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1.
E. G. Lunev V. A. Ivanov A. G. Kirichenko E. M. Lemeshko S. V. Motyzhev 《Physical Oceanography》2011,20(5):366-378
The autonomous drifting buoys equipped with satellite link turn into one of the most important components of the global system
of operative observations of the ocean and the surface layer of the atmosphere. However, on the regional level, the problem
of analysis of the surface circulation of waters in the coastal zone and sea straits remains quite urgent because the available
drifters cannot be used in this case due to their sizes and long intervals between measurements. We present the results of
development and testing of a new drifter system aimed at measuring currents. The system is based on the use of buoys operating
at depths less than 1 m. To improve the space-and-time resolution of measurements, the buoys are equipped with receivers of
the global positioning system (GPS) and GSM modems for the data transfer via cellular communication networks. The drifter system guarantees the possibility of determination
of the coordinates of buoys with a resolution of 3 min in time and 14 m in space. We describe the specific features of the
design of the proposed information-and-measuring drifter system and present the first results of application of new buoys
called “minidrifters” for the pilot monitoring of currents in the Kerch Strait. 相似文献
2.
Comparison of Kuroshio surface velocities derived from satellite altimeter and drifting buoy data 总被引：2，自引：0，他引：2
Sea-surface geostrophic velocities for the Kuroshio region calculated from TOPEX/POSEIDON altimetry data together within situ oceanographic data are compared with surface velocities derived from drifting buoy trajectories. The geostrophic velocities
agree well with the observed velocities, suggesting that the Kuroshio surface layer is essentially in geostrophic balance,
within measurement error. The comparison is improved a little when the centrifugal acceleration is taken into account. The
observed velocities are divided into the temporal mean and fluctuation components, and the partitioning of velocities between
these two components is examined. For the Kuroshio region, most of the fluctuation components of the velocities derived from
drifting buoys are found to be positive. This result suggests that Eulerian mean velocities for the Kuroshio region estimated
from drifting buoy data tend to be larger than actual means, due to the buoy’s tendency to sample preferentially in the high-velocity
Kuroshio. 相似文献
3.
Radii and angular velocities in the motions of drifting buoys deployed in the Kuroshio are estimated by fitting circles to the trajectories of two drifting buoys, one with a drogue at 300 m depth and the other at 800 m depth. The buoys were deployed in the Kuroshio where it was flowing counter-clockwise around the large cold water mass south of Honshu. The same technique was applied to two drifting buoys with drogues at 300 m depth placed in the Kuroshio where it flowed clockwise around Oshima Island in Sagami Bay. The centrifugal forces were 7% and 6% as large as the Coriolis forces in the Kuroshio around the cold water mass, and they were –56% and –42% as large as the Coriolis forces in the current around the Oshima Island. The temperature gradient observed in the Oshima-West Channel suggested that the pressure gradient there was smaller due to the centrifugal force acting against the Coriolis force than the pressure gradient to be balanced with the Coriolis force. 相似文献
4.
From 1988 to 1993, 23 satellite-tracked drifting buoys entered the Kamchatka Current. The buoy trajectories showed a well-formed, high-speed current that originated near Shirshov Ridge, and flowed southward through Kamchatka Strait. During some years, the buoys turned eastward at 50°N, while in other years they were transported as far south as Japan (40°N). Only one buoy entered the Sea of Okhotsk. Eddies were evident in many of the buoy trajectories. Greatest maximum daily velocities (>100 cm s–1) were observed south of Kamchatka Strait, with 50–60 cm s–1 being more common. 相似文献
5.
《Deep Sea Research Part I: Oceanographic Research Papers》2002,49(2):245-266
During the autumn–winter of 1996–1997, drifting buoy trajectories and infrared satellite images provided new information on the characteristics of several mesoscale phenomena generated by the Algerian Current (AC) in the western Mediterranean Sea. A mesoscale event, as defined by previous studies, consists of a meander of the current associated with a surface anticyclonic eddy inside its crest, a transitory surface cyclonic eddy (Ec) upstream from the crest, and a deep anticyclonic eddy just below the meander. Most events propagate eastward along the coast at a few km per day until they are forced, mainly by the topography at the entrance to the channel of Sardinia, to detach from the coast and propagate seaward. They thus become open-sea anticyclonic eddies and generally complete an anticlockwise circuit in the Algerian basin. Surface buoys were launched upstream from an event and across it near 1°E. They made it possible to characterise the anticyclonic and cyclonic surface eddy features, and for the first time clearly showed the meander, which is in general not well depicted with images. It has thus been definitely demonstrated that most of the AC (speeds of several tens of cm/s) crosses the relatively slowly propagating events. As usual, the event we sampled reached a mature stage characterised by a vanishing of the Ec, and increased up to ∼100 km. Its arrest and decrease before it reached the channel of Sardinia, which is not so usual, was contemporaneous to the reappearance of the Ec and could be related to the growing of another coastal eddy upstream. At the entrance to the channel of Sardinia (near 7–8°E), the trajectories and images also documented another event which was larger (up to ∼120 km) and in the phase of detachment. Since the buoys drifted alternately to the west and to the east between this event and the coast, it is clear that an event can detach only temporarily and allow part of the AC to flow eastward directly. As indicated by infrared images, the definitive detachment occurred after all the buoys escaped from the event. The whole in situ and satellite data set is fully consistent with all the previous observations of the AC mesoscale variability, and quantitatively supports the proposed hypotheses for the event structure. It is consistent with laboratory experiments and some results of numerical models of coastal instability processes. 相似文献
6.
Lagrangian validation of numerical drifter trajectories using drifting buoys: Application to the Agulhas system 总被引：1，自引：0，他引：1
E. van Sebille P.J. van Leeuwen A. Biastoch C.N. Barron W.P.M. de Ruijter 《Ocean Modelling》2009,29(4):269-276
The skill of numerical Lagrangian drifter trajectories in three numerical models is assessed by comparing these numerically obtained paths to the trajectories of drifting buoys in the real ocean. The skill assessment is performed using the two-sample Kolmogorov–Smirnov statistical test. To demonstrate the assessment procedure, it is applied to three different models of the Agulhas region. The test can either be performed using crossing positions of one-dimensional sections in order to test model performance in specific locations, or using the total two-dimensional data set of trajectories. The test yields four quantities: a binary decision of model skill, a confidence level which can be used as a measure of goodness-of-fit of the model, a test statistic which can be used to determine the sensitivity of the confidence level, and cumulative distribution functions that aid in the qualitative analysis. The ordering of models by their confidence levels is the same as the ordering based on the qualitative analysis, which suggests that the method is suited for model validation. Only one of the three models, a 1/10° two-way nested regional ocean model, might have skill in the Agulhas region. The other two models, a 1/2° global model and a 1/8° assimilative model, might have skill only on some sections in the region. 相似文献
7.
Formulation, implementation and examination of vertical coordinate choices in the Global Navy Coastal Ocean Model (NCOM) 总被引：3，自引：3，他引：3
Charlie N. Barron A. Birol Kara Paul J. Martin Robert C. Rhodes Lucy F. Smedstad 《Ocean Modelling》2006,11(3-4):347-375
A 1/8° global version of the Navy Coastal Ocean Model (NCOM) is described with details of its formulation, implementation, and configuration of the vertical coordinate. NCOM is a baroclinic, hydrostatic, Boussinesq, free-surface ocean model that allows its vertical coordinate to consist of σ coordinates for the upper layers and z-levels below a user-specified depth. This flexibility allows implementation of a hybrid σ–z coordinate system that is expected to mitigate some of the weaknesses that can be associated with either pure coordinate option. For the global NCOM application, the σ–z coordinate is used to allow terrain-following σ coordinates in the upper ocean, providing better resolution and topographic fidelity in shelf regions where flow is most sensitive to its representation. Including z coordinates for deeper regions efficiently maintains high near-surface vertical resolution in the open ocean. Investigation into the impact of the selected coordinate system focuses on differences between atmospherically-forced free-running (no assimilation) global solutions using σ–z and pure z coordinates. Comparisons with independent temperature observations indicate that global NCOM using the σ–z coordinate has improved skill relative to its z coordinate implementation. Among other metrics, we show that in comparison with time series of surface temperature from National Oceanic Data Center (NODC) buoys, mostly located in coastal regions, root mean squared differences (RMSD) improved for 63% and correlation improved for 71% of the stations when σ–z coordinates were used instead of pure z. For the exclusively open-ocean Tropical Atmosphere-Ocean (TAO) buoys, differences between the simulations were small, with the σ–z showing smaller RMSD for 45% of the stations and higher correlation for 65% of the stations. Additional comparisons using temperature profile observations further confirm a tendency for improved performance using the hybrid σ–z coordinates. 相似文献
8.
Naoto Ebuchi Yasushi Fukamachi Kay I. Ohshima Kunio Shirasawa Masao Ishikawa Toru Takatsuka Takaharu Daibo Masaaki Wakatsuchi 《Journal of Oceanography》2006,62(1):47-61
Three High Frequency (HF) ocean radar stations were installed around the Soya/La Perouse Strait in the Sea of Okhotsk in order
to monitor the Soya Warm Current (SWC). The frequency of the HF radar is 13.9 MHz, and the range and azimuth resolutions are
3 km and 5 deg., respectively. The radar covers a range of approximately 70 km from the coast. The surface current velocity
observed by the HF radars was compared with data from drifting buoys and shipboard Acoustic Doppler Current Profilers (ADCPs).
The current velocity derived from the HF radars shows good agreement with that observed using the drifting buoys. The root-mean-square
(rms) differences were found to be less than 20 cm s−1 for the zonal and meridional components in the buoy comparison. The observed current velocity was also found to exhibit reasonable
agreement with the shipboard ADCP data. It was shown that the HF radars clearly capture seasonal and short-term variations
of the SWC. The velocity of the Soya Warm Current reaches its maximum, approximately 1 m s−1, in summer and weakens in winter. The velocity core is located 20 to 30 km from the coast, and its width is approximately
40 km. The surface transport by the SWC shows a significant correlation with the sea level difference along the strait, as
derived from coastal tide gauge records at Wakkanai and Abashiri.
Deceased. 相似文献
9.
A Leeway-Trace model was established for the traceability analysis of drifting objects at sea. The model was based on the Leeway model which is a Monte Carlo-based ensemble trajectory model, and a method of realistic traceability analysis was proposed in this study by using virtual spatiotemporal drift trajectory prediction. Here,measured data from a drifting buoy observation experiment in the northern South China Sea in April 2019,combined with surface current data obtained from the finite volu... 相似文献
10.
认识海洋中的物质如何散播对于理解海洋环境变化和人类活动污染在海洋中的扩散过程具有非常重要的意义。利用历史海表漂流浮标观测数据,对日本福岛以东海域的表层物质散播轨迹进行了拉格朗日示踪分析和观测模拟试验研究。结果发现,福岛以东海域海表浮标的散播路径主要分为东、南两支,其中速度较快的东支为主要通道,沿黑潮延伸体汇入北太平洋流,最短用时大约22个月即可到达北美西海岸;南支则沿黑潮延伸体以南的大范围南向流向西南方向运移,速度较慢且明显受涡旋活动影响,最快大约5个月即可到达吕宋海峡和中国台湾以东海域,进而进入南海和东海等中国近海海域。通过开展观测模拟试验,发现海表浮标散播的概率密度分布呈现以福岛附近海域为核心、向西南和正东方向递减扩展的形态,其中,到达中国近海的浮标主要通过吕宋海峡进入。文章详细讨论了研究结果的局限性、不足之处,以及因基于大量现场观测而具备的重要参考价值。 相似文献
11.
利用船载CTD仪、国外剖面浮标(APEX)和实验室盐度计等标准仪器设备,在西北太平洋海域对2种型号国产剖面浮标(COPEX和HM2000)进行了现场比测试验,并对观测资料质量进行了定性和定量分析与评价.结果表明:(1) COPEX和HM2000型剖面浮标观测的盐度资料均能达到国际Argo计划提出的±0.01的精度要求;(2)HM2000的最小观测深度离海面1 m以内,最大观测深度基本稳定在2 000 m左右,并能保持在1000 m深度附近漂移,而COPEX的最小观测深度在8～9 m之间,最大观测深度则在1 800～1 900 m之间波动,且漂移深度都在600～800 m之间;(3)COPEX和HM2000都获得了70条以上有效观测剖面.总体而言,两种国产剖面浮标观测的温、盐度资料都是可信、可靠的.但试验中暴露的一些问题和不足仍有待不断改进和完善. 相似文献
12.
Research and development of the New Generation Sea Surface Temperature for Open Ccean (NGSST-O) product and its demonstration operation 总被引：1，自引：0，他引：1
Futoki Sakaida Hiroshi Kawamura Shin Takahashi Teruhisa Shimada Yoshimi Kawai Kohtaro Hosoda Lei Guan 《Journal of Oceanography》2009,65(6):859-870
Real-time generation and distribution of the New Generation Sea Surface Temperature for Open Ocean (NGSST-O) product began
in September 2003 as a demonstration operation of the Global Ocean Data Assimilation Experiment (GODAE) High-Resolution Sea
Surface Temperature Pilot Project. Satellite sea surface temperature (SST) observations from infrared radiometers (AVHRR,
MODIS) and a microwave radiometer (AMSR-E) are objectively merged to generate the NGSST-O product, which is a quality-controlled,
cloud-free, high-spatial-resolution (0.05° gridded), wide-coverage (13–63° N, 116–166° E), daily SST digital map. The NGSST-O
demonstration operation system has been developed in cooperation with the Japanese Space Agency (JAXA) and has produced six
years of continuous data without gaps. Comparison to in situ SSTs measured by drifting buoys indicates that the root mean-square error of NGSST-O has been kept at approximately 0.9°C. 相似文献
13.
We summarize the results of reconstruction of the monthly average surface circulation in the Southern Ocean according to the paths of autonomous drifting buoys launched in the course of the First Global Geophysical Experiment (FGGE) according to the Program of Investigation of Global Atmospheric Processes in 1978–1980. The data of numerical analysis reveal significant annual and seasonal variability in the behavior of the integral characteristics of the Antarctic Circumpolar Current, the west extension of the Agulhas Current, the zone of convergence of the Falkland and Brasil Currents, and the cyclonic gyres in the Weddell and Ross Seas. It is established that the dynamics of the large-scale surface circulation in the Southern Ocean can be described by two or three empirical orthogonal modes. In general, we observe a strong correlation between the locations of the zones with high kinetic energy of currents and the zones of bottom rise. 相似文献
14.
The origins and evolutions of two anticyclonic eddies in the northeastern South China Sea (SCS) were examined using multi-satellite
remote sensing data, trajectory data of surface drifting buoys, and in-situ hydrographic data during winter 2003/2004. The results showed that buoy 22918 tracked an anti-cyclonic warm-core eddy (AE1)
for about 20 days (December 4–23, 2003) in the northeastern SCS, and then escaped from AE1 eventually. Subsequently to that,
buoy 22517 remained within a different anti-cyclonic warm-core eddy (AE2) for about 78 days (from January 28 to April 14,
2004) in the same area. It drifted southwestward for about 540 km, and finally entered into the so-called “Luzon Gyre”. Using
inference from sea level anomaly (SLA), sea surface temperature (SST), geostrophic currents and the buoys’ trajectories, it
is shown that both eddies propagated southwestward along the continental slope of the northern SCS. The mean speeds of AE1
and AE2 movements were 9.7 cm/s and 10.5 cm/s, respectively, which are similar to the phase speed of Rossby waves in the northern
SCS. The variation of instantaneous speeds of the eddy movement and intensity of anticyclonic eddy may suggest complex interactions
between an anticyclonic eddy and its ambient fluids in the northern SCS, where the eddy propagated southwestward with Rossby
waves. Furthermore, SLA and SST images in combination with the temperature and salinity profiles obtained during a cruise
suggested that AE1 was generated in the interior SCS and AE2 was shed from the “Kuroshio meander”. 相似文献
15.
基于中国北极考察布放浮标观测和数值模拟的海冰和积雪厚度变化分析 总被引：1，自引：0，他引：1
Sea ice and the snow pack on top of it were investigated using Chinese National Arctic Research Expedition(CHINARE) buoy data.Two polar hydrometeorological drifters,known as Zeno? ice stations,were deployed during CHINARE 2003.A new type of high-resolution Snow and Ice Mass Balance Arrays,known as SIMBA buoys,were deployed during CHINARE 2014.Data from those buoys were applied to investigate the thickness of sea ice and snow in the CHINARE domain.A simple approach was applied to estimate the average snow thickness on the basis of Zeno~ temperature data.Snow and ice thicknesses were also derived from vertical temperature profile data based on the SIMBA buoys.A one-dimensional snow and ice thermodynamic model(HIGHTSI) was applied to calculate the snow and ice thickness along the buoy drift trajectories.The model forcing was based on forecasts and analyses of the European Centre for Medium-Range Weather Forecasts(ECMWF).The Zeno~ buoys drifted in a confined area during 2003–2004.The snow thickness modelled applying HIGHTSI was consistent with results based on Zeno~ buoy data.The SIMBA buoys drifted from 81.1°N,157.4°W to 73.5°N,134.9°W in 15 months during2014–2015.The total ice thickness increased from an initial August 2014 value of 1.97 m to a maximum value of2.45 m before the onset of snow melt in May 2015;the last observation was approximately 1 m in late November2015.The ice thickness based on HIGHTSI agreed with SIMBA measurements,in particular when the seasonal variation of oceanic heat flux was taken into account,but the modelled snow thickness differed from the observed one.Sea ice thickness derived from SIMBA data was reasonably good in cold conditions,but challenges remain in both snow and ice thickness in summer. 相似文献
16.
Yu. B. Ratner A. P. Tolstosheev A. L. Kholod S. V. Motyzhev 《Physical Oceanography》2009,19(3):170-185
We consider some specific features of creation of the database according to the results of drifter experiments carried out
in the Black Sea in 2001–2006. The general statistical information on all buoy studies in the sea is presented. The criteria
used to filter the primary data are suggested. The principles of formation and structuring of the drifter database are presented.
As an example, we describe the procedure and the results of comparison of model estimates with the data of contact measurements
of the sea-surface temperature by drifting buoys. 相似文献
17.
为了解大型附着生物对近海圆盘浮标污损的特点，对布设在珠江口东南海域和北部湾东北部海域的4个圆盘浮标的大型附着生物群落进行分析研究。结果表明，浮标侧壁大型附着生物的丰度和生物量分别为400.00～78 296.00 ind./m2和659.42～62 276.00 g/m2，底部的丰度和生物量则为412.00～66 585.00 ind./m2和1 861.60～60 784.00 g/m2，多数情况下浮标底部大型附着生物的丰度和生物量高于侧壁。浮标底部的香农?威纳(Shannon-Wiener)多样性指数(H′)介于2.39～3.06之间，马格列夫(Margalef)丰富度指数(d)为4.02～6.98，皮洛(Pielou)均匀度指数(J′)为0.88～0.91；而浮标侧壁的H′为0.64～2.79，d为1.10～4.89，J′为0.58～0.96，其中H′和d均表现出底部高于侧壁。聚类分析和非度量多维标度分析结果表明，在30%的相似性水平上，可将各站位浮标侧壁和底部的大型附着生物群落分为4个群组，其中浮标底部基本上可归成1个群组，但浮标侧壁之间差异较大。单因子相似性分析和相似性百分比结果则显示，浮标侧壁和底部的生物群落结构存在明显差异，蔓足类和刺胞动物应是造成该差异的主要因素。总体来看，浮标底部相对于浮标侧壁更易被大型附着生物污损。 相似文献
18.
本文在构建黄海浒苔漂移输运模型的基础上耦合了生长消亡过程的生态模块,利用CFSR(Climate Forecast System Reanalysis)再分析数据、国家海洋环境预报中心全球业务化海洋学预报系统(Chinese Global operational Oceanography Forecasting System,CGOFS)黄东海再分析数据和CFS(Climate Forecast System products)预报数据,结合国家卫星海洋应用中心黄海绿潮遥感资料,选取浒苔灾害在时空动态演变过程方面存在明显差异的2016年和2019年,开展了黄海浒苔漂移输运和生长消亡过程的数值模拟,进行敏感实验和年度预测检验。结果表明,该模型可以有效刻画2016年黄海浒苔发展趋势的显著特征,对浒苔的漂移路径、影响范围和相对生物量变化特征的数值模拟结果与监测实况较为吻合。在2019年的年度预测应用上,针对浒苔漂移输运路径的方向、影响海域的时间、生物量较往年的变化等方面,模拟效果也都比较理想,体现出该模型在实际业务化预报应用中的可靠性和有效性。 相似文献
19.
Wind-induced drift of objects at sea: The leeway field method 总被引：3，自引：0，他引：3
Øyvind Breivik Arthur A. AllenChristophe Maisondieu Jens Christian Roth 《Applied Ocean Research》2011,33(2):100-109
A method for conducting leeway field experiments to establish the drift properties of small objects (0.1-25 m) is described. The objective is to define a standardized and unambiguous procedure for condensing the drift properties down to a set of coefficients that may be incorporated into existing stochastic trajectory forecast models for drifting objects of concern to search and rescue operations and other activities involving vessels lost at sea such as containers with hazardous material.An operational definition of the slip or wind and wave-induced motion of a drifting object relative to the ambient current is proposed. This definition taken together with a strict adherence to a 10 m wind speed allows us to refer unambiguously to the leeway of a drifting object. We recommend that all objects if possible be studied using what we term the direct method, where the object’s leeway is studied directly using an attached current meter.We establish a minimum set of parameters that should be estimated for a drifting object for it to be included in the operational forecast models used for prediction of search areas for drifting objects.We divide drifting objects into four categories, depending on their size. For the smaller objects (less than 0.5 m), an indirect method of measuring the object’s motion relative to the ambient current must be used. For larger objects, direct measurement of the motion through the near-surface water masses is strongly recommended. Larger objects are categorized according to the ability to attach current meters and wind monitoring systems to them.The leeway field method proposed here is illustrated with results from field work where three objects were studied in their distress configuration; a 1:3.3 sized model of a 40-foot Shipping container, a World War II mine and a 220 l (55-gallon) oil drum. 相似文献
20.
研究核电站附近海域漂流海藻的漂流路径对保障核电站冷源安全具有重要意义。本研究根据辽东湾东部海域漂流海藻的分布特征,构建该海域的二维水动力和粒子追踪数值预测、预报模型,基于近年实际观测的海流和潮位数据,对水动力模型进行验证,并根据2019年5月至8月释放北斗和GPS浮标采集数据,对该海域相同工况下的海藻漂移路径进行校验,均吻合良好。同时,对该海域7月大潮期,取水口附近海域的海藻堵塞风险进行了模拟分析,得到各不同工况下,漂流海藻到达取水口定义威胁区范围内的时间。结果表明,该数值模型能够对漂流海藻的漂移路径进行准确模拟,可为科学规避或有效减轻漂流海藻对核电站冷源取水口的堵塞风险提供技术支撑。 相似文献