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Numerical simulation and preliminary analysis of typhoon waves during three typhoons in the Yellow Sea and East China Sea 预览
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作者 WANG Ning HOU Yijun +1 位作者 LI Shuiqing LI Rui 《海洋湖沼学报(英文)》 CSCD 2019年第6期1805-1816,共12页
In this study,typhoon waves generated during three typhoons(Damrey(1210),Fung-wong(1416),and Chan-hom(1509))in the Yellow Sea and East China Sea were simulated in a simulating waves nearshore(SWAN)model,and the wind f... In this study,typhoon waves generated during three typhoons(Damrey(1210),Fung-wong(1416),and Chan-hom(1509))in the Yellow Sea and East China Sea were simulated in a simulating waves nearshore(SWAN)model,and the wind forcing was constructed by combining reanalyzed wind data with a Holland typhoon wind model.Various parameters,such as the Holland fitting parameter(B)and the maximum wind radius?,were investigated in sensitivity experiments in the Holland model that affect the wind field construction.Six different formulations were considered and the parameters determined by comparing the simulated wind results with in-situ wind measurements.The key factors affecting wave growth and dissipation processes from deep to shallow waters were studied,including wind input,whitecapping,and bottom friction.Comparison with in-situ wave measurements suggested that the KOMEN scheme(wind input exponential growth and whitecapping energy dissipation)and the JONSWAP scheme(dissipation of bottom friction)resulted in good reproduction of the significant wave height of typhoon waves.A preliminary analysis of the wave characteristics in terms of wind-sea and swell wave revealed that swell waves dominated with the distance of R to the eye of the typhoon,while wind-sea prevailed in the outer region up to six to eight times the R values despite a clear misalignment between wind and waves.The results support the hypothesis that nonlinear wave-wave interactions may play a key role in the formation of wave characteristics. 展开更多
关键词 HOLLAND simulating WAVES nearshore(SWAN) typhoon WAVES Yellow SEA East China SEA wind-sea SWELL
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Trends of sea surface temperature and sea surface temperature fronts in the South China Sea during 2003–2017 预览
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作者 Yi Yu Hao-Ran Zhang +1 位作者 Jiangbo Jin Yuntao Wang 《海洋学报:英文版》 SCIE CAS CSCD 2019年第4期106-115,共10页
The trends of the sea surface temperature(SST)and SST fronts in the South China Sea(SCS)are analyzed during 2003–2017 using high-resolution satellite data.The linear trend of the basin averaged SST is 0.31℃per decad... The trends of the sea surface temperature(SST)and SST fronts in the South China Sea(SCS)are analyzed during 2003–2017 using high-resolution satellite data.The linear trend of the basin averaged SST is 0.31℃per decade,with the strongest warming identified in southeastern Vietnam.Although the rate of warming is comparable in summer and winter for the entire basin,the corresponding spatial patterns of the linear trend are substantially different between them.The SST trend to the west of the Luzon Strait is characterized by rapid warming in summer,exceeding approximately 0.6℃per decade,but the trend is insignificant in winter.The strongest warming trend occurs in the southeast of Vietnam in winter,with much less pronounced warming in summer.A positive trend of SST fronts is identified for the coast of China and is associated with increasing wind stress.The increasing trend of SST fronts is also found in the east of Vietnam.Large-scale circulation,such as El Nino,can influence the trends of the SST and SST fronts.A significant correlation is found between the SST anomaly and Nino3.4 index,and the ENSO signal leads by eight months.The basin averaged SST linear trends increase after the El Nino event(2009–2010),which is,at least,due to the rapid warming rate causing by the enhanced northeasterly wind.Peaks of positive anomalous SST and negatively anomalous SST fronts are found to co-occur with the strong El Nino events. 展开更多
关键词 South China SEA SEA SURFACE TEMPERATURE SEA SURFACE TEMPERATURE FRONTS WARMING trend wind stress
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Linking Monsoon Activity with River-Derived Sediments Deposition in the Northern South China Sea 预览
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作者 GE Qian XU Dong +2 位作者 YE Liming YANG Kehong YAO Zhigang 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第5期1098-1104,共7页
The history of the East Asian monsoon(EAM)since Last Glacial Maximum is reconstructed based on records in a sediment core retrieved from the northern South China Sea.The provenance of organic carbon and the EAM’s evo... The history of the East Asian monsoon(EAM)since Last Glacial Maximum is reconstructed based on records in a sediment core retrieved from the northern South China Sea.The provenance of organic carbon and the EAM’s evolution are investigated using combined organic carbon,grain size,and AMS 14 C dating analysis.Responding to the strong winter monsoon,the marine organic matter was dominated in the sediments,andδ13 C of organic matter was high during the last glacial period.During the Holocene,the primary productivity decreased and the dilution effect of riverine inorganic clastics strengthened.Accordingly,the total organic carbon contents andδ13 C values decreased,and terrestrial organic matter content increased in the core sediments.The 4μm grain size fraction,as the environmental sensitive grain size component,is determined to reconstruct the paleoclimatic records.During the last glacial period,the contents of 4μm grain size component were mainly controlled by the sea level changes.Upon the Holocene,the influence of the sea level changes weakened and the roles of current system and provenance strengthened.The correlation between the EAM and solar insolation forcing is also discussed in this paper. 展开更多
关键词 organic carbon GRAIN size SEA level current system South China SEA East Asian MONSOON
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Distribution and Sources of Organic Matter in Surface Sediments of the Northern Bering and Chukchi Seas by Using Bulk and Tetraether Proxies 预览
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作者 JI Zhongqiang JIN Haiyan +5 位作者 STEIN Ruediger LI Zhongqiao BAI Youcheng LI Hongliang ZHANG Yang CHEN Jianfang 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第3期563-572,共10页
The organic matter (OM) preserved in Arctic Ocean sediments is of great importance to the global carbon budget. How-ever, works that apply multiple proxies to determine the distribution and concentration of organic ca... The organic matter (OM) preserved in Arctic Ocean sediments is of great importance to the global carbon budget. How-ever, works that apply multiple proxies to determine the distribution and concentration of organic carbon (OC) in the surface sedi-ments of the northern Bering and Chukchi Seas remain limited. Here a multiproxy approach based on bulk OM parameters and the branched vs. isoprenoid tetraether (BIT) index was used to investigate the distribution and sources of OM in the surface sediments of the northern Bering and Chukchi Seas. Binary and ternary mixing models were applied to trace the contribution of different OC sources to the total OC in the study area. The δ13C values of the sediments provided by the binary model showed that the proportion of terrestrial OC fell in the range of 27.4%–79.8% (46.2% on average). The BIT index returned the lowest fraction (4.8%–27.3%, 12.0% on average). The ternary mixing model was employed to determine the plant-, soil-, and marine-derived fractions of the total OM. The ternary model showed that 11.5%±6.3%, 31.4%±9.5%, and 57.1%±12.4% of OM in the sediment of the study area was derived from soil, plants, and marine sources, respectively. The differences in OM composition between the west and east sides of the Chukchi Sea were controlled by OM inputs from key water masses (i.e., Anadyr Water and Alaska Coastal Water), river discharge, and the nutrient supply from the Pacific inflow that supports marine productivity. 展开更多
关键词 northern BERING SEA CHUKCHI SEA organic matter GDGTs BULK parameters
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Transition Periods Between Sea Ice Concentration and Sea Surface Air Temperature in the Arctic Revealed by an Abnormal Running Correlation 预览
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作者 JI Xupeng ZHAO Jinping 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第3期633-642,共10页
This study used the synthetic running correlation coefficient calculation method to calculate the running correlation coefficients between the daily sea ice concentration(SIC) and sea surface air temperature(SSAT) in ... This study used the synthetic running correlation coefficient calculation method to calculate the running correlation coefficients between the daily sea ice concentration(SIC) and sea surface air temperature(SSAT) in the Beaufort-Chukchi-East Siberian-Laptev Sea(BCEL Sea), Kara Sea and southern Chukchi Sea, with an aim to understand and measure the seasonally occurring changes in the Arctic climate system. The similarities and differences among these three regions were also discussed. There are periods in spring and autumn when the changes in SIC and SSAT are not synchronized, which is a result of the seasonally occurring variation in the climate system. These periods are referred to as transition periods. Spring transition periods can be found in all three regions, and the start and end dates of these periods have advancing trends. The multiyear average duration of the spring transition periods in the BCEL Sea, Kara Sea and southern Chukchi Sea is 74 days, 57 days and 34 days, respectively. In autumn, transition periods exist in only the southern Chukchi Sea, with a multiyear average duration of only 16 days. Moreover, in the Kara Sea, positive correlation events can be found in some years, which are caused by weather time scale processes. 展开更多
关键词 ARCTIC SEA ice CONCENTRATION SEA surface air temperature synthetic running CORRELATION coefficient transition period
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Estimating biological reference points for Largehead hairtail(Trichiurus lepturus)fishery in the Yellow Sea and Bohai Sea 预览
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作者 Yupeng Ji Qun Liu +2 位作者 Baochao Liao Qingqing Zhang Ya’nan Han 《海洋学报:英文版》 SCIE CAS CSCD 2019年第10期20-26,共7页
It is important to find a reliable method to estimate maximum sustainable yield(MSY)or total allowable catch(TAC)for fishery management,especially when the data availability is limited which is a case in China.A recen... It is important to find a reliable method to estimate maximum sustainable yield(MSY)or total allowable catch(TAC)for fishery management,especially when the data availability is limited which is a case in China.A recently developed method(CMSY)is a data-poor method,which requires only catch data,resilience and exploitation history at the first and final years of the catch data.CMSY was used in this study to estimate the biological reference points for Largehead hairtail(Trichiurus lepturus,Temminck and Schlegel)in the Yellow Sea and Bohai Sea,based on the fishery data from China Fishery Statistical Year Books during 1986 to 2012.Additionally,Bayesian state-space Schaefer surplus production model(BSM)and the classical surplus production models(Schaefer and Fox)performed by software CEDA and ASPIC,were also projected in this study to compare with the performance of CMSY.The estimated MSYs from all models are about 19.7×104–27.0×104 t,while CMSY and BSM yielded more reasonable population parameter estimates(the intrinsic population growth rate and the carrying capacity).The biological reference points of B/BMSY smaller than 1.0,while F/FMSY higher than 1.0 revealed an over-exploitation of the fishery,indicating that more conservative management strategies are required for Largehead hairtail fishery. 展开更多
关键词 CMSY surplus production models maximum sustainable yield Yellow Sea and Bohai Sea Trichiuruslepturus
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Preliminary Findings on Distribution of Bali Sardinella (Sardinella lemuru) in Relation to Oceanographic Conditions during Southeast Monsoon in Bali Strait Using Remotely Sensed Data 预览
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作者 Achmad Fachruddin Syah Nurul Setyowati Eko Susilo 《海洋科学杂志(英文)》 2019年第1期25-30,共6页
Bali sardinella (Sardinella lemuru) is the main fishing catches in Bali Strait. The distribution of S. lemuru and its preferred oceanographic condition were investigated from remotely sensed data. The objectives of th... Bali sardinella (Sardinella lemuru) is the main fishing catches in Bali Strait. The distribution of S. lemuru and its preferred oceanographic condition were investigated from remotely sensed data. The objectives of this study were to elucidate the distribution of S. lemuru and the preferred oceanographic condition of S. lemuru in Bali Strait using remotely sensed data. Sea surface temperature (SST) and sea surface chlorophyll-a (chl-a) were downloaded from ocean colour website meanwhile the fishing location generated from daily Visible Infrared Imaging Radiometer Suite (VIIRS) boat detection (VDB), downloaded from NOAA website. The results showed that at the beginning of southeast monsoon (April), most of the fishing location appeared in the north part of Bali Strait, and moved to south part of Bali Strait at the end of the southeast monsoon (September). The results also revealed that most of fishing location of S. lemuru located in SST value of 26℃– 30℃ and chl-a value of 0.3 – 0.8 mg/m3. Integration VDB data and oceanographic condition generated from remotely sensed data could form the basis for fisheries management and information system, such as S. lemuru in Bali Strait, in the future. 展开更多
关键词 Main fishing CATCHES SEA SURFACE temperature SEA SURFACE CHLOROPHYLL-A visible infrared imaging radiometer suite boat detection
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Concentration and Characterization of Colored Dissolved Organic Matter in the Surface Microlayer and Subsurface Water of the Yellow Sea and the East China Sea 预览
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作者 ZHANG Jing ZHAO Junjie +1 位作者 YANG Guipeng LIU Weifeng 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第2期383-393,共11页
The distribution and chemical properties of colored dissolved organic matter(CDOM)in the Yellow Sea and the East China Sea during December 2011-January 2012 were investigated.The input of freshwater and biological act... The distribution and chemical properties of colored dissolved organic matter(CDOM)in the Yellow Sea and the East China Sea during December 2011-January 2012 were investigated.The input of freshwater and biological activities had an evident influence on the CDOM levels(characterized by the light absorption coefficient at the wavelength of 355 nm a355)in the study area.The spatial distribution of CDOM levels displayed a gradually decreasing trend from the coastal waters(0.37m^-1)to the open sea(0.18m^-1).The spectral slope ratio(the slope ratio SR defined as S275-295:S350-400)during the cruise was correlated with salinity,and exhibited a large variation from inshore(average of 2.515)to offshore sites(average of 5.327)compared with the distribution of a355.The values of SR were related to CDOM molecular weight(MW).The a355,SR,and chlorophyll a in 37 samples collected from the surface microlayer were significantly correlated with those in the corresponding subsurface water samples,implying a strong exchange action between the microlayer and bulk water.The a355 and SR of CDOM exhibited significant microlayer enrichment,with mean enrichment factors(EFs)of 1.72 and 1.62,respectively. 展开更多
关键词 COLORED dissolved organic matter(CDOM) absorption coefficient spectral SLOPE ratio YELLOW SEA East China SEA
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Fishery biology of whitespotted conger Conger myriaster (Brevoort, 1856) in the Yellow Sea and East China Sea 预览
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作者 Xiuxia Mu Chi Zhang +3 位作者 Ying Xue Chongliang Zhang Binduo Xu Yiping Ren 《海洋学报:英文版》 SCIE CAS CSCD 2019年第6期18-24,共7页
Whitespotted conger Conger myriaster is a commercially important species in the seas around China, Korea and Japan. The coastal waters of China serve as an important feeding ground for congers, but the spatio-temporal... Whitespotted conger Conger myriaster is a commercially important species in the seas around China, Korea and Japan. The coastal waters of China serve as an important feeding ground for congers, but the spatio-temporal variations in the fishery and biological characteristics of the population have been rarely evaluated and less well understood in this area. We studied the growth, spawning and feeding characteristics of C. myriaster on the basis of samples collected from October 2016 to April 2017 in the Yellow Sea and East China Sea. A total of 529 specimens were collected, with ages ranging from 1 to 6 years and total length ranging from 132 mm to 834 mm. The parameters of von Bertalanffy growth equation L∞ and k were 1 026 mm and 0.226 a^–1, respectively;the sex ratio was 88:0 (female: male) in the East China Sea and 2.67:1 in the South Yellow Sea;the development stage of ovary ranged from peri-nucleolus stage to secondary yolk globule stage, and the testis of two males was at midmeiotic stage;Crustacean was the major prey for conger of small length, and food source shift to fish with somatic growth. The results showed substantial differences from previous studies in Japan and Korean waters, as well as from China seas in the 1980s, suggesting potential spatiotemporal changes in the biological characteristics of C. myriaster. This study may improve current understanding of the fishery biology of C. myriaster in the Yellow Sea and East China Sea. 展开更多
关键词 Conger myrisater age and growth GONAD development STOMACH CONTENTS YELLOW SEA and East China SEA
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Numerical Simulation of Bohai Oil Spill in the Winter Sea Ice Period 预览
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作者 WANG Kun DU Jing +4 位作者 LIU Ming WU Jin-hao JIANG Heng-zhi JIN Sheng SONG Lun 《中国海洋工程:英文版》 SCIE EI CSCD 2019年第2期185-197,共13页
The Bohai Sea is a seasonal icy sea area that has the lowest latitude of any sea experiencing icing in the northern hemisphere, and simulation studies on oil spills during its sea ice period are the key to analyzing w... The Bohai Sea is a seasonal icy sea area that has the lowest latitude of any sea experiencing icing in the northern hemisphere, and simulation studies on oil spills during its sea ice period are the key to analyzing winter oil spill accidents. This study applied the three-dimensional free surface to establish a high-resolution hydrodynamic model and simulate tidal distributions in the Bohai Sea. Then, the oil spill model of the open sea area and thermodynamic model were combined to establish a numerical model for the Bohai oil spill during the winter sea ice period. The hydrodynamic model and sea ice growth and melting model were verified, and the parameters were adjusted based on the measured values, which indicate that the numerical model established in this paper is of high accuracy, stability and ubiquity. Finally, after checking the calculations repeatedly, the diffusion coefficient for the Bohai Sea was determined to be 1.0×10^–7 m^2/s. It is better that the comprehensive weathering attenuation coefficient is lower than that of a non-winter oil spill, with 1.3×10^–7 m^2/s being the most appropriate coefficient. This study can provide the reliable technical support for the operational safety and reduction in losses caused by winter oil spill accidents for the petroleum industry. 展开更多
关键词 hydrodynamic MODEL SEA ICE growth and melt MODEL oil SPILL WINTER ICE PERIOD Bohai SEA
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一种具有重力补偿的串联弹性执行器接触力控制方法 预览
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作者 张婷 徐建明 董建伟 《计算机测量与控制》 2019年第9期90-94,104共6页
针对机械臂末端安装串联弹性执行器(Series Elastic Actuator,SEA)与环境或工件接触作业工况,考虑SEA端部负载对接触面压力随机械臂运动姿态变化的问题,研究一种具有重力补偿的SEA接触力控制方法;首先分析了一种基于滚珠丝杆模组的SEA与... 针对机械臂末端安装串联弹性执行器(Series Elastic Actuator,SEA)与环境或工件接触作业工况,考虑SEA端部负载对接触面压力随机械臂运动姿态变化的问题,研究一种具有重力补偿的SEA接触力控制方法;首先分析了一种基于滚珠丝杆模组的SEA与Staubli TX90 组合的力控制实验装置结构,建立了SEA与工件接触过程的动力学模型,提出了一种具有输入重力补偿的PD型SEA弹簧力控制方法,该方法在没有接触力传感器的情况下,依据机械臂关节角对SEA端部负载进行重力输入补偿,通过检测弹簧压缩变形量,计算并反馈弹簧力实现对接触力的控制;最后通过SEA与正弦面工件接触力控制实验,并对力传感器采集的接触力信号进行频谱分析,验证了所提出控制方法的有效性。 展开更多
关键词 SEA 机械臂 PD型 重力补偿 力控制
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Satellite-observed trends in the Arctic sea ice concentration for the period 1979–2016 预览
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作者 WANG Yunhe BI Haibo +5 位作者 HUANG Haijun LIU Yanxia LIU Yilin LIANG Xi FU Min ZHANG Zehua 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第1期18-37,共20页
Arctic sea ice cover has decreased dramatically over the last three decades.This study quantifi es the sea ice concentration(SIC)trends in the Arctic Ocean over the period of 1979–2016 and analyzes their spatial and ... Arctic sea ice cover has decreased dramatically over the last three decades.This study quantifi es the sea ice concentration(SIC)trends in the Arctic Ocean over the period of 1979–2016 and analyzes their spatial and temporal variations.During each month the SIC trends are negative over the Arctic Ocean,wherein the largest(smallest)rate of decline found in September(March)is-0.48%/a(-0.10%/a).The summer(-0.42%/a)and autumn(-0.31%/a)seasons show faster decrease rates than those of winter(-0.12%/a)and spring(-0.20%/a)seasons.Regional variability is large in the annual SIC trend.The largest SIC trends are observed for the Kara(-0.60%/a)and Barents Seas(-0.54%/a),followed by the Chukchi Sea(-0.48%/a),East Siberian Sea(-0.43%/a),Laptev Sea(-0.38%/a),and Beaufort Sea(-0.36%/a).The annual SIC trend for the whole Arctic Ocean is-0.26%/a over the same period.Furthermore,the infl uences and feedbacks between the SIC and three climate indexes and three climatic parameters,including the Arctic Oscillation(AO),North Atlantic Oscillation(NAO),Dipole anomaly(DA),sea surface temperature(SST),surface air temperature(SAT),and surface wind(SW),are investigated.Statistically,sea ice provides memory for the Arctic climate system so that changes in SIC driven by the climate indices(AO,NAO and DA)can be felt during the ensuing seasons.Positive SST trends can cause greater SIC reductions,which is observed in the Greenland and Barents Seas during the autumn and winter.In contrast,the removal of sea ice(i.e.,loss of the insulating layer)likely contributes to a colder sea surface(i.e.,decreased SST),as is observed in northern Barents Sea.Decreasing SIC trends can lead to an in-phase enhancement of SAT,while SAT variations seem to have a lagged infl uence on SIC trends.SW plays an important role in the modulating SIC trends in two ways:by transporting moist and warm air that melts sea ice in peripheral seas(typically evident inthe Barents Sea)and by exporting sea ice out of the Arctic Ocean via passages into the Greenland and Barents Seas, 展开更多
关键词 SEA ice concentration(SIC) Arctic Ocean SURFACE air temperature(SAT) SEA SURFACE temperature(SST) SURFACE wind(SW) INTERANNUAL and DECADAL oscillation
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branch of the Pacific to Indian Ocean throughflow at the Karimata Strait 预览
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作者 Zexun Wei Shujiang Li +8 位作者 R.Dwi Susanto Yonggang Wang Bin Fan Tengfei Xu Budi Sulistiyo T.Rameyo Adi Agus Setiawan A.Kuswardani Guohong Fang 《海洋学报:英文版》 SCIE CAS CSCD 2019年第4期1-11,共11页
Besides the Indonesian throughflow(ITF),the South China Sea throughflow(SCSTF)also contributes to the water transport from the Pacific to the Indian Ocean.However,this South China Sea(SCS)branch at the Karimata Strait... Besides the Indonesian throughflow(ITF),the South China Sea throughflow(SCSTF)also contributes to the water transport from the Pacific to the Indian Ocean.However,this South China Sea(SCS)branch at the Karimata Strait is poorly observed until 2007,even though its importance has been suggested by numerical studies for decades.In this paper,we review the nearly 10-year field measurement in the Karimata Strait by the execution of the projects of“SCS-Indonesian Seas Transport/Exchange(SITE)and Impacts on Seasonal Fish Migration”and“The Transport,Internal Waves and Mixing in the Indonesian Throughflow regions(TIMIT)and Impacts on Marine Ecosystem”,which extend the observations from the western Indonesian seas to the east to include the main channels of the ITF,is introduced.Some major achievements from these projects are summarized. 展开更多
关键词 SOUTH China SEA INDONESIAN seas INDONESIAN throughflow(ITF) Karimata STRAIT SOUTH China SEA THROUGHFLOW
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Kuroshio intrusion into the South China Sea with an anticyclonic eddy: evidence from underwater glider observation 预览
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作者 LIU Zenghong CHEN Xingrong +2 位作者 YU Jiancheng XU Dongfeng SUN Chaohui 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第5期1469-1480,共12页
In this study, high-resolution temperature and salinity data obtained from three Sea-Wing underwater gliders were used together with satellite altimeter data to track the vertical thermohaline structure of an anticycl... In this study, high-resolution temperature and salinity data obtained from three Sea-Wing underwater gliders were used together with satellite altimeter data to track the vertical thermohaline structure of an anticyclonic eddy that originated from the loop current of the Kuroshio southwest of Taiwan, China. One of the gliders crossed the entire eddy and it observed a remarkable warm anomaly of as much as 3.9℃ extending to 500 dbar from the base of the mixed layer. Conversely, a positive salinity anomaly was found to be above 200 dbar only in the anticyclonic eddy, with a maximum value of >0.5 in the mixed layer. Below the mixed layer, water of higher salinity (>34.7) was found, which could have been preserved through constrained vertical mixing within the anticyclonic eddy. The salinity in the upper layer of the anticyclonic eddy was much similar to that of the northwestern Pacific Ocean than the northern South China Sea, reflecting Kuroshio intrusion with anticyclonic eddy shedding from the loop current. 展开更多
关键词 anticyclonic EDDY South China SEA KUROSHIO Sea-Wing underwater GLIDER
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Seasonal and interannual variability of water mass sources of Indonesian throughflow in the Maluku Sea and the Halmahera Sea 预览
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作者 Lu Wang Lei Zhou +3 位作者 Lingling Xie Quanan Zheng Qiang Li Mingming Li 《海洋学报:英文版》 SCIE CAS CSCD 2019年第4期58-71,共14页
So far,large uncertainties of the Indonesian throughflow(ITF)reside in the eastern Indonesian seas,such as the Maluku Sea and the Halmahera Sea.In this study,the water sources of the Maluku Sea and the Halmahera Sea a... So far,large uncertainties of the Indonesian throughflow(ITF)reside in the eastern Indonesian seas,such as the Maluku Sea and the Halmahera Sea.In this study,the water sources of the Maluku Sea and the Halmahera Sea are diagnosed at seasonal and interannual timescales and at different vertical layers,using the state-of-the-art simulations of the Ocean General Circulation Model(OGCM)for Earth Simulator(OFES).Asian monsoon leaves clear seasonal footprints on the eastern Indonesian seas.Consequently,the subsurface waters(around 24.5σθand at~150 m)in both the Maluku Sea and the Halmahera Sea stem from the South Pacific(SP)during winter monsoon,but during summer monsoon the Maluku Sea is from the North Pacific(NP),and the Halmahera Sea is a mixture of waters originating from the NP and the SP.The monsoon impact decreases with depth,so that in the Maluku Sea,the intermediate water(around 26.8σθand at~480 m)is always from the northern Banda Sea and the Halmahera Sea water is mainly from the SP in winter and the Banda Sea in summer.The deep waters(around 27.2σθand at~1 040 m)in both seas are from the SP,with weak seasonal variability.At the interannual timescale,the subsurface water in the Maluku Sea originates from the NP/SP during El Ni?o/La Ni?a,while the subsurface water in the Halmahera Sea always originates from the SP.Similar to the seasonal variability,the intermediate water in Maluku Sea mainly comes from the Banda Sea and the Halmahera Sea always originates from the SP.The deep waters in both seas are from the SP.Our findings are helpful for drawing a comprehensive picture of the water properties in the Indonesian seas and will contribute to a better understanding of the ocean-atmosphere interaction over the maritime continent. 展开更多
关键词 water mass INDONESIAN THROUGHFLOW MONSOON ENSO Maluku SEA Halmahera SEA
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Temperature variability caused by internal tides in the coastal waters of east coast of Peninsular Malaysia 预览
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作者 Nur Hidayah Roseli Mohd Fadzil Akhir 《海洋学报:英文版》 SCIE CAS CSCD 2019年第1期22-31,共10页
The effects of tidal currents (i.e., barotropic and internal tides) are important in the biogeochemistry of a coastal shelf sea. The high-frequency of currents and near-bottom temperatures collected in three consecuti... The effects of tidal currents (i.e., barotropic and internal tides) are important in the biogeochemistry of a coastal shelf sea. The high-frequency of currents and near-bottom temperatures collected in three consecutive southwest monsoon seasons (May, June, July and August of 2013 until 2015) is presented to reveal the role of the tidal currents to the temperature variability in the coastal shelf sea of the east coast of Peninsular Malaysia (ECPM), south of the South China Sea (SCS). The results of a spectral density and harmonic analysis demonstrate that the near-bottom temperature variability and the tidal currents are influenced by diurnal (O1 and K1) and semidiurnal (M2) tidal currents. The spectral density of residual currents (detided data) at 5, 10 and 16 m depth also shows significant peaks at the diurnal tidal frequency (K1) and small peaks at the semidiurnal tidal frequency (M2) indicating the existence of internal tides. The result of the horizontal kinetic energy (HKE) shows a strong intermittent energy of internal tides in the ECPM with the strongest energy is found at 16 m depth during a sporadic cooling event in June and July. A high horizontal cross-shore heat flux (16 m) also indicates strong intrusions of cooler water into the ECPM in June and July. During the short duration of cold pulse water observed in June and July, a cross-wavelet analysis also reveals the strong relationship between the near-bottom temperatures and the internal tidal currents at the diurnal tidal frequency. The intrusion of this cooler water is probably related to the monsoon-induced upwelling in June. It is loosely interpreted that the interaction between the strong barotropic tides and the steep slope in the central basin of the SCS under the stratified condition in southwest monsoon has generated these internal tides. The dissipation of internal tides from the slope area probably has driven the cold-upwelled water into the ECPM coastal shelf sea when the upwelling intensity is the highest in June and July. 展开更多
关键词 EAST COAST of Peninsular Malaysia South China SEA BAROTROPIC tidal currents internal TIDES nearbottom temperature coastal SHELF SEA
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Dynamic of ENSO towards upwelling and thermal front zone in the east coast of Peninsular Malaysia 预览
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作者 Nurul Rabitah Daud Mohd Fadzil Akhir Aidy M Muslim 《海洋学报:英文版》 SCIE CAS CSCD 2019年第1期48-60,共13页
The El Nino Southern Oscillation (ENSO) is a natural phenomenon that relates to the fluctuation of temperatures over the Pacific Ocean. The ENSO significantly affects the ocean dynamics including upwelling event and c... The El Nino Southern Oscillation (ENSO) is a natural phenomenon that relates to the fluctuation of temperatures over the Pacific Ocean. The ENSO significantly affects the ocean dynamics including upwelling event and coastal front. A recent study discovered the seasonal upwelling in the east coast of Peninsular Malaysia (ECPM), which is significant to the fishery industry in this region. Thus, it is vital to have a better understanding of the influence of ENSO towards the coastal upwelling and thermal front in the ECPM. The sea surface temperature (SST) data achieved from moderate resolution imaging spectroradiometer (MODIS) aboard Aqua satellite are used in this study to observe the SST changes from 2005 to 2015. However, due to cloud cover issue, a reconstruction of data set is applied to MODIS data using the data interpolating empirical orthogonal function (DINEOF) to fill in the missing gap in the dataset based on spatial and temporal available data. Besides, a wavelet transformation analysis is done to determine the temperature fluctuation throughout the time series. The DINEOF results show the coastal upwelling in the ECPM develops in July and reaches its peak in August with a clear cold water patch off the coast. There is also a significant change of SST distribution during the El Nino years which weaken the coastal upwelling event along the ECPM. The wavelet transformation analysis shows the highest temperature fluctuation is in 2009-2010 which indicates the strongest El Nino throughout the time period. It is suggested that the El Nino is favourable for the stratification in water column thus it is weakening the upwelling and thermal frontal zone formation in ECPM waters. 展开更多
关键词 ENSO thermal FRONTAL ZONE COASTAL UPWELLING SEA surface temperature South China SEA
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Variations in Dissolved Methane in the Yellow SeaDuring the Spring Algal Blooms of 2009 预览
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作者 YE Wangwang ZHANG Guiling +2 位作者 LI Peipei ZHOU Feng LIU Chenggang 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第4期896-912,共17页
Methane (CH4) is an important greenhouse gas and oceans are net sources of atmospheric CH4. The effects of environ- mental factors on the CH4 variation during different phases of the spring algal blooms were examined ... Methane (CH4) is an important greenhouse gas and oceans are net sources of atmospheric CH4. The effects of environ- mental factors on the CH4 variation during different phases of the spring algal blooms were examined during two cruises conducted in the Yellow Sea (YS) from February to April of 2009. During the pre-bloom period from February to March, low CH4 saturation (< 134%) was observed in the surface water, except at two nearshore stations where the CH4 levels were above 140% in March due to mixing with the coastal water. During the bloom period, CH4 increased obviously at two bloom-tracking stations, especially at the surface with mean saturations of 140% and 170%. The increase in CH4 concentration/saturation is thought to be the result of in situ CH4 production. The particulate organic carbon (POC) and chlorophyll a contents were believed to be important factors that influ- enced the CH4 production. In addition, the presence of different dominant phytoplankton species and the grazing pressure may have stimulated the CH4 production by supplying potential methanogenic substrates (such as dimethylsulphoniopropionate (DMSP)). Both the incubation data and the in situ estimations further evidenced the significant influence of the spring blooms on the CH4 production. The calculated sea-to-air CH4 fluxes during the bloom period were not significantly higher than those during the pre-bloom period despite the bloom-increased CH4 saturation. This is due to the variation in physical forcing (such as wind speed), which is the main driver for determining the CH4 flux. Finally, we estimated the annual CH4 flux in the YS as 9.0 μmol m 2 d 1;the findings suggest that the YS is a natural source of atmospheric CH4. 展开更多
关键词 CH4 Yellow Sea ALGAL BLOOM sea-to-air flux CH4 production
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基于运动矢量投影的帧率转换算法 预览
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作者 张迪 黄倩 陈斯斯 《计算机与现代化》 2019年第5期80-85,共6页
提出一种基于运动矢量投影的帧率转换算法。在运动估计阶段,采用连续消除算法SEA,将该算法与全搜索相结合,对块匹配准则的计算过程进行优化,可以在保证图像质量的同时减小计算复杂度。在运动矢量场投影过程中,定义一个新的运动矢量选取... 提出一种基于运动矢量投影的帧率转换算法。在运动估计阶段,采用连续消除算法SEA,将该算法与全搜索相结合,对块匹配准则的计算过程进行优化,可以在保证图像质量的同时减小计算复杂度。在运动矢量场投影过程中,定义一个新的运动矢量选取标准,在匹配准则的基础上添加了块的位置信息,相对于传统标准,本标准更能代表内插块的真实运动,准确性更高。在运动补偿阶段,针对投影过程中产生的重叠现象,采用自适应加权补偿插值算法,考虑所有重叠投影块的运动信息。对于产生的空洞现象,采用运动矢量中值滤波的算法来填充。实验结果表明,该算法可以减少运动信息的丢失,插值效果更加准确。 展开更多
关键词 SEA 运动矢量投影 帧率转换 运动估计 像素加权 中值滤波
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The in situ observation of modelled sea ice drift characteristics in the Bohai Sea 预览
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作者 Yu Yan Wei Gu +1 位作者 Yingjun Xu Qian Li 《海洋学报:英文版》 SCIE CAS CSCD 2019年第3期17-25,共9页
Sea ice drift is mainly controlled by ocean currents, local wind, and internal ice stress. Information on sea ice motion, especially in situ synchronous observation of an ice velocity, a current velocity, and a wind s... Sea ice drift is mainly controlled by ocean currents, local wind, and internal ice stress. Information on sea ice motion, especially in situ synchronous observation of an ice velocity, a current velocity, and a wind speed, is of great significance to identify ice drift characteristics. A sea ice substitute, the so-called 'modelled ice', which is made by polypropylene material with a density similar to Bohai Sea ice, is used to complete a free drift experiment in the open sea. The trajectories of isolated modelled ice, currents and wind in the Bohai Sea during non-frozen and frozen periods are obtained. The results show that the currents play a major role while the wind plays a minor role in the free drift of isolated modelled ice when the wind is mild in the Bohai Sea. The modelled ice drift is significantly affected by the ocean current and wind based on the ice–current–wind relationship established by a multiple linear regression. The modelled ice velocity calculated by the multiple linear regression is close to that of the in situ observation, the magnitude of the error between the calculated and observed ice velocities is less than12.05%, and the velocity direction error is less than 6.21°. Thus, the ice velocity can be estimated based on the observed current velocity and wind speed when the in situ observed ice velocity is missing. And the modelled ice of same thickness with a smaller density is more sensitive to the current velocity and the wind speed changes. In addition, the modelled ice drift characteristics are shown to be close to those of the real sea ice, which indicates that the modelled ice can be used as a good substitute of real ice for in situ observation of the free ice drift in the open sea, which helps solve time availability, safety and logistics problems related to in situ observation on real ice. 展开更多
关键词 Bohai SEA modelled ICE in SITU observation SEA ICE DRIFT
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