Near inertial motion excited by wind change in a margin of the Typhoon 9019   总被引：1，自引：0，他引：1  

Akio Maeda  Kazuki Uejima  Toru Yamashiro  Masahito Sakurai  Hiroshi Ichikawa  Masaki Chaen  Keisuke Taira  Shinjirou Mizuno 《Journal of Oceanography》1996,52(3):375-388

An excitation of inertial oscillation in the upper layer east of course of Typhoon 9019 was fortuitously observed at three surface buoys deployed during the Ocean Mixed Layer Experiment (OMLET). The observed inertial oscillation was compared with wind fluctuation measured at Ocean Weather Station T (29°N, 135°E) which was placed at the center of a triangle with three vertexes occupied by the respective surface buoys. Inertial oscillation is effectively excited in the mixed layer at the eastern margin of the typhoon by a rapid decrease of wind rather than by prevailing strong wind. It is shown by means of a least square deviation that the inertial oscillation observed in the mixed layer has a period of 23.9 hours shorter than the local inertial period of 24.7 hours. This shorter period suggests that the inertial oscillation has the finite velocities of phase and group as an inertial internal wave. A theoretically obtained ratio of vertical component of group velocity to that of phase velocity, approximately agrees with observed value. The inertial internal wave is excited by fluctuation of divergence with near inertial period in the mixed layer.  相似文献   

Application of Monte-Carlo statistical experiments in design of ocean engineering——Estimating the parameters, models and probabilities     

Liu Defu  Shi Jiangang  Zhou Zhigang 《海洋学报(英文版)》1990,9(4):587-597

Recently, some results have been acquired with the Monte- Carlo statistical experiments in the design of ocean en gineering. The results show that Monte-Carlo statistical experiments can be widely used in estimating the parameters of wave statistical distributions, checking the probability model of the long- term wave extreme value distribution under a typhoon condition and calculating the failure probability of the ocean platforms.  相似文献   

一种新的温度记录器     

吴葆仁  Albert Bradley 《中国海洋大学学报(自然科学版)》1989,(1)

本文提出一个以带有定时器的低功耗微处理机为主体的温度记录器。其定时器用于开动微处理机,可由一个开关定为0.5、1、3或30分钟。仪器通过处理一个电容器向热敏电阻放电的时间来测量温度。仪器在工作中能显示温度值,并把温度值保存在微处理机的RAM之中。总共资料容量为2816次测值,量程为0～35℃,精度±0.1℃,分辨±0.02℃。 温度记录器具有液晶显示器,可直接读出温度值,配有标准计算机接口RS-232,能把保存的资料方便地倒给个人计算机。 这项工作是伍兹霍尔海洋研究所A.Bradley博士指导的。他提出的原理对研制可靠而廉价的温度记录器是一条新的途径。  相似文献   

南海区重点岸段海岸侵蚀现状成因分析与防治对策   总被引：4，自引：0，他引：4  

刘孟兰  郑西来  韩联民  林端  罗一丹  方宏达  柯东胜  彭晓娟  陈嘉辉 《海洋通报》2007,26(4):80-84

在2003年与2006年对南海区琼州海峡两岸重点岸段(雷州市徐闻县龙塘镇赤坎村岸段、海南省海口市镇海村岸段和新海村岸段)的海岸侵蚀进行了现场监测,测量了侵蚀的长度、宽度和面积。对两年现场测量结果进行比较分析,结果表明:海岸侵蚀长度的平均速度为200m/a,宽度的平均速度为20m/a,面积的平均速度为4000m2/a。应用了地质分析、水动力分析、极端海洋气候影响分析等新的理论和方法重点分析了海岸侵蚀的成因,并提出了一些对策,供相关部门参考。  相似文献   

条斑紫菜壳孢子超微结构研究          下载免费PDF全文

周文君  李?? 赟  戴继勋 《海洋科学》2007,31(2):1-4

应用戊二醛、锇酸固定,环氧树脂包埋,醋酸双氧铀-柠檬酸铅制作切片,以透射电镜观察条斑紫菜(Porphyra yezoensis)壳孢子的超微结构,结果表明:壳孢子外包被一层薄的细胞壁,中央为一个由同心片层结构的类囊体膜构成的轴生星状色素体,色素体中有一个无淀粉鞘包被的蛋白核,类囊体膜上附有嗜锇性的质体小球.壳孢子细胞核位于色素体的一侧,呈不规则的长圆形,核仁偏于核的一侧.在胞质中分布有线粒体、红藻淀粉、液泡等细胞器.与放散前的成熟壳孢子囊枝细胞超微结构比较,成熟壳孢子超微结构的变化主要有细胞壁变薄,色素体结构松散甚至退化,蛋白核分裂,液泡数量增多而红藻淀粉数量减少等,这些变化反映了成熟壳孢子基本细胞特征,同时反映了在壳孢子生长发育过程中温度下降、光照时间缩短和光照强度减弱等环境因素的变化.  相似文献   

Effects on zooplankton of a warmer ocean: Recent evidence from the Northeast Pacific     

David L. Mackas  Sonia Batten 《Progress in Oceanography》2007,75(2):223-252

The consequences for pelagic communities of warming trends in mid and high latitude ocean regions could be substantial, but their magnitude and trajectory are not yet known. Environmental changes predicted by climate models (and beginning to be confirmed by observations) include warming and freshening of the upper ocean and reduction in the extent and duration of ice cover. One way to evaluate response scenarios is by comparing how “similar” zooplankton communities have differed among years and/or locations with differing temperature. The subarctic Pacific is a strong candidate for such comparisons, because the same mix of zooplankton species dominates over a wide range of temperature climatologies, and observations have spanned substantial temperature variability at interannual-to-decadal time scales. In this paper, we review and extend copepod abundance and phenology time series from net tow and Continuous Plankton Recorder surveys in the subarctic Northeast Pacific. The two strongest responses we have observed are latitudinal shifts in centers of abundance of many species (poleward under warm conditions), and changes in the life cycle timing of Neocalanus plumchrus in both oceanic and coastal regions (earlier by several weeks in warm years and at warmer locations). These zooplankton data, plus indices of higher trophic level responses such as reproduction, growth and survival of pelagic fish and seabirds, are all moderately-to-strongly intercorrelated (∣r∣ = 0.25-0.8) with indices of local and basin-scale temperature anomalies. A principal components analysis of the normalized anomaly time series from 1979 to 2004 shows that a single “warm-and-low-productivity” vs. “cool-and-high-productivity” component axis accounts for over half of the variance/covariance. Prior to 1990, the scores for this component were negative (“cool” and “productive”) or near zero except positive in the El Niño years 1983 and 1987. The scores were strongly and increasingly positive (“warm” and “low productivity”) from 1992 to 1998; negative from 1999 to 2002; and again increasingly positive from 2003-present. We suggest that, in strongly seasonal environments, anomalously high temperature may provide misleading environmental cues that contribute to timing mismatch between life history events and the more-nearly-fixed seasonality of insolation, stratification, and food supply.  相似文献   

西太平洋暖池研究的新进展   总被引：4，自引：0，他引：4  

张立峰  许建平  何金海 《海洋科学进展》2006,24(1):108-116

对近几年国内外有关热带西太平洋暖池的现场观测、暖池物理机制、暖池与ENSO的关系、暖池异常变化对气候的影响等方面的最新研究进展作了回顾;同时,对目前暖池研究中存在的几个问题进行了简要的讨论。  相似文献   

渤海夏季实测潮流特征   总被引：3，自引：0，他引：3  

乔璐璐  鲍献文  吴德星 《海洋工程》2006,24(2):45-52

对渤海内11个测站的夏季潮流资料进行调和分析。对不同仪器、不同时间段潮流资料的分析结果进行比较,并通过潮流调和常数进一步计算潮流椭圆要素,据此分析分潮流最大流速的垂直分布,渤海全日潮和半日潮的潮流旋转方向和潮流性质。  相似文献   

海洋环境立体监测系统的设计方法   总被引：9，自引：1，他引：9  

罗续业  周智海  曹东  李彦 《海洋通报》2006,25(4):69-77

“九五”和“十五”期间,在国家海洋863计划的支持下,我国分别在上海和台湾海峡及毗邻海域建立了两个区域性海洋环境立体监测示范系统。在这两个示范系统的技术研究成果的基础上,通过分析国际海洋立体监测系统的设计模型,提出了区域性海洋环境立体监测系统的设计原则和设计方法,包括:系统结构、数据与信息服务通信网络、数据处理中心、数据流程以及系统功能等方面的设计方法。  相似文献   

Evidence of sediment gravity flows induced by trawling in the Palamós (Fonera) submarine canyon (northwestern Mediterranean)     

《Deep Sea Research Part I: Oceanographic Research Papers》2006,53(2):201-214

Three mooring arrays were deployed in the Palamós Canyon axis with sediment traps, current meters and turbidimeters installed near the bottom and in intermediate waters. Frequent sharp and fast turbidity peaks along with current speed increases were recorded, particularly at 1200 m depth in spring and summer. During these events, near-bottom water turbidity increased by up to more than one order of magnitude, current velocity by two to four times and horizontal sediment fluxes by one to three orders of magnitude. When these events occurred, 9–11 days integrated downward particle fluxes collected by the near-bottom sediment trap increased by two to three times. These events were identified as sediment gravity flows triggered by trawling activities along the northern canyon wall. Sediment eroded by the trawling nets at 400–750 m depth on this wall seems to be channeled through a gully and transported downslope towards the canyon axis, where the 1200 m mooring was located. The sediment gravity flows recorded at the 1200 m site were not detected at deeper instrumented sites along the canyon axis, suggesting that they affect local areas of the canyon without traveling long distances downcanyon. These observations indicate that trawling can generate frequent sediment gravity flows and increase sediment fluxes locally in submarine canyons. Furthermore, in addition to the various natural processes currently causing sediment gravity flows and other sediment transport events, human activities such as trawling must be taken into account in modern submarine canyon sediment dynamics studies.  相似文献