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Development of in-situ Marine Sediment Geo-Acoustic Measurement System with Real-Time and Multi Frequencies (the Second Generation) 认领 引用 被引量：9
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作者 陶春辉 邓显明 +6 位作者 李红星 周建平 金肖兵 傅顺声 Wlkens R. H 顾春华 何拥华 《China Ocean Engineering》 SCIE EI 2009年第4期769-778,共10页
Compared with the laboratory acoustic measurement of sediment samples, the in-situ acoustic measurement in marine sediment is considered more accurate and rehable, because it covers all of the surrounding environment ... Compared with the laboratory acoustic measurement of sediment samples, the in-situ acoustic measurement in marine sediment is considered more accurate and rehable, because it covers all of the surrounding environment factors and avoids the disturbance during the course of sampling and transporting of sediment samples. A new multi-frequency in-situ geoacoustic measurement system （MFIS^AMS） has been developed. The system can provide acoustic vdocity （compressional wave） and attenuation profiles of the uppermost 4 - 8 m sediment in the seafloor. It consists of 8 channels with 12 frequencies （multi-frequencies） and 0.5 - 2 MHz sampling rates. The data collected can be transmiuted in real-time. Associated with inclinometer and altimeter, it can provide the data for depth emendation. Acoustic velocity and attenuation data have been obtained from two in-situ experiments conducted in the Hangzhou Bay. 展开更多
关键词 marine sediment in-situ acoustic measurement acoustic velocity and attenuation
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Oceanic pycnocline depth retrieval from SAR imagery in the existence of solitary internal waves 认领 引用 被引量：7
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作者 YANG Jingsong HUANG Weigen +2 位作者 XIAO Qingmei ZHOU Chenghu HSU Mingkuang 《Acta Oceanologica Sinica》 SCIE CAS 2005年第5期46-49,共4页
Oceanic pycnocline depth is usually inferred from in situ measurements. It is attempted to estimate the depth remotely. As solitary internal waves occur on oceanic pycnocline and propagate along it, it is possible to ... Oceanic pycnocline depth is usually inferred from in situ measurements. It is attempted to estimate the depth remotely. As solitary internal waves occur on oceanic pycnocline and propagate along it, it is possible to retrieve the depth indirectly in virtue of the solitary internal waves. A numerical model is presented for retrieving the pycnocline depth from synthetic aperture radar （SAR） images where the solitary internal waves are visible and when ocean waters are fully stratified. This numerical model is constructed by combining the solitary internal wave model and a two-layer ocean model. It is also assumed that the observed groups of solitary internal wave packets on the SAR imagery are generated by local semidiurnal tides. A case study in the East China Sea shows a good agreement with in situ CTD （conductivity-temperature-depth） data. 展开更多
关键词 SAR pycnocline depth solitary internal waves
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A new algorithm for reconstructing the three-dimensional flow field of the oceanic mesoscale eddy 认领 引用
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作者 Chao Yan Jing Feng +1 位作者 Ping-Lv Yang Si-Xun Huang 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第12期175-181,共7页
A new algorithm for reconstructing the three-dimensional flow field of the oceanic mesoscale eddies is proposed in this paper,based on variational method.Firstly,with the numerical differentiation Tikhonov regularizer... A new algorithm for reconstructing the three-dimensional flow field of the oceanic mesoscale eddies is proposed in this paper,based on variational method.Firstly,with the numerical differentiation Tikhonov regularizer,we reconstruct the continuous horizontal flow field on discrete grid points at each layer in the oceanic region,in terms of the horizontal flow field observations.Secondly,benefitting from the variational optimization analysis and its improvement,we reconstruct a three-dimensional flow field under the constraint of the horizontal flow and the vertical flow.The results of simulation experiments validate that the relative error of the new algorithm is lower than that of the finite difference method in the case of high grid resolution,which still holds in the case of unknown observational errors or in the absence of vertical velocity boundary conditions.Finally,using the reanalysis horizontal data sourcing from SODA and the proposed algorithm,we reconstruct three-dimensional flow field structure for the real oceanic mesoscale eddy. 展开更多
关键词 mesoscale eddy numerical differentiation Tikhonov regularization variational optimization analysis
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An analytical study on the second-order resonance system of tide in an ideal partially-enclosed bay 认领 引用
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作者 WONG Lai Ah DONG Lixian +1 位作者 CHEN Jay Chung SU Jilan 《Acta Oceanologica Sinica》 SCIE CAS 2005年第5期1-13,共13页
In the numerical studies of a real tide M4 resonance system, the Xiangshan Port which is a partially-closed bay, Dong et al. [1999. Acta Oceanologica Sinica, 21 （3）： 1-6] found the interesting phenomenon that the a... In the numerical studies of a real tide M4 resonance system, the Xiangshan Port which is a partially-closed bay, Dong et al. [1999. Acta Oceanologica Sinica, 21 （3）： 1-6] found the interesting phenomenon that the advection plays an important role in inhibiting the growth of the amplitude of the tidal second-order resonance response （M4）. This result is contrary to the general traditional ideas for a non-resonance system. How this phenomenon is interpreted and what internal mechanism is behind the phenomenon are the main focuses of this study. The followings are examined： （1） the dynamic features of a second-order resonance system of tide; （2） the dominating factors on the second-order resonance responses; （3） the effects of both the friction and the advection on the second-order resonance responses; and （4） their roles in dominating the second-order resonance response and internal mechanisms by using the analytical methods. The respective results show that： （1） Both the bottom friction and the advection play significant roles in dominating the magnitude of the amplitude of the second-order resonance responses; （2） the effect of the friction on the second-order resonance response depends on the distribution ratio of the work-done of the system to friction force exhausted into between the damping of the first-order system and the inner excitation of the second-order system; （3） the advection plays a positive role in increasing the amplitude of the second-order non-resonance response in the second order non-resonance of tide; （4） in a second-order resonance system of tide, the effect of the advection may be either to increase or to decrease the amplitudes of the second-order resonance responses of tide, which depends on the distribution ratio mentioned above. 展开更多
关键词 tide second-order resonance advection
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An upper ocean response to Typhoon Bolaven analyzed with Argo profiling floats 认领 引用 被引量：25
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作者 LIU Zenghong XU Jianping +1 位作者 SUN Chaohui WU Xiaofen 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第11期90-101,共12页
In situ observations from Argo profiling floats combined with satellite retrieved SST and rain rate are used to investigate an upper ocean response to Typhoon Bolaven from 20 through 29 August 2012. After the passage ... In situ observations from Argo profiling floats combined with satellite retrieved SST and rain rate are used to investigate an upper ocean response to Typhoon Bolaven from 20 through 29 August 2012. After the passage of Typhoon Bolaven, the deepening of mixed layer depth（MLD）, and the cooling of mixed layer temperature（MLT） were observed. The changes in mixed layer salinity（MLS） showed an equivalent number of increasing and decreasing because the typhoon-induced salinity changes in the mixed layer were influenced by precipitation, evaporation, turbulent mixing and upwelling of thermocline water. The deepening of the MLD and the cooling of the MLT indicated a significant rightward bias, whereas the MLS was freshened to the left side of the typhoon track and increased on the other side. Intensive temperature and salinity profiles observed by Iridium floats make it possible to view response processes in the upper ocean after the passage of a typhoon. The cooling in the near-surface and the warming in the subsurface were observed by two Iridium floats located to the left side of the cyclonic track during the development stage of the storm, beyond the radius of maximum winds relative to the typhoon center. Water salinity increases at the base of the mixed layer and the top of the thermocline were the most obvious change observed by those two floats. On the right side of the track and near the typhoon center when the typhoon was intensified, the significant cooling from sea surface to a depth of 200×10^4 Pa, with the exception of the water at the top of the thermocline, was observed by the other Iridium float. Owing to the enhanced upwelling near the typhoon center, the water salinity in the near-surface increased noticeably. The heat pumping from the mixed layer into the thermocline induced by downwelling and the upwelling induced by the positive wind stress curl are the main causes for the different temperature and salinity variations on the different sides of the track. It seems that more time is required for the anomalies in the subsurface to be restored to pretyphoon conditions than for the anomalies in the mixed layer. 展开更多
关键词 Typhoon Bolaven Argo profiling floats upper ocean response ocean heat content
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Distribution characteristics of seamount cobalt-rich ferromanganese crusts and the determination of the size of areas for exploration and exploitation 认领 引用 被引量：18
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作者 HE Gaowen MA Weilin +5 位作者 SONG Chengbing YANG Shengxiong ZHU Benduo YAO Huiqiang JIANG Xunxiong CHENG Yongshou 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2011年第3期63-75,共13页
In 2001, the International Seabed Authority （ISBA） initiated the consideration relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferromanganese Crust... In 2001, the International Seabed Authority （ISBA） initiated the consideration relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferromanganese Crusts in the Area at its 7th session. Since then, the consideration of the Regulations has been mainly focused on the size of areas to be allocated for exploration and exploitation of the crusts. This paper, based on the investigation data and the analysis of the distribution characteristics of the crusts, suggests a model for determining the size of areas for exploration and exploitation of the crusts, taking into account various factors such as production scale, crust thickness and grade, mineable area proportion, recovery efficiency, exploration venture, and so on. Through the modeling, the paper suggests that the exploration area （the area covered by each application for approval of a plan of work for exploration of cobalt-rich crusts） shall be 4 856 km2 and the exploitation area （the mine site area） shall be 1 214 km2, for 20 years of 1 million wet tonnes annual production. 展开更多
关键词 cobalt-rich ferromanganese crusts exploration and exploitation area seamounts regulation on exploration
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Crustal Structure across the Northwestern Margin of South China Sea:Evidence for Magma-poor Rifting from a Wide-angle Seismic Profile 认领 引用 被引量：17
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作者 DING Weiwei Michael SCHNABEL +2 位作者 Dieter FRANKE RUAN Aiguo WU Zhenli 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2012年第4期854-866,共13页
We present results from a 484 km wide-angle seismic profilie acquired in the northwest part of the South China Sea （SCS） during OBS2006 cruise. The line that runs along a previously acquired multi-channel seismic li... We present results from a 484 km wide-angle seismic profilie acquired in the northwest part of the South China Sea （SCS） during OBS2006 cruise. The line that runs along a previously acquired multi-channel seismic line （SO49-18） crosses the continental slope of the northern margin, the Northwest Subbasin （NWSB） of the South China Sea, the Zhongsha Massif and partly the oceanic basin of the South China Sea. Seismic sections recorded on 13 ocean-bottom seismometers were used to identify refracted phases from the crustal layer and also reflected phases from the crust-mantle boundary （Moho）. Inversion of the traveltimes using a simple start model reveals crustal images in the study area. The velocity model shows that crustal thickness below the continental slope is between 14 and 23 kin. The continental part of the line is characterized by gentle landward mantle uplift and an abrupt oeeanward one. The velocities in the lower crust do not exceed 6.9 km/s. With the new data we can exclude a high-velocity lower crustal body （velocities above 7.0 kin/s） at the location of the line. We conclude that this part of the South China Sea margin developed by a magma-poor rifting. Both, the NWSB and the Southwest Sub-basin （SWSB） reveal velocities typical for oceanic crust with crustal thickness between 5 and 7 kin. The Zhongsha Massif in between is extremely stretched with only 6-10 km continental crust left. Crustal velocity is below 6.5 kin/s; possibly indicating the absence of the lower crust. Multi-channel seismic profile shows that the Yitongansha Uplift in the slope area and the Zhongsha Massif are only mildly deformed. We considered them as rigid continent blocks which acted as rift shoulders of the main rift subsequently resulting in the formation of the Northwest Sub-basin. The extension was mainly accommodated by a ductile lower crustal flows, which might have been extremely attenuated and flow into the oceanic basin during the spreading stage. We compared the crustal structures along the northern margin and found an east-west thicken trend of the crust below the continent slope. This might be contributed by the east-west sea-floor spreading along the continental margin. 展开更多
关键词 P-wave velocity model magma-poor rifting lower crust flow South China Sea
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The formation and tectonic evolution of Philippine Sea Plate and KPR 认领 引用 被引量：13
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作者 FANG Yinxia LI Jiabiao +2 位作者 LI Mingbi DING Weiwei ZHANG Jie 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2011年第4期75-88,共14页
The Philippine Sea Plate has an extremely special tectonic background.As an oceanic plate,it is almost entirely surrounded by subduction zones with complex internal tectonic features.On the basis of enormous published... The Philippine Sea Plate has an extremely special tectonic background.As an oceanic plate,it is almost entirely surrounded by subduction zones with complex internal tectonic features.On the basis of enormous published literature,this paper offers a comprehensive overview of the tectonic and evolution history of the Philippine Basin and the Kyushu-Palau Ridge(KPR)in the Philippine Sea Plate,and discusses the geological features of KPR.Referring to relevant definitions of various"ridges"stipulated in United Nations Convention on the Law of the Sea,so the KPR is believed to be a remnant arc formed during the opening of the Parece Vela and Shikoku Basins in the Philippine Sea Plate.It is a submarine ridge on oceanic plate rather than a submarine elevation.And thus,it is not a natural component of the Japan continental margin. 展开更多
关键词 Philippine Sea Plate West Philippine Basin KPR submarine ridge
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Seasonal Variations of Net-Phytoplankton Community Structure in the Southern Yellow Sea 认领 引用 被引量：12
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作者 GAO Yu JIANG Zhibing +3 位作者 LIU Jingjing CHEN Quanzhen ZENG Jiangning HUANG Wei 《Journal of Ocean University of China》 SCIE CAS 2013年第4期557-567,共11页
Based on the field survey data of four cruises in 2011,all phytoplankton communities in the southern Yellow Sea (SYS) were investigated for the species composition,dominant species,abundance and diversity indices.A to... Based on the field survey data of four cruises in 2011,all phytoplankton communities in the southern Yellow Sea (SYS) were investigated for the species composition,dominant species,abundance and diversity indices.A total of 379 species belonging to9 phyla were identified,of which the most abundant group was Bacillariophyta (60.9%) ,followed by Pyrrophyta (23.7%) and Haptophyta (6.9%) .The seasonal distribution of abundance was:summer (4137.1×103ind m 3) >spring (3940.4×103ind m 3) >winter (3010.6×103ind m 3) >autumn (340.8×103ind m 3) ,while the horizontal distribution showed a decreasing tendency from inshore to offshore regions.The dominant species of phytoplankton varied in different seasons.The dominant species were Thalassiosira pacifica,Skeletoema spp.and Chaetoceros cinctus in spring,Chaetoceros debbilis,Chaetoceros pseudocurvisetus and Chaetoceros curvisetus in summer,Thalassiosira curviseriata,Alexandrium catenella and Ceratium fusus in autumn,Paralia sulcata,Phaeocystis sp.and Bacillaria paradoxa in winter,respectively.In SYS,the group of temperate coastal species was the major ecotype,and the groups of the central SYS species and oceanic species were also important constituents.The average values of Shannon-Weaver diversity index (H’) and Pielou evenness index (J) were 2.37 and 0.65 respectively.The indices H’and J in the open sea were higher than those in coastal waters.Obvious co-variation tendencies between H’and J were observed in all but the summer cruise of this survey. 展开更多
关键词 phytoplankton community structure diversity temperature salinity Southern Yellow Sea
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Petrophysical characteristics of rocks and sulfides from the SWIR hydrothermal field 认领 引用 被引量：8
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作者 TAO Chunhui WU Tao +3 位作者 JIN Xiaobing DOU Bingjun LI Huaiming ZHOU Jianping 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第12期118-125,共8页
Study of petrophysical properties of rocks in seafioor hydrothermal fields has great significance for inves- tigation of seafloor hydrothermal activities, especially for polymetallic sulfides prospecting. In the prese... Study of petrophysical properties of rocks in seafioor hydrothermal fields has great significance for inves- tigation of seafloor hydrothermal activities, especially for polymetallic sulfides prospecting. In the present study, based on the current experimental conditions, we conducted systematic experiments to measure the magnetic susceptibility, electrical resistivity, porosity, density, as well as acoustic wave velocity of seafloor rocks and sulfides. Subsequently, we measured the physical characteristics of hydrothermal sulfides, basalts and peridotites which were collected from newly discovered seafloor hydrothermal fields at 49.6°E, 50.5°E, 5 1°E, 63.5°E, and 63.9°E of the Southwest Indian Ridge （SWIR）. Previously available and newly collected data were combined to characterize the physical differences between polymetallic sulfides and rocks. We also discussed the impact of hydrothermal alteration on the bedrock and demonstrated how these petrophysical properties of rocks can help in geophysical prospecting of seafloor hydrothermal fields as indicators. 展开更多
关键词 SWIR rock polymetallic sulfides physical properties hydrothermal alteration
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An effective method for improving the accuracy of Argo objective analysis 认领 引用 被引量：16
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作者 ZHANG Chunling XU Jianping +1 位作者 BAO Xianwen WANG Zhenfeng 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第7期66-77,共12页
Based on the optimal interpolation objective analysis of the Argo data, improvements are made to the em- pirical formula of a background error covariance matrix widely used in data assimilation and objective anal- ysi... Based on the optimal interpolation objective analysis of the Argo data, improvements are made to the em- pirical formula of a background error covariance matrix widely used in data assimilation and objective anal- ysis systems. Specifically, an estimation of correlation scales that can improve effectively the accuracy of Ar- go objective analysis has been developed. This method can automatically adapt to the gradient change of a variable and is referred to as ＂gradient-dependent correlation scale method＂. Its effect on the Argo objective analysis is verified theoretically with Gaussian pulse and spectrum analysis. The results of one-dimensional simulation experiment show that the gradient-dependent correlation scales can improve the adaptability of the objective analysis system, making it possible for the analysis scheme to fully absorb the shortwave information of observation in areas with larger oceanographic gradients. The new scheme is applied to the Argo data obiective analysis system in the Pacific Ocean. The results are obviously improved. 展开更多
关键词 gradient-dependent correlation scale background error covariance optimal interpolation,spectrum analysis Argo data
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Sedimentary records of eutrophication in the Changjiang Estuary upwelling area over last 100 a 认领 引用 被引量：13
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作者 FENG Xuwen JING Xianglong +3 位作者 YU Xiaoguo LI Hongliang CHEN Jianfang QIAN Jiangchu 《Acta Oceanologica Sinica》 SCIE CAS 2008年第6期49-61,共13页
The upwelling area in the Changjiang Estuary was selected to collect the core, where the red tide occurred frequently and hypoxic existed. The total organic carbon （TOC）, total nitrogen （TN）, biogenic silica （BSi... The upwelling area in the Changjiang Estuary was selected to collect the core, where the red tide occurred frequently and hypoxic existed. The total organic carbon （TOC）, total nitrogen （TN）, biogenic silica （BSi） and stable organic carbon isotopic ratios（δ13 Corg） were determined on the 210pb-dated sediment core. The concentrations of TOC, TN, BSi as well as their sedimentation fluxes have in- creased to some extent since the 1970s. TOC and TN fluxes increased about 45%, 36% respectively. The average δ13 Coorg value in the core was -23.67 ×10^-3 which remained nearly constant before the 20 century. The δ13 Corg values increased after the 1900s, two marked increases were observed from the 1950s and the 1970s. A simple δ13 Cors model was used to estimate the contribution of terrigenous and marine organic matter inputs for the sediment, which indicated the increase in accumulation since the 1970s has been almost exclusively marine. The increasing of marine organic matter accumulation （TOC, TN and BSi） was corresponding with the increasing of fertilizer consumption and the NO3-N budgets from the Changjiang River. The riverine runoff of fertilizers and nutrients stimulated the algae blooming. Enhanced primary production resulted in an enrichment of organic matter in the sediment. These data support the hypothesis that anthropogenic nutrient loading has been a significant factor on the eutrophication in the Changjiang Estuary. 展开更多
关键词 Changjiang Estuary total organic carbon total nitrogen biogenic silica stable carbon isotopes eutrophication
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First observation of Karlodinium venef icum from the East China Sea and the coastal waters of Germany 认领 引用 被引量：7
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作者 WANG Hongxia LU Douding +3 位作者 HUANG Haiyan GOBEL Jeaaette DAI Xinfeng XIA Ping 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2011年第6期112-121,共10页
Harmful algal blooms often occurred in the East China Sea （ECS） and the German coastal waters of the North Sea but Karlodinium veneficum had not been taxonomically reported. Two strains of Karlodinium （LAMB090611 a... Harmful algal blooms often occurred in the East China Sea （ECS） and the German coastal waters of the North Sea but Karlodinium veneficum had not been taxonomically reported. Two strains of Karlodinium （LAMB090611 and LAMB010601） were isolated from the two areas in 2009. The morphological characteristics and molecular phylogeny of two strains are compared on the basis of observation of a light microscope, a scanning electron microscope （SEM）, a laser scanning micro-scope （LSM） and an internal transcribed spacer （ITS） sequence data. The mean cell length of strain LAMB090611 is （14.2 ± 1.8） μm （range 11.1–18.7 μm） and mean width is （10.8 ± 1.5） μm （range 8.2– 14.7 μm）. The mean cell length of strain LAMB010601 is （15.1 ± 1.2） μm （range 12.7–17.9 μm） and the mean width is （11.4 ± 1.1） μm （range 9.1–14.7 μm）, respectively. The two strains are similar in morphological characteristics, including a straight apical groove, distinct ventral pore, sulcal extension, cingulum displacement, two or four irregular shaped chloroplasts within the cell and almost equal sized epicone and hypocone. The large and round nucleus is located at the center or at the hypocone of the cell. The sequence length of the ECS strain LAMB090611 and the German strain LAMB010601 is 640 and 646 bp, respectively. The GC content is 49%. The nucleotide similarity of the two strains is 98.1%. The sequence divergence is 0.003. Both strains are confirmed as Karlo-dinium veneficum （D. Ballantine） J. Larsen and this is the first taxonomic report from China and Germany coastal waters. The population dynamics of this toxic species in the ECS and German coastal waters needs to be investigated in the near future. 展开更多
关键词 Karlodinium veneficum East China Sea morphological characteristic scanning electron microscope internal transcribed spacer phylogeny
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Practical implementation of Hilbert-Huang Transform algorithm 认领 引用 被引量：52
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作者 黄大吉 赵进平 苏纪兰 《Acta Oceanologica Sinica》 SCIE CAS 2003年第1期1-14,共14页
Hilbert-Huang Transform (HHT) is a newly developed powerful method for nonlinear and non-stationary time series analysis. The empirical mode decomposition is the key part of HHT, while its algorithm was protected by N... Hilbert-Huang Transform (HHT) is a newly developed powerful method for nonlinear and non-stationary time series analysis. The empirical mode decomposition is the key part of HHT, while its algorithm was protected by NASA as a US patent, which limits the wide application among the scientific community. Two approaches, mirror periodic and extrema extending methods, have been developed for handling the end effects of empirical mode decomposition. The implementation of the HHT is realized in detail to widen the application. The detailed comparison of the results from two methods with that from Huang et al. (1998, 1999), and the comparison between two methods are presented. Generally, both methods reproduce faithful results as those of Huang et al. For mirror periodic method (MPM), the data are extended once forever. Ideally, it is a way for handling the end effects of the HHT, especially for the signal that has symmetric waveform. The extrema extending method (EEM) behaves as good as MPM, and it is better than MPM for the signal that has strong asymmetric waveform. However, it has to perform extrema envelope extending in every shifting process. 展开更多
关键词 Hilbert-Huang Transform (HHT) signal processing Empirical Mode Decomposition (EMD)
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Response of winter cohort abundance of Japanese common squid Todarodes pacificus to the ENSO events 认领 引用 被引量：9
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作者 YU Wei ZHANG Yang +2 位作者 CHEN Xinjun YI Qian QIAN Weiguo 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2018年第6期61-71,共11页
The Japanese common squid Todarodes pacificus is an economically important species with one year lifespan,which is significantly influenced by climatic and environmental variability. According to the fishery data of t... The Japanese common squid Todarodes pacificus is an economically important species with one year lifespan,which is significantly influenced by climatic and environmental variability. According to the fishery data of the winter cohort of T. pacificus from 2003 to 2012, as well as environmental data and the Oceanic Ni？o index（ONI,which was defined by the sea surface temperature（SST） anomaly in the Ni？o 3.4 region）, variations in the SST,chlorophyll a（Chl a） concentration, suitable spawning area（SSA） and sea surface height anomaly（SSHA） on the spawning ground of T. pacificus were examined under the El Ni？o and La Nina conditions. Their influences on squid abundance（defined by catch per unit effort, CPUE） were further assessed. The results showed that seasonal changes were found in SST, Chl a and SSA on the spawning ground of T. pacificus. Correlation analysis suggested that annual CPUE was significantly positively correlated with Chl a and SSA（p〈0.05）, but had insignificant relationship with SST（p〉0.05）. Moreover, the El Ni？o and La Ni？a events tended to dominate the changes of SSA and Chl a concentration in the key area between 25°–29°N and 122.5°–130.5°E, driving the variability of squid abundance. However, this influence varied with the intensity of each anomalous climatic event： the weak El Ni？o event occurred, the spawning ground was occupied by waters with enlarged SSA but with extremely low Chl a concentration, leading to low squid recruitment, the CPUE then decreased; the moderate intensity of El Ni？o event resulted in shrunk SSA but with high Chl a concentration on the spawning ground, the squid recruitment and CPUE increased; the moderate intensity of La Ni？a events yielded elevated SSA and high Chl a concentration on the spawning ground, the squid recruitment and CPUE dramatically increased. Our findings suggested that the ENSO events played crucial effects on the incubating and feeding conditions of the winter cohort of T. pacificus during the spawning season and ultimately affected its abundance. 展开更多
关键词 Todarodes pacificus squid abundance spawning ground El Nino La Nina
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Composition of algal pigments in surface freshen layer after ice melt in the central Arctic 认领 引用 被引量：7
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作者 ZHUANG Yanpei JIN Haiyan +5 位作者 GU Fan ZHANG Yang BAI Youcheng JI Zhongqiang LU Yong CHEN lianfang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第8期122-130,共9页
Seasonal meltwater input creates a thin freshen layer in surface seawater under ice, which largely shifts the algae assemblages. Our recent observation of photosynthetic pigments in the high Arctic showed that ice bot... Seasonal meltwater input creates a thin freshen layer in surface seawater under ice, which largely shifts the algae assemblages. Our recent observation of photosynthetic pigments in the high Arctic showed that ice bottom and 5 m of seawater under ice contained relatively high concentration of fucoxanthin, while chlorophyll b and lutein were the major diagnostic pigments in ice-water interface and 0 m of seawater under ice. Additionally, a notable change of dominant phytoplankton occurred in the top 5 m of seawater under ice, from chlorophytes-dominated at surface to diatoms-dominated at 5 m depth, which might attribute to the sharp salinity gradient （salinity from 12.5 to 28.1） in the surface seawater under ice. Our results imply that phytoplankton community in surface layer under ice would become more chlorophytes in the future warming Arctic Ocean. 展开更多
关键词 the Arctic Ocean seawater under ice pigments nutrients phytoplankton community
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Calcareous Nannofossils and Molecular Fossils in Cobalt-rich Crusts and their Response to the P/E Global Event 认领 引用 被引量：6
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作者 ZHANG Haisheng ZHAO Jun +3 位作者 HAN Zhengbing LU Bing WU Guanghai PULYAEVA I.A. 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2013年第5期1264-1274,共11页
A biostratigraphic study on calcareous nannofossils from the CM3D06 Co-rich ferromanganese crust from the Magellan seamounts in the northwestern Pacific enabled estimation of depositional age.The bio-imprinting of cal... A biostratigraphic study on calcareous nannofossils from the CM3D06 Co-rich ferromanganese crust from the Magellan seamounts in the northwestern Pacific enabled estimation of depositional age.The bio-imprinting of calcareous nannofossils and other fossil species suggests six age ranges for the nannofossils:late Cretaceous,late Paleocene,(early,middle,late)Eocene,middle Miocene,late Pliocene,and Pleistocene.Gas chromatography(GC)and gas chromatography-mass spectrometry(GC-MS)were used to test the Co-rich crusts,and a variety of molecular fossils were detected,such as chloroform bituminous"A",n-alkane,isoprenoid and sterol.Peak carbon and molecular indices(such as C23-/C24+,CPI,Pr/Ph,PrC17,PhCxs and j13C)indicate that the parent organic matter is dominated by marine phytoplankton and thallogen whereas there is little input of terrestrial organic matter.Researches on calcareous nannofossils,molecular fossils and molecular organic geochemistry data reveal that the Paleocene/Eocene(P/E)global event is recorded in the cobalt-rich crusts from the northwestern Pacific Ocean.A succession of biomes can be observed near the 85 mm boundary(about 55 Ma),i.e.,the disappearance of the late Cretaceous Watznaueria barnesae and Zigodicus spiralis,and Broisonia parka microbiotas above the P/E boundary,and the bloom of Coccolithus formosus,Discoaster multiradiatus,Discoaster mohleri and Discoaster sp.below the boundary.Typical parameters of molecular fossils,such as saturated hydrocarbon components and carbon-number maxima,Pr/Ph,Pr/C17,Ph/C18,distribution types of sterols,Ts/Tm ratios and bacterial hopane,also exhibit dramatic changes near the P/E boundary.These integrated results illustrate that the biome succession of calcareous nannofossils,relative content of molecular fossils and molecular indices in the cobalt-rich crusts near the 85 mm boundary faithfully record the P/E global event. 展开更多
关键词 Late Cretaceous cobalt-rich crust calcareous nannofossils molecular fossils Paleocene-Eocene boundary PETM
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Variations in organic carbon loading of surface sediments from the shelf to the slope of the Chukchi Sea,Arctic Ocean 认领 引用 被引量：6
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作者 LI Zhongqiao WANG Xinyi +3 位作者 JIN Haiyan JI Zhongqiang BAI Youcheng CHEN Jianfang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第8期131-136,共6页
The content of organic carbon （OC） normalized to the specific surface area （SSA） of sediment is widely used to trace variations in OC loading （OC/SSA）. This study presents observations of OC/SSA of surface sedim... The content of organic carbon （OC） normalized to the specific surface area （SSA） of sediment is widely used to trace variations in OC loading （OC/SSA）. This study presents observations of OC/SSA of surface sediments collected in the Chukchi Sea, a typical Arctic marginal sea. Shelf sediments exhibit much higher OC/SSA values than slope sediments in the study area. Compared with OC/SSA values reported from the East Siberian Shelf and Mackenzie River, the slope sediments possess lower OC loading. This abrupt decrease in OC/SSA is mostly related to the lower primary production on slope as well as possible oxidization processes. The results of linear regression analysis between OC and SSA indicate a sedimentary source rock for the OC in the Chukchi Sea sediments. Moreover, shelf sediments with low SSA possess a larger rock OC fraction than slope sediments do. The dataset of the present study enables a more thorough understanding of regional OC cycling in the Chukchi Sea. 展开更多
关键词 Chukchi Sea Arctic surface sediments organic carbon loading carbon cycle
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The black water around the Changjiang (Yangtze) Estuary in the spring of 2003 认领 引用 被引量：8
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作者 BAI Yan HE Xianqiang +2 位作者 PAN Delu ZHU Qiankun GONG Fang 《Acta Oceanologica Sinica》 SCIE CAS 2009年第4期23-31,共9页
The Changjiang （Yangtze） Estuary is located in the East China Sea shelf with shallow water. Affected by the tide mixing and the runoff of the Changjiang River and the Qiantang River the turbidity is very high. Gener... The Changjiang （Yangtze） Estuary is located in the East China Sea shelf with shallow water. Affected by the tide mixing and the runoff of the Changjiang River and the Qiantang River the turbidity is very high. Generally, the water-leaving radiance is high in the turbid water because of the large particle scattering. Based on the in-situ data and ocean color remote sensing data of SeaWiFS, it was found that there was a black water region with the normalized water-leaving radiances less than 0.5 mW/（cm2-μm2-sr）. The optical principle of the occurrence of this black water was analyzed by the inherent optical properties and the ocean color components. The results show that black water is caused by the relative low values of the suspended particle matter concentration and the back scattering ratio. In the black water region, the percentage of the phytoplankton absorption was relatively high, and the large size of the phytoplankton caused the low value of the particle backscattering ratio. 展开更多
关键词 Black water Changjiang Estuary Inherent optical properties Ocean color remote sensing
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Impact of the cord-grass Spartina alterniflora on sedimentary and morphological evolution of tidal salt marshes on the Jiangsu coast,China 认领 引用 被引量：19
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作者 WANG Aijun GAO Shu JIA Jianjun 《Acta Oceanologica Sinica》 SCIE CAS 2006年第4期32-42,共11页
The tidal flats of the Wanggang area, on the Jiangsu coast, represent the largest continuously distributed coastal wetland in terms of area coverage in China, and the dynamics of tidal flat accretion and erosion is hi... The tidal flats of the Wanggang area, on the Jiangsu coast, represent the largest continuously distributed coastal wetland in terms of area coverage in China, and the dynamics of tidal flat accretion and erosion is highly complicated. The cord-grass Spartina alterniflora, which was introduced artificially into the Jiangsu coast, has significant influences on the regional tidal flat evolution in terms of deposition rate, spacial sediment distribution patterns and tidal creek morphology. On the basis of the data set of bed elevation and accumulation rate for different periods of time, the applicability of the Pethick - Allen model to the Jiangsu tidal salt marshes is discussed. In addition, caesium-137 dating was carried out for sediment samples collected from the salt marsh of the Wangang area. In combination with the caesium-137 analysis and the data collected from literature, the Pethick - Allen model was used to derive the accumulation rate in the Wanggang tidal flat for the various periods. The results show that the pattern of tidal flat accretion has been modified, due to more rapid accretion following the iatroduction of S. alterniflora to the region. Surficial sediment samples were collected from representative profiles and analyzed for grain size with a laser particle analyzer. The result shows that fine-grained sediment has been trapped by the plant, with most of the sediment deposited on the Suaeda salsa and Spartina angelica flats being derived from drainage creeks rather than the from gently sloping tidal flats. Remote sensing analysis and in situ observations indicate that the creeks formed in the S. alterniflora flat have a relatively small ratio of width to depth, a relatively high density, and are more stable than the other tidal flat creek systems in the study area. 展开更多
关键词 Spartina alterniflora tidal flat sedimentation morphological evolution Jiangsu coast
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