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The correlation between polycyclic aromatic hydrocarbons (PAHs) and organic carbon is an important indicator of the marine environment. In this paper, twenty-six surface sediment samples were collected from the Bohai Sea and the North Yellow Sea as the study area, and the contents of sixteen PAHs ranged from 71.34 ng·g−1 to 240.78 ng·g−1 with an average of 143.26 ng·g−1 by gas chromatography. The source analysis indicated the source of PAHs in the surface sediments of the study area was more complex, and the percentage of combustion sources was higher than that of petroleum sources, which might cause less negative ecological risks. The average content of total organic carbon (TOC) was 5.25%, as determined by automatic potentiometric titration, and the content of TOC was higher in the Bohai Sea than in the North Yellow Sea. TOC was significantly correlated with HWM-PAHs but was not correlated with LWM-PAHs, which proved organic matter was more effective in controlling high-molecular-weight PAHs than low-molecular-weight PAHs in the surface sediments of the Bohai Sea and the North Yellow Sea. [ABSTRACT FROM AUTHOR]

A regional ocean ensemble simulation with slightly different initial conditions demonstrates that internal variability is formed (not only) in the Bohai and Yellow Sea. In this paper, we analyze the relationship between the internal variability and the baroclinic instability, (represented by the Eady predicted theoretical diffusivity K t ; the larger the K t , the stronger the baroclinic instability level). In the ensemble, with tidal forcing, the spatial correlation between the Eady predicted theoretical diffusivity K t and the internal variability amounts to 0.80. Also, the time evolution trends of baroclinic instability and internal variability are similar. Based on this evidence, baroclinic instability may be a significant driver for internal variability. This hypothesis is validated using an additional ensemble of simulations, which is identical to the first ensemble, but this time, the tides are inactivated. This modification leads to an increase in internal variability, combined with the strengthening of baroclinic instability. In addition, the baroclinic instability level and internal variability variation co-vary consistently when comparing summer and winter seasons, both with and without tides. Our interpretation is that a stronger baroclinic instability causes more potential energy to be transformed into kinetic energy, allowing the unforced disturbances to grow. [ABSTRACT FROM AUTHOR]

Chinese continental margins are experiencing remarkable environmental changes driven by anthropogenic activities and climate change. As an important habitat and sea-based fish farming resource in China, the Bohai was selected as a case study to understand how ecosystems and social interactions are influenced by multi-stressors. The Bohai ecosystem has been considerably modified. The Bohai coastline has been significantly changed (e.g., total sea area decreased and morphology changed) by sea reclamation and riverine sediment transport related to agriculture and erosion. Therefore, the strict reclamation policy and “Grain-for-Green” program have been issued to protect the coastline. Nutrient concentrations and composition have been changed by fertilizer application, wastewater discharge, and variations in seasonal patterns of riverine nutrient fluxes. Hence, pollution control and prevention are necessary. More seriously, fishing resources have been altered, as a result of environmental changes and overfishing. Therefore, a summer fishing ban and stock enhancement should be vital besides environmental improvement. This study can help to predict and mitigate impacts on global continental margins that are experiencing similar environmental stress.

Tides are of great importance for ocean mixing and nearshore ocean engineering. Bottom friction is a major factor in tidal dissipation and is usually parameterized by the bottom friction coefficient (BFC). BFC is a critical parameter in numerical tidal models and is known to vary with time and space, as calculated with measured data. However, it is difficult to accurately adjust the spatially-temporally varying BFC in numerical tidal models. Based on the relationship between the spatially-temporally varying BFC estimated by adjoint data assimilation and the simultaneously simulated current speed, an empirical formula of BFC with a dependence on the current speed is proposed. This new empirical formula of BFC is compared with several traditional empirical formulas, including the constant BFC, the Chezy-Manning BFC, and two depth-dependent BFCs. When the four principal tidal constituents (M2, S2, K1, and O1) in the Bohai, Yellow and East China Seas (BYECS) are simulated, the mean vector error between the simulated results obtained using the current speed-dependent BFC and the TOPEX/Poseidon satellite altimetry data (the tidal gauge data) is 8.81 cm (10.62 cm), which is decreased by up to 8.1% (18.2%) compared with those using the several commonly used empirical formulas of BFC. Furthermore, in the sensitivity experiments where only the M2 tide in the BYECS, the M2, S2, K1, and O1 tides in the Bohai and Yellow Sea (BYS), and the M2, S2, K1, and O1 tides in the South China Sea (SCS) are simulated, the errors between the simulated results obtained by using current speed-dependent BFC and the tidal gauge data are less than those using the other empirical formulas of BFC, further demonstrating the superiority of the current speed-dependent BFC proposed in this study. From numerical model experiments, the current speed-dependent BFC can adequately reflect the spatial and temporal variations of BFC and improve the simulation accuracy of tides, thus having a broad application scope.

The paper analyzes the significance of ceramic vessels in the ritual and everyday life of the early medieval population of the south-western Primorye. The sources used in the work are materials from the following three nearby sites: Chernyatino-2 settlement, Sinelnikovo-1 ancient town and Chernyatino-5 burial ground dated the Late Mohe and Early Bohai periods (7th – 9th centuries AD). An analysis of ceramic collections revealed certain preferences in the selection of vessels placed in the graves. A comparison with residential complexes demonstrated that these were small containers, usually kitchenware, intended for individual use. Also, some of the items were made specifically for burial, as evidenced by carelessness in the making of the vessels, and disregard of proportions. The author comes to a conclusion about the special role of ceramics in the ritual. While other components of the burial ritual are highly variable, ceramic remains an essential component in burials throughout the entire period of the burial ground’s operation, which in turn indicates the unchanging spiritual and religious beliefs of the population of this region in changing historical conditions.

In the Bohai, sea ice drift may lead to severe vibration and fatigue failure of structures. Therefore, accurate and rapid sea ice forecasting is critical to ensure the safety of offshore structures. In this study, a short-term forecast model of regional sea ice is presented by combining field monitoring, environmental forecasting, and Elman neural network methods. Data for the winters of 2013–2014, 2017–2018, and 2018–2019 were adopted to train the sea ice model. Forecasts of sea ice parameters, such as the ice thickness, speed, and direction, were provided for offshore flexible structures. The results show that the forecast accuracy of the Elman network model decreases with an increase in forecasting period, while the actual ice thickness exhibits a positive correlation with the forecast accuracy. In comparison with wavelet neural network methods, the Elman network model attains a significantly lower demand on the time length of training data. Furthermore, the Elman network model achieves a higher accuracy in regional sea ice forecasting than does the hybrid Lagrangian–Eulerian model. [ABSTRACT FROM AUTHOR]

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Copyright of Natural Gas & Oil is the property of Editorial Department of Natural Gas & Oil and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The ecological risks of trace metals (Cu, Zn, As, Cd, Pb, and Hg) and PAHs in seawater from three typical bays of the Bohai Sea (the Liaodong Bay, Bohai Bay, and Laizhou Bay) were comprehensively assessed by recompiling 637 sites. Results highlighted that scrutiny should be given to the ecological risks of Cu (3.80 μg/L) in the Bohai Bay and Hg (0.23 μg/L) in the Laizhou Bay. Conversely, the Liaodong Bay exhibited negligible ecological risks related to trace metals. The risks of ΣPAHs in the Liaodong Bay, Bohai Bay, and Laizhou Bay were moderate, with mean concentrations of 368.16 ng/L, 731.93 ng/L, and 187.58 ng/L, respectively. The source allocation of trace metals and PAHs required consideration of spatial variability and anthropogenic factors, which greatly affected the distribution and composition of these pollutants. The combined ecological risks in the Bohai Bay (6.80 %) and Laizhou Bay (5.43 %) deserved more attention. [Display omitted] • The ecological risk of Cu (3.80 μg/L) in the Bohai Bay deserved attention. • The Liaodong Bay exhibited negligible ecological risks related to trace metals. • The ecological risks of ΣPAHs in the three bays were moderate. • The combined ecological risk of the Bohai Bay (6.80 %) was the highest. [ABSTRACT FROM AUTHOR]

Bohai is a typical marginal oil field in an ice region, where most of the oil and gas platforms are economical. Sea ice is the main factor that affects the safety of oil and gas platforms in Bohai. Due to the complexity of the ice load and ice-induced vibrations, there are large security risks when developing Bohai oil and gas in the winter. It is difficult to ensure the safe production of oil and gas in winter using existing sea ice disaster warning technologies. Based on winter oil and gas production in the Bohai Sea’s Liaodong Bay, a set of suitable sea ice management systems is proposed in this paper. These systems integrate sea ice monitoring, risk assessment and risk prediction technologies. Based on the risk warning system, an ice management model of a Bohai ice platform has been put into practice, which ensures the safe production of the platform in winter.

Trophic transfer of cyclic methyl siloxanes (CMS) in aquatic ecosystems is an important criterion for assessing its environmental risks. This study researched the trophic transfer of four CMS (octamethylcyclotetrasiloxane (D 4), decamethylcyclopentasiloxane (D 5), dodecamethylcyclohexasiloxane (D 6), and tetradecamethylcycloheptasiloxane (D 7)) in marine food web from zooplankton up to seabirds in the Chinese Bohai Sea. In the zooplankton-invertebrate-fish-seabird based food web, the significant trophic magnifications were found for D 4 to D 6 (D 4 : R2 = 0.040, p < 0.05, D 5 : R2 = 0.26, p < 0.0001, D 6 : R2 = 0.071, p < 0.001), and the significant trophic dilution was found for D 7 (R2 = 0.026 and p < 0.05). The trophic magnification factors (TMF) for D 4 to D 7 were 1.7 (95% confidence interval: 1.1–2.6), 3.5 (2.5–5.0), 1.8 (1.3–2.6), and 0.63 (95% CI: 0.40–0.99) respectively. In the zooplankton-invertebrate-fish based food web, both significant trophic magnification for D 5 (R2 = 0.16, p < 0.0001, TMF = 3.0) and significant trophic dilution for D 7 (R2 = 0.073, p < 0.01, TMF = 0.4) were found, but for D 4 and D 6 , the trophic magnifications were not significant (D 4 : R2 = 0.010, p = 0.23, D 6 : R2 = 0.010, p = 0.23). The trophic transfer of the legacy contaminant BDE-47 and BDE-99 were also conducted as the benchmark chemicals and significant positive correlation was found. As far as we know, this is the first research on the trophic transfer of CMS in the zooplankton-invertebrate-fish-bird food chain which provided new insight of these compounds in the area. • Trophic transfer of cVMS was assessed in marine food web from Bohai Sea, China. • Trophic magnifications for D 4 to D 6 and trophic dilution for D 7 was found. • Trophic magnifications of D 4 and D 6 were affected by food web configuration. • TMF values of D 4 to D 7 show a trend of rising first and then falling against K OW. [ABSTRACT FROM AUTHOR]

The Liao shi [Liaoshi] (遼史) suggests that in 926 the Liao empire destroyed the state of Bohai, and afterward forced the Bohai people into servitude and resettlement across the empire. Modern archaeology together with epigraphical sources in the Kitan language confirm some of this narrative, but suggest a far more complicated story. Researches by scholars such as Aisingioro Ulhicun, Yoshimoto Michimasa, Im Sangsŏn, Sawamoto Mitsuhiro and Wang Shanjun have shed new light on the political circumstances of the Liao invasion of Bohai in 926 and the subsequent status of its inhabitants. A majority of the Bohai population remained in their traditional territories, where Bohai aristocrats, soldiers and high-ranking officials retained distinct roles in local administration. This essay looks at Bohai influence upon Liao administrative practices, the status of Bohai aristocrats of the Da lineage and elites such as Gao Mohan, and the probable outlines of Bohai demography to suggest that the Bohai role in transmission of Northeastern political traditions, in particular, may have been much more important than would be suggested on the basis of standard literary resources. Instead of being a doomed people whose identities and social structures evaporated after Liao resettlement policies stranded them in remote and inhospitable surroundings, the Bohai story may actually be one of political continuity and a seminal influence upon their successors, the Jurchens and ultimately the Manchus.

The issue of relations between the Bohai people after the destruction of their state in AD 926 and the southern neighboring state, Koryŏ, is a very complicated and important one for understanding the fate of ethnic groups in East Asia. As is known, after 926 many Bohai people immigrated to Koryŏ, because they considered this state a comfortable place to live. However, after a century the situation changed and the Bohai people preferred to live in other regions. This article considers the reasons for the movement of the population from the former Bohai state and analyzes the specifics of the relations between the Bohai population and the Koryŏ kingdom. [ABSTRACT FROM AUTHOR]

Abrupt changes in freshwater inputs from large rivers usually imply regime shifts in coastal water environments. The influence of a water regulation event on the age of the Yellow River water in the Bohai was modeled using constituent-oriented age and residence time theory to better understand the change in the environmental function of the hydrodynamic field owing to human activities. The water ages in Laizhou Bay, the central basin, and the Bohai strait are sensitive to water regulation. The surface ages in those areas can decrease by about 300 days, particularly in July, and the age stratification is also strengthened. A water regulation event can result in declines in the water age in early July ahead of declines in the water age under climatological conditions (without the regulation event) by about 1 and 5 months in the central basin and Laizhou Bay, respectively. The change in the coastal circulation due to the water regulation event is the primary reason for the change in the Yellow River water age. The high Yellow River flow rate can enhance the density flow and, therefore, reduce the age of the Yellow River water. The subsequent impact of a single water regulation event can last about 1.0 to 4.0 years in different subregions. [ABSTRACT FROM AUTHOR]

A parameterized internal tide dissipation term and self-attraction and loading (SAL) tide term are introduced in a barotropic numerical model to investigate the dynamics of semidiurnal tidal constituents M 2 and S 2 in the Bohai Sea, Yellow Sea and East China Sea (BYECS). The optimal parameters for bottom friction and internal dissipation are obtained through a series of numerical computations. Numerical simulation shows that the tide-generating force contributes 1.2% of M 2 power for the entire BYECS and up to 2.8% for the East China Sea deep basin. SAL tide contributes 4.4% of M 2 power for the BYECS and up to 9.3% for the East China Sea deep basin. Bottom friction plays a major role in dissipating tidal energy in the shelf regions, and the internal tide effect is important in the deep water regions. Numerical experiments show that artificial removal of tide-generating force in the BYECS can cause a significant difference (as much as 30 cm) in model output. Artificial removal of SAL tide in the BYECS can cause even greater difference, up to 40 cm. This indicates that SAL tide should be taken into account in numerical simulations, especially if the tide-generating force is considered. [ABSTRACT FROM AUTHOR]

Interannual variability of cyclones that are generated over the eastern Asian continent and passed over the Yellow, Bohai, and East China seas (YBE cyclones) in spring is analyzed using reanalysis datasets for the period of 1979⁻2017. Possible causes for the variability are also discussed. Results show that the number of YBE cyclones exhibits significant interannual variability with a period of 4⁻5 years. Developing cyclones are further classified into two types: rapidly developing cyclones and slowly developing cyclones. The number of rapidly developing cyclones is highly related to the underlying sea surface temperature (SST) anomalies (SSTA) and the atmospheric baroclinicity from Lake Baikal to the Japan Sea. The number of slowly developing cyclones, however, is mainly affected by the North Atlantic Oscillation (NAO) in the preceding winter (DJF); it works through the upper-level jet stream over Japan and the memory of ocean responses to the atmosphere. Positive NAO phase in winter is associated with the meridional tripole pattern of SSTA in the North Atlantic Ocean, which persists from winter to the following spring (MAM) due to the thermal inertia of the ocean. The SSTA in the critical mid-latitude Atlantic region in turn act to affect the overlying atmosphere via sensible and latent heat fluxes, leading to an increased frequency of slowly developing cyclones via exciting an anomalous eastward-propagating Rossby wave train. These results are confirmed by several numerical simulations using an atmospheric general circulation model.

Using hourly sea level data from four tide gauges, the changes of the extreme sea level in the Bohai Sea were analyzed in this work. Three components (i.e., mean sea level, tide and surge) as well as the tide–surge interaction were studied to find which component was important in the changes of extreme sea levels. Significant increasing trends exist in the mean sea level at four tide gauges from 1980 to 2016, and the increase rate ranges from 0.2 to 0.5 cm/year. The mean high tide levels show positive trends at four tide gauges, and the increasing rate (0.1 to 0.3 cm/year) is not small compared with the long-term trends of the mean sea levels. However, the mean tidal ranges show negative trends at Longkou, Qinhuangdao and Tanggu, with the rate from about −0.7 to −0.2 cm/year. At Qinhuangdao and Tanggu, the annual surge intensity shows explicit long-term decreasing trend. At all four tide gauges, the storm surge intensity shows distinct inter-annual variability and decadal variability. All four tide gauges show significant tide–surge interaction, the characteristics of the tide–surge interaction differ due to their locations, and no clear long-term change was found. Convincing evidence implies that the extreme sea levels increase during the past decades from 1980 to 2016 at all tide gauges, with the increasing rate differing at different percentile levels. The extreme sea level changes in the Bohai Sea are highly affected by the changes of mean sea level and high tide level, especially the latter. The surge variation contributes to the changes of extreme sea level at locations where the tide–surge interaction is relatively weak.

The coastline detection is one of the main applications of the Gaofen-3 satellite in the ocean field. However, the capability of Gaofen-3 SAR image in coastline detection has not yet been validated. In this paper, two Gaofen-3 SAR images, acquired in 2016, were used to extract the coastlines of the regions of Bohai and Taihu in China, respectively. The classical Fuzzy C-means (FCM) method was used in the coastline detection, but had been improved by combining the Wavelet decomposition algorithm to better suppress the inherent speckle noises of SAR image. Coastline detection results obtained from two Sentinel-1 SAR images acquired on the same regions were compared with those of the Gaofen-3 images. By using the manually delineated coastlines as the standards in the qualitative evaluations, improvements of about 12.0%, 8.3%, 23.8%, and 9.4% can be achieved by the improved FCM method with respect to the indicators of mean, RMSE, PGSD, and P90%, respectively; demonstrating that the Gaofen-3 data is superior to the Sentinel-1 data in the detection of coastline.

The history of the Bohai studies in Russia is more than 150 years old. During those years Russian scholars have produced a number of interesting and valuable publications and combine use of written sources with study of the archeological sites. But for a long time they did not pay attention to bone remains. Only in the 1970s did Russian specialists begin to study osteological materials and this research gave a great deal of information about agriculture and other aspects of the Bohai people. In spite of this, osteological studies in the Russian Far East remain unknown in the Western academic world in many aspects, largely because almost all Russian scholars usually do not publish in English. [ABSTRACT FROM AUTHOR]

The state of Bohai (on Korean reading – Parhae, 발해) existed in what is modern Russian Primorye region (Приморский край/Maritime Region), North Korea and Northeastern China, from the late seventh to the early tenth centuries AD. It played an important role in the history of the area as a major regional power for over two centuries. Recently, the history of Bohai has begun to attract scholarly interest. However, North Korean studies of Bohai remain basically almost unknown in the Western world. In this article, I present the history of Bohai studies in the Democratic People’s Republic of Korea (DPRK). In this article, I analyze not only North Korean studies of Bohai but also the opinions of the Korean scholars on the subject. They are rather specific for North Koreans who have unique access to the archaeological and historical materials on Bohai but are also subjected to unusually severe political pressures. The history of Bohai has now become an object of active political games which are related to territorial claims based on alleged archaeological and historical material. This situation increases the general interest in Bohai but also makes honest and unbiased research more difficult. [ABSTRACT FROM PUBLISHER]

Author of this work considers the Bohai person Gao Mouhan, who was military and political leader in Bohai state, Koryo kingdom and Khitan Empire. He made a big contribution for development of the Liao Empire and destruction of Chinese states. In spite of Gao Mouhan had a big influence for many events in the East Asia, his military and political activities are little-known. Therefore author analyses his activity not only in Liao Empire, but in Koryo too. Gao Mouhan moved between Koryo, areas of former Bohai kingdom and Khitan state. Author considered and analyzed reasons of his immigration, role of Gao Mouhan in events, specifics of development of these countries at that period. The goal of this work are analysis of person and activity by Gao Mohan, study his role for events in East Asian history and consideration materials about this leader. Author uses materials not only in European (Russian, German and English), but in Asian languages (Korean and Chinese) too. [ABSTRACT FROM AUTHOR]

Bohai (698 A.D. – 926 A.D.) was a medieval state in East Asia. The Tang Empire in 713 recognized Bohai and considered this state as kingdom from the 760s. However, the status of Bohai was unclear. Although Bohai was a formal vassal of the Tang Empire, it followed its own independent path, not only in its internal policies, but also in its foreign relations. Furthermore, it regarded itself as an empire. The provincial system of Bohai imitated an imperial system, but the status of provincial powers in the Bohai state is not clear. The aim of this article is to consider and analyze provincial power structures in Bohai and the status of the provinces within the Bohai state. [ABSTRACT FROM AUTHOR]

Nutrient transport patterns in the Huanghe (Yellow River) were investigated using biogeochemical observations carried out during 2001–2011 to examine how nutrient transports were affected by water–sediment regulation events and their potential effects on the adjacent Bohai ecosystem. The concentrations and composition of nutrients in the Huanghe had an obvious change during the water–sediment regulation events, which increased dissolved nutrient transports with a similar amplitude like freshwater discharge, while amplified particulate nutrient transports. Dissolved inorganic nitrogen was the predominant species of total dissolved nitrogen. Particulate phosphorus was the major form of phosphorus affected by high content of suspended particulate matter. Phosphate represented 68% of total dissolved phosphorus. The BSi was 20% of the sum of BSi and dissolved silicate. Nutrient transport patterns highly depend on freshwater discharge. The regulation events have shifted the seasonal patterns of water and nutrient transports with high flow condition occurring at least two months prior to the normal peak flow. Abundant nutrients were transported to the coastal water and nutrient imbalance was aggravated, most likely resulting in strong impacts on the adjacent Bohai ecosystem. [ABSTRACT FROM AUTHOR]

Copyright of Bylye Gody is the property of Cherkas Global University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The problem of interpretation of war between the Tang Empire and Bohai in period 732-735. Bohai kingdom (698 - 926) was the first state in the history of the Russian Far East. This article considers the most discussed period of the history of Bohai -- its war against Chinese Empire Tang. This military conflict changed the political situation not only on the Korean Peninsula, but in East Asia in general. This war also influenced political contacts in the Far East significantly. On the basis of different materials and studies of events in the neighboring states and tribes, the authors have analyzed events leading up to the war, the military operations in the war itself and the results of this conflict. [ABSTRACT FROM AUTHOR]

Copyright of Bylye Gody is the property of Cherkas Global University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The history of the kingdom of Parhae (Ch. Bohai, J. Bokkai, 698-926) has been studied and debated in East Asia since the early twentieth century. Despite the scarcity of textual sources, over the past few decades, sophisticated analyses of a range of aspects of Parhae politics, society, and culture have been produced by scholars writing in Korean, Japanese, Chinese, and Russian. Only very recently, however, have significant efforts- led by Korean scholars-been made to expand the history of Parhae into English language scholarship. This article serves to place these more widely accessible contributions into the context of the international and multilingual negotiation over how the history of Parhae should be understood. Readers from other disciplines who encounter this scholarship are in effect hearing only a single speaker who in practice is engaged in a lively conversation with many participants. The present study is intended to address specifically the needs of such readers, and suggests that the emphasis on "multiculturalism" in contemporary Korean society may aid Korean scholars' engagement with international audiences on the Parhae issue. [ABSTRACT FROM AUTHOR]

The hydrodynamics of marginal seas exhibit internal variability unprovoked by external forcing. To date, the role of tides in reducing this "noise" has not been evaluated. We investigated the effect of tides on internal variability in the Bohai and Yellow Sea. To do so, we conducted three ensembles of numerical experiments using the three-dimensional Finite-Volume Coastal Ocean Model (FVCOM) with tidal forcing, with "half-tidal" forcing, and without tidal forcing, while everything else was unchanged, and determined the intensity of the signal-to-noise ratio (hereinafter referred to as the S/N ratio), with the "signal" represented by the variance of the coherent variations of the different simulations subject to the same atmospheric variability and the noise represented by the intra-ensemble variance. The S/N ratio was determined for depth-averaged velocities, surface temperature, and surface salinity. The first result was that in all three ensembles, noise emerged but with different intensities. In the ensemble with tidal forcing, unprovoked variability emerged primarily at smaller scales. When the tides were weakened or turned off, the S/N ratios were reduced, more so in the Yellow Sea than in the Bohai. The increase in the S/N ratio was largest for large scales and for depth-averaged velocity. The reduction in tidal forcing resulted in an approximately 30% increase in S/N ratios in the Bohai at large scales. Thus, the absence of tidal forcing favored the emergence of increased unprovoked variability at large and medium scales but not at small scales. A hypothesis for explaining this scale-selective effect of tides, based on the stochastic climate model, is suggested. • The FVCOM is used to analyze the scale and signal-to-noise ratio S/N ratios of internal variability in the Bohai and Yellow Sea. • Based on an ensemble of simulations, scale dependency of S/N ratios also exist in shallow and coastal sea, the Bohai and Yellow Sea. • We use three ensembles of simulations with tidal forcing turned on, halved, and turned off, to analyze the tide effects on internal variability. • The S/N ratios tend to decrease when tidal forcing is turned off at large and medium scales, but not for small scales. [ABSTRACT FROM AUTHOR]

The problem of understanding of the political status of Bohai state. Bohai (698 - 926) was a medieval state in East Asia. Tang Empire in 713 recognized Bohai as dukedom and considered this state as kingdom from the 760s. However, status of Bohai was unclear. Although Bohai was a formal vassal of the Tang Empire, it followed its own independent path, not only in its internal policies, but also in its foreign relations. Furthermore, it regarded itself as an empire. The aim of this article is to consider and analyze specifics, changes of political status of the Bohai state and its influence to international relation and position of Bohai population in East Asia at medieval period. [ABSTRACT FROM AUTHOR]

Abstract: Biogeochemical observations were carried out to address the influence of major sources on nutrient composition and the ecosystem of the Bohai. Relatively high concentrations of nutrients off the Huanghe mouth and the shallow water areas were observed in the Bohai suggesting the effects of tidal and residual currents and anthropogenic perturbation. Sediment in the Bohai represents a source for ammonium, phosphate and dissolved silicate, while it is a sink for nitrite and nitrate. Benthic nutrient fluxes were 2–3 times higher than the riverine input with the regeneration rate of phosphate being slower relative to DIN and dissolved silicate. The release of dissolved silicate and phosphate from sediments may mitigate the decrease of dissolved silicate and phosphate due to the reduction of freshwater discharge. Compared with submarine groundwater discharge, nutrient regeneration in sediment provides similar DIN flux, 2–5 times phosphate and dissolved silicate fluxes. DIN/P molar ratios in the three mentioned sources were 155–845, indicating that phosphorus limitation for phytoplankton growth could be intensified, which likely results in changes of ecosystems of the Bohai. [Copyright &y& Elsevier]

The article discusses foreign relations between the Bohai state, which existed in the Primor'e region of Russia, North Korea, and Northeastern China, and Silla, a state located in the southern part of the Korean peninsula, from the late seventh to the early 10th century. The author examines the history of Bohai using Chinese, Japanese, and Korean texts in the absence of Bohai texts. He concludes that Silla imitated the Tang Empire's system of foreign policy by denying equal relations with Bohai and examines Bohai's cultural and social influences on other states. A timeline of Bohai history which ends with the destruction of the Bohai state by the Khitans is provided.

Abstract: EU GeoCapacity (Assessing European Capacity for Geological Storage of Carbon Dioxide) is a 3-year project that ran from January 1st 2006 to December 31st 2008, and that was carried out by 26 partners in 21 countries including China, providing the first detailed pan-European assessment of CO2 storage capacity. Other outcomes were the development of innovative methods for capacity assessment, economic modelling and site selection. An important mission was to initiate scientific collaboration, with China and other CSLF members (e.g. Russia). In China, the study was applied to the Hebei Province, which is located in the Bohai Basin, NE China. The inventory of emission sources was performed for the entire Hebei Province, while storage potential was studied in one of the major tectonic units of the basin, the Jizhong depression, in the south of the Province. The distribution of the main CO2 emitters by sector has shown that besides the power sector, industry must be considered, in particular iron/steel and cement sectors accounting for one third of the total. Least cost transport was calculated using a methodology developed by 3E/INET (Tsinghua University) and BRGM (Chen et al., 2010) and applied also to the other CCS projects in China. The NZEC Conference, held in Beijing (28–20 October 2009) to close phase 1 and launch phase 2 of this European programme in China, concluded that storage is the most critical issue. At the present early stage, low-cost capture and transport should be preferred. Therefore, should incentives, performing investigation tools and adequate partnership be in place, several small-scale demonstration projects from local industry to local storage sites are recommended to improve knowledge and operating conditions prior to any ambitious project. CCS deployment in the Hebei province could be performed from local sources to local sinks of CO2. However, EOR is limited by the present water cut or reservoir geometry and geothermal reconversion might be profitable. Tertiary aquifers would be a good target, but the Neogene (Guantao, Minghuazhen formations) seems restricted to other uses (geothermal, water supply). Therefore, more coordination between geothermal exploration and CCS, and new objectives in the deeper Tertiary (Paleogene) would be suitable for CCS deployment. [Copyright &y& Elsevier]

Abstract: The Bozhong Depression in Bohai Bay was previously ranked as an unfavorable exploration region due to concerns about reservoir, trapping integrity and top seal risks. In the mid 1900s, a few explorationists began to view the petroleum accumulation conditions more positively. They argued that rapid Neogene subsidence could have generated a new suite of source potential and that recent continued fault movements may have provided the needed conduits for upward hydrocarbon migration. They predicted the existence of lacustrine facies that could supply the needed lateral and top seals for the intensively faulted traps. These radical thoughts were gradually formulated into a new concept for the Neogene targets. This paradigm shift in exploration concepts has, since 1995, led to the discovery of nine (9) major oil fields with a combined in-place reserves more than double those discovered in the previous thirty (30) years. Some of these Neogene reservoirs appear to be at a dynamic balance between hydrocarbon escape and charge. It is speculated that the required driving energy for the charge may have come from earthquake activities. [Copyright &y& Elsevier]

This article analyzes the 1631-33 mutiny led by Kong Youde against the Ming state on the Shandong peninsula and argues that the conflict emerged directly out of the social tensions between local populations and the displaced migrant refugees of the Bohai gulf region. The maritime integration of the Shandong coast city of Dengzhou with the commercial networks of the Liaodong peninsula and the island archipelagoes of the Bohai, together with the militarization of this regional space, created the social conditions in which Kong Youde could mobilize migrant discontent and attempt to construct his own independent military regime. [ABSTRACT FROM AUTHOR]

Meso- and microplastics (MMPs) have attracted attention as globally dispersed environmental pollutants. However, little is known about the transfers of MMPs between aquatic and terrestrial systems. A large watershed-estuarine area of Bohai Sea was used as a case study, and soils and sediments were sampled adjacent to each other at a wide range of sites. MMPs were detected in all sediments (6.7–320 MMPs/kg) and soils (40–980 MMPs/kg), with the average abundance in soils double that in sediments on a dry mass basis. MMPs < 1 mm were most abundant and the dominant shape was film in both sediments and soils. Over twenty polymer types were detected and their compositions in sediments and soils were different. MMP abundance in sediments was lower in the upper catchment than the lower catchment, while the abundance of soil MMPs was the opposite. Despite the proximity of the sampling locations, no clear relationship was identified between the soil and sediment MMPs, suggesting low transfer between the two compartments and high heterogeneity of the sources. The missing associations between aquatic and terrestrial MMPs should be systematically examined in future studies, which is crucial for understanding the environmental fate and impacts of MMPs. [Display omitted] • Relationships between aquatic and terrestrial meso-microplastics (MMPs) are studied. • Average abundance of MMPs in soils doubles that in sediments on a dry mass basis. • Film MMPs <1 mm are the most abundant in both sediments and soils. • Sediment and soil MMPs show different distribution, polymer types, and colors. • No association is found between adjacent sediment and soil MMPs. [ABSTRACT FROM AUTHOR]

Abstract: Methods, based on spatial analysis of the different criteria to be taken into consideration for building scenarios of CO2 Capture and Storage (CCS), have been developed and applied to real case studies in the Hebei Province (northeast China). The total CO2 emissions from point sources in the province amount to 220Mt/y, mainly from power plants, and from iron-steel, cement, ammonia plants, and refineries. Storage opportunities can be found in the Bohai Basin, characterised by a strong tectonic subsidence during the Tertiary, with several kilometres of accumulated clastic sediments. Two complementary methods were designed to best match sources and sinks, accounting for the cost of transport, injection and storage: an algorithm working on pairs of sources and sinks, and a spatial analyse on costs grids using functions of ArcGIS software which takes into account the additional costs of pipeline construction due to landform and land use. [Copyright &y& Elsevier]

Abstract: The Cooperation Action Carbon Capture and Storage China-EU project (COACH) is a three-year EC Framework 6 co-funded collaborative project with Chinese and EU partners investigating geological storage options in the Bohai Basin, China. This paper discusses interim assessments of storage potential for the Dagang oilfield complex (Tianjin Municipality), deep saline aquifers in the Jiyang depression (Shandong province) and the Kailuan coalfield (Hebei Province). Source-sink matching options are also discussed using large ‘point source’ data collected for the Shandong Province. [Copyright &y& Elsevier]

Abstract: Ocean color and sea surface temperature data from Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Terra satellite are used to study the cross-shelf circulation and transport of suspended sediments in the Yellow and the East China Seas. The ocean color images show a significant turbid water plume extending in the southeast direction from the Subei coasts of China to the shelf edge south of Cheju during fall–winter, suggesting significant cross-shelf currents in the Yellow Sea/East China Sea in winter. The currents transport suspended sediments from the area of the old Huanghe mouth into the Okinawa Trough. Part of the turbid plume joins the Yellow Sea Warm Current to enter the Yellow Sea trough in winter. The satellite images suggest that the time scales of cross-shelf transport and surface-to-subsurface descending of the suspended sediments are a few weeks. The turbid plume grows in fall, reaches its maximum expansion and intensity in winter–spring, and subsides in late spring. In summer, the plume becomes coastally trapped. Substantial interannual variations of the intensity and coverage of the turbid plume are indicated by the observations. In comparison, the Changjiang Diluted Water in summer only transports a small amount of the Changjiang suspended sediment to the outer shelf south of Cheju, which does not enter the Yellow Sea owing to the weak intrusion of the Yellow Sea Warm Current in summer. The dynamics of the cross-shelf circulation in the Yellow Sea in winter are hypothesized to be associated with (1) the convergence of the Yellow Sea Coastal Current and the Taiwan Warm Current off the Changjiang mouth and (2) the time-dependent forcing of the northerly wind bursts that drives the intrusion of the Yellow Sea Warm Current. [Copyright &y& Elsevier]

ABSTRACT: The effects of waves on Surface Drag Coefficient (SDC) and surface mixing length were analyzed and discussed by carrying out three-dimensional current modeling for the Bohai Sea in the present work. A three-dimensional coupled hydrodynamical-ecological model for regional and shelf seas (COHERENS) incorporating the influences of wave-current interactions was coupled with the third-generation wave model swan taking into account time-varying currents. The effects of waves on currents were included in the SDC, surface mixing length and bottom drag coefficient. Firstly, the formulations in Donelan were incorporated into the COHERENS to account for wave-dependent SDC. In order to compare simulation results for the wave-dependent SDC, the simulation for wind-dependent SDC was also carried out. Second, Wave-Induced Surface Mixing Length (described as WISML sometimes in this paper) was incorporated into the COHERENS. Four numerical experiments were conducted to discuss the effects of two kinds of wave processes. Generally, the values of time series of current velocity and water surface elevation given by the simulation with all of the three wave processes have a good agreement with observed data. The existence of WISML changes obviously current vertical profiles and the existence of the wave dependent SDC modifies the current field of both top and bottom layers with the wind-dependent SDC. [Copyright &y& Elsevier]

Within the frame of a Sino-German Joint Research Program, two cruises of “R/V Dong Fang Hong 2” were carried out in September–October 1998 and April–May 1999, respectively, to understand the dynamics of nutrients in the Bohai. Nutrient species (NO3−, NO2−, NH4+, PO43− and SiO32−) are determined colorimetrically on board for five anchor and 30 grid stations. In situ incubation experiments are performed to determine planktonic nutrient uptake and benthic exchange flux. Nutrient concentrations display short-term variability and seasonal change in the Bohai, with higher levels in shallow coastal waters than in the Central Bohai. The influence of riverine discharge on nutrient levels can be seen from salinity isopleths, nutrient distribution and species ratios. Near-bottom (nb) waters have similar nutrient concentrations as to the surface waters in the Central Bohai, whereas stratification takes place in the Bohai Strait and North Yellow Sea. In situ incubation experiments provide evidence that the uptake ratio (i.e. N, P) by phytoplankton is proportional to the ratios among nutrient species in ambient waters. Based on the data of this study and previously publications, a preliminary estimate of nutrient budgets via riverine input and atmospheric deposition is established. The results indicate that atmospheric deposition gains importance over rivers in delivering nutrients into the Bohai and sustain the new production, following recent decrease in riverine inflow caused by drought periods in North China and damming practices. A historical review of nutrient data indicates that concentrations of nitrogen increase and phosphorus and silica decrease in the Central Bohai over last 40 years. This potentially has an important influence on the health of ecosystem in Bohai (e.g. food web and community structure), though further study is needed to examine the scenario in more detail. [Copyright &y& Elsevier]