RESEARCH ON RED TIDE OCCURRENCES USING ENCLOSED EXPERIMANTAL ECOSYSTEMS IN WEST XIAMEN HARBOR, CHINA——RELATIONSHIP BETWEEN VARIOUS FACTORS AND RED TIDE OCCURRENCES

ＩＮＴＲＯＤＵＣＴＩＯＮＲｅｄｔｉｄｅｓｏｃｃｕｒｒｅｄｉｎＸｉａｍｅｎＨａｒｂｏｒｉｎ1986ａｎｄ1987.Ｔｈｅｌｏｃａｌｍａｒｉｎｅｓｃｉｅｎｔｉｓｔｓｃｌｏｓｅｌｙｏｂｓｅｒｖｅｄｔｈｅｓｅｒｅｄｔｉｄｅｓａｎｄｏｂｔａｉｎｅｄｍｕｃｈｕｓｅｆｕｌｄａｔａ(Ｚｈａｎｇｅｔａｌ.,1988;Ｄｕ,1989;Ｚｈｕａｎｇ,1991;Ｃｈｅｎｇｅｔａｌ.,1993).Ｂｕｔｓｉｍｕｌｔａｎｅｏｕｓｔｒａｎｓｉｅｎｔｗａｔｅｒｍｏｖｅｍｅｎｔａｌｗａｙｓｍａｄｅｉｔｄｉｆｆｉｃｕｌｔｔｏｉｎｖｅｓｔｉｇａｔｅｔｈｅｓｅｒｅｄｔｉ…     

A LAYERED NUMERICAL MODEL FOR SIMULATING THE GENERATION AND PROPAGATION OF INTERNAL TIDES OVER CONTINENTAL SLOPE Ⅲ. NUMERICAL EXPERIMENTS AND SIMULATION

ＩＮＴＲＯＤＵＣＴＩＯＮＴｏｔｅｓｔｔｈｅｌａｙｅｒｅｄｔｈｒｅｅ ｄｉｍｅｎｓｉｏｎａｌｎｏｎｌｉｎｅａｒｎｕｍｅｒｉｃａｌｍｏｄｅｌｐｒｅｓｅｎｔｅｄｉｎＰａｒｔＩ,ｉｔｗａｓａｐ ｐｌｉｅｄｔｏａｓｔｒａｔｉｆｉｅｄ ,ｒｅｃｔａｎｇｕｌａｒ,ａｎｄｔｗｏ ｌａｙｅｒｓｅａａｒｅａｗｉｔｈｓｔｅｐ ｌｉｋｅｔｏｐｏｇｒａｐｈｙｔｏｓｉｍｕｌａｔｅｔｈｅｇｅｎｅｒａｔｉｏｎａｎｄｐｒｏｐａｇａｔｉｏｎｏｆｉｎｔｅｒｎａｌｔｉｄｅｓ.Ｔｈｅｉｎｔｅｒｎａｌｔｉｄｅｖｅｌｏｃｉｔｉｅｓｏｆｔｈｅｕｐｐｅ…     

“我国近海有害赤潮发生的生态学、海洋学机制及预测防治”研究进展

介绍国家重点基础研究发展计划项目（“973”项目）“我国近海有害赤潮发生的生态学、海洋学机制及预测防治”的研究背景和主要研究内容,即以我国赤潮高发区东海作为主要研究海域,重点开展重要有害赤潮种的生物学特征及生态适应策略研究;近海赤潮高发区有害赤潮与富营养化的关系研究;近海赤潮高发区有害赤潮生消关键物理过程、数值模拟与预测研究;有害赤潮的危害机理及防治机理研究等。简要报道了项目通过现场综合航次获得的东海大规模赤潮发生前后水文、化学和生物学等诸多要素的变化特征,以及结合实验室模拟研究,在探索重要赤潮生物种群变化的动力学过程及其调控机理等方面取得的进展。另外,对项目的研究前景进行了展望。     

基于MODIS数据的珠江口悬沙扩散形态对风和径流的响应

Cloud-free moderate-resolution imaging spectroradiometer(MODIS) images of the Zhujiang(Pearl) River Estuary(ZRE) taken between 2002 and 2012 are retrieved and used to study the spatial and temporal patterns of suspended sediment concentrations(SSCs) across the estuary under runoff, wind, and tropical storm conditions.Five typical dispersal patterns of suspended sediments in the estuary are defined: Case I shows generally low SSCs under low dynamics; Case Ⅱ shows a river-dominant dispersal pattern of suspended sediments from the outlets,particularly from Modaomen, Jiaomen, Hengmen, and others; Case Ⅲ shows wind-dominant dispersal of high SSCs derived from the west shoal and southwesterly transport under a strong NE wind; Case IV is the combination of relatively large runoff and wind; and Case V is caused by a strong tropical storm with high river discharge and wind, which is characterized by the high SSCs across the entire estuary that are transported eastward by winddriven and buoyancy currents outside the estuary. Runoff is a dominant factor that controls seasonal and annual SSC variations in the ZRE, with the area of high SSCs being largest in the summer and smallest in the spring. The correlation coefficients between the monthly averaged river-suspended sediment discharge and the area of the high SSCs are approximately 0.6. The wind power over the west shoal increases with a wind speed, which induces more sediment resuspension and shows a close relationship between the wind speed and high SSC area.     

基于单形进化优化算法的重力固体潮信号解混及谱相关分析

为了揭示地球固体潮中谐波成分间的相关乘性调制关系与非相关叠加关系,并根据这些关系来分析重力固体潮信号中隐含的潮汐谐波。根据地球、月球与太阳旋转轨道的位置关系,建立了一个引潮力的正交分解模型。进一步,基于改进单形进化智能优化算法的独立分量分析的重力固体潮正交分解模型上,利用谱相关方法,对重力固体潮的独立成分进行谱相关分析,从而完整实现了潮汐谐波加性正交分解之后的乘性解调。最后,结合实际观测数据,并引入理论信号作为参考背景,利用以上模型与算法进行对比处理和分析。研究表明,所提出的模型与方法可以有效地实现潮汐谐波的正交分解,凸显能量较弱的长周期谐波分量,并从谱相关图谱中反映潮汐谐波调制关系的变化。     

Observations of semidiurnal internal tidal currents off central Chile (36.6°S)

Observations of semidiurnal internal tidal currents from three moorings deployed on the continental shelf off central Chile during summer and winter of 2005 are reported. The spectra of the baroclinic currents showed large peaks at the semidiurnal band with a dominant counterclockwise rotation, which was consistent with internal wave activity. The amplitude of the barotropic tidal currents varied according to the spring–neap cycle following the sea level fluctuations. In contrast, the amplitudes of the internal tide showed high spatial-temporal variability not directly related to the spring–neap modulation. Near the middle of the continental shelf and near the coast (San Vicente Bay) the variance of the semidiurnal baroclinic current is larger than the variance of its barotropic counterpart. The vertical structure of the baroclinic tidal current fluctuations was similar to the structure of the first baroclinic internal wave mode. In general, in the three study sites the variance of the baroclinic current was larger near the surface and bottom and tended to show a minimum value at mid depths. Kinetic energy related to semidiurnal internal waves was larger in winter when stratification of the water column was stronger. During summer, upwelling and the decrease of freshwater input from nearby rivers reduced the vertical density stratification. The amplitude of the semidiurnal internal tide showed a tendency to be enhanced with increasing stratification as observed in other upwelling areas. The continental shelf break and submarine canyons, which limit the continental shelf in the alongshore direction, represent near-critical slopes for the semidiurnal period and are suggested to be the main internal tide generation sites in the study region.     

小马村井动水位固体潮汐观测实验与排水装置改造

小马村井动水位观测副管设计不合理导致固体潮汐不明显,为此进行固体潮汐观测实验,此后固体潮汐较为明显。因为该井有原油上漂,排水装置的排水口经常堵塞,清淤后需人工调节流量,所以动水位观测难以恢复原状。2017年12月改造排水装置后,结果比较理想。     

全球Schwideski海潮模型K1、O1分波在中国大陆产生的地倾斜负荷潮

本文根据计算地倾斜负荷潮的积分Green函数方法,计算了全球Schwiderski海潮模型K₁、O₁分波在中国大陆产生的地倾斜负荷潮,绘制了K₁、O₁分波负荷潮椭圆及其长轴迹线,沿长轴方向分量的等潮时线,长、短半轴等值线诸地倾斜负荷潮参量在中国大陆境内的分布图,给出了它们的空间分布图象,为国内的地倾斜固体潮研究提供了重要的参考资料.     

Tide-Induced Eddies and Upwelling in a Semi-enclosed Basin: Nan Wan

Nan Wan is a 20 km wide tidally-dominated embayment situated between two headlands on the south coast of Taiwan. During spring tides, sudden sea-surface temperature drops occur twice each tidal cycle in the western and central regions of the bay, but only once in the eastern region. Shipboard ADCP surveys, moored measurements and numerical modelling results demonstrate that the headlands on either side of the bay generate strong tidally-induced eddies within the bay on each phase of the tide. The geometry of the region leads to considerable difference in size between the flood and ebb eddies. The flood eddy fills the entire basin, while the ebb eddy fills the western and central region only. The strong (relative vorticity ≈10–16 f) cyclostrophic eddies are only weakly affected by Earth's rotation, and thus upwelling occurs within each eddy, causing two temperature drops per tidal cycle in the western and central region, while only one drop in the eastern region.     

The lunar tide in sporadic E

It seems that the wind shear theory is accepted for the explanation of sporadic E at mid and low latitudes. Some examples from Arecibo are displayed to show this. The effect of lunar tides should then modify the wind-shear theory in a manner that yields the observed features of the lunar tide in the critical frequency foEs and the height h′Es of the sporadic E. This is shown to imply that the phase of the lunar tide in h’Es should be the same as the phase of the lunar tide in the eastward wind and that the phase of the lunar tide in foEs is three hours later. Hourly values of foEs, fbEs (the blanketing critical frequency) and h′Es from several observatories are analysed for the lunar semidiurnal tide. It is found that the phase of the tide in foEs is often about 3 hours later than for h′Es in agreement with the theory. Seasonal variations in the tide are also examined with the statistically most significant results (largest amplitudes) usually occurring in summer. After reviewing the many difficulties associated with determining the lunar tide in Es, both experimentally and theoretically, the analysed phase results are compared with what might be expected from Hagan’s global scale wave model. Agreement is only fair (a success rate of 69% among the cases examined) but probably as good as might be expected.