副热带东北太平洋混合层深度及其对潜沉的影响

The present climate simulations of the mixed layer depth(MLD) and the subduction rate in the subtropical Northeast Pacific are investigated based on nine of the CMIP5 models. Compared with the observation data,spatial patterns of the MLD and the subduction rate are well simulated in these models. The spatial pattern of the MLD is nonuniform, with a local maximum MLD(140 m) region centered at(28°N, 135°W) in late winter. The nonuniform MLD pattern causes a strong MLD front on the south of the MLD maximum region, controls the lateral induction rate pattern, and then decides the nonuniform distribution of the subduction rate. Due to the inter-regional difference of the MLD, we divide this area into two regions. The relatively uniform Ekman pumping has little effect on the nonuniform subduction spatial pattern, though it is nearly equal to the lateral induction in values. In the south region, the northward warm Ekman advection(–1.75×10~(–7) K/s) controls the ocean horizontal temperature advection(–0.85×10~(–7) K/s), and prevents the deepening of the MLD. In the ensemble mean, the contribution of the ocean advection to the MLD is about –29.0 m/month, offsetting the sea surface net heat flux contribution(33.9 m/month). While in the north region, the southward cold advection deepens the MLD(21.4 m/month) as similar as the heat flux(30.4 m/month). In conclusion, the nonuniform MLD pattern is dominated by the nonuniform ocean horizontal temperature advection. This new finding indicates that the upper ocean current play an important role in the variability of the winter MLD and the subduction rate.     

A description of short period temperature fluctuations in the upper ocean

Dynamical properties of short-period temperature fluctuations are studied. Water temperature was measured continuously at several depths at the following stations: at 38°29.5′N, 141°35.8′E (100 m depth) on the continental shelf off Miyagi Prefecture in the summer of 1967, at 35°01.8′N, 139°0.8.5′E (100 m depth) in Sagami Bay in the summer of 1968, and at 32°32.2′N, 129°53.7′E (74 m depth) in Tachibana Bay in the summer of 1970. These measurements were made with a thermistor array laid down from the R. V.Tanseimaru (Ocean Research Institute, University of Tokyo) which was fixed with bow and stern anchors. Significant temperature fluctuations found at the first and the third stations are thought to be due to first mode internal waves having amplitude 3 to 5 m and period 5 to 20 minutes. The wave length of the waves is estimated to be 25 m to 400 m from the observed density structure. At the second station, we found second-mode internal waves. The period, amplitude and wave length of the waves are about 30 minutes, 1.3 m and 600 m, respectively. In all cases, the spectral density of the temperature fluctuations decreases with increase in frequency. However, the decrease obey neither the ?3 power law nor the ?5/3 power law. Coherences in the temperature fluctuations between two depths of measurement in the seasonal thermocline are significantly high in the range of frequencies lower than the local Brunt-Väisälä frequency, but are low in the higher frequency range. At the first and the third stations, the difference in the level of coherences between the lower frequencies and the higher frequencies are large. Phase differences between two depths in the thermocline are small in the lower frequency range. This suggests that the first-mode internal waves are predominant over higher-mode internal waves and over other disturbances.     

A modeling study of acoustic propagation through movingshallow-water solitary wave packets

Propagation of 400-Hz sound through continental-shelf internal solitary wave packets is shown by numerical simulation to be strongly influenced by coupling of normal modes. Coupling in a packet is controlled by the mode coefficients at the point where sound enters the packet, the dimensions of the waves and packet, and the ambient depth structures of temperature and salinity. In the case of a moving packet, changes of phases of the incident modes with respect to each other dominate over the other factors, altering the coupling over time and thus inducing signal fluctuations. The phasing within a moving packet varies with time scales of minutes, causing coupling and signal fluctuations with comparable time scales. The directionality of energy flux between high-order acoustic modes and (less attenuated) low-order modes determines a gain factor for long-range propagation. A significant finding is that energy flux toward low-order modes through the effect of a packet near a source favoring high-order modes will give net amplification at distant ranges. Conversely, a packet far from a source sends energy into otherwise quiet higher modes. The intermittency of the coupling and of high-mode attenuation via bottom interaction means that signal energy fluctuations and modal diversity fluctuations at a distant receiver are complementary, with energy fluctuations suggesting a source-region packet and mode fluctuations suggesting a receiver-region packet. Simulations entailing 33-km propagation are used in the analyses, imitating the SWARM experiment geometry, allowing comparison with observations     

西南印度洋龙方斤热液区羽流信号的检测与通量估算

热液流体在物理化学特征方面与周围海水存在较大差异,探测温度异常和浊度异常是寻找热液羽状流信号的重要手段。本文采用“大洋一号”科考船第20航次的拖曳CTD数据和浊度数据,以及21航次的定点CTD数据,研究了西南印度洋龙方斤热液区的温度异常和浊度异常现象。研究表明热液区中性浮力层在水深2 550~2 650 m间,厚度约为100 m,温度异常达0.01 ℃;水深 2 750~2 800 m间亦有温度异常,最大可达0.08 ℃;温度异常水深处存在相应的浊度异常。深层背景海水位温和位密间存在简单线性关系。此外,经初步估计,热液活动区初始浮力通量为8.78×10^-4 m⁴/s³;通过中性浮力层估算热液热通量,约为130±43 MW。     

中沙群岛海域春夏交季温盐分布特征

中沙群岛主要由中沙大环礁和黄岩岛组成,其温盐分布对于本区渔业生产、航海保障和水下通讯等具有重要意义。尤其是春夏之交的季节转换时期,该海域水温和盐度及其相应的跃层特性存在显著的季节变化,掌握其季节变化特征具有重要现实意义。本文基于2019年5月（南海春夏季风转换期）中沙大环礁、黄岩岛和2020年6月（夏季风爆发期）中沙大环礁海域大面站调查数据分析,发现中沙大环礁海域水温和盐度分布特征在夏季风爆发前后具有显著的差异性,2个航次的温跃层分布也呈现出较大不同,2019年5月黄岩岛海域温盐中上层分布与中沙大环礁相似,但底层有所差异,跃层深度也较大。2020年6月中沙大环礁内水体升温较快,各层水温均高于2019年5月,其中以底层水体升温最为显著;2019年5月中沙大环礁内水温水平梯度较大,且随着水深加大水平梯度也越大,2020年6日水平温度梯度逐渐减小。2个航次的盐度分布与水温分布较为相似。结合调查时段的海表热通量变化和卫星高度计资料分析认为,2019年5月中沙大环礁西南部海洋吸热高于东北部,故表层水温西南高东北低;2020年6月至7月环礁西南部海洋吸热低于东北部,故表层水温西南低东北高。由于中尺度涡的作用,中沙大环礁区域局部产生低温高盐或高温低盐水,并导致2020年6月中沙大环礁大部分海域的温跃层加深。     

Authigenic carbonates from methane seeps of the northern Congo fan: Microbial formation mechanism

Authigenic carbonates were collected from methane seeps at Hydrate Hole at 3113 m water depth and Diapir Field at 2417 m water depth on the northern Congo deep-sea fan during RV Meteor cruise M56. The carbonate samples analyzed here are nodules, mainly composed of aragonite and high-Mg calcite. Abundant putative microbial carbonate rods and associated pyrite framboids were recognized within the carbonate matrix. The δ¹³C values of the Hydrate Hole carbonates range from ?62.5‰ to ?46.3‰ PDB, while the δ¹³C values of the Diapir Field carbonate are somewhat higher, ranging from ?40.7‰ to ?30.7‰ PDB, indicating that methane is the predominant carbon source at both locations. Relative enrichment of ¹⁸O (δ¹⁸O values as high as 5.2‰ PDB) are probably related to localized destabilization of gas hydrate. The total content of rare earth elements (REE) of 5% HNO₃-treated solutions derived from carbonate samples varies from 1.6 ppm to 42.5 ppm. The shale-normalized REE patterns all display positive Ce anomalies (Ce/Ce* > 1.3), revealing that the carbonates precipitated under anoxic conditions. A sample from Hydrate Hole shows a concentric lamination, corresponding to fluctuations in δ¹³C values as well as trace elements contents. These fluctuations are presumed to reflect changes of seepage flux.     

Seasonal and depth variations in molecular and isotopic alkenone composition of sinking particles from the western North Pacific

Seasonal and depth variations in alkenone flux and molecular and isotopic composition of sinking particles were examined using a 21-month time-series sediment trap experiment at a mooring station WCT-2 (39°N, 147°E) in the mid-latitude NW Pacific to assess the influences of seasonality, production depth, and degradation in the water column on the alkenone unsaturation index U^K′₃₇. Analysis of the underlying sediments was also conducted to evaluate the effects of alkenone degradation at the water–sediment interface on U^K′₃₇. Alkenone sinking flux and U^K′₃₇-based temperature showed strong seasonal variability. Alkenone fluxes were higher from spring to fall than they were from fall to spring. During periods of high alkenone flux, the U^K′₃₇-based temperatures were lower than the contemporary sea-surface temperatures (SSTs), suggesting alkenone production in a well-developed thermocline (shallower than 30 m). During low alkenone flux periods, the U^K′₃₇-based temperatures were nearly constant and were higher than the contemporary SSTs. The nearly constant carbon isotopic ratios of C_37:2 and C_38:2 alkenones suggest that alkenones produced in early fall were suspended in the surface water until sinking. The alkenone sinking flux decreased exponentially with increasing depth. The decreasing trend was enhanced during the periods of high alkenone flux, suggesting that fresh and labile particles sank from spring to fall, while old and stable particles sank from fall to spring. The U^K′₃₇-based temperature usually increased with increasing depth. The preservation efficiency of alkenones was ∼2.7–5.2% at the water–sediment interface. Despite the significant degradation of the alkenones, there was little difference in U^K′₃₇ levels between sinking particles and the surface sediment.     

长江口外海域冬、春季水温变化规律研究

收集了1963—1996年长江口外海域水温的观测数据,分析了该海域冬、春季表层、10m层、20m层和30m层不同层次水温的季节和年际变化规律,以及其间水温垂向结构的变化。季节变化上,表层多年平均水温在8月最高,3月最低,底层多年平均水温9月最高,3月最低。年际变化上,冬季在1979年存在一个由冷到暖的跃迁;4月水温的年际变化较冬季复杂,表层、10m层、20m层和30m层水温分别在1979、1973、1973和1975年发生从冷到暖的跃迁。水平分布上,冬季除东南角小范围表层水温降低外,沿岸及北部海区表层水温均升高,春季北部和南部中间海域水温升高,升温幅度由表层至30m层逐渐变小。垂向结构上,冬季表底混合均匀,表层与20m层的年际变化相关系数高达0.97,春季表层与20m层的水温差存在10年左右的变化周期。本文将一些可能影响春季水温年际变化的因素与海温进行了比较并发现,在冷期,春季表层海温与长江口外海域气温相关较暖期好,相关指数为0.79;而暖期的春季表层与20m层的水温差与净热通量相关系数较高,为0.65。     

Monthly Variation of Sea-Air Temperature Differences in the Korean Coast

Monthly variations of sensible heat, latent heat and momentum fluxes and the modification of sea temperature to air temperature were examined at four coastal stations—Sokcho, Kangnung, Ulsan and Chungmu in the path of the East Korea Warm Current from the year of 1981 to 1990, which was one of main migration routes of Japanese common squid. The difference between monthly averaged sea surface and air temperatures at the 10 m height above the sea surface mainly became negative values from April through August, while they had positive ones from September through March. Monthly variability of the temperature differences is significant in both summer and winter, while it is generally small in spring and fall. Negative values of sensible heat fluxes, which indicated a heat gain by the sea through heat conduction across the air-sea interface were found at the four coastal stations from April to August. Minimum values of sensible heat fluxes at Sokcho, Kangnung and Chungmu were in June, except for Ulsan in August. To the contrary, positive sensible heat flux implying a heat loss from sea toward atmosphere occurred from October to February with a maximum in December. Latent heat fluxes due to condensation of moist air over sea surface had small magnitudes from April to August and those due to evaporation of water particles from the sea surface into the lower atmosphere had relatively large magnitudes from October to March. Minimum values of latent heat fluxes also occurred in June except for August in Ulsan. Momentum flux was small from June to August under weak wind in summer, but it was large from December to February under strong wind in winter. Regression equations between sea surface temperature and air temperature at the 10 m height above the sea surface had very high correlation coefficients from 0.92-0.98, except for 0.78-0.84 of Ulsan, which was partially affected by upwelling of cool water from the bottom into the sea surface. Similar to the sea surface, correlation coefficients were over 0.83-0.97 except for 0.70-0.79 for Ulsan at the 10 m depth of sea and were over 0.70-0.95 except for 0.59-0.82 for Ulsan at the 20 m depth.     

Growth Aspects and Magnesium Carbonate Concentrations of the Reef Building Octocoral Heliopora coerulea (Pallas) after Transplantation

Abstract. An experiment to test C have's hypothesis on temperature dependent MgCO₃ concentrations in marine calcareous skeletons was undertaken by transplanting colonies of Heliopora coerulea. The corals were transferred from a shallow lagoon with high average temperatures to the outer bottom of a fringing reef, 16 m depth, with low average temperatures. Against expectation, a statistically significant increase of average mol % concentrations from 0.48 to 0.54 % for upper growth regions and from 0.49 to 0.62% for lower growth regions was obtained. Temperature records during the experimentation period and the above data indicate that the mol% MgCO₃ concentration in the skeleton of living Heliopora colonies increases when transplanted to an environment with a lower temperature average than that of their original growth site, and with seasonal temperature fluctuations which are smaller in the experimental site than in the control site. Temperature fluctuations at the control site were up to 2.5 times greater than at the experimental site for most of the observation months. This supports the conclusion that the parameters a) minimum temperature and b) temperature stability of the environment are essential for the incorporation of Mg into the carbonate skeleton matrix of marine organisms. Within this study the results of a quantitative chemical analysis of the carbonate skeleton of H. coerulea are presented and growth data of transplanted colonies compared with those from the control site.     

地热对海洋影响的实验室模拟

This study, using laboratory experiments and scaling analysis, evaluates the influence of geothermal heating on global oceanic circulation. Upon a well-developed large-scale convective flow, an additional heat flux perturbation δF/F is employed. The increments of flow and thermal properties, including eddy diffusivity KT, flow velocity V and bottom temperature Tb, are found to be independent of the applied heat flux F. Together with the scaling analysis of convective flow at different configurations, where the flow is thermally driven in the relatively low or extremely high turbulent thermal convections or the horizontal convection, the variances of flow properties, δKT/KT and δV/V, are found to be close to 0.5% and 0.75% at δF/F=2%. This means that the small heat flux perturbation plays a negligible role in the global convective flow. However, δTb/ΔT is found to be 1.5% at δF/F=2%, which would have a significant effect in the local region. The results might provide a clue to understanding the influence of geothermal heating on global oceanic circulation. It is expected that geothermal heating will contribute less than 1% in turbulent mixing and volume flux to global oceanic circulation, so its influence can be negligible in this situation. However, when it comes to the local environment, the influence of geothermal heating cannot be ignored. For example, temperature increases of about 0.5°C with geothermal heating would have a significant effect on the physical environments within the benthic boundary layer.     

南海表面浮力通量、水型变性及南海"暖水"的消长分析

利用英国南安普敦海洋中心(SOC)海-气界面的热量和淡水通量资料以及世界大洋图集(WOA01)的海面温度和盐度资料计算了南海表面各月的有效浮力通量及水型变性矢量场,分析了南海表层暖水形成和发展的季节性特征。研究结果表明,南海表层暖水的发展、维持以及消亡在很大程度上受到海洋表层浮力通量的影响;此外,南海上层水体密度的垂直结构和变化也深受表面浮力通量和表层水型变性的影响。在中、北部,南海的垂向结构季节性变化较为明显,其中冬季表层水体的下沉强度最大,深度最深,而夏季表层水体却无下沉趋势。     

On vertical velocity fluctuations and internal tides in an upwelling region off the west coast of India

Hourly fluctuations of vertical velocity in relation to components of flow and wind and temperature oscillations at a morring site in the shelf waters off the west coast of India are discussed. The vertical velocities were computed from a time series of vertical temperature profiles assuming that horizontal advection of temperature is negligible. The computed values at a depth of 40 m during the 72-h period of observation were of the order of 10⁻¹ to 10⁻²cm s⁻¹, with a mean value of −2·77 × 10⁻² cm s⁻¹ indicating a net upward movement of water. The computed vertical velocity showed fluctuations of about 2–3 h, in addition to weaker signals of about 12 h. Based on the spectral estimates, we speculate that these fluctuations of 2–3 h in the vertical velocity may be caused by the fluctuations in the along-shore wind. The oscillations of isotherms found in the temperaturedepth time series and the spectral estimates of temperature and cross-shore flow component showed a periodicity of about 12 h, which indicated the presence of semi-diurnal internal waves. The fact that these internal wave troughs were associated with the measured onshore flow suggested that the waves were propagating offshore. The computed stability parameters showed little evidence of instability or mixing. It was found that the isotherm troughs in the temperaturedepth time series at about 12-h period coincided with high vertical shear in the cross-shore direction and low values of Brunt Vaisälä frequency.     

Settling fluxes in Saanich and Jervis Inlets, British Columbia, Canada: sources and seasonal patterns

We conducted a multi-year sediment-trap experiment in Saanich and Jervis Inlets, British Columbia, Canada. Moorings with traps positioned at three depths were placed near the mouth and toward the head of each fjord, and deployments were monthly. We present fluxes of total mass, biogenic silica (BSi), particulate organic carbon (POC) and aluminium (Al), as well as the δ¹³C signal of the POC, and we compare the sediment-trap fluxes to primary-production measurements made during the experiment.Diatomaceous silica and aluminosilicates were the primary components of the settling flux, while organic matter from marine (largely diatoms) and terrestrial sources was occasionally a significant portion of the sinking material. Fluxes of BSi and POC were highest in the spring and summer, tracing maxima in local primary production. These fluxes decreased, increased or remained constant with depth due to water-column remineralisation and variability in processes that cause fluxes to increase with depth. Al fluxes followed local precipitation and river runoff at the landward stations, and with remarkable faithfulness in Saanich Inlet. Near the mouths, there was little seasonality in Al flux, and the increases of flux with depth reveal sedimentary plumes at each fjord’s sill. Tidal and deepwater-renewal components of the plumes are evident, and the plume in Saanich Inlet was particularly intense. Fluxes of Al to deep sediment traps associated with renewal flows were also observed toward the head of each fjord.Marine δ¹³C endmembers are estimated from relationships between δ¹³C and BSi concentrations, and measures of soil δ¹³C from each fjord were available. These endmembers are used with the δ¹³C record to quantify marine and terrigenous contributions to the POC flux. Marine POC composed 54-72% of the total POC caught by shallow sediment traps in spring and summer, and 36-54% in fall and winter. Primary production and sediment-trap fluxes are used to estimate annually averaged export ratios (shallow-trap flux:autotrophic assimilation) for marine POC and Si. POC export ratios (0.092-0.14) were low for these productive waters, but they compare with other results based on sediment-trap fluxes from coastal waters where terrigenous OC has been subtracted. Export ratios of Si were calculated using an estimated Si:C assimilation ratio and, therefore, are susceptible to error, but the high results (>0.8) suggest that BSi was exported more efficiently than POC. The possibility that POC was preferentially lost after interception by sediment traps is also considered. Primary production and settling fluxes were higher in Saanich Inlet than in Jervis Inlet, while export ratios of OC and Si were similar in both fjords, away from the nepheloid layer near the sill of Saanich Inlet.     

Seasonal variation of pteropods from the Western Arabian Sea sediment trap

Sediment trap samples collected from the Western Arabian Sea yielded a rich assemblage of intact and non-living (opaque white) pteropod tests from a water depth of 919 m during January to September 1993. Nine species of pteropods were recorded, all (except one) displaying distinct seasonality in abundance, suggesting their response to changing hydrographical conditions influenced by the summer/winter monsoon cycle. Pteropod fluxes increased during the April–May peak of the intermonsoon, and reached maximum levels in the late phase of the southwest summer monsoon, probably due to the shallowing of the mixed layer depth. This shallowing, coupled with enhanced nutrient availability, provides ideal conditions for pteropod growth, also reflected in corresponding fluctuations in the flux of the foraminifer Globigerina bulloides. Pteropod/planktic foraminifer ratios displayed marked seasonal variations, the values increasing during the warmer months of April and May when planktic foraminiferal fluxes declined. The variation in fluxes of calcium carbonate, organic carbon and biogenic opal show positive correlations with fluxes of pteropods and planktic foraminifers. Calcium carbonate was the main contributor to the total particulate flux, especially during the SW monsoon. In the study area, pteropod flux variations are similar to the other flux patterns, indicating that they, too could be used as a potential tool for palaeoclimatic reconstruction of the recent past.     

Potential environmental control of free shallow gas in the seafloor of Eckernförde Bay,Germany

The depth of the free methane gas horizon in Eckernförde Bay, Western Baltic Sea, was monitored over 4 months in 1-h intervals with an echo sounder mounted on a tower at the seafloor. The depth to the top of the free gas varied between 50 cm and 100 cm below seafloor. Short-term fluctuations of free gas depth are related for the most part to changes of total pressure (air pressure and water level), the observation period was too short to demonstrate the effect of the annual temperature cycle.The correlation of gas depth changes and total pressure agrees well with theory which predicts a linear influence of pressure fluctuations on gas solubility. Since the methane content in the pore water of Eckernförde Bay is at the saturation limit environmental changes (pressure and temperature variations) cannot be buffered and have an instant impact on free gas presence.The implications of this observation are manifold. Geo-technically, the bearing strength of the seafloor is altered by the presence of gas bubbles. Similarly, sonar systems are influenced by the presence of gas bubbles which alter the acoustic seafloor properties. Of ecological interest is that pressure drops can trigger a sudden ebullition of the greenhouse gas methane from the seafloor into the atmosphere.     

Dynamique Spatio-temporelle du Bactérioplancton d'une aire marine Méditerranéenne perturbée par l'effluent urbain de l'agglomération marseillaise

The sewage originated by the city of Marseilles (more than 1 M inhabitants) is entering the sea water at surface level in the calanque of Cortiou (6–8 km east of the city). In the 6 km ² basin concerned with the polluted flux, bacterial communities demonstrate some behavorial analogies with other plankton. In spite of organic and mineral enrichments, both bacterial and phytoplanktonic densities are similar to those of the oligotrophic surrounding sea water. As for zooplanktonic species, which are able to resist in polluted environments, bacteria show capabilities to grow in various cultural conditions. No effect of the annual temperature cycle is noted on bacterial numbers. But, considering the bacterial community dynamics, the mechanisms leading to these similarities are quite different for bacteria. Heterotrophic bacteria mineralize the exogenous organic matter far from the ‘point source’, as demonstrated by the good correlation between N-NH₄ and viable counts (r=0·98). The fluctuations of the numbers of viable heterotrophs and total coliforms (incubated at 37°C) are similar (r=0·98 for n=60) showinga low selective effect of the temperature and the capability for the same bacteria to grow both on selective or not selective medium. The biomass production resulting is shown by high values of the frequency of dividing cells and is due to heterotrophic bacteria. Bacterial production is more important in the more polluted part of the basin (N-NE), but, the bacterial density is regulated by factors varying in relation to the distance to the source of sewage. Near the mouth of the outlet sedimentation, dispersion, zooplanktonic grazing of particles with attached bacteria and bacterial predators grazing on free-living bacteria are the major causes of bacterial disappearance. In the west and south areas, where pollutants and organic material are diluted, the amount of substrate necessary for energy maintenance also plays a role. On the other hand, in these areas, no attempt was made to detect viable but not active cells in direct counts.     

Role of the climatological and current variability on shelf-slope exchanges of particulate matter: Evidence from the Rhône continental margin (NW Mediterranean)

Climatological, current and particulate flux data were gathered in the Grand-Rhône canyon on the Gulf of Lions continental margin for one year (Jan. 1988–Jan 1989). Time series were analyzed to determine the influence of physical exchange processes on particulate matter at the shelf-edge, with a special emphasis on the Northern Current variability.The synoptic variability of the Northern Current was linked to meanders of 2–5 day period. Its meso-scale activity presented a seasonal signal with maximum values in early spring. Peaks of particulate fluxes in the upper traps were little affected by large river and atmospheric inputs, but rather by enhanced shelf-slope exchanges at the shelf edge due to intense cross-slope fluctuations of the Northern Current. These fluctuations caused cross-isobath flows near the bottom, which appeared to be a potential mechanism in transporting particles off the shelf. At 900 m depth, high-flux events measured by sediment traps were primarily linked to periods of higher cross-slope current oscillations. This correlation suggests that vertical motions caused by these oscillations contribute to the suspended particulate matter transport through the process of bringing higher suspended material concentrations from above to greater depths. Vertical velocity estimates were derived through temperature fluctuations combined with vertical temperature gradient and from the kinematic boundary condition. A simple diffusion model indicates that the vertical turbulent mixing of suspended particulate matter, induced by the cross-slope current oscillations, yields downward fluxes of particles comparable to those collected by sediment traps.     

渤海中部海底恒温层温度及泥温相位随深度变化特征

利用渤海中部两点一年中４个季节泥温观测资料，近似确定两测点海底恒温层泥温分别为１１．０℃和１１．７℃。认国泥温随深度变化可视为一垂向波－泥温波，并利用这一概念分析了泥温相位随深度变化特征，８＾＃，Ａ（Ｂ）平台测点泥温波波长分别为ｌ８＝８ｍ和ｌＡ（Ｂ）＝１０ｍ。研究建议，以０．５ｍ处多年泥温平均值作为海底恒温层温度。