more extensive area in comparison with the climatologically-mean case due to the abnormally powerful wind prevailing in the winter of 2010 and decaying gradually thereafter. Resulting from the reduced Changjiang River discharge, the CDW spreading toward the Cheju Island in the summer of 2011 was weaker than the long-term mean and was confined to flow southward in the other seasons. The other water masses seemed normal without noticeable anomalies in 2011. The Yellow Sea Coastal Current （YSCC） water, driven by the northerly wind, flowed southeastward as a whole except for its northeastward surface layer in summer. The Taiwan Warm Current （TWC） was the strongest in summer and the weakest in winter in its northward movement. The Kuroshio water with an enhanced onshore intrusion in autumn was stable in hydrographic features apart from the seasonal variation of its surface layer.

We compared data of sea surface wind from the European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA-Interim) with that collected from eight buoys deployed in the Yellow and East China seas. The buoy data covered a period from 2010 to 2011, during which the longest time series without missing data extended for 329 days. Results show that the ERA-Interim wind data agree well with the buoy data. The regression coefficients between the ERA-Interim and observed wind speed and direction are greater than 0.7 and 0.79, respectively. However, the ERA-Interim wind data overestimate wind speed at most of the buoy stations, for which the largest bias is 1.8 m/s. Moreover, it is found from scatter plots of wind direction that about 13% of the ERA-Interim wind data can be classified as bad for wind speeds below 6 m/s. Overall, the ERA-Interim data forecast both the wind speed and direction well, although they are not very representative of our observations, especially those where the wind speed is below 6 m/s.