It is fundamental and useful to investigate how deep learning forecasting models(DLMs)perform compared to operational oceanography forecast systems(OFSs).However,few studies have intercompared their performances using...It is fundamental and useful to investigate how deep learning forecasting models(DLMs)perform compared to operational oceanography forecast systems(OFSs).However,few studies have intercompared their performances using an identical reference.In this study,three physically reasonable DLMs are implemented for the forecasting of the sea surface temperature(SST),sea level anomaly(SLA),and sea surface velocity in the South China Sea.The DLMs are validated against both the testing dataset and the“OceanPredict”Class 4 dataset.Results show that the DLMs'RMSEs against the latter increase by 44%,245%,302%,and 109%for SST,SLA,current speed,and direction,respectively,compared to those against the former.Therefore,different references have significant influences on the validation,and it is necessary to use an identical and independent reference to intercompare the DLMs and OFSs.Against the Class 4 dataset,the DLMs present significantly better performance for SLA than the OFSs,and slightly better performances for other variables.The error patterns of the DLMs and OFSs show a high degree of similarity,which is reasonable from the viewpoint of predictability,facilitating further applications of the DLMs.For extreme events,the DLMs and OFSs both present large but similar forecast errors for SLA and current speed,while the DLMs are likely to give larger errors for SST and current direction.This study provides an evaluation of the forecast skills of commonly used DLMs and provides an example to objectively intercompare different DLMs.展开更多
Quality control(QC)is an essential procedure in scatterometer wind retrieval,which is used to distinguish good-quality data from poor-quality wind vector cells(WVCs)for the sake of wind applications.The current wind p...Quality control(QC)is an essential procedure in scatterometer wind retrieval,which is used to distinguish good-quality data from poor-quality wind vector cells(WVCs)for the sake of wind applications.The current wind processor of the China-France Oceanography Satellite(CFOSAT)scatterometer(CSCAT)adopts a maximum likelihood estimator(MLE)-based QC method to filter WVCs affected by geophysical noise,such as rainfall and wind variability.As the first Ku-band rotating fan-beam scatterometer,CSCAT can acquire up to 16 observations over a single WVC,giving abundant information with diverse incidence/azimuth angles,as such its MLE statistical characteristics may be different from the previous scatterometers.In this study,several QC indicators,including MLE,its spatially averaged value(MLE_(m)),and the singularity exponents(SE),are analyzed using the collocated Global Precipitation Mission rainfall data as well as buoy data,to compare their sensitivity to rainfall and wind quality.The results show that wind error characteristics of CSCAT under different QC methods are similar to those of other Ku-band scatterometers,i.e.,SE is more suitable than other parameters for the wind QC at outer-swath and nadir regions,while MLE_(m) is the best QC indicator for the sweet region WVCs.Specifically,SE is much more favorable than others at high wind speeds.By combining different indicators,an improved QC method is developed for CSCAT.The validation with the collocated buoy data shows that it accepts more WVCs,and in turn,improves the quality control of CSCAT wind data.展开更多
The Journal of Ocean University of China(Oceanic and Coastal Sea Research)is a comprehensive academic quarterly sponsored by the Ocean University of China,published one volume per year.This journal is devoted to the p...The Journal of Ocean University of China(Oceanic and Coastal Sea Research)is a comprehensive academic quarterly sponsored by the Ocean University of China,published one volume per year.This journal is devoted to the publication of the theoretical and applied research results on oceanography and marine fisheries.The fields covered include the physical,chemical,biological,geo-logical,environmental,engineering and technological aspects of these sciences.The types of papers include research papers,notes,technical reports,science and technology letters,reviews and overviews,etc.It has been indexed by SCI-E since 2012.展开更多
南海北部雷琼海岸的珊瑚礁是研究古海平面变化的重要标志物.但因重建标准不统一,海平面重建结果存在显著时空差异性.本研究通过对海南岛东部珊瑚礁区27块现代滨珊瑚微环礁的顶面高程进行实地测量,精确量化其海平面指示意义;同时对该区...南海北部雷琼海岸的珊瑚礁是研究古海平面变化的重要标志物.但因重建标准不统一,海平面重建结果存在显著时空差异性.本研究通过对海南岛东部珊瑚礁区27块现代滨珊瑚微环礁的顶面高程进行实地测量,精确量化其海平面指示意义;同时对该区域65个已发表的海平面标志点数据进行重新校正,重建了更可靠的海平面变化历史.研究表明,这些顶部死亡但整体存活的现代滨珊瑚已达到生长上限,其顶面高程位于清澜港平均潮位以下146.09 cm,最低低潮位(lowest low tide,LLT)以下15.09 cm,且生长上限高差仅±8.35 cm,呈现典型的滨珊瑚微环礁发育形态,证实其生长主要受最低低潮位控制,是理想的海平面标志物.海平面重建结果显示,在(6 143±34) cal a BP至(3 013±9) cal a BP期间,南海北部相对海平面呈波动下降趋势,变化范围为(25.0±9.8) cm至(136.09±9.80) cm.与周边地区海平面记录对比发现,中全新世高海平面的出现时间和高度存在差异,这可能与标志物的高程估算方法及测年技术差异有关.此外,将研究结果和GIA模型(ICE-6G_HetML14)预测结果对比显示,南海北部雷琼海岸3个地点的中晚全新世海平面数据均低于模型预测曲线,表明该区域过去几千年可能经历构造沉降过程.本研究结果为预测南海北部未来海平面变化趋势提供重要科学依据,也为区域构造演化研究提供新视角.展开更多
The Brillouin scattering spectrum has been used to investigate the properties of a liquid medium.Here,we propose an improved method based on the double-edge technique to obtain the Brillouin spectrum of a liquid.We ca...The Brillouin scattering spectrum has been used to investigate the properties of a liquid medium.Here,we propose an improved method based on the double-edge technique to obtain the Brillouin spectrum of a liquid.We calculated the transmission ratios and deduced the Brillouin shift and linewidth to construct the Brillouin spectrum by extracting the Brillouin edge signal through filtered double-edge data.We built a detection system to test the performance of this method and measured the Brillouin spectrum for distilled water at different temperatures and compared it with the theoretical prediction.The observed difference between the experimental and theoretical values for Brillouin shift and linewidth is less than 4.3 MHz and 3.2 MHz,respectively.Moreover,based on the double-edge technique,the accuracy of the extracted temperatures and salinity is approximately 0.1°C and 0.5‰,respectively,indicating significant potential for application in water detection and oceanography.展开更多
Physical properties of sea water,such as salinity,temperature,density and acoustic velocity,could be demarcated through degradation of energy caused by water absorption,attenuation and other factors.To overcome the ch...Physical properties of sea water,such as salinity,temperature,density and acoustic velocity,could be demarcated through degradation of energy caused by water absorption,attenuation and other factors.To overcome the challenging difficulties in the quick monitoring of these physical properties,we have explored the high resolution marine seismic survey to instantly characterize them.Based on the unique wavefield propagating in the sea water,we have developed a new approach to suppress the noise caused by the shallow sea water disturbance and obtain useful information for estimating the sea water structure.This approach improves seismic data with high signal-to-noise ratio and resolution.The seismic reflection imaging can map the sea water structure acoustically.Combined with the knowledge of local water body structure profile over years,the instant model for predicting the sea water properties could be built using the seismic data acquired from the specially designed high precision marine seismic acquisition.This model can also be updated with instant observation and the complete data processing system.The present study has the potential value to many applications,such as 3D sea water monitoring,engineering evaluation,geological disaster assessment and environmental assessment.展开更多
Within the context of developing a research presence in the Antarctic region, the first phase of the Chinese Polar Programs covered the period 2011-2015, which almost coincided with the 12th Five-Year Plan （2011-2015...Within the context of developing a research presence in the Antarctic region, the first phase of the Chinese Polar Programs covered the period 2011-2015, which almost coincided with the 12th Five-Year Plan （2011-2015）. For the promotion of full understanding of the progress of Chinese expeditions and research in Antarctica, the observations and achievements of cruises during 2011-2015 are summarized in this paper. Four Antarctic cruises （28th-31st） were performed in the Prydz Bay and Antarctic Peninsula regions during the first phase of the Polar Programs. These cruises performed systemic collections of physical oceanographic and meteorological data to support further research on the ice-ocean-atmosphere interactions in Antarctica. Overall, 248 CTD/LADCP stations, 66 microstructure profiles, 507 XBT/XCTDs, 181 air sounding balloons, 58000 total gaseous mercury （TGM） concentrations, 452 aerosol samples, 294 atmospheric samples, 11 moorings, and 28 surface drifters were acquired or deployed during the four cruises. Using these extensive observations and other data, Chinese scientists have achieved new recognition in the fields of Southern Ocean physical oceanography and meteorology, as well as in other interdisciplinary subjects. These studies, which have been associated with scientific techniques, instrumentation, ocean circulation, water mass formation, energy transformation, and carbon uptake, have elucidated the dynamic mechanisms and potential effects of climate change in Antarctica. Finally, some observations based on experience gained during previous Chinese Antarctic Research and Expedition campaigns are summarized with advice for the improvement of future investigations in the Antarctic region.展开更多
As a part of the National Report of China for the International Association for Physical Science of Ocean （IAPSO）, the main research results of Chinese scientists in Arctic physical oceanography during 2007-2010 are...As a part of the National Report of China for the International Association for Physical Science of Ocean （IAPSO）, the main research results of Chinese scientists in Arctic physical oceanography during 2007-2010 are reviewed in this paper. This period overlaps with the International Polar Year （IPY）, which is a catalyst for nations to emphasize activities and research in the polar regions. The Arctic also experienced a rapid change in sea ice, ocean, and climate during this time. China launched two Arctic cruises with the R/V XUE LONG icebreaker, in 2008 and 2010, which provided more opportunities for Chinese scientists to investigate the Arctic Ocean and its change. During this period, Chinese scientists participated in more than ten other cruises with international collaborations. The main research covered in this paper includes the upper ocean characteristic, ocean and sea ice optics, kinematics of sea ice and the Arctic impact on global climate change. The progress in sea ice optics, the observation technologies and Arctic Oscillation are especially remarkable.展开更多
In order to satisfy the increasing demand for the marine forecasting capacity,the Bohai Sea,the Yellow Sea and the East China Sea Operational Oceanography Forecasting System(BYEOFS)has been upgraded and improved to Ve...In order to satisfy the increasing demand for the marine forecasting capacity,the Bohai Sea,the Yellow Sea and the East China Sea Operational Oceanography Forecasting System(BYEOFS)has been upgraded and improved to Version 2.0.Based on the Regional Ocean Modeling System(ROMS),a series of comparative experiments were conducted during the improvement process,including correcting topography,changing sea surface atmospheric forcing mode,adjusting open boundary conditions,and considering atmospheric pressure correction.(1)After the topography correction,the volume transport and meridional velocity maximum of Yellow Sea Warm Current increase obviously and the unreasonable bending of its axis around 36.1°N,123.5°E disappears.(2)After the change of sea surface forcing mode,an effective negative feedback mechanism is formed between predicted sea surface temperature(SST)by the ocean model and sea surface radiation fluxes fields.The simulation errors of SST decreased significantly,and the annual average of root-mean-square error(RMSE)decreased by about 18%.(3)The change of the eastern lateral boundary condition of baroclinic velocity from mixed Radiation-Nudging to Clamped makes the unreasonable westward current in Tsushima Strait disappear.(4)The adding of mean sea level pressure correction option which forms the mean sea level gradient from the Bohai Sea and the Yellow Sea to the western Pacific in winter and autumn is helpful to increasing the fluctuation of SLA and outflow of the Yellow Sea when the cold high air pressure system controls the Yellow Sea area.展开更多
The submesoscale processes, including submesoscale eddies and fronts, have a strong vertical velocity, can thus make important supplements to the nutrients in the upper ocean. Using legacy multichannel seismic data AP...The submesoscale processes, including submesoscale eddies and fronts, have a strong vertical velocity, can thus make important supplements to the nutrients in the upper ocean. Using legacy multichannel seismic data AP25 of cruise EW9101 acquired northeast of the South Shetland Islands(Antarctic Peninsula) in February 1991, we identified an oceanic submesoscale eddy with the horizontal scale of ~4 km and a steep shelf break front that has variable dip angles from 5° to 10°. The submesoscale eddy is an anticyclonic eddy, which carries warm core water, can accelerate ice shelves melting. The upwelling induced by shelf break front may play an important role in transporting nutrients to the sea surface. The seismic images with very high lateral resolution may provide a new insight to understand the submesoscale and even small-scale oceanic phenomena in the interior.展开更多
Submarine seep plumes are a natural phenomenon in which different types of gases migrate through deep or shallow subsurface sediments and leak into seawater in pressure gradient.When detected using acoustic data,the l...Submarine seep plumes are a natural phenomenon in which different types of gases migrate through deep or shallow subsurface sediments and leak into seawater in pressure gradient.When detected using acoustic data,the leaked gases frequently exhibit a flame-like structure.We numerically modelled the relationship between the seismic response characteristic and bubble volume fraction to establish the bubble volume fraction in the submarine seep plume.Results show that our models are able to invert and predict the bubble volume fraction from field seismic oceanography data,by which synthetic seismic sections in different dominant frequencies could be numerically simulated,seismic attribute sections(e.g.,instantaneous amplitude,instantaneous frequency,and instantaneous phase)extracted,and the correlation between the seismic attributes and bubble volume fraction be quantitatively determined with functional equations.The instantaneous amplitude is positively correlated with bubble volume fraction,while the instantaneous frequency and bubble volume fraction are negatively correlated.In addition,information entropy is introduced as a proxy to quantify the relationship between the instantaneous phase and bubble volume fraction.As the bubble volume fraction increases,the information entropy of the instantaneous phase increases rapidly at the beginning,followed by a slight upward trend,and finally stabilizes.Therefore,under optimal noise conditions,the bubble volume fraction of submarine seep plumes can be inverted and predicted based on seismic response characteristics in terms of seismic attributes.展开更多
The current advances in the study of geochemistry and paleo-oceanography of the Co-rich crust are reviewed in this paper. We summarize the study of geochemistry of the Co-rich crust, discuss the diffusion of elements ...The current advances in the study of geochemistry and paleo-oceanography of the Co-rich crust are reviewed in this paper. We summarize the study of geochemistry of the Co-rich crust, discuss the diffusion of elements in the Co-rich crust and the exchange with ambient seawater. Besides, we discuss the effect of phosphatization and substrate rocks on the composition of the Co-rich crust. We also introduce the application of stable isotopes(including the stable isotopes of Pb, Nd, and Hf), radioactive isotopes (including the radioactive isotopes of Be, U and Th), and elements (including the major elements, minor elements and rare earth elements) to the study of paleo-oceanography of the Co-rich crust.展开更多
The first satellite jointly developed by China and France,China-France Oceanography Satellite（CFOSAT）,will be launched on a LM carrier rocket in the second half of 2018 announced at a press conference jointly held b...The first satellite jointly developed by China and France,China-France Oceanography Satellite（CFOSAT）,will be launched on a LM carrier rocket in the second half of 2018 announced at a press conference jointly held by the China National Space Administration（CNSA）and French embassy in Beijing.The satellite is being tested at a Beijingbased AIT center of CNSA.CFOSAT is an oceanic satellite supported under a joint project of CNSA and the National Center for Space Studies（CNES）of France.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42375062 and 42275158)the National Key Scientific and Technological Infrastructure project“Earth System Science Numerical Simulator Facility”(EarthLab)the Natural Science Foundation of Gansu Province(Grant No.22JR5RF1080)。
文摘It is fundamental and useful to investigate how deep learning forecasting models(DLMs)perform compared to operational oceanography forecast systems(OFSs).However,few studies have intercompared their performances using an identical reference.In this study,three physically reasonable DLMs are implemented for the forecasting of the sea surface temperature(SST),sea level anomaly(SLA),and sea surface velocity in the South China Sea.The DLMs are validated against both the testing dataset and the“OceanPredict”Class 4 dataset.Results show that the DLMs'RMSEs against the latter increase by 44%,245%,302%,and 109%for SST,SLA,current speed,and direction,respectively,compared to those against the former.Therefore,different references have significant influences on the validation,and it is necessary to use an identical and independent reference to intercompare the DLMs and OFSs.Against the Class 4 dataset,the DLMs present significantly better performance for SLA than the OFSs,and slightly better performances for other variables.The error patterns of the DLMs and OFSs show a high degree of similarity,which is reasonable from the viewpoint of predictability,facilitating further applications of the DLMs.For extreme events,the DLMs and OFSs both present large but similar forecast errors for SLA and current speed,while the DLMs are likely to give larger errors for SST and current direction.This study provides an evaluation of the forecast skills of commonly used DLMs and provides an example to objectively intercompare different DLMs.
基金The National Key Research and Development Program of China under contract Nos 2022YFC3104900 and 2022YFC3104902.
文摘Quality control(QC)is an essential procedure in scatterometer wind retrieval,which is used to distinguish good-quality data from poor-quality wind vector cells(WVCs)for the sake of wind applications.The current wind processor of the China-France Oceanography Satellite(CFOSAT)scatterometer(CSCAT)adopts a maximum likelihood estimator(MLE)-based QC method to filter WVCs affected by geophysical noise,such as rainfall and wind variability.As the first Ku-band rotating fan-beam scatterometer,CSCAT can acquire up to 16 observations over a single WVC,giving abundant information with diverse incidence/azimuth angles,as such its MLE statistical characteristics may be different from the previous scatterometers.In this study,several QC indicators,including MLE,its spatially averaged value(MLE_(m)),and the singularity exponents(SE),are analyzed using the collocated Global Precipitation Mission rainfall data as well as buoy data,to compare their sensitivity to rainfall and wind quality.The results show that wind error characteristics of CSCAT under different QC methods are similar to those of other Ku-band scatterometers,i.e.,SE is more suitable than other parameters for the wind QC at outer-swath and nadir regions,while MLE_(m) is the best QC indicator for the sweet region WVCs.Specifically,SE is much more favorable than others at high wind speeds.By combining different indicators,an improved QC method is developed for CSCAT.The validation with the collocated buoy data shows that it accepts more WVCs,and in turn,improves the quality control of CSCAT wind data.
文摘The Journal of Ocean University of China(Oceanic and Coastal Sea Research)is a comprehensive academic quarterly sponsored by the Ocean University of China,published one volume per year.This journal is devoted to the publication of the theoretical and applied research results on oceanography and marine fisheries.The fields covered include the physical,chemical,biological,geo-logical,environmental,engineering and technological aspects of these sciences.The types of papers include research papers,notes,technical reports,science and technology letters,reviews and overviews,etc.It has been indexed by SCI-E since 2012.
文摘南海北部雷琼海岸的珊瑚礁是研究古海平面变化的重要标志物.但因重建标准不统一,海平面重建结果存在显著时空差异性.本研究通过对海南岛东部珊瑚礁区27块现代滨珊瑚微环礁的顶面高程进行实地测量,精确量化其海平面指示意义;同时对该区域65个已发表的海平面标志点数据进行重新校正,重建了更可靠的海平面变化历史.研究表明,这些顶部死亡但整体存活的现代滨珊瑚已达到生长上限,其顶面高程位于清澜港平均潮位以下146.09 cm,最低低潮位(lowest low tide,LLT)以下15.09 cm,且生长上限高差仅±8.35 cm,呈现典型的滨珊瑚微环礁发育形态,证实其生长主要受最低低潮位控制,是理想的海平面标志物.海平面重建结果显示,在(6 143±34) cal a BP至(3 013±9) cal a BP期间,南海北部相对海平面呈波动下降趋势,变化范围为(25.0±9.8) cm至(136.09±9.80) cm.与周边地区海平面记录对比发现,中全新世高海平面的出现时间和高度存在差异,这可能与标志物的高程估算方法及测年技术差异有关.此外,将研究结果和GIA模型(ICE-6G_HetML14)预测结果对比显示,南海北部雷琼海岸3个地点的中晚全新世海平面数据均低于模型预测曲线,表明该区域过去几千年可能经历构造沉降过程.本研究结果为预测南海北部未来海平面变化趋势提供重要科学依据,也为区域构造演化研究提供新视角.
基金supported by the National Natural Science Foundation of China (Grant No. 62175072, No. 62175072 and No. 12074209)the Open Project of State Key Laboratory of Low-Dimensional Quantum Physics (Grant No. KF202008)support from International Postdoctoral Exchange Fellowship Program (Talent-Introduction Program)。
文摘The Brillouin scattering spectrum has been used to investigate the properties of a liquid medium.Here,we propose an improved method based on the double-edge technique to obtain the Brillouin spectrum of a liquid.We calculated the transmission ratios and deduced the Brillouin shift and linewidth to construct the Brillouin spectrum by extracting the Brillouin edge signal through filtered double-edge data.We built a detection system to test the performance of this method and measured the Brillouin spectrum for distilled water at different temperatures and compared it with the theoretical prediction.The observed difference between the experimental and theoretical values for Brillouin shift and linewidth is less than 4.3 MHz and 3.2 MHz,respectively.Moreover,based on the double-edge technique,the accuracy of the extracted temperatures and salinity is approximately 0.1°C and 0.5‰,respectively,indicating significant potential for application in water detection and oceanography.
基金the Natural Science Foundation of China(41176077)Subject of 973(2009CB219505)+2 种基金Natural Science Foundation of Shandong(ZR2010DM012)Basic Research Special Foundation of the Third Institute of Oceanography affiliated to the State Oceanic Administration(TIOSOA,2009004)the Science Research Project for the South China Sea of Ocean University of China for their financial support to this work
文摘Physical properties of sea water,such as salinity,temperature,density and acoustic velocity,could be demarcated through degradation of energy caused by water absorption,attenuation and other factors.To overcome the challenging difficulties in the quick monitoring of these physical properties,we have explored the high resolution marine seismic survey to instantly characterize them.Based on the unique wavefield propagating in the sea water,we have developed a new approach to suppress the noise caused by the shallow sea water disturbance and obtain useful information for estimating the sea water structure.This approach improves seismic data with high signal-to-noise ratio and resolution.The seismic reflection imaging can map the sea water structure acoustically.Combined with the knowledge of local water body structure profile over years,the instant model for predicting the sea water properties could be built using the seismic data acquired from the specially designed high precision marine seismic acquisition.This model can also be updated with instant observation and the complete data processing system.The present study has the potential value to many applications,such as 3D sea water monitoring,engineering evaluation,geological disaster assessment and environmental assessment.
基金supported by the Chinese Polar Environment Comprehensive Investigation & Assessment Programs (Grant nos. CHINARE2017-01-01, CHINARE2017-04-01)the National Natural Science Fund of China (Grant nos. 41306206, U1406404)the Basic Scientific Fund for National Public Research Institutes of China (Grant no. 2015P06)
文摘Within the context of developing a research presence in the Antarctic region, the first phase of the Chinese Polar Programs covered the period 2011-2015, which almost coincided with the 12th Five-Year Plan （2011-2015）. For the promotion of full understanding of the progress of Chinese expeditions and research in Antarctica, the observations and achievements of cruises during 2011-2015 are summarized in this paper. Four Antarctic cruises （28th-31st） were performed in the Prydz Bay and Antarctic Peninsula regions during the first phase of the Polar Programs. These cruises performed systemic collections of physical oceanographic and meteorological data to support further research on the ice-ocean-atmosphere interactions in Antarctica. Overall, 248 CTD/LADCP stations, 66 microstructure profiles, 507 XBT/XCTDs, 181 air sounding balloons, 58000 total gaseous mercury （TGM） concentrations, 452 aerosol samples, 294 atmospheric samples, 11 moorings, and 28 surface drifters were acquired or deployed during the four cruises. Using these extensive observations and other data, Chinese scientists have achieved new recognition in the fields of Southern Ocean physical oceanography and meteorology, as well as in other interdisciplinary subjects. These studies, which have been associated with scientific techniques, instrumentation, ocean circulation, water mass formation, energy transformation, and carbon uptake, have elucidated the dynamic mechanisms and potential effects of climate change in Antarctica. Finally, some observations based on experience gained during previous Chinese Antarctic Research and Expedition campaigns are summarized with advice for the improvement of future investigations in the Antarctic region.
基金supported by the National Department Public Benefit Research Foundation (Grant no.201105022)the National Natural Science Foundation of China(Grant nos. 40876006, 40976111)
文摘As a part of the National Report of China for the International Association for Physical Science of Ocean （IAPSO）, the main research results of Chinese scientists in Arctic physical oceanography during 2007-2010 are reviewed in this paper. This period overlaps with the International Polar Year （IPY）, which is a catalyst for nations to emphasize activities and research in the polar regions. The Arctic also experienced a rapid change in sea ice, ocean, and climate during this time. China launched two Arctic cruises with the R/V XUE LONG icebreaker, in 2008 and 2010, which provided more opportunities for Chinese scientists to investigate the Arctic Ocean and its change. During this period, Chinese scientists participated in more than ten other cruises with international collaborations. The main research covered in this paper includes the upper ocean characteristic, ocean and sea ice optics, kinematics of sea ice and the Arctic impact on global climate change. The progress in sea ice optics, the observation technologies and Arctic Oscillation are especially remarkable.
基金The National Key Research and Development Program of China under contract No.2017YFA0604203the National Natural Science Foundation of China under contract Nos 42176029 and 41806003。
文摘In order to satisfy the increasing demand for the marine forecasting capacity,the Bohai Sea,the Yellow Sea and the East China Sea Operational Oceanography Forecasting System(BYEOFS)has been upgraded and improved to Version 2.0.Based on the Regional Ocean Modeling System(ROMS),a series of comparative experiments were conducted during the improvement process,including correcting topography,changing sea surface atmospheric forcing mode,adjusting open boundary conditions,and considering atmospheric pressure correction.(1)After the topography correction,the volume transport and meridional velocity maximum of Yellow Sea Warm Current increase obviously and the unreasonable bending of its axis around 36.1°N,123.5°E disappears.(2)After the change of sea surface forcing mode,an effective negative feedback mechanism is formed between predicted sea surface temperature(SST)by the ocean model and sea surface radiation fluxes fields.The simulation errors of SST decreased significantly,and the annual average of root-mean-square error(RMSE)decreased by about 18%.(3)The change of the eastern lateral boundary condition of baroclinic velocity from mixed Radiation-Nudging to Clamped makes the unreasonable westward current in Tsushima Strait disappear.(4)The adding of mean sea level pressure correction option which forms the mean sea level gradient from the Bohai Sea and the Yellow Sea to the western Pacific in winter and autumn is helpful to increasing the fluctuation of SLA and outflow of the Yellow Sea when the cold high air pressure system controls the Yellow Sea area.
基金financially supported by National Polar Special Program “Impact and Response of Antarctic Seas to Climate Change” (Grant nos. IRASCC 01-03-01, 01-03-02)funded by the National Natural Science Foundation of China (Grant no. 41976048)the National Key R&D Program of China (Grant no. 2018YFC0310000)。
文摘The submesoscale processes, including submesoscale eddies and fronts, have a strong vertical velocity, can thus make important supplements to the nutrients in the upper ocean. Using legacy multichannel seismic data AP25 of cruise EW9101 acquired northeast of the South Shetland Islands(Antarctic Peninsula) in February 1991, we identified an oceanic submesoscale eddy with the horizontal scale of ~4 km and a steep shelf break front that has variable dip angles from 5° to 10°. The submesoscale eddy is an anticyclonic eddy, which carries warm core water, can accelerate ice shelves melting. The upwelling induced by shelf break front may play an important role in transporting nutrients to the sea surface. The seismic images with very high lateral resolution may provide a new insight to understand the submesoscale and even small-scale oceanic phenomena in the interior.
基金Supported by the Natural Science Foundation of Shandong Province(No.ZR2022MD074)the Laboratory for Marine Mineral Resources+3 种基金Qingdao National Laboratory for Marine Science and Technology(No.MMRKF201810)the National Natural Science Foundation of China(No.41606077)the National Key R&D Program of China:HighPrecision Characterization Technology of Gas Hydrate Reservoir(No.2017YFC0307406-03)supported by the Shandong Province Taishan Scholar Construction Project。
文摘Submarine seep plumes are a natural phenomenon in which different types of gases migrate through deep or shallow subsurface sediments and leak into seawater in pressure gradient.When detected using acoustic data,the leaked gases frequently exhibit a flame-like structure.We numerically modelled the relationship between the seismic response characteristic and bubble volume fraction to establish the bubble volume fraction in the submarine seep plume.Results show that our models are able to invert and predict the bubble volume fraction from field seismic oceanography data,by which synthetic seismic sections in different dominant frequencies could be numerically simulated,seismic attribute sections(e.g.,instantaneous amplitude,instantaneous frequency,and instantaneous phase)extracted,and the correlation between the seismic attributes and bubble volume fraction be quantitatively determined with functional equations.The instantaneous amplitude is positively correlated with bubble volume fraction,while the instantaneous frequency and bubble volume fraction are negatively correlated.In addition,information entropy is introduced as a proxy to quantify the relationship between the instantaneous phase and bubble volume fraction.As the bubble volume fraction increases,the information entropy of the instantaneous phase increases rapidly at the beginning,followed by a slight upward trend,and finally stabilizes.Therefore,under optimal noise conditions,the bubble volume fraction of submarine seep plumes can be inverted and predicted based on seismic response characteristics in terms of seismic attributes.
文摘The current advances in the study of geochemistry and paleo-oceanography of the Co-rich crust are reviewed in this paper. We summarize the study of geochemistry of the Co-rich crust, discuss the diffusion of elements in the Co-rich crust and the exchange with ambient seawater. Besides, we discuss the effect of phosphatization and substrate rocks on the composition of the Co-rich crust. We also introduce the application of stable isotopes(including the stable isotopes of Pb, Nd, and Hf), radioactive isotopes (including the radioactive isotopes of Be, U and Th), and elements (including the major elements, minor elements and rare earth elements) to the study of paleo-oceanography of the Co-rich crust.
文摘The first satellite jointly developed by China and France,China-France Oceanography Satellite（CFOSAT）,will be launched on a LM carrier rocket in the second half of 2018 announced at a press conference jointly held by the China National Space Administration（CNSA）and French embassy in Beijing.The satellite is being tested at a Beijingbased AIT center of CNSA.CFOSAT is an oceanic satellite supported under a joint project of CNSA and the National Center for Space Studies（CNES）of France.
