潮汐调和分析的一种算法

本文在常规潮汐调和分析方法的基础上，提出了一种由高低潮资料进行潮汐分析的算法。具体计算表明，该算法与现今通用的常规算法（即等间隔最小二乘法）相比，既可大大减少所需原始样本量，在相同记录长度内，是常规算法的三分之一还少，同时减少样本处理的前期工作量；又能保证潮位拟合的精度和预报的可信度，两者精度相当，结果一致。该算法原理简单、实用有效，对于局部样本缺损较易处理，具有实际应用价值。     

胶州湾三维变动边界的潮流数值模拟

基于Blumberg等（1986）的河口、陆架和海洋模式，引入变边界处理技术，建立了胶州湾三维变动边界的潮流模型，模型以σ-正交曲线坐标下三维非线性潮波方程为基本方程，引入2.5阶瑞封闭方程组，采用分裂算子法数值求解方程组，利用湍封闭方程求解垂直紊动粘滞系数，采用干湿网格方法模拟潮流漫滩过程，三维变动边界潮流模型计算结果与实测值吻合良好。     

Detailed measurements during a transient front in a small subtropical estuary

High-resolution measurements of velocity and physio-chemistry were conducted before, during and after the passage of a transient front in a small subtropical system about 2.1 km upstream of the river mouth. Detailed acoustic Doppler velocimetry measurements, conducted continuously at 25 Hz, showed the existence of transverse turbulent shear between 300 s prior to the front passage and 1300 s after. This was associated with an increased level of suspended sediment concentration fluctuations, some transverse shear next to the bed and some surface temperature anomaly.     

Undular tidal bore dynamics in the Daly Estuary, Northern Australia

Measurements in the macro-tidal Daly Estuary show that the presence of an undular tidal bore contributed negligibly to the dissipation of tidal energy. No recirculation bubble was observed between a trough and the following wave crest in the lee waves following the undular bore. This differs to stationary undular bores in laboratory experiments at larger Froude numbers where a recirculation bubble exists. Secondary motions and the turbulence generated by the undular bore had no measurable influence on the sediment transport. This situation contrasts with the intense sediment resuspension observed in breaking tidal bores. The tidally averaged sediment budget in the Daly Estuary was controlled by the asymmetry of tidal currents. The undular bore may widen the river by breaking along the banks that it undercuts, leading to bank slippage. A patch of river-wide macro-turbulence of 3-min duration occurred about 20 min after the passage of the bore during accelerating tidal currents.     

Benthic photosynthesis in submerged Wadden Sea intertidal flats

In this study we compare benthic photosynthesis during inundation in coarse sand, fine sand, and mixed sediment (sand/mud) intertidal flats in the German Wadden Sea. In situ determinations of oxygen-, DIC- and nutrient fluxes in stirred benthic chamber incubations were combined with measurements of sedimentary chlorophyll, incident light intensity at the sediment surface and scalar irradiance within the sediment. During submergence, microphytobenthos was light limited at all study sites as indicated by rapid response of gross photosynthesis to increasing incident light at the sea floor. However, depth integrated scalar irradiance was 2 to 3 times higher in the sands than in the mud. Consequently, gross photosynthesis in the net autotrophic fine sand and coarse sand flats during inundation was on average 4 and 11 times higher than in the net heterotrophic mud flat, despite higher total chlorophyll concentration in mud. Benthic photosynthesis may be enhanced in intertidal sands during inundation due to: (1) higher light availability to the microphytobenthos in the sands compared to muds, (2) more efficient transport of photosynthesis-limiting solutes to the microalgae with pore water flows in the permeable sands, and (3) more active metabolic state and different life strategies of microphytobenthos inhabiting sands.     

潮汐对瞬态气候响应模拟的影响研究

In this study, the impact of oceanic processes on the sensitivity of transient climate change is investigated using two sets of coupled experiments with and without tidal forcing, which are termed Exp_Tide and Exp_Control,respectively. After introducing tidal forcing, the transient climate response(TCR) decreases from 2.32 K to 1.90 K,and the surface air temperature warming at high latitudes decreases by 29%. Large ocean heat uptake efficiency and heat storage can explain the low TCR in Exp_Tide. Approximately 21% more heat is stored in the ocean in Exp_Tide(1.10×10~(24) J) than in Exp_Control(0.91×10~(24) J). Most of the large ocean warming occurs in the upper 1 000 m between 60°S and 60°N, primarily in the Atlantic and Southern Oceans. This ocean warming is closely related to the Atlantic Meridional Overturning Circulation(AMOC). The initial transport at mid-and high latitudes and the decline in the AMOC observed in Exp_Tide are both larger than those observed in Exp_Control. The spatial structures of AMOC are also different with and without tidal forcing in present experiments. The AMOC in Exp_Tide has a large northward extension. We also investigated the relationship between AMOC and TCR suggested by previous studies using the present experiments.     

杭州湾乍浦断面潮流分布特征

根据2000年9月在杭州湾乍浦断面设置的8个潮流同步观测站的资料,对该断面潮流分布特征进行了分析和探讨,结果表明:该断面大潮涨急时呈现两个大流速核;断面南部的流速要比北部的大,涨潮流速大于落潮流速。这对了解杭州湾水文特征有着一定意义,同时为杭州湾跨海大桥的设计建设提供参考。     

春夏季南黄海西部沿岸低盐水入侵温跃层现象的研究

2000年6月至2002年6月春夏季期间,在南黄海春夏季南黄海西部沿岸低盐水入侵温跃层现象的研究鱼产卵场进行了4个航次的多学科调查,海洋水文观测分析结果表明:在苏北浅滩外侧、成山头—石岛外侧的层化海区的温跃层中存在低盐水现象.春夏增温季节温跃层加强,低盐水入侵现象逐渐增强;入侵强度也存在年际变化.苏北浅滩入侵低盐水舌向北偏东方向延伸,水舌较宽,入侵较远;石岛附近入侵低盐水舌向南偏西方向延伸,水舌较窄,入侵较弱.温跃层中低盐水是由于沿岸低盐水入侵造成的,并与当地的潮锋现象存在密切的关系.     

Tidal fluxes of nutrients and suspended sediments at the North Inlet–Winyah Bay National Estuarine Research Reserve

Beginning June of 1993 suites of 13 water samples have been collected at Oyster Landing, North Inlet (SC), every 20 days covering two consecutive tidal cycles at 2.07 h intervals. In order to ascertain whether this large (and still growing) water chemistry data set can be used to determine tidal fluxes of nutrients and sediments, we coupled measured concentrations to estimates of instantaneous tidal discharge based on a basin water storage curve and hindcast tides. The mean advective fluxes of all constituents, including salt, showed statistically significant exports. This result, however, is largely due to an ebb bias in the sampling protocol, which resulted in 52% of the samples being collected on ebb tide versus a theoretical percentage of 48%. When this bias was corrected by reducing the mean discharge (−610 l s⁻¹) to a value (−125 l s⁻¹) that produced a balance between the mean advective and dispersive salt fluxes, the advective fluxes of the other constituents were reduced to values that are not significantly different from zero. In addition to a statistically significant dispersive influx of salt, significant dispersive exports were found for DON, NH₄, DOP, PO₄ and DOC. All particulate constituents (PN, PP, ISS and OSS) yielded dispersive fluxes that were not significantly different from zero. Annual material budgets for the Oyster Landing basin based on the dispersive fluxes of all constituents (except salt) are generally similar in magnitude and direction to those measured by [Dame, R.F., Spurrier, J.D., Williams, T.M., Kjerfve, B., Zingmark, R.G., Wolaver, T.G., Chrzanowski, T.H., McKeller, H.N., Vernberg, F.J., 1991. Annual material processing by a salt marsh-estuarine basin in South Carolina, USA. Marine Ecology Progress Series 72, 153–166.] in the nearby and ecologically similar Bly Creek basin, indicating that the dispersive fluxes determined in this study are realistic. We offer suggestions for improving the reliability and usefulness of future Oyster Landing water quality data.