渤海湾北岸海陆风及湍流强度特征分析

利用渤海湾北岸祥云岛岸基站2017—2018年观测数据和两座梯度测风塔2011—2013年观测资料分别分析了当地海陆风和湍流强度特征,并重点对不同天气系统所致大风条件下的湍流强度特点做了剖析。结果表明:渤海湾北岸海陆风特征明显,昼夜风向主要由SSW向ENE转变,夏季昼夜风向转换尤为显著。整体而言,风速和湍流强度随高度增大分别呈增大、减小趋势,且近海面层湍流强度小于近地层湍流强度。湍流强度具有显著的季节性特征,夏季大、冬季小、春秋季变化不明显,且近海面层湍流强度相对近地层变化平缓。近海面层70 m及以下湍流强度在偏东大风条件下反而比近地层湍流强度大,雷雨大风期间近海面层和近地层均出现湍流强度随高度增大而增大、风速随高度增大而减小的特殊情况,台风靠近风塔时各层风速显著增大、湍流强度变化不明显,但台风中心到达时湍流强度迅速增至峰值,二者时间一致并早于风速最小值出现时间约1 h。近海面层和近地层有8%～10%样本的湍流强度超出了IEC-61400设计标准,建议渤海湾北岸风力发电风机抗湍流参数调整至0. 43～0. 49。     

Heat balance of the surface layer of the sea at ocean weather station T

Heat balance of the upper 200 m of the sea south of Japan is studied, by the use of marine meteorological and oceanographic data at Ocean Weather Station T (29°N, 135°E), intensively obtained from June 1950 to November 1953. Local time change of the heat content in the surface layer and the net heat flux through the air-sea interface are calculated directly from these data, and the heat convergence in the sea is estimated from their residuals. Regarding the relative importance of one- and three-dimensional processes, it is found that, on a time scale of a few days to one month, the variation of heat content depends on heat convergence in the sea, while on a seasonal time scale, the heat content is determined primarily by the heat flux through the sea surface in December through February, by heat convergence within the sea from March to May, and by both processes from June to November. It is inferred that the heat convergence in the sea is caused by advection of water masses which are bounded by sharp fronts. Spectral analysis of sea surface temperature indicates that they typically take 2 to 3 days to pass the station, and their typical size is estimated as around 20 km by assuming the typical advection velocity of water masses to be 10 cm s^?1.     

The sea/land breeze in the northern coastal area of Shandong Peninsula

In this paper the seasonal variation and structural characteristics of the sea/ land breeze in the northern coastal area of" Shandong Peninsula are studied in two ways: one is the analysis of the observed wind data, and the other is numerical simulation and experiments. Firstly, the hour to hour wind data through the year 1984 at Longkou Meteorological Station and Yantai Oceanographic Station are analysed through energy spectra and hodograph. It is revealed from the analysed results that the effects of the sea/ land breeze in the area are notable in spring, summer and fall, especially in May. However, in winter the effects of sea / land breeze are not obvious. because the cold noitherly is prevailing. Secondly, a two-dimensional non- linear model of primitive equations is used to study the sea / land breeze circulation in May in the area. The results of numerical simulation consist basically with the analysed results of the observed sea / land breeze. A reasonable theoretical structure of the sea / land     

渤海湾西岸海风时空演变特征观测分析

应用2008年全年天津地区14个气象站的逐小时资料和6 h一次的地面常规资料,对渤海湾西岸(天津)海风时空演变特征进行了统计分析,结果表明:2008年全年渤海湾西岸的海风盛行于春夏季的14—17时,海风发生频率的最大值出现在夏季,近海站的海风风速主要集中在2—4 m/s,且春季的海风强度最大,秋季最弱,风向主要以东和南-东南方向为主;海岸带附近建立的海风一半以上都可向内陆传播至30 km远,最大可向内陆传播70 km以远,海风强度的空间分布则呈现出近海站高于远海站,近郊站大于城市站的特点。     

Water and flow variations in Sagami Bay under the influence of the Kuroshio path

Variations of water and flow in Sagami Bay in relation to the Kuroshio path variations are examined by using 100m-depth temperature and salinity data from 25 stations as well as sea level data from five stations (Minami-Izu, ItÔ, Ôshima, Aburatsubo, Mera). In regard to temperature, anomalies from the mean seasonal variations are used. Results show that water properties are clearly different between the three typical paths of the Kuroshio. The difference is more remarkable in temperature than in salinity; temperature is higher during the typical large-eander (LM) path, and lower during the offshore non-large-meander (NLM) path, compared with the nearshore NLM path. Temperature anomaly and salinity distributions, as well as the Ôshima minus Minami-Izu and Ôshima minus Mera sea-level differences strongly suggest that the flows during the typical LM path are distributed as hitherto described in past studies, that is, water in the mouth region of the bay flows clockwise around Ôshima from the west channel to the east channel, and a counterclockwise eddy exists in the interior. On the other hand, flows during the nearshore and offshore NLM paths seem to be quite different from those during the typical LM path; velocities are very weak, and the directions of circulation is frequently reversed. This tendency also can be seen during parts of LM period in which the Kuroshio takes a non-typical LM path.Water properties in Sagami Bay are most characteristic during transitions between nearshore and offshore NLM paths. During transitions from nearshore to offshore NLM paths, temperatures are extremely high as a whole in the bay, while during reverse transitions, both temperatures and salinities are very low in the entire region.     

夏季降雨过程对南海上层盐度的可能影响

根据对1998年南海中部、北部航次的海水盐度观测资料以及GPCP-1DD(Global Precipitation Climatology Project,1 Degree Daily Precipitation Estimate)降雨资料,研究了夏季风期间降雨过程对南海上层盐度的可能影响。个例和合成分析表明,当有降雨过程发生时,降雨对南海上层盐度的影响深度为85—110m,上层盐度恢复所需要的时间为14—42d左右。此外还利用NCEP/NCAR(National Center for Environmental Prediction/National Center for Atmospheric Research)再分析资料的逐月风场资料以及基于法国AVISO(Archiving,Validation and Interpretation of Satellite Oceanographic Data)提供的融合海平面高度异常资料计算的地转流场分析平流效应对其可能产生的影响。     

On the problem of heat balance in integral models of the upper ocean

The heat balance equations for the mixed layer, the jump layer modelled by the temperature discontinuity surface, the heat flux, current velocity, and the thermocline, where the temperature is parameterized vertically, are derived in the spatial unsteady hydrodynamic integral model of the upper ocean.Translated by Mikhail M. Trufanov.     

Pelagic chaetognaths in Sagami Bay and Suruga Bay,Central Japan

Pelagic chaetognaths in Sagami Bay and Suruga Bay, Central Japan, were studied. Their community structure was very similar in both of these bays. Four genera and 26 species were identified. In Sagami Bay the habitat segregation by depths was clearly obtained. The population and species number of epipelagic (0–200 m) chaetognaths were larger in summer than in winter. The populations of meso- (200–500 m) and bathypelagic (500–1,000 m) species were smaller than that of epipelagic ones and fairly stable seasonally.     

Heat oscillation in the upper ocean of the southern South China Sea

Data used in this study are temperature/depth profiles taken over the upper 400 m of the ocean in the southern South China Sea (4°-14° N, 106°-120° E) for the period 1961-1973. The data are analyzed on the grid 2 (latitude) by 2 (longitude) in space and bimonthly in time. The vertically averaged temperature (TAV) over the upper 100 m of the ocean is calculated as the estimate of the heat content in the upper ocean.The TAV is cooler in the northwest region of the study area and warmer in the southeast in the annual and seasonal mean figures. The first EOF (Empirical Orthogonal Function) of anomalous TAV accounts for 41 % of the total variance for the period 1961-1973. The time function associated with it displays a significant interannual changes in the heat content, with 2-4 a oscillation period and associated with the ENSO events. During ENSO event TAV increases with the tendency of increasing towards equator along the basin. This anomalous states also exist in the water layers below 100 m depth. T     

An isotopic perspective on the correlation of surface ocean carbon dynamics and sea ice melting in Prydz Bay (Antarctica) during austral summer

The stable carbon isotope composition of particulate organic carbon (δ¹³C_POC) and naturally occurring long-lived radionuclide ²²⁶Ra (T_1/2=1600 a) were applied to study the variations of upper ocean (<100 m) carbon dynamics in response to sea ice melting in Prydz Bay, East Antarctica during austral summer 2006. Surface δ¹³C_POC values ranged from −27.4‰ to −19.0‰ and generally decreased from inner bay (south of 67°S) toward the Antarctic Divergence. Surface water ²²⁶Ra activity concentration ranged from 0.92 to 2.09 Bq/m³ (average 1.65±0.32 Bq/m³, n=20) and increased toward the Antarctic Divergence, probably reflecting the influence of ²²⁶Ra-depleted meltwater and upwelled ²²⁶Ra-replete deep water. The fraction of meltwater, f_i, was estimated from ²²⁶Ra activity concentration and salinity using a three-component (along with Antarctic Summer Surface Water, and Prydz Bay Deep Water) mixing model. Although the fraction of meltwater is relatively minor (1.6–11.9%, average 4.1±2.7%, n=20) for the surface waters (sampled at ~6 m), a positive correlation between surface δ¹³C_POC and f_i (δ¹³C_POC=0.94×f_i−28.44, n=20, r²=0.66, p<0.0001) was found, implying that sea ice melting may have contributed to elevated δ¹³C_POC values in the inner Prydz Bay compared to the open oceanic waters. This is the first time for a relationship between δ¹³C_POC and meltwater fraction to be reported in polar oceans to our knowledge. We propose that sea ice melting may have affected surface ocean δ¹³C_POC by enhancing water column stability and providing a more favorable light environment for phytoplankton photosynthesis, resulting in drawdown of seawater CO₂ availability, likely reducing the magnitude of isotope fractionation during biological carbon fixation. Our results highlight the linkage of ice melting and δ¹³C_POC, providing insights into understanding the carbon cycling in the highly productive Antarctic waters.     

Dissolved iron and zinc in Sagami Bay and the Izu-Ogasawara Trench

Using a clean seawater sampling system for trace metals onboard the R. V. Shinsei-Maru, newly launched in 2013, we investigated the vertical distributions of dissolved iron and zinc in Sagami Bay and the Izu-Ogasawara Trench. We applied appropriate clean sampling and filtering processes for trace metals, so that uncontaminated seawater samples were successfully collected. The distribution of zinc in the trench area was similar to that of silicate and the same as that previously reported in the subtropical North Pacific. There were spatial variations in the iron (Fe) distribution in the trench areas. We used previously reported information about biogeochemical cycling in the trench area, and found that Fe has a residence time of 29 years in the water column. The short residence time of Fe (29 years) corresponds to the vertical variations of dissolved Fe in the water column.     

The response of the upper ocean to tropical cyclone Viyaru over the Bay of Bengal

Better forecast of tropical cyclone(TC) can help to reduce risk and enhance management. The TC forecast depends on the scientific understanding of oceanic processes, air-sea interaction and finally, the atmospheric process. The TC Viyaru is taken as an example, which is formed at the end of 11 May 2013 and sustains up to 17 May 2013 during pre-monsoon season. Argo data are used to investigate ocean response processes by comparing pre-and post-conditions of the TC. Eight oceanic parameters including the sea surface temperature(SST), the sea surface salinity(SSS), and the barrier layer thickness(BLT), the 26°C isotherm depth in the ocean(D26), the isothermal layer depth(ILD), the mixed layer depth(MLD), the tropical cyclone heat potential(TCHP) and the effective oceanic layer for cyclogenesis(EOLC) are chosen to evaluate the pre-and post-conditions of the TC along the track of Viyaru. The values of the SST, D26, BLT, TCHP and EOLC in the pre-cyclonic condition are higher than the post-cyclonic condition, while the SSS, ILD and MLD in the post-cyclonic condition are higher than the pre-cyclonic condition of the ocean due to strong cyclonic winds and subsurface upwelling. It is interesting that the strong intensity of the TC reduces less SST and vice versa. The satisfied real time Argo data is not available in the northern Bay of Bengal especially in the coastal region. A weather research and forecasting model is employed to hindcast the track of Viyaru, and the satellite data from the National Center Environmental Prediction are used to assess the hindcast.     

Transport processes deduced from geochemistry and the void ratio of surface core samples, deep sea Sagami Bay, central Japan

Sagami Bay is a deep-water foreland basin with an average sedimentary rate of approximately 0.1 g/cm²/year. It is an appropriate area to study for better understanding of sedimentary processes in a setting with a high sedimentation rate. Seven multiple core samples, 30-50 cm thick, were obtained from Sagami Bay. Four of the core samples were taken from the Tokyo submarine fan system (Tokyo canyon floor, Tokyo fan valley and its levee, the distal fan margin). Two samples were obtained from the Sakawa fan delta and the adjacent topographic high. The remaining one was from an escarpment of the Sagami submarine fault. Variations in chemical composition can be recognized at every coring site. They show two different sediment sources: the sediments of the Tokyo submarine fan system and those from Sakawa fan delta. Further, there are differences in chemical composition between canyon floor and levees even within the Tokyo submarine fan system. The results suggest that the sedimentary process is strongly controlled not by vertical particle settling but by a hyperpycnal flow process. The proxies obtained from the core samples do not reflect conditions in the water column immediately overlying the sea floor. Rather, they are controlled by conditions on the adjacent continental shelf or/and shallow basins, which are the areas of primary accumulation.     

Quantitative studies on the smaller macrobenthos inhabiting various topographical environments around the Sagami bank in the deep-sea system of Sagami Bay

A survey was made in an area of complicated topography within the deep-sea system of Sagami Bay. Samples were obtained quantitatively with the Smith-McIntyre bottom-sampler of 1/10 m² and were washed through a screen of 1.0 mm mesh. The biomass, the number of individuals and the number of species were studied at each station in relationship to submarine topography. All the items showed more or less parallel features in three topographical environments. High figures were found on the top of the bank and low ones in the canyon, while those values obtained in the sloping environment were intermediate and variable. The percent composition of the quantitatively important animal groups was rather constant throughout the top of the bank, and in this hahitat the faunal diversity was higher than in the others. From the distributional patterns of the species, and also from the species composition and dominancy at each station, the benthic communities of the bank-top and of the canyon were known to be distinct. In the sloping environment, however, the benthic assemblages at some stations were related to the bank-top community, either being its impoverished phase or with several elements peculiar to the slope, while at the remaining stations they were rather peculiar but related to the canyon community. All the aspects of the benthic ecology mentioned above were found to be closely related, both in their general and special features, to the nature of the sediments, in which three major types were recognized corresponding to the above three topographical environments. From the nature of the sediment, water movement, if any, can be expected on the top of the bank, and this is reflected in the preponderance of plankton- and/or ceston feeders making up this benthic community. Within the canyon, there were found the impoverishment of benthic community which is supposed to be due to the stagnant environment. The biomasses of the whole area were compared to those in other regions in the form of cumulative curves. In the deep-sea system of Sagami Bay which is well surrounded by land, the biomasses were only slightly lower than those of the shallow-sea system on the shelves in neighbouring regions, and those of a shallow enclosed bay were an order of magnitude higher than these figures. Those in the offshore parts of the continental shelf, remote from the coast, were nearly an order of magnitude lower. This work is carried out as a part of JIBP-PM Project     

The probable subarctic elements found in the bathyal megalobenthos in Sagami Bay

Megalobenthic samples trawled from the bathyal zone in Sagami Bay contain some probable subarctic elements, such asSebastolobus macrochir, Clidoderma asperrimum, Solaster paxillatus, Macoma calcarea, Cryptonatica clausa, Eunatica pallida, Volutomitra alaskana, Paralomis multispina andPandalus hyspinotus, among others. The mechanism and process of invasion of such cold-water species into the deep-sea zone in Sagami Bay are not simple. There are some evidences that these animals are propagating in Sagami Bay. The occurrences of subarctic fish there are not unusual because of their strong swimming ability. The benthic animals that have planktonic larval stages might be dispersed in the same process as in the Oyashio plankton translocated by Oyashio Undercurrent. However, the mechanism and process of dispersions of egg-carrying crustaceans and egg-case producing gastropods remain unanswered. Perhaps, the palaeo-oceanographical and evolutional considerations will help to solve the problem.Contribution B-557 from Tokai Regional Fisheries Research Laboratory.     

Numerical study of the seasonal salinity budget of the upper ocean in the Bay of Bengal in 2014

Impact factors on the salinity budget, especially the eddy salt fluxes and smaller-scale diffusive salt fluxes for the upper 50 m of the Bay of Bengal (BoB) in ...     

台湾海峡西岸海陆风气候特征及其环流形势分析

利用福建内陆以及沿海的站点观测资料、NCEP再分析资料以及EOF方法,对比分析了台湾海峡西岸不同区域海陆风气候特征及其对应的大气环流形势。结果表明:空间分布上看,海峡西岸的海陆风平均频次呈现南北多,中部少的特点。时间分布上看,4、5月以及夏末秋初海陆风日较多,冬季相对较少。北、中、南部海风(陆风)的平均起风时间呈现一种阶梯变化,北部最早,南部最晚。当副热带高压加强西伸控制华南大部分区域,且地面没有明显主导系统时,海峡西岸更容易出现海陆风。这可能是由于副高加强能够导致海陆热力温差加大,从而导致海陆风更易出现。     

Processes controlling cobalt distribution in two temperate estuaries,Sagami Bay and Wakasa Bay,Japan

Concentrations of cobalt (Co) in surface waters from the Sagami River to northern Sagami Bay and from the Yura River to southwestern Wakasa Bay in Japan were determined in order to investigate the factors governing the distribution of this metal during estuarine mixing. Dissolved (<0.2 μm) and particulate (>0.2 μm) Co showed non-conservative mixing behavior with low or mid-salinity maxima within those two estuarine regions, indicating benthic remobilization and/or sewage input apart from riverine input during the estuarine mixing. These results are supported by a suite of complementary measurements of other parameters, such as manganese, phosphate, and suspended particulate matter concentrations. In addition, the concentration ratio of dissolved Co to total Co (dissolved plus particulate) increased along the salinity gradient, implying the potential for desorption of this metal from suspended particulate matter on estuarine mixing.