热带西太平洋海－气热量交换研究

本文根据ＴＯＧＡ研究计划第１、２、３、８共４个航次考察结果，对热带西太平洋海－气热量交换进行了分析。结果表明，１９８６－１９８７年埃尔尼诺事件发生前，热带西太平洋海－气热量交换非常强烈，埃尔尼诺事件发生后，海－气热量交换反而减弱；在台风环流内，海－气热量交换也非常强烈。热带西太平洋对大气加热场的变化与海表面温度的变化并不一致；１９８６－１９８７年埃尔尼诺事件发生时，不但中太平洋水温异常增暖，同时西太平洋西部洋域表层水也在增暖；热带太平洋信风的加强对热带西太平洋暖池的建立和热带太平洋西风的爆发导致１９８６－１９８７年埃尔尼诺事件的发生似乎是至关重要的，西风爆发首先出现在中太平洋热带海域，然后逐渐往西扩展；西太平洋热带海域主要以潜热的方式把热量输送给大气。潜热加热效应在低纬度热带海洋上的极大值均与热带天气系统的活动有紧密联系。大气主要是从热带西太平洋洋域获得热量。     

2008/2009年冬季南海冷涌天气过程的海-气热通量交换及热量收支

冬季风期(11月—翌年3月)南海显著的气候特点是盛行东北季风并频繁地发生冷涌天气过程。使用2008年10月到2009年4月在西沙群岛永兴岛近海进行的海-气通量观测试验资料,分析了西沙海域冬季风期,尤其是冷涌时段的海-气通量交换和热量收支特征。结果表明:冬季风前期由于海-气温差增大,感热通量比西南季风期稍增加;潜热通量平均值与西南季风期接近;太阳总辐射明显降低,大气长波辐射减小,海洋热量净收入成为负值,使得秋季之后海面温度不断降低。冷涌期间海-气之间的感热通量高于冬季风期平均值,潜热通量大部分(1月份之前)也高于冬季风期平均值;由于潜热通量增大和太阳短波辐射减小,1月份之前的冷涌过程海洋热量净收支普遍出现较大负值,海洋失热量强于冬季风期,甚至强于2008年台风过程平均值。到了冬季后期太阳总辐射增强,海洋热量净收入转为正值,海水温度又逐渐升高。季节之间比较,观测区感热通量以冬季风期间最大,秋季次之,春季最小;而潜热通量夏季风期出现最大值,冬季次之,秋季最小。     

埃尔－尼诺过程与渤海气温异常

本文统计分析了渤海气温异常月份与埃尔－尼诺过程的关系，结果得出：在埃尔－尼诺年及其前后一年，渤海气温异常冷月占优势；在埃尔－尼诺持续期内，春季渤海气温出现异常冷月的百分率高达７３％。埃尔－尼诺与渤海气温异常关系的分析结果，表明了在海－气相互作用过程中，二者互为因果关系的事实。     

热带西太平洋海－气热量通量研究──Ⅲ．冬季天气过程海－气热量交换的特征

根据执行ＴＯＧＡ／ＣＯＡＲＥ研究计划在热带西太平洋进行考察的结果，对调查海区海－气界面热量交换进行了分析。结果表明：冬季在热带扰动的影响下，调查海区海－气热量交换非常强烈，在风速较小、天气情况良好的情况下，调查海区海水得到的热量远大于失去的热量，调查海区海水对大气加热的变化与表层海水温度的变化并不一致，热带太平洋信风的加强对暖池的建立似乎是至关重要的。     

辽东半岛南部冷流降雪的统计特征及相关要素分析

辽东半岛南部地区及周边海域在特定的季节、天气形势和条件下可能会造成灾害性的冷流降雪天气, 提高冷流降雪预报准确性, 对沿海地区防灾减灾具有重要意义。本文利用1981—2021 年辽宁地区各气象站逐日降水资料及ERA5 再分析资料, 运用统计学和物理量诊断方法对辽东半岛南部地区冷流降雪的气候特征、发生规律及成因进行了分析。研究结果表明：辽东半岛南部地区冷流降雪强度弱, 主要以小雪为主; 降雪次数和降雪量均呈现南多北少的特点, 前者年际变化趋势平稳而后者较大; 12 月是冷流降雪发生的主要月份, 而11 月和2 月是降雪强度较强的月份。冷流降雪的产生和较大的海洋表面与大气温差、低层不稳定层结、海陆地形作用有密切关系; 当500 hPa 和850 hPa 影响系统为冷涡或低槽、辽东半岛南部及周边海域低层为偏北风且相对湿度条件较好、1 000 hPa 对应正相对涡度等条件时, 可以预测辽东半岛南部可能出现冷流降雪; 海表温度（Sea Surface Temperature, SST） 与850 hPa 温度之差直接决定了地面冷流降雪量的大小。     

热带西太平洋海—气热量通量研究：Ⅲ.冬季天气过程海—气热量交换的特征

根据执行ＴＯＧＡ／ＣＯＡＲＥ研究计划在热带西太平洋进行考察的结果，对调查海区海－气界面热量交换进行了分析。结果表明：冬季在热带扰动的影响下，调查海区海－气热量交换非常强烈；在风速较小、天气情况良好的情况下，调查海区海水得到的热量远大于失去的热量，调查海区海水对大气加热的变化与表层海水温度的变化并不一致；热带太平洋信风的加强对暖池的建立似乎是至关重要的。     

一次典型大范围冷流暴雪个例的诊断分析

利用常规天气图和WRF模式模拟的数据,对2010年12月30日发生在山东半岛的一次冷流暴雪过程进行了天气学诊断分析。结果表明:(1)这是一次典型的大范围冷流暴雪过程,500hPa低涡位置偏南(43°N以南)、850hPa西北冷平流范围广,强度强是造成本次暴雪范围大的主要原因,为强冷流降雪的产生提供了有利条件。(2)降雪的水汽来自渤海,由西北风向山东半岛输送,并在半岛北部辐合;高湿区集中在850hPa以下,湿层较为浅薄。(3)降雪落区与高相当位温脊的位置存在着对应关系,强降雪通常发生在脊线附近;θe等值线向上凸起的高能区集中在750hPa以下,大气不稳定层结较低。(4)强烈的上升运动集中在对流层低层750hPa以下,上升运动越强,降雪量越大。⑸受地形影响,西北风吹向辽东半岛时转为东北风,西北风与东北风在渤海中东部至山东半岛形成切变线,切变线的方向和位置决定了降雪的强度与落区;风速在半岛北部低山丘陵前辐合,有利于产生上升运动,使得降雪加强。     

1983 El Nino盛期洋面的热量平衡

本文利用1983年1月份(1982/83年埃尔尼诺最强时期)的海、气资料,对35°N-35°S、45°E-75°W的印度洋、太平洋海域获得的净辐射、海洋向大气传输的潜热、感热通量及获得的净热量作了计算,计算结果表明,冬半球的潜热、感热向上输送大于夏半球,南半球热带中太平洋感热由大气传给海洋,但数值较小;东太平洋大气获得的潜热通量比常年平均值小.净辐射基本上呈纬向分布,云量对其影响很大,海表面温度(SST)和净辐射有很好相关关系,高SST区与净辐射低值区对应,E1 Nino期间的SST异常使得中太平洋海域洋面获得的净辐射减少,而该处洋面上大气获得的潜热通量则较多,故海洋净获得热量减少.净热量平衡,冬半球海洋一般为大气的能源,夏半球为大气的能汇.     

1983 El Nino盛期洋面的热量平衡

本文利用1983年1月份(1982/83年埃尔尼诺最强时期)的海、气资料,对35°N—35°S、45°E—75°W的印度洋、太平洋海域获得的净辐射、海洋向大气传输的潜热、感热通量及获得的净热量作了计算,计算结果表明,冬半球的潜热、感热向上输送大于夏半球,南半球热带中太平洋感热由大气传给海洋,但数值较小;东太平洋大气获得的潜热通量比常年平均值小.净辐射基本上呈纬向分布,云量对其影响很大,海表面温度(SST)和净辐射有很好相关关系,高SST区与净辐射低值区对应,E1 Nino期间的SST异常使得中太平洋海域洋面获得的净辐射减少,而该处洋面上大气获得的潜热通量则较多,故海洋净获得热量减少.净热量平衡,冬半球海洋一般为大气的能源,夏半球为大气的能汇.     

渤、黄、东海年平均海面热量平衡状况及其与海洋环流的关系

用1958—1967年海上调查和船舶报水文气象资料,计算了渤、黄、东海海面热量平衡各分量及其总和的年平均状况;分析了各热量分量的平面分布;估算了各分量的量级;讨论了海面热量平衡与水团分布和海洋环流的关系。结果表明,在海、气界面上,海洋获得的热量主要来自太阳辐射;失去的热量主要是由于海水的蒸发;暖流区海洋失热最多,尤其在黑潮主干区明显。同时还指出,年平均各热量分量的总和基本上反映了海洋环流的形势,而海洋内部的平流热输送为本海区带来大量的热量,从而弥补了通过海、气界面海洋释放给大气的热量。     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

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.     

A Review of Some Environmental Issues Affecting Marine Mining

This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested.     

Increased Particle Fluxes at the INDEX Site Attributable to Simulated Benthic Disturbance

Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Determination of In Situ Sediment Shear Strength from Advanced Piston Corer Pullout Forces

The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments.     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

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.     

Flow Cytometric Analysis of Coastal Lagoon Bacterioplankton and Picophytoplankton: Fixation and Storage Effects

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.     

《Acta Oceanologica Sinica》Vol. 33(2014) contents

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INFORMATION FOR AUTHORS

<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,