An instability theory of air-sea interaction for coastal upwelling

A surface wind (seabreeze), thermally generated by differential sea surface temperature, is introduced to Gill-Clarke’s model (1974) through wind stress for investigating the effects of Seabreeze on coastal upwelling. A coupled air-sea system is treated as an eigenvalue problem. The solutions show that the thermally forced local winds break down the coastal Kelvin wave into three parts: small-scale (L<100 km) growing and stationary modes, mesoscale (100 km200 km) coastal Kelvin modes. The consistency of the length scale between the most growing mode predicted by this model and the observed cold/warm alternation pattern of surface water near the Peruvian Coast (around 15oS) implies that Seabreeze may play some role in coastal upwelling.     

A Post-Processing Method for the Removal of Refraction Artifacts in Multibeam Bathymetry Data

Sound refraction artifacts are often present in multibeam swath bathymetry data. For a flat array, the artifacts are usually more serious in outer beams than in inner beams. In a 3D topographical mapping they appear as ridges that parallel the tracks of the vessel. To shorten the survey time, the outer beams should be utilized as often as possible. Therefore, the refraction errors should be removed. In this paper, we present a model of reduced sound speed profile that consists of three water layers. The sound speed of the two upper layers has a constant gradient, and the third layer has the same sound speed as the most bottom measured layer. The model parameters can be searched based on the principle of the minimum difference of depth between the overlap of two neighboring swaths. The horizontal position and depth of each beam can be accordingly recalculated using the model parameters. To avoid being trapped in local optimum, the initial search scope is limited according to assumed lunch angle and travel time in each subregion. The method is verified by comparing the simulated and real data.     

Low Salinity, Cool-Core Cyclonic Eddy Detected Northwest of Luzon during the South China Sea Monsoon Experiment (SCSMEX) in July 1998

To detect eddies, intensive surveys of the northeast South China Sea (SCS) (114°30′–121°30′ E, 17°–22°N) were conducted in July 1998 during the international SCS Monsoon Experiment (SCSMEX), the U.S. Navy using Airborne Expendable Bathythermograph and Conductivity-Temperature-Depth sensors (AXBT/AXCTD), and the Chinese Academy of Sciences using Acoustic Doppler Current Profilers (ADCP). The hydrographic survey included 307 AXBT and 9 AXCTD stations, distributed uniformly throughout the survey area. The ADCP survey had two sections. The velocity field inverted from the AXBT/AXCTD data and analyzed from the ADCP data confirm the existence of a low salinity, cool-core cyclonic eddy located northwest of Luzon Island (i.e., the Northwest Luzon Eddy). The radius of this eddy is approximately 150 km. The horizontal temperature gradient of the eddy increases with depth from the surface to 100 m and then decreases with depth below 100 m. The cool core was evident from the surface to 300 m depth, being 1°–2°C cooler inside the eddy than outside. The tangential velocity of the eddy is around 30–40 cm/s above 50 m and decreases with depth. At 300 m depth, it becomes less than 5 cm/s. This revised version was published online in August 2006 with corrections to the Cover Date.     

北黄海菲律宾蛤仔帕金虫汉行病害的研究

2000年7月－11月，对我国北黄海沿岸滩涂增养殖的菲律宾蛤仔Ruditapes philippinarum大规模死亡进行了研究，并对病害暴发与温度、盐度的相关性进行了探讨。利用FTM培养和组织切片方法对病害流行海域的菲律宾蛤仔进行了检测。结果表明，蛤仔体内寄生了大量病原帕金虫Perkinsus sp，感染率为20％－100％，感染强度为3－3565936cell/ind或2－1670615cell/g组织。感染强度与蛤仔大小有关，个体越小，感染程度越轻。经感染试验，进一步确定了帕金虫大量繁殖是引起蛤仔大规模死亡的原因。病害始于7月下旬，止于10月下旬；最初暴发于庄河栗子房海域，尔后逐渐向东西两侧海域蔓延。病害暴发时要主要受温度影响，高于20℃易于暴发帕金虫病害；流行范围主要受盐度影响，盐度为20－32海域适宜帕金虫病害的流行。     

Synoptic distributions of thermal surface mixed layer and thermocline in the southern yellow and East China Seas

Synoptic distributions of thermal surface mixed layer and thermocline were identified using four airborne expendable bathythermograph (AXBT) surveys (September 1992 and February, May, and September 1993) in the southern Yellow and East China Seas. Seasonality and a dominant driving mechanism of the surface mixed layer were examined. The dominant driving mechanisms differ between seasons and between on-shelf and off-shelf regimes. Currents, eddies, and migration of bottom cold waters (on the shelf) also affect the surface mixed layer. Thermocline thickness, temperature difference from thermocline top to bottom, and thermocline intensity in warm seasons were measured, and their synoptic features were also discussed.     

海浪方向谱的阵列测量

本文在系统分析国内外有关方向谱测量工作的基础上,根据实验室模型试验结果,采用由五个测波仪组成的“T”形阵列,于1991年6～7月同在渤海8号采油平台上首次进行了方向谱阵列测量,获得了宝贵的阵列测量资料。测量实施表明,选择最佳测量方案及性能稳定的测波仪器,对测量结果是至关重要的。     

利用Jason-1数据监测呼伦湖水位变化

卫星测高为内陆水域水位变化的实时和连续监测提供了一种高效的技术工具．但是这种应用受到数据点覆盖稀疏的限制。利用Jason-13年（2002-2004）GDRs测高数据作简单的数据编辑,并进行必要的地球物理改正．最后得到内蒙古地区呼伦湖水位变化的时间序列。呼伦湖地区由于近年来持续干旱,水位呈现明显的下降趋势．年平均下降约0．3～0．5m。在一般的内陆水域．水位变化主要取决于降雨量和蒸发量,所以,根据卫星测高所得的水位变化信息．可以为区域气候变化的研究提供一种全新的技术与方法。     

库车再生前陆盆地冲断构造楔特征

库车再生前陆盆地冲断构造楔由一系列向南运动的逆冲断层和相关褶皱组成。冲断楔的北部以断层转折褶皱、断层传播褶皱、双重逆冲构造为主。断层楔的前缘发育了很好的滑脱膝折背斜,全为盲断层控制,形成隐蔽式前锋。冲断层的就位从中新世开始,自北向南迁移,前锋的构造形成在第四纪。造成逆冲断层的地壳水平缩短作用速度在中新世较慢,平均为0．355mm/a,上新世中期达0．82mm/a,而到上新世晚期和第四纪速度增大了约一个数量级,达到1．29－3mm/a。     

3种模式下钻孔灌注桩桩-土剪切特性现场试验研究

不同的桩-土剪切模式对桩-土剪切位移量的大小和桩侧摩阻力的发挥有重要影响。对抗压桩、顶拔桩和负摩擦桩等3种模式的6根钻孔灌注桩的剪切特性进行了现场加载试验与长期监测。通过对不同桩型的桩身应变、桩顶位移和桩周土沉降等试验资料的系统分析,建立了"侧阻-位移"曲线确定各模式桩-土剪切位移量和不同深度的极限侧阻力。根据不同桩-土剪切模式极限侧阻力的发挥特征,分析了桩-土相对运动方向、剪切边界约束条件、剪切位移量、加载速率和剪切历时等5个因素对极限侧阻力发挥的不同影响。讨论了利用现场顶拔桩试验结果对桩负摩阻力增大段的极限负摩阻力进行预测的可行性,供同行参考借鉴。