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上层海洋通过海气交换影响大气-海洋耦合系统，海浪引起的垂向混合影响上层海洋结构，从而在气候预测过程中发挥着重要的作用。本文基于国家海洋局第一海洋研究所地球系统模式（FIO-ESM），以2016年为例，分别开展了耦合和关闭海浪模式情况下的短期气候预测实验，分析浪致混合对北太平洋海表温度（SST）季节性预测的影响。通过对模式预测的SST异常（SSTA）进行定量评估发现，浪致混合能够显著降低北太平洋高纬度海区预测误差，在（45°N，150°E）附近海区SSTA改善可达1℃，气候模式能够更好地预测SSTA的经向分布特征，特别是能够准确地反映25°~45°N海区SSTA分布特征。通过分析有浪和无浪两个实验的热收支贡献发现，垂向混合是导致上层海洋温度差异的主导影响因子。海浪通过改变垂向混合，使2016年北太平洋SST在高纬度海区大幅降低，在低纬度海区略有升高，最终提升了模式对北太平洋SST的季节性预测能力。 相似文献
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本文利用美国华盛顿数值天气预报中心(KWBC)的3—5天预报的1000hPa等势面的格点高度场(5°×5°)资料,由“海上风的边界层模式”计算的风场,应用“一个参数的大洋波谱模式”,进行了北太平洋海浪数值预报的试验,试验结果表明,尽管输入风场资料存在一定误差,计算的浪场与3─5天后的实测浪场仍有较好的吻合。 相似文献
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南印度洋海浪场时空特征分析 总被引：1，自引：0，他引：1
根据 1950 —1995 年共 46 a 的南印度洋船舶气象报资料，按 5°× 5°网格统计的海浪要素进行分析研究。通过分析每月各要素的等值线分布图，得出南印度洋海浪场季节变化特点不如北半球各大洋显著，但仍有较明显的季节变化，只是季节性差异较小，冬季比夏季海浪强盛，相应的平均波高、大浪大涌频率也较大；盛行风浪传播方向、涌浪传播方向基本一致，10°S 以北为季风气候区，而其它海域则信风区常年盛行 SE 向浪，40°S 以南盛行偏 W 向浪。本文提供了南印度洋海域较为翔实的海浪场资料及变化规律。 相似文献
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西北太平洋风场和海浪场特点分析 总被引：6，自引：1，他引：5
本文根据1950～1995年共46a的西北太平洋气象船舶报资料,按5°×5°网格统计的风、浪要素进行分析研究,阐明了西北太平洋风、浪、涌的特点及其变化规律。该区是世界最典型的季风气候区,季风时期的风向、浪向、涌向基本一致,赤道地区常年盛行东北浪。冬季季风比夏季季风强盛,相应的平均波高、大浪大涌频率也较大。该海域与北印度洋同属季风气候区,但其特点正好相反。本文为船舶在西北太平洋航行、作业和科学试验以及军事活动,提供了较翔实的风场和浪场资料及变化规律。 相似文献
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台湾海区的风浪特点及分布规律 总被引：1，自引：0，他引：1
收集了1960～1990年间的31 a国际气象船舶报资料,以中国台湾周边海区为中心,范围自20°N～28°N,116.5°E～124°E,划分为1°×1°网格单位,对风向、风速、浪向、浪高、周期等要素进行累年逐月统计和作图.通过分析研究,我们发现了该区的风浪特点和分布规律冬季风浪以台湾海峡中部为最大,尤其是澎湖列岛北部地区(风速大于20 m/s,浪高大于3.0m),但在台湾西南部沿岸以高雄为中心,风浪最小;夏季风浪以台湾海峡南口为最大(风速大于13.0 m/s,浪高大于2.0 m),台湾海峡风浪最小(风速小于1.0m/s,浪高小于1.5m).这些新的特点,在以往的2°×2°或5°×5°的大网格分析研究中是显示不出来的. 相似文献
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为了描述北太平洋上空Hadley 环流的纬向结构特征, 利用NCEP 再分析资料(1979～2010 年), 研究了北太平洋上空Hadley 环流纬向结构的季节和年际变化。发现在西太平洋, Hadley 环流季节性上升支呈西北-东南倾斜, 其垂向核心位于对流层中层, 纬向核心在北半球冬季(夏季)位于日界线附近(150°E); 而永久性上升支主要在东太平洋, 其垂向核心位于对流层低层, 且沿经度东移逐渐增强。根据纬向环流结构特征, 北半球冬季环流形态分为3 个区域: 160°E 以西, 主要表现为低层辐合高层辐散;160°E～130°W, 主要表现为高层辐合; 130°W 以东, 表现为低层辐合高层辐散特征。相似地, 北半球夏季环流形态也可沿纬向分为如下3 个区域: 165°E 以西、165°E～165°W 和165°W 以东, 分别对应东亚夏季风主导经圈环流区、过渡区、Hadley 环流主导经圈环流区。在年际变化上, 北太平洋Hadley 环流与ENSO 有很强的相关, 这与前人的研究是一致的。因此北太平洋上空Hadley 环流具有显著的空间性态, 并且对应时间尺度不同, 影响其变化的主要因素也不尽相同。 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding. 相似文献
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《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
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Hoi-Soo Jung Kap-Sik Jeong Yong-Shik Chu Sung-Hyun Park Ki-Hyune Kim 《Marine Georesources & Geotechnology》2001,19(3):181-195
Grain size and water content in box-core sediments from the Clarion-Clipperton fracture zone (C-C zone) in the northeast equatorial Pacific were analyzed in detail to understand the downcore variations across a hiatus between Quaternary and Tertiary layers. Grain-size distributions in the topmost core sediments show two modes: a coarse mode (peaked at 50 μm) and a fine mode (at 2-25 μm). The coarse mode disappears gradually with depth accompanied by the dissolution of siliceous fossil tests, whereas the fine mode coarsens due to the formation of authigenic minerals. Water content increases abruptly across a color boundary between an upper pale brown layer and a lower dark brown layer that is the hiatus between Quaternary and Tertiary layers. Abundant smectites and microvoid molds, which are created by the prolonged fossil dissolution in the underlying sediment, are attributed for the abrupt downcore variation of water content. Overall variations in grain size and water content in the topmost core sediments in the western C-C zone are possibly constrained by the dissolution of biogenic siliceous fossils. Variations in geotechnical properties related to these changes must be considered in the design of nodule collectors. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2001,24(1):27-33
This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake. 相似文献
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This study tests the hypothesis that the in situ void ratio of surficial marine sediments may be predicted from shear wave velocity-depth data with a reliability equal to that of other methods currently available. Shear wave velocity is fundamentally controlled by the number of grain-to-grain contacts per unit volume of material and by the effective stress across those contacts. In this study, three previously established empirical formulae are used to predict void ratio from velocity-depth data. Field data were acquired along a transect off the northern Californian coast across which water depth increased from 35 to 70 m and seafloor sediment type varied from sand to silty-sand, respectively. A towed seafloor sled device was used to collect shear wave refraction data, and a marked, systematic decrease in velocity was observed along the line, ranging from 35-70 m/s for the coarse, near-shore material to 25-40 m/s for the finer, offshore deposits. Void ratios predicted from these velocities were compared with data measured directly from box-core samples. Of the formulae used for prediction, two agree remarkably well with the control data. Both predicted and control values increase from 0.6-0.8 for the sandy material to 1.1-1.5 for the silty-sand. Thus, this study does not disprove the hypothesis set and demonstrates the potential of field shear wave velocity-depth data as a means of delineating spatial variation in void ratio for surficial marine sediments in a remote, nondestructive manner. 相似文献
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Particulate samples were collected from the Changjiang river system during a flood period, in May 1997, and POC, stable isotope and lipids associated with particles were examined. Results showed the decrease (0.84% ～ 1.88%) of organic carbon content from the upper reaches to the estuary.δ13C values of particulate organic carbon was in the range of -24.9×10-3 to -26.6×10-3, which were close to the isotopic signature of continental C3 vegetation. Total particulate n-alkanes concentrations varied from 1.4 to 10.1μg/dm3,or from 23.7 to 107μg/g of total suspended matter. Fatty acids were present in all the samples, from 1.4 to 5.4μg/dm3, with saturated and unsaturated straight-chain and branched compounds in the carbon number range from C12 to C30. Both δ13C and the ratio of carbon content to nitrogen content indicate the predominance of terrestrial inputs (soil organic matter) among the particles. The biomarker approach has been used to identify the relative portion of terrigenous and autochthonous fraction in the particulate samples. The distribution of fatty acids suggests a striking phytoplanktonic and microbial signal in most particle samples. The terrestrial alkanes are used to estimate the contribution of terrestrial inputs along the mainstream. 相似文献