Validity of sea surface temperature observed with the TRITON buoy under diurnal heating conditions     

Yoshimi Kawai  Hiroshi Kawamura  Sumio Tanba  Kentaro Ando  Kunio Yoneyama  Norio Nagahama 《Journal of Oceanography》2006,62(6):825-838

In order to investigate the validity of buoy-observed sea surface temperature (SST), we installed special instruments to measure near-surface ocean temperature on the TRITON buoy moored at 2.07°N, 138.06°E from 2 to 13 March 2004, in addition to a standard buoy sensor for the regular SST measurement at 1.5-m depth. Large diurnal SST variations were observed during this period, and the variations of the temperatures at about 0.3-m depth could be approximately simulated by a one-dimensional numerical model. However, there was a notable discrepancy between the buoy-observed 1.5-m-depth SST (SST_1.5m) and the corresponding model-simulated temperature only during the daytime when the diurnal rise was large. The evaluation of the heat balance in the sea surface layer showed that the diurnal rise of the SST_1.5m in these cases could not be accounted for by solar heating alone. We examined the depth of the SST_1.5m sensor and the near-surface temperature observed from a ship near the buoy, and came to the conclusion that the solar heating of the buoy hull and/or a disturbance in the temperature field around the buoy hull would contribute to the excessive diurnal rise of the SST_1.5m observed with the TRITON buoy. However, the temperature around the hull was not sufficiently homogenized, as suggested in a previous paper. For the diurnal rise of the SST_1.5m exceeding 0.5 K, the daytime buoy data became doubtful, through dynamics that remain to be clarified. A simple formula is proposed to correct the unexpected diurnal amplitude of the buoy SST_1.5m.  相似文献   

南海东北部表层沉积中有孔虫的分布及其环境意义   总被引：11，自引：0，他引：11  

徐建  黄宝琦  陈荣华  张富元 《热带海洋学报》2001,20(4):6-13

为了探讨南海东北部表层沉积中有孔虫分布的规律，选取184个表层样进行分析，结果发现有孔虫的垂向分布与碳酸盐的溶解作用密切相关。在2300－2500m水深以下，浮游有孔虫丰度迅速减小，而底栖有孔虫占有孔虫全群的比值BF／（BF＋PF）以及底栖有孔虫胶结质壳类的百分含量则迅速增加，这三者随水深的变化在3400－3500m处有一明显的转变，被认为是南海东北部CCD面（碳酸盐补偿深度）所在的位置，且该研究区内碳酸盐补偿深度南部较北部深100m。浮游有孔虫水平分布除了受表层海水温度的的控制外，黑潮南海分支以及吕宋岛北端上升流区带来的富营养水体的存在也起很重要的作用。  相似文献   

Structural monitoring of offshore platforms using impulse and relaxation response     

Lalu Mangal  V. G. Idichandy  C. Ganapathy 《Ocean Engineering》2001,28(6)

Monitoring offshore platforms, long span bridges, high rise buildings, TV towers and other similar structures is essential for ensuring their safety in service. Continuous monitoring assumes even greater significance in the case of offshore platforms, which are highly susceptible to damage due to the corrosive environment and the continuous action of waves. Also, since a major part of the structure is under water and covered by marine growth, even a trained diver cannot easily detect damage in the structure. In the present work, vibration criterion is adopted for structural monitoring of jacket platforms. Artificial excitation of these structures is not always practicable and ambient excitation due to wind and waves may not be sufficient for collecting the required vibration data. Alternate methods can be adopted for the same purpose, for example, the application of an impact or a sudden relaxation of an applied force for exciting the structure. For jacket platforms, impact can be applied by gently pushing the structure at the fender while relaxation can be accomplished by pulling the structure and then suddenly releasing it using a tug or a supply vessel in both cases. The present study is an experimental investigation on a laboratory model of a jacket platform, for exploring the feasibility of adapting vibration responses due to impulse and relaxation, for structural monitoring. Effects of damage in six members of the platform as well as changes in deck masses were studied. A finite element model of the structure was used to analyze all the cases for comparison of the results as well as system identification. A data acquisition and analysis procedure for obtaining the response signatures of the platform due to the impulse and relaxation procedure was also developed for possible adoption in on-line monitoring of offshore platforms. From the study, it has been concluded that both impulse and relaxation responses are useful tools for monitoring offshore jacket platforms. The present work forms the basis for the development of an automated, on-line monitoring system for offshore platforms, using neural networks.  相似文献   

黄、东海海域水团发育对底质沉积物分布的影响   总被引：6，自引：0，他引：6  

郭志刚  杨作升  王兆祥 《中国海洋大学学报(自然科学版)》1995,(1)

通过对黄、东海海域底质沉积物中的细粒级粘土矿物组合特征和全粒级碳酸盐含量分析、对比上覆水团和悬浮体资料，探讨研究区水团发育消长对底质沉积物分布的影响作用。结果表明研究区可以划分为长江冲淡水影响的长江型物质沉积区；黄海水影响的黄河型物质沉积区和黑潮水以及东海次表层水影响的残留型物质沉积区。而水团发育消长可直接影响下伏底质的分布特征。黄河型物质沉积区与残留型物质沉积区的分界相应于黄海冷水向东南扩展与黑潮次中层混合水向陆架爬升互为消长的长期综合平衡位置，而黄海冷水向东南的扩展范围代表着黄河物质在陆架向东南扩展沉积的最大范围．  相似文献   

GIS新引擎——“真图”数据解决方案     

李德仁  ;郭晟  ;胡庆武  ;刘守军  ;魏建魁 《测绘软科学研究》2008,(3)

提出了一种基于移动测量系统技术的"真图"数据解决方案。一方面极大地丰富了GIS数据源,另一方面通过相应的真图影像数据管理软件及开发包扩展GIS功能,为各行业应用提供了地理信息数据解决方案。  相似文献   

基于Web 2.0的GIS模型共享平台研究   总被引：5，自引：2，他引：3  

唐中实  饶顺斌  谢喆  赵红蕊  王海葳 《测绘科学》2008,33(4)

本文提出了基于Web 2.0建立GIS模型共享平台的设想,以期建立一个能够让用户创造模型和组织数据的GIS模型共享平台,并基于模型共享平台建立原型系统。借鉴了Web 2.0的数据自组织形式,按标签分类的方式让用户参与元数据组织,以适应各个领域用户的需求。同时为改变以往被动等待用户查询信息的方式,原型系统按RSS标准主动发布有价值信息,用户可以在第一时间获知系统更新。原型系统功能用网络服务封装,并提供客户端程序,提高了系统适用范围。原型系统的建立,证实了构建基于Web 2.0的GIS模型共享平台的价值和可行性。  相似文献   

四元体系Na~ ∥Cl~-,CO_3~(2-),B_4O_7~(2-)-H_2O 273K介稳相平衡研究     

《矿物岩石》2008,(4)

采用等温蒸发法研究简单四元体系Na ∥Cl-,CO32-,B4O72--H2O273K时的介稳相平衡,并测定该体系273K平衡液相中各组分的溶解度及密度,该体系的介稳相图和密度组成图显示:该四元体系在273K时的相图由3条溶解度单变量线、3个结晶区及1个共饱和点组成。体系属简单共饱型,无复盐或固溶体形成,3个结晶区分别对应单盐Na2CO3·10H2O,NaCl和Na2B4O7·10H2O。共饱点E处于Na2CO3·10H2O,NaCl及Na2B4O7·10H2O3盐共饱和,所对应的平衡液相组成为w(Na2CO3)=6.81%,w(NaCl)=21.69%,w(Na2B4O7)=0.65%,w(H2O)=70.85%。研究体系在273K下,Na2CO3·10H2O是碳酸钠盐的唯一析出形式,且硼酸钠对碳酸钠有盐析作用。  相似文献   

鄂尔多斯坳陷湖盆缓坡型三角洲前缘沉积微相分带及成因分析——以定边-安边地区延长组长6油组为例   总被引：1，自引：0，他引：1  

LI Feng-jie  JIANG Bin  ZHAO Jun-xingInstitute of Sedimentary Geology  Chengdu University of Technology  Chengdu  China 《矿物岩石》2008,(3)

运用沉积相分析理论对鄂尔多斯盆地定边-安边地区晚三叠世延长组坳陷湖盆缓坡型三角洲前缘沉积微相组合进行系统研究,共识别出其组合形式有:水下分流河道叠加组合、河口坝叠加组合、水下分流河道与河口坝叠加组合以及河口坝与远砂坝、席状砂的叠加组合等4大类9种类型。并深入研究三角洲前缘沉积微相组合的时空分布规律,以三角洲前缘坡折带为界,将三角洲前缘分为"台型前缘"、"坡型前缘"和"盆型前缘"三部分,各部分有独特的沉积微相组合形式。高分辨率层序地层学的基准面旋回原理和沉积物体积分配原理表明:短期基准面的规律性变化影响着储层砂体的成因类型、叠加组合形式和空间分布规律,据此建立坳陷湖盆三角洲前缘不同沉积微相组合的成因分布模式。  相似文献   

基于遗传算法的空基导航信号增强平台组网优化方法研究     

YANG Long  周建华  CHEN Jin-ping 《全球定位系统》2008,33(3):9-13

根据空基导航信号增强平台的工作原理设计了组网优化评价指标;然后简单介绍了遗传算法的基本原理,对空基增强平台的空间位置进行了二进制编码;最后采用通用的遗传算法对空基导航信号增强平台空间分布进行优化搜索。仿真实验结果证明该算法能够对空基导航信号增强平台进行有效布置,覆盖范围内导航服务误差分布合理,并且能够根据实际要求对空基平台进行优化调整。  相似文献   

黑海西北部冷泉碳酸盐岩的沉积岩石学特征及氧化还原条件的稀土元素地球化学示踪   总被引：3，自引：1，他引：2  

冯东  陈多福 《现代地质》2008,22(3):390-396

黑海西北部罗马尼亚大陆架(水深120m)和乌克兰陆坡(水深190m)发育冷泉碳酸盐岩结壳。XRD测试表明此结壳主要由高镁方解石和文石组成。结壳中与渗漏系统微生物活动有关的凝块和葡萄状文石等特殊的沉积组构非常发育。冷泉碳酸盐岩酸可溶部分(碳酸盐岩相矿物)的稀土元素含量很低(0.068×10-6~2.817×10-6),稀土元素页岩标准化配分模式显示罗马尼亚大陆架冷泉碳酸盐岩具有明显的Ce负异常,乌克兰陆坡冷泉碳酸盐岩具Ce的正异常,表明它们是分别在氧化和还原环境中沉积的。稀土元素和V、Cd和U等微量元素的含量在泥晶中最高,亮晶中最低,可能反映成岩过程对元素含量有控制作用。  相似文献