排序方式： 共有36条查询结果，搜索用时 15 毫秒
1.
The characteristics of currents and tidal currents in the Andaman Sea(AS) are studied during the second half of2016 using observed data from a moored acoustic Doppler current profiler(ADCP) deployed at 8.6°N, 95.6°E.During the observation period, the mean flow is 5–10 cm/s and largely southward. The root mean square and kinetic energies of the low and high frequency flows, which are divided by a cutoff period of 5 d, are at the same level, indicating their identical importance to the total current. A power spectrum analysis shows that intraseasonal oscillations, a tidal-related semilunar month signal, a semidiurnal tidal signal and periods of 3–4 d are prominent. The barocliny of an eddy kinetic energy is stronger than the mean kinetic energy, both of which are the strongest on the bottom and the weakest at 70 m depth. Residual currents are largely southward(northward) during the summer(winter) monsoon season. Two striking peaks of the southward flow cause the 80 d period of meridional currents. The first peak is part of a large-scale circulation, which enters the AS through the northern channel and exits through the southern channel, and the second peak is part of a local vortex. The 40 d oscillation of the zonal current is forced by geostrophic variations attributed to local and equatorial remote forcing. The tidal current is dominated by semidiurnal constituents, and among these, M2 and N2 are the top two largest major axes. Moreover, astronomical tidal constituents MM and MSF are also significant. Diurnal constituents are weak and shallow water tides are ignorable. The aims are to introduce the new current data observed in the AS and to provide initial insights for the tidal and residual currents in the Andaman Sea. 相似文献
2.
渤海夏季环流的高分辨率海浪-潮汐-环流耦合模式研究 总被引：2，自引：0，他引：2
The Bohai Sea is a shallow semi-enclosed inner sea with an average depth of 18 m and is located at the west of the northern Yellow Sea. The climatological circulation pattern in summer of the Bohai Sea is studied by using a wave-tide-circulation coupled model. The simulated temperature and the circulation agree with the observation well. The result shows that the circulation pattern of the Bohai Sea is jointly influenced by the tidal residual current, wind and baroclinic current. There exists an obvious density current along the temperature front from the west part of the Liaodong Bay to the offshore area of the Huanghe Estuary. In the Liaodong Bay there exists a clockwise gyre in the area north to the 40°N. While in the area south to the 40°N the circulation shows a two-gyre structure, the flow from the offshore area of the Huanghe Estuary to the Liaodong Bay splits into two branches in the area between 39°N and 40°N. The west branch turns into north-west and forms an anti-clockwise gyre with the south-westward density current off the west of the Liaodong Bay. The east branch turns to the east and forms a clockwise gyre with the flow along the east coast of the Liaodong Bay. The forming mechanism of the circulation is also discussed in this paper. 相似文献
3.
黄海冷水团演变过程及其与邻近水团关系的分析 总被引：43，自引：12，他引：43
黄海冷水团是出现在黄海的一种独特的水文现象.文中利用覆盖整个黄海的GDEM三维水温资料,结合近期一些大型调查所获得的有关观测研究结果,首先较系统地分析了黄海冷水团的形成和演变过程,并对冷水团3个冷中心的季节演变提出了一些与前不同的认识.同时,通过对黄海冷水团形成、发展和消亡与该海域温跃层演变关系的分析,进一步揭示了黄海冷水团演变的机理.然后,探讨了黄海冷水团演变过程中与青岛和仁川东南海域冷水团以及东海北部底层冷水的关系.分析表明,在黄海冷水团发展的鼎盛时期,青岛冷水团和仁川东南海域冷水团以及东海北部底层冷水皆包络其中. 相似文献
4.
南黄海春季水温分布特征的分析 总被引：7，自引：2，他引：7
利用美国海军的空间分辩率为10′×10′月平均的GDEM三维水温资料,研究了南黄海春季水温的分布特征及其演变过程。分析结果较清晰地显示了春季南黄海的水温分布如何从冬季的垂直均匀型过渡到夏季的层化结构。分析还表明:春季南黄海水温的水平和垂直结构皆比冬季更为复杂,并出现若干个较特殊的水文现象,例如,在34°40′~36°20′N的南黄海西侧出现了“青岛冷水团”,而在35°30′~37°20′N的南黄海东侧,初次发现存在着一个类似性质的冷水团,称其为“仁川外海冷水团”。此外,在冷水团的邻近海域还存在着中层冷水。 相似文献
5.
陆架波的性质如频散关系、形成机制等受地形影响。研究地形对陆架波的性质影响具有重要意义。基于陆架拦截波理论,数值计算了分段线性地形下不同宽度陆架上陆架拦截波的频散关系、长波假设下波动的相速度、阻尼情况下的波动耗散率以及强迫波的外力影响因子。分析了陆架宽度及坡度对自由及强迫陆架拦截波性质的影响。陆架宽度影响陆架拦截波的频散关系。陆架变宽,使得长波频散曲线的斜率增大。陆架宽度的增加使第一模态陆架拦截波有明显的性质变化:相速度增大,波动受辐散影响的程度变大,摩擦衰减距离增大,且风应力旋度在波动的生成机制中起到的作用渐强。在宽的陆架上,研究陆架拦截波的生成及强迫波的振幅时,应充分考虑风应力旋度的作用。第二、三模态波动的相速度受陆架坡度的影响较大,但摩擦衰减距离基本都在200km左右,几乎不随陆架宽度改变,属于局地波。 相似文献
6.
本文基于2006—2007年春、夏、秋、冬季CTD观测的盐度资料分析了苏北沿岸水盐度的季节变化特征,并利用冬、夏季盐度场变化估算了苏北沿岸水的淡水来源。结果表明:冬季苏北沿岸水在东北季风的驱动下顺岸南下,在离开苏北浅滩后转向东南进入东海;夏季低盐的苏北沿岸水分多支向北、向东流出沿岸区,后者汇入南黄海夏季冷水团环流中。估算结果表明苏北沿岸水的淡水来源主要是苏北沿岸的入海径流水,约占总量的65%,次之是降水/蒸发量通量和长江冲淡水沿江苏沿岸的北向扩展。 相似文献
7.
根据桶形基础的特殊形式,采用普通经纬仪对桶基安装误差进行测量是比较困难的。提出了根据空间立体几何原理对桶形基础平台进行桶基安装误差测量并保证安装精度的方法。 相似文献
8.
LOESS四维客观分析在中国近海的应用 总被引：2，自引：0，他引：2
利用全国海洋综合调查资料和世界大洋数据库(WOD)资料,运用局部加权回归法(LOESS)四维客观分析方案对中国近海的温度场进行了客观分析,将散布在空间中的温度资料点插值到均一的网格中。在分析中充分考虑了中国海曲折复杂的海岸特点,将底深调整系统(TAR)和障碍调整系统(BAR)整合到四维插值系统中,使得资料点空间权重的计算更为合理。计算结果显示,LOESS客观分析方案充分考虑了空间因素(经度、纬度、深度)和时间因素,能客观反映出中国近海一年四季的温度时间-空间结构。通过与Kriging插值方法的对比,发现LOESS方法能更精确地把中国近海温度结构反映出来。 相似文献
9.
陆架海区温跃层特征量的一种计算方法--拟阶梯函数逼近法 总被引：9，自引：2，他引：9
在中国陆架海区调查获得的CDT资料表明，陆架区的水文要素垂直结构大都可以理想化为三层垂直结构模式：上均匀层、跃层和下均匀层。提出了一种用3条线段构成的拟阶梯函数拟合水文要素垂直剖面的方法，利用最小二乘法求出2个拐点的位置，即温跃层的上界和下界，取2个拐点的联线的斜率作为温跃层强度。对陆架海区各种不同的温度要素垂直结构形态整理归纳，分为正跃层、逆跃层、单方向多跃层和正逆跃层混合4种类型。各种类型均可按照一个或多个拟阶梯函数进行最小二乘拟合来获得温跃层的特征量。 相似文献
10.