Assimilating satellite SST/SSH and in-situ T/S profiles with the Localized Weighted Ensemble Kalman Filter

The Localized Weighted Ensemble Kalman Filter(LWEnKF) is a new nonlinear/non-Gaussian data assimilation(DA) method that can effectively alleviate the filter degradation problem faced by particle filtering, and it has great prospects for applications in geophysical models. In terms of operational applications, along-track sea surface height(AT-SSH), swath sea surface temperature(S-SST) and in-situ temperature and salinity(T/S) profiles are assimilated using the LWEnKF in the northern South China ...     

Bias correction of sea surface temperature retrospective fore-casts in the South China Sea

Offline bias correction of numerical marine forecast products is an effective post-processing means to improve forecast accuracy. Two offline bias correction methods for sea surface temperature(SST) forecasts have been developed in this study: a backpropagation neural network(BPNN) algorithm, and a hybrid algorithm of empirical orthogonal function(EOF) analysis and BPNN(named EOF-BPNN). The performances of these two methods are validated using bias correction experiments implemented in the South...     

20世纪夏威夷最大海啸的地质证据

夏威夷历史海啸记录包含远距离和当地产生的海啸,由这些事件引起的人员伤亡和对建筑、环境造成的破坏与损失是惊人的,但是在近来才有一些对历史海啸沉积事件的综合性的研究.夏威夷多岩石的海岸线的演变主要是海啸和风暴的贡献,然而区分风暴和海啸是很难的,特别是相关的小的历史海啸事件.因此夏威夷海啸的研究往往关注于大的古海啸沉积事件.研究表明远距离产生的事件,如1946年阿留申海啸对瓦胡岛岩石岸线的演变具有重要影响.活火山也有助于岩石岸线的形成,且容易引发当地海啸.现代活动的Kilauea火山南侧海域的逐步沉降并没有引起太平洋范围内的破坏性的大海啸,但引发了局部一系列重要的海啸事件,这些事件的周期被估计认为是200年.     

Validation and application of soil moisture active passive sea surface salinity observation over the Changjiang River Estuary

Using sea surface salinity(SSS)observation from the soil moisture active passive(SMAP)mission,we analyzed the spatial distribution and seasonal variation of SSS around Changjiang River(Yangtze River)Estuary for the period of September 2015 to August 2018.First,we found that the SSS from SMAP is more accurate than soil moisture and ocean salinity(SMOS)mission observation when comparing with the in situ observations.Then,the SSS signature of the Changjiang River freshwater was analyzed using SMAP data and the river discharge data from the Datong hydrological station.The results show that the SSS around the Changjiang River Estuary is significantly lower than that of the open ocean,and shows significant seasonal variation.The minimum value of SSS appears in July and maximum SSS in December.The root mean square difference of daily SSS between SMAP observation and in situ observation is around 3 in both summer and winter,which is much lower than the annual range of SSS variation.In summer,the diffusion direction of the Changjiang River freshwater depicted by SSS from SMAP is consistent with the path of freshwater from in situ observation,suggesting that SMAP observation may be used in coastal seas in monitoring the diffusion and advection of freshwater discharge.     

团结奋进再创辉煌——中国海洋卫星事业发展20年回顾

我国是管理海域辽阔,海岸线漫长,资源丰富的海洋大国。大力发展海洋事业,事关国家的长治久安和经济社会的可持续发展。加强对海洋的观测和了解,准确预报海洋灾害,合理开发利用海洋资源,努力保护海洋生态环境,有效维护国家海洋主权与权益,是广大海洋工作者和海洋管理部门的神圣使命和战略任务。国家海洋局从建局以来,就一直积极发展海洋科学技术,着力强化海洋观测系统建设,不断提高对海洋的持久观测能力,为海洋事业实现跨越式发展提供了强有力的支撑。     

海洋湖沼通报征稿启事

一、本刊为海洋与湖沼科学的综合性学术刊物。内容包括:1.海洋与湖沼科学研究的论文、调查及实验报告;2.海洋与湖沼科学的综合评述、重要书刊和论文的评介;3.国内外海洋与湖沼科学的先进经验及学术动态。二、投稿须知1.来稿的图、表及说明要清楚、准确,置于文中相应位置。论文要求文字、语法符合汉语规范,标点使用要恰当。电子稿书写请按宋体5号字、1.5倍行距。文中使用照片的,请寄冲     

国际海岸清洁日 斑海豹协会在行动

2011年9月17日是国际海岸清洁日。由辽宁省盘锦市保护斑海豹志愿者协会发起,盘锦市180多名环保志愿者来到辽河入海口的斑海豹栖息地三道沟和六道沟海岸,捡拾海边不可降解的白色垃圾。这是盘锦市第一次组织和参与国际海岸清洁日活动。这次活动早在8月就在盘锦市保护斑海豹志愿者协会论坛上发帖通知,并在《辽河晚报》发布了征召志愿者的公告。协会会员和广大志愿者积极报名参加,上至70多岁的老人,下至7、8岁的孩童,有的是一家三口自驾车参加活动。17日是个周末,     

科技短消息

腰围增大,大脑萎缩?与相对较瘦的老年人相比,肥胖老年人的大脑认知区域较小,这使得他们的大脑年龄至少比实际年龄老了16岁。从前有研究表明,中年肥胖会增大日后患老年痴呆的风险,而老年痴呆通常伴随着大脑萎缩。美国加州大学的科学家们选择了94     

Analysis of cultivable aerobic bacterial community composition and screening for facultative sulfate-reducing bacteria in marine corrosive steel

Anaerobic, aerobic, and facultative bacteria are all present in corrosive environments. However, as previous studies to address corrosion in the marine environment have largely focused on anaerobic bacteria, limited attention has been paid to the composition and function of aerobic and facultative bacteria in this process. For analysis in this study, ten samples were collected from rust layers on steel plates that had been immersed in seawater for diff erent periods (i.e., six months and eight years) at Sanya and Xiamen, China. The cultivable aerobic bacterial community structure as well as the number of sulfate-reducing bacteria (SRB) were analyzed in both cases, while the proportion of facultative SRB among the isolated aerobic bacteria in each sample was also evaluated using a novel approach. Bacterial abundance results show that the proportions are related to sea location and immersion time;abundances of culturable aerobic bacteria (CAB) and SRB from Sanya were greater in most corrosion samples than those from Xiamen, and abundances of both bacterial groups were greater in samples immersed for six months than for eight years. A total of 213 isolates were obtained from all samples in terms of CAB community composition, and a phylogenetic analysis revealed that the taxa comprised four phyla and 31 genera. Bacterial species composition is related to marine location;the results show that Firmicutes and Proteobacteria were the dominant phyla, accounting for 98.13% of the total, while Bacillus and Vibrio were the dominant genera, accounting for 53.06% of the total. An additional sixfacultative SRB strains were also screened from the isolates obtained and were found to encompass the genus Vibrio (four strains), Staphylococcus (one strain), and Photobacterium (one strain). It is noteworthy that mentions of Photobacterium species have so far been absent from the literature, both in terms of its membership of the SRB group and its relationship to corrosion.     

不同软基处理方法适用性比较

总结分析了国内外现有的软土地基处理的各种方法。通过对采用不同方法进行软基处理的工程实例处理效果的定量对比，发现不同软基处理方法的适用性差异很大，多数工程中仅用一种方法很难达到设计要求，而两种或多种方法联合则可望取得更好的效果。     

海底管道拖管法分析和研究

海底管道铺设是海洋油气工程建设的一项重要内容.海底管道铺设的方法有铺管船法和拖管法.铺管船法受铺管船舶资源的限制,而拖管法铺管不依赖铺管船,在一定的条件下,可以节约费用,因此研究拖管法铺管就非常有意义.文中首先介绍各种管道铺设施工方法,并对各种方法的优缺点进行比较.然后分别分析研究了浮拖法、底拖法和离底拖法三种拖管方法的施工工艺及管道应力变形,并结合实例对三种拖管方法的拖管过程进行了分析.     

中国大陆互花米草分布特征及其主要防控措施

互花米草的快速入侵及扩散将导致入侵地的生态系统失衡。我国大陆从北到南的沿海地区分布着大面积的互花米草,严重降低了海岸带的生物多样性及生态屏障功能。我国各地防控互花米草入侵的主要方法包括物理、化学和生物防治三大类。目前各地采用的刈割、碾埋、围堰水淹等单一的防治方法可有效治理小面积的互花米草入侵,对大面积或成片互花米草的治理效果欠佳。文章通过分析比较现有的治理方法,结合科研实践经验,提出了将物理防治法、化学防治法和生物演替法有机结合起来,适宜中国不同地区互花米草的综合整治方法。     

剖面法测量近岸水体遥感反射率的新方法

光学剖面法是测量遥感反射率的首选方法。根据我国近岸水体的特点,提出采用下行辐照度剖面补偿剖面测量时环境影响的方法,估算水面之下遥感反射率[rrs(λ)]。从对实际测量数据的应用效果可见,同站位多次测量的rrs(λ),其相对偏差可控制在10％之内。     

A New Method of Profiling Remote-Sensing Reflectance of Coastal Waters

The profiling method is the first method to select in measuring the remotesensing reflectance. In the light of the characteristics of China‘s coastal waters, we develop a new method to compensate the environment‘s effects with the downwelling irradiance‘s profile and to estimate the underwater remote-sensing reflectance rrs(λ). The result indicates that the relative deviation of repetitious rrs(λ) in one station is around 10%.     

Applying invariant eigen-operator method to deriving normal coordinates of general classical Hamiltonian

For classical Hamiltonian with general form we find a new convenient way to obtain its normal coordinates, namely, let H be quantised and then employ the invariant eigen-operator (IEO) method (Fan et al. 2004 Phys. Lett. A 321 75) to derive them. The general matrix equation, which relies on M and L, for obtaining the normal coordinates of H is derived.     

Assessment of CPTU and static load test methods for predicting ultimate bearing capacity of pile

For the static pressure pile, the most important is to determine the standard value of ultimate bearing capacity of single pile. At present, the bearing capacity of pile foundation is usually determined by the cone penetration test (CPT) test. The empirical formula was used in practice, but the effect of excess pore water pressure generated in the penetration on the measured cone-tip resistance and side friction is neglected. In this study, based on the field test results at Fengyu playground at Yancheng Institute of Technology by CPT and CPTU methods, the bearing capacity of pile was predicted by the standardized methods, the LCPC (France method) and CPTU direct prediction methods. The prediction was also compared with the results by the static load test method. The prediction accuracy of the CPTU method was then discussed as well. The results reveal that the accuracy of the CPTU method was the highest, which was consistent with the results obtained by the static load test method. It is the best method and worthy of being applied for predicting bearing capacity of piles in engineering applications.     

水文资料插值计算方法探讨

本文利用5种常用的插值计算方法,对海洋实测资料序列中的某些固定节点进行插值计算,然后根据均方误差和图形拟合相结合的方法,探讨插值计算方法的适用性及应用条件并得出结论:阿基玛插值和三点拉格朗日插值效果拟合性最好,具有普遍应用性,多点拉格朗日和线性插值较为中性,在插值步长不大的条件下,插值效果较好,而牛顿插值不稳定,应用条件相对苛刻.     

基于Powell定理的一个无约束最优化直接方法(英文)

在求解无约束最优化问题的直接方法中,Powell方法被认为是最有效的。改进的Powell方法每产生一个新的共轭向量需要作n 1次直线搜索。这个新向量有可能与原来的向量组线性相关。这不仅破坏了算法的二次收敛性,而且对每个新产生的向量都必需作相关性判别,以决定是否作向量替换。可见,要产生n个共轭方向至少需要n(n 1)次直线搜索及n次判别与向量替换。 作者在Powll定理的基础上给出了一个新的算法。这个算法从一维空间直接搜索出发,逐维扩张建立新的共轭向量。这样,产生n个共轭向量仅需n (n(n 1))/2次直线搜索。这大体相当于改进Powell方法的一半。由于每步计算的所在空间维数不同,不会出现线性相关的情况,所以无需判别与替换。且由此立知新算法是二次收敛的。还给出了对于非二次函数收敛性定理。作者用一个二次函数及二个非二次函数在同样精度要求、同一个初始点的情况下作了计算对比,由附表可以看出,新算法所用CPU时间少于改进Powell算法的1/5。     

海浪方向谱估计方法的比较

分别利用数值模拟和实测资料对目前被认为分辨力较高的最大似然法(MLM)、扩展本征矢方法(EEV)、扩展最大滴方法(EMEP)以及贝叶斯方法(BDM)等四种海浪方向谱估计方法的可靠性进行了分析,从不同频率、不同噪声水平和不同方向集中度三个角度检验其再现性、稳定性和实用性,结果表明MLM、EEV和BDM大致给出相同的方向分布,其中BDM的再现性最好,但实用性逊于MLM和EEV,EMEP由于稳定性差,不适用于实测资料的分析.