The radial tidal current field accounts for the formation of the radial sand ridges in the South Yellow Sea. Understanding the formation and evolution of this radial tidal current field is vital to assessing the morph...The radial tidal current field accounts for the formation of the radial sand ridges in the South Yellow Sea. Understanding the formation and evolution of this radial tidal current field is vital to assessing the morphodynamic features in the area. A semi-enclosed rectangular basin with and without a coastal barrier was schematized from the topography of the Bohai Sea and Yellow Sea. The 2D tidal current field in this basin was simulated using the DELFT3D-FLOW model. The concept of tidal wave refraction, which highlights the effect of the sloped or stepped submarine topography on the propagation of the tidal waves, was introduced to explain the formation of the radial tidal current field. Under the effect of tidal wave refraction, co-phase lines of the counterclockwise rotating tidal wave and incident tidal wave are transformed into clockwise and counterclockwise deflections, respectively, leading to the convergence and divergence of the flow field. Regardless of whether a coastal barrier exists or not, the outer radial tidal current field might emerge over certain topography. The responses of the radial tidal current field in this basin to the environmental variations such as coastline changes and bottom erosions were discussed. Results show that local protrusion near the focal point of the radial tidal current field will have limited effects on the location of the tidal system. However, a remarkable shift of the amphidromic point toward the entrance and central axis of this basin and a movement of the focal point of the radial tidal current field toward the entrance could be caused by the significant seaward coastline advance and submarine slope erosion.展开更多
基于普林斯顿海洋模式(POM)建立了MASNUM(Laboratory of MArine Science and NUmerical Modeling)海浪-潮流-环流耦合模式,对长江口外及浙江沿岸海域夏季的上升流现象进行了数值模拟,并从潮运动的角度分析了其动力机制,对该海域潮致上...基于普林斯顿海洋模式(POM)建立了MASNUM(Laboratory of MArine Science and NUmerical Modeling)海浪-潮流-环流耦合模式,对长江口外及浙江沿岸海域夏季的上升流现象进行了数值模拟,并从潮运动的角度分析了其动力机制,对该海域潮致上升流的形成机理给出了一种新的解释.研究表明,该海域上升流的潮生机制同时体现在正压和斜压2个方面:单纯的正压潮余流能够通过底层辐合和沿地形坡度爬升两种过程产生上升流;在斜压海洋环境下,强烈的潮混合作用在近岸陆坡区形成显著的锋面,锋面两侧存在明显的密度差异,该密度差异造成的水平压力梯度诱生出沿锋面的次级环流,其上升流分支出现在锋区附近.数值试验表明,潮运动是该海域上升流的一个极为重要的诱发因子,甚至占主导地位.研究还发现,与单纯模拟M2分潮相比,对M2,S2,K1及O14个主要分潮耦合计算有助于改善正压潮致上升流的模拟结果.展开更多
In this paper, a calculation formula on spherical pattern of tide-isostasy model is established. The calculation indicated that for the oceanic crust plate which central angle is over 90°, a huge value(its equiva...In this paper, a calculation formula on spherical pattern of tide-isostasy model is established. The calculation indicated that for the oceanic crust plate which central angle is over 90°, a huge value(its equivalence is 108 N)of accumulative force moment in the crustal isostatic movement caused by tide can trigger off relative motion of plate, resulting in earthquake and volcanic eruption. The seismic wave features during the year 2001-2004 is an obvious example. The paracycles, i.e. 4, 12, 60, 36, 243, 372 and 396 years of tidal fluctuation can provide an explanation for some respective natural disasters. For example, La Madre paracycle about 60 years corresponds to the global disasters,earthquake and typhoon disasters.展开更多
Although late Qing and Republican China failed to witness an enlightenment movement in the European sense, China did go through an enlightenment process of its own. Chinese mercantilism, in close association with indu...Although late Qing and Republican China failed to witness an enlightenment movement in the European sense, China did go through an enlightenment process of its own. Chinese mercantilism, in close association with industrialization and the rise of capitalism, constituted an intellectual movement that cannot be overlooked. The mercantile enlightenment expressed in mercantilism went through various evolutionary stages, from birth to development to maturation. In this process, the values and beliefs of China＇s feudal agrarian society were rejected and attacked and the new values championed by industrialists and merchants grew and spread. Although China＇s enlightenment movement had its limitations, it played an important role in promoting the country＇s transformation from an agrarian to an industrialized society and helped lay the foundation for China＇s modernization. It also has implications for the rebuilding of commericial morality in China.展开更多
A modified Gauss-Markov model with weighted constraints was constructed by combining satellite altimeter and tide gauge records. Vertical motion rates of nine tide gauge stations around the Bohal Sea and Yellow Sea ar...A modified Gauss-Markov model with weighted constraints was constructed by combining satellite altimeter and tide gauge records. Vertical motion rates of nine tide gauge stations around the Bohal Sea and Yellow Sea are estimated. This is the first time systematic estimates have been derived in this region. Downward trends were seen at the six tide gauge stations located at Tanggu, Longkou, Laohutan, Bayuquan, Xiaochangshan, and Yantai; with vertical motion rates of-1.82±0.50, -1.65±0.46, -0.88±0.42, -0.58±0.62, -0.13±0.43, and -0.01±0.43 mm/yr, respectively. Upward trends were seen at the three tide gauge stations located at Qinhuangdao, Huludao and Chengshantou; with vertical motion rates of 1.12±0.46, 0.55±0.49 and 0.26±0.44 mm/yr, respectively. There was significant subsidence in Tanggu and Longkou, and a rising trend in Qinhuangdao. According to our results, the rate of sea level rise calculated from these tide gauge records can be improved using a more accurate measurement of the land elevation accounting for lifting or subsidence. The model derived can be used to estimate vertical motions of tide gauge stations, and can be widely applied to revise the benchmark levels of tide gauges.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.51179067,51379072)the Special Funds for Scientific Research on Public Welfare of Ministry of Water Resources of China(No.201201045)the College Graduate Research and Innovation Project of Jiangsu Province,China(No.CXZZ12_0254)
文摘The radial tidal current field accounts for the formation of the radial sand ridges in the South Yellow Sea. Understanding the formation and evolution of this radial tidal current field is vital to assessing the morphodynamic features in the area. A semi-enclosed rectangular basin with and without a coastal barrier was schematized from the topography of the Bohai Sea and Yellow Sea. The 2D tidal current field in this basin was simulated using the DELFT3D-FLOW model. The concept of tidal wave refraction, which highlights the effect of the sloped or stepped submarine topography on the propagation of the tidal waves, was introduced to explain the formation of the radial tidal current field. Under the effect of tidal wave refraction, co-phase lines of the counterclockwise rotating tidal wave and incident tidal wave are transformed into clockwise and counterclockwise deflections, respectively, leading to the convergence and divergence of the flow field. Regardless of whether a coastal barrier exists or not, the outer radial tidal current field might emerge over certain topography. The responses of the radial tidal current field in this basin to the environmental variations such as coastline changes and bottom erosions were discussed. Results show that local protrusion near the focal point of the radial tidal current field will have limited effects on the location of the tidal system. However, a remarkable shift of the amphidromic point toward the entrance and central axis of this basin and a movement of the focal point of the radial tidal current field toward the entrance could be caused by the significant seaward coastline advance and submarine slope erosion.
文摘基于普林斯顿海洋模式(POM)建立了MASNUM(Laboratory of MArine Science and NUmerical Modeling)海浪-潮流-环流耦合模式,对长江口外及浙江沿岸海域夏季的上升流现象进行了数值模拟,并从潮运动的角度分析了其动力机制,对该海域潮致上升流的形成机理给出了一种新的解释.研究表明,该海域上升流的潮生机制同时体现在正压和斜压2个方面:单纯的正压潮余流能够通过底层辐合和沿地形坡度爬升两种过程产生上升流;在斜压海洋环境下,强烈的潮混合作用在近岸陆坡区形成显著的锋面,锋面两侧存在明显的密度差异,该密度差异造成的水平压力梯度诱生出沿锋面的次级环流,其上升流分支出现在锋区附近.数值试验表明,潮运动是该海域上升流的一个极为重要的诱发因子,甚至占主导地位.研究还发现,与单纯模拟M2分潮相比,对M2,S2,K1及O14个主要分潮耦合计算有助于改善正压潮致上升流的模拟结果.
文摘In this paper, a calculation formula on spherical pattern of tide-isostasy model is established. The calculation indicated that for the oceanic crust plate which central angle is over 90°, a huge value(its equivalence is 108 N)of accumulative force moment in the crustal isostatic movement caused by tide can trigger off relative motion of plate, resulting in earthquake and volcanic eruption. The seismic wave features during the year 2001-2004 is an obvious example. The paracycles, i.e. 4, 12, 60, 36, 243, 372 and 396 years of tidal fluctuation can provide an explanation for some respective natural disasters. For example, La Madre paracycle about 60 years corresponds to the global disasters,earthquake and typhoon disasters.
基金funded by the key research bases of humanities and social sciences of the Ministry of Education(No.:13JJD770012)Central China Normal University(No.:CCNU13B007)
文摘Although late Qing and Republican China failed to witness an enlightenment movement in the European sense, China did go through an enlightenment process of its own. Chinese mercantilism, in close association with industrialization and the rise of capitalism, constituted an intellectual movement that cannot be overlooked. The mercantile enlightenment expressed in mercantilism went through various evolutionary stages, from birth to development to maturation. In this process, the values and beliefs of China＇s feudal agrarian society were rejected and attacked and the new values championed by industrialists and merchants grew and spread. Although China＇s enlightenment movement had its limitations, it played an important role in promoting the country＇s transformation from an agrarian to an industrialized society and helped lay the foundation for China＇s modernization. It also has implications for the rebuilding of commericial morality in China.
基金supported by the National Natural Science Foundation of China(Grant Nos.4140603241206021&41376014)+4 种基金the National Basic Research Program of China(Grant No.2012CB955601)the National Key Technology R&D Program of China(Grant No.2014BAB12B02)the Key Technology R&D Program of Tianjin(Grant No.14ZCZDSF00012)the Open Fund of the State Key Laboratory of Satellite Ocean Environment Dynamics at the Second Institute of OceanographySOA(Grant No.SOED1305)
文摘A modified Gauss-Markov model with weighted constraints was constructed by combining satellite altimeter and tide gauge records. Vertical motion rates of nine tide gauge stations around the Bohal Sea and Yellow Sea are estimated. This is the first time systematic estimates have been derived in this region. Downward trends were seen at the six tide gauge stations located at Tanggu, Longkou, Laohutan, Bayuquan, Xiaochangshan, and Yantai; with vertical motion rates of-1.82±0.50, -1.65±0.46, -0.88±0.42, -0.58±0.62, -0.13±0.43, and -0.01±0.43 mm/yr, respectively. Upward trends were seen at the three tide gauge stations located at Qinhuangdao, Huludao and Chengshantou; with vertical motion rates of 1.12±0.46, 0.55±0.49 and 0.26±0.44 mm/yr, respectively. There was significant subsidence in Tanggu and Longkou, and a rising trend in Qinhuangdao. According to our results, the rate of sea level rise calculated from these tide gauge records can be improved using a more accurate measurement of the land elevation accounting for lifting or subsidence. The model derived can be used to estimate vertical motions of tide gauge stations, and can be widely applied to revise the benchmark levels of tide gauges.
