Optical water type discrimination and tuning remote sensing band-ratio algorithms: Application to retrieval of chlorophyll and Kd(490) in the Irish and Celtic Seas

This paper assesses the feasibility of applying remote sensing algorithms based on blue/green reflectance ratios to Case 2 waters. Two algorithms from the SeaDAS (NASA) image processing package, OC4v4 for surface chlorophyll concentration, Chl, and K(490) for the attenuation coefficient for downward irradiance at 490 nm, K_d(490), were investigated using an extensive set of observations from the Irish and Celtic Seas. In situ data from a profiling radiometer were used as inputs for the algorithms to avoid uncertainties in atmospheric correction procedures, and direct measurements of Chl and K_d490 and were used for validation purposes. The standard versions of the algorithms performed poorly: OC4v4 generally overestimated Chl (with a very low coefficient of determination), and K(490) progressively underestimated K_d490 for values greater than 0.3 m⁻¹. A two-step procedure for level 2 product generation was therefore devised in which the numerical coefficients of OC4v4 and K(490) were tuned for the two optical water types known to occur most frequently in this region (McKee, D., Cunningham, A., 2006. Identification and characterisation of two optical water types in the Irish Sea from in situ inherent optical properties and seawater constituents. Estuarine, Coastal and Shelf Science 68, 305–316) by statistical regression on a data set of 102 stations from the Irish and Celtic Seas. The water types were distinguished by the magnitude of their normalised water leaving radiance signals at 665 nm, nL_w(665), and appropriate versions of the tuned algorithms applied to each water type. When this procedure was tested on an independent data set of 19 stations from the Bristol Channel, Chl values were recovered with an RMS error of 0.36 mg m⁻³ and K_d(490) values with an RMS error of 0.095 m⁻¹. The identification of water types from water-leaving radiance signals, and the application of band-ratio algorithms tuned for specific water types, may therefore provide a simple means of improving the quality of remote sensing products in optically complex shelf seas.     

Experimental Study on Vortex-Induced Vibrations of Submarine Pipeline near Seabed Boundary in Ocean Currents

1 .IntroductionThe submarine pipeline is a commonfacility widely usedfor offshore oil and gastransport . Whena pipeline is installed on a seabed and not buried,unsupportedspans may exist insomelocations ,es-peciallyinthe uneven zones of the seabed.The spa…     

南海海域叶绿素浓度分布特征的卫星遥感分析

介绍了第二代海洋水色传感器SeaWiFS资料的特点汲其基本处理方法，海水叶绿素浓度提取方法，对南海域表层海水叶绿素浓度分布的时空变化特征及其与营养物质和南海环流的关系进行了初步分析。     

海洋环境荷载下输液立管的静、动力特性研究

考虑管内流动流体和管外海洋环境荷载共同作用 ,建立海洋立管侧向运动微分方程。用Hermite插值函数离散 ,在微机上编写海洋立管静、动力分析程序 ,通过计算分析研究管内流体对立管侧向变形和应力的作用 ;另外 ,探讨管内流体的流动速度和立管顶端的预张力对立管动力特性的影响。结果表明 ,立管变形和应力均随管内流体流动速度增加而增大 ,同时内流速度的增大会降低立管的固有频率 ,但适当增大立管顶端预张力会抵消内流流速增加引起的固有频率下降。     

三次样条函数在海洋水文资料整理中的应用

本文引入三次样条函数插值法,并尝试用于海洋资料处理。根据渤海及北黄海部分海洋站的历史资料进行了试验。用SHARP—PC—1211袖珍计算机进行计算,并将资料处理的结果与传统的过程曲线法订正值作了比较。结果表明,二者之间的误差不大,而样条函数拟合更好。作者认为三次样条函数插值法是可行的,在处理海洋资料时间序列中是有效的。在有温跃层的地方,如何应用,本文也给出了必要的说明。     

石斑鱼虹彩病毒SGIV在宿主细胞内依赖微管运动的行为特征

病毒是非常微小的简单生物, 不能独立生存, 必须借助宿主细胞完成自身的繁衍。病毒侵染进入细胞后, 通常借助于微管通过黏稠的细胞质运动到特定的复制位点。然而, 有关病毒依赖微管运动行为的精细动态研究还比较少。石斑鱼虹彩病毒(Singapore grouper iridovirus, SGIV)为虹彩病毒科蛙病毒属的一个新种, 是海水养殖鱼类的重要病毒性病原, 对海水养殖业造成重大经济损失。利用单粒子示踪技术实时追踪了SGIV病毒粒子沿微管运动的行为, 观察到SGIV在细胞边缘至微管中心之间的双向运动, 最高瞬时速度约0.2μm·s^-1, 均表现为主动运输。病毒粒子运动至微管交叉位置会减速迂回, 而后或受限于此, 平均运动速率约0.008μm·s^-1, 或通过交叉处继续快速运动, 最高瞬时速度为0.2μm·s^-1。同时, SGIV感染会影响微管的形态结构, 随着SGIV感染, 微管逐渐围绕细胞核和病毒加工厂形成环状结构。研究结果初步揭示了SGIV病毒和细胞微管之间相互作用的复杂过程, 丰富了我们对虹彩病毒胞内生命活动的认识, 有助于深入地理解海水鱼类虹彩病毒感染致病机理。     

弯睾鲫吸虫[Carassotrema flecterotestis(Zhukov,1971)comb.nov.]及其毛蚴发育观察

本文对取自台湾海峡棱鮻 (Lizacarinatus)消化道的弯睾软穴吸虫 (HapalotremaflecterotestisZhukov, 1971)进行重新描述,并对其毛蚴的体外发育进行观察.根据Yamaguti(1971)区分单孔科 (Haploporidae)和叉盘科 (Waretrematidae)的标准,同意李敏敏(1984)将其从单孔科移出并入叉盘科.在与叉盘科已知属比较后,我们发现该吸虫除睾丸形状外,其他主要特征与鲫吸虫属 (CarassotremaPark, 1938)的相似.因此,我们拟将其作为后者的同物异名,并将该吸虫重新命名为弯睾鲫吸虫 [Caras sotremaflecterotestis(Zhukov, 1971)comb. nov. ].实验结果表明:在室温 7~24℃(均值为 15. 3℃)条件下,其虫卵从单个卵细胞到毛蚴孵出共需 12d.     

海洋作业渔船管理系统的设计与运行试验

对渔政管理指挥系统建设项日中的业务软件部分渔船管理系统的设计方案进行了介绍。根据我国渔洋作业渔船的实际管理模式，提出了渔船管理系统设计方案。系统通过网络化的业务处理和管理流程，规范渔船建造、审批、登记以及捕捞许可证发放等管理业务，实现渔船控制指标的统一分配，以控制捕捞业发展规模和保护我国的渔业资源。系统以Microsoft VB6．0，Delphi6．0开发，在Window98／2000／XP环境下运行。通过运行试验，对系统运行环境进行了评估，为渔政管理信息化的建设、系统升级提供了经验和技术依据。