Internal solitary waves(ISWs)are an essential dynamic process in the ocean due to their large amplitude and long propagation distance.Traditional satellite observations provide only twodimensional observations of ocea...Internal solitary waves(ISWs)are an essential dynamic process in the ocean due to their large amplitude and long propagation distance.Traditional satellite observations provide only twodimensional observations of ocean signatures induced by ISWs.The Surface Water and Ocean Topography(SWOT)satellite has drawn significant attention due to its high resolution and threedimensional observation capabilities.SWOT can generate high-precision three-dimensional sea surface topography,capture sea surface undulations,and reveal ISW-related surface oscillations,thus offering a new perspective for studying ISWs.We collected 43 SWOT observations with clear ISW signatures in the Lombok Strait from August 2023 to June 2024.Based on collected data,the ISW imaging characteristics and distributions were analyzed,and the ISW-related sea level anomaly(SLA)data were measured by the SWOT to calculate the ISW amplitude and reveal the amplitude variations during the propagation along the wave crest.The ISW amplitudes generally range between 10 and 100 m,with most ISW amplitudes between 20 and 40 m.By analyzing two consecutive generated ISW packets,we identified the spreading effect along ISW wave crests,which manifests as ISW amplitude decrease with increase in propagation distance,and the amplitude distribution is non-uniform along the wave crest.Further analysis of the propagation paths of the maximum amplitude of ISW moving northward through the Lombok Strait revealed that these maxima are predominantly oriented in northeast direction.Finally,the relationship between the amplitude of ISW and the resulting SLA was analyzed.The Pearson correlation coefficient between these two variables is as high as 0.90,which suggests a strong positive correlation between amplitude and SLA.Furthermore,this relationship is closely related to the water depth,indicating that the three-dimensional sea surface observations provided by SWOT offer crucial observational data for the inversion of amplitudes of ISW.展开更多
The Malacca Strait(MS)is a vital conduit for the exchange of water and sediment between the Indian Ocean and the Pacific Ocean,serving as a critical‘gateway'for sediment transport.Here,we present the geochemical ...The Malacca Strait(MS)is a vital conduit for the exchange of water and sediment between the Indian Ocean and the Pacific Ocean,serving as a critical‘gateway'for sediment transport.Here,we present the geochemical characteristics of surface sediments in the MS to elucidate the relationship between terrestrial material inputs and modern oceanic dynamic transport processes in the strait.The results reveal that the MS can be divided into three distinct geochemical provinces.ProvinceⅠ,located in the central region of the strait,is characterized by residual deposits.The preservation of these residual deposits can be attributed to the restricted sediment supply and the relatively weaker modern sedimentary hydrodynamic conditions.ProvinceⅡ,situated to the north of ProvinceⅠ,exhibits provenance differences between its southern and northern regions.The northern region is primarily supplied by sediments originating from the eastern shelf of the Andaman Sea,whereas sediments derived from Sumatra and the Sunda Shelf are predominantly deposited in the southern part of ProvinceⅡ.ProvinceⅢextends along the western coast of the Malaysian Peninsula,with sediments primarily sourced from the Malaysian Peninsula and the Sunda Shelf,while contributions from Sumatra and the eastern shelf of the Andaman Sea are negligible.River sediments from the Malaysian Peninsula and Sumatra are transported northwestward along their respective coasts by prevailing currents,which also facilitate the transportation of Sunda Shelf sediments within the strait,while sediments from the eastern shelf of the Andaman Sea are delivered to the MS via southward coastal currents during the southwest monsoon period.The southward currents and well-developed eddies potentially impede the northward transport of sediments from the Sunda Shelf and restrict the distribution of Andaman Sea sediments within the strait.This study substantially enhances the understanding of source-to-sink processes in the Indo-Pacific region.展开更多
The impacts of the Luzon Strait transport on shallow meridional overturning circulation(SMOC)in the South China Sea(SCS)have been pointed out by previous studies,but the issue whether the Luzon Strait transport domina...The impacts of the Luzon Strait transport on shallow meridional overturning circulation(SMOC)in the South China Sea(SCS)have been pointed out by previous studies,but the issue whether the Luzon Strait transport dominates the SMOC formation still remains open.The Helmholtz decomposition is applied based on the ocean general circulation model for the earth simulator products to address this issue.Results show that the motion caused by the Luzon Strait transport is characterized as an obvious southward flow between 13°N and 20°N.After this motion being removed,the clockwise winter SMOC and the anticlockwise summer SMOC can still exist significantly.The SMOC existence and its seasonal variation are also reproduced in the numerical simulation with the Luzon Strait closed.Both results of the Helmholtz decomposition and numerical experiment suggest that the SMOC formation and its seasonal variation are not dominated by the Luzon Strait transport.The SCS monsoon is the primary driving factor for the SMOC,which is related to the physical processes within the SCS.展开更多
El Niño-Southern Oscillation(ENSO)affects the changes in ocean physical elements in Taiwan Strait(TWS)primarily by regulating the strength of the East Asian Winter Monsoon(EAWM)and the intrusion of the Kuroshio.A...El Niño-Southern Oscillation(ENSO)affects the changes in ocean physical elements in Taiwan Strait(TWS)primarily by regulating the strength of the East Asian Winter Monsoon(EAWM)and the intrusion of the Kuroshio.Additionally,the fluctuating impact between nutrient-poor seawater with high dissolved inorganic carbon(DIC)that infiltrates owing to the Kuroshio during El Niño phases and nutrient-rich seawater with low DIC from the South China Sea(SCS)carried by the EAWM during La Niña phases determines the nutrient content in TWS,thereby sculpting appropriate or unsuitable biochemical environment.In this study,based on high-resolution sea-surface partial pressure of carbon dioxide(pCO_(2))data,we investigate the relationship between pCO_(2)level of TWS and ENSO events in winter.The physical mechanisms affecting the anomalous distribution of pCO_(2)level during ENSO are also explored.Stepwise regression was employed to identify the optimal influencing factors for modeling pCO_(2).Results indicate a significant positive correlation between Niño3.4 index and pCO_(2),which is significantly influenced by factors such as sea-surface temperature(SST),chlorophyll-a(Chl a),and DIC.These are related to the anomalously strong Kuroshio intrusion and weaker EAWM during El Niño years.It brings a large amount of high SST water with low nutrient concentration and high DIC,which is detrimental to CO_(2)dissolution and phytoplankton growth over the TWS,leading to an increase in pCO_(2).Conversely,pCO_(2)level is significantly low under the influence of SCS seawater during La Niña years.Based on the characterization of the pCO_(2)level response to ENSO,the carbon balance at TWS can be explored.展开更多
The Indonesian Throughflow(ITF),mainly through the Makassar Strait,transports amounts of water and salt from the tropical Pacific Ocean to the Indian Ocean,playing a crucial role in modulating heat and energy budget b...The Indonesian Throughflow(ITF),mainly through the Makassar Strait,transports amounts of water and salt from the tropical Pacific Ocean to the Indian Ocean,playing a crucial role in modulating heat and energy budget between two oceans.The South China Sea Throughflow(SCSTF)significantly contributes to the net transport of the ITF via Karimata Strait and Mindoro-Sibutu Passage.However,the specific proportion and variability of South China Sea(SCS)water joining the ITF are still unclear.Based on high-resolution reanalysis data and a Lagrangian particle tracking method-Connectivity Modelling System(CMS),we quantified the proportion and variability of SCS water joining the ITF in the Makassar Strait.The results show that about 16.41%of the particles released in the Makassar Strait could be back-tracked from the SCS and 42.45%from the western Pacific Ocean.The particles through Mindoro Strait and Karimata Strait are about 10.55%and 3.39%,respectively.About 14.56%and 15.42%particles are trapped in the Sulu and Sulawesi seas.The proportion of SCS water shows significant interannual variability,which is highly related to El Niño-Southern Oscillation(ENSO)events.The correlation coefficient between interannual change of SCS water volume proportion and the Niño 3.4 index is 0.75,with an increase of about 24%during El Niño years and a decrease of about−22%during La Niña years.The proportion also varies with the depth of particles released,showing two peaks at surface and subsurface depths of 5 m and 110 m,respectively.展开更多
Diurnal and semi-diurnal tides in the Taiwan Strait and its adjacent areas are calculated by using a two-dimensional finite-difference model. Compared with data of more than 20 observation stations around the Taiwan S...Diurnal and semi-diurnal tides in the Taiwan Strait and its adjacent areas are calculated by using a two-dimensional finite-difference model. Compared with data of more than 20 observation stations around the Taiwan Strait, the model-produced results agree quite well with those of previous researches using observational data from coastal tidal gauge stations. According to the results, the co-tidal and co-range charts are given. Furthermore, the characteristics of 8 major tidal constituents have been uminated respectively. The result shows that： （1） The tide motion can be attributed to the interaction between the degenerative rotary tidal system in the north and the progressive tidal system in the south. （2） The southward and northward tidal waves of semi-diurnal tide converge in the middle of the Taiwan Strait while the diurnal tidal waves propagate southwestward through the Taiwan Strait and the Luzon Strait. （3） The maximum amplitude of semi-diurnal tides exists at the area between the Meizhou Bay and Xinghua Bay, and that of diurnal tides appears in the region to the east of the Leizhou Peninsula, （4） The patterns of co-tidal and co-range charts of N2, K2 and P1, Q1 tidal constituents are similar to those of M2, S2 and K1 O1 tidat constituents, respectively展开更多
Based on 4 cruise surveys from July 2006 to October 2007 in the Taiwan Strait, the species composition, community structure and spatio-temporal distribution of dinoflagellate were studied. A total of 131 dinoflagellat...Based on 4 cruise surveys from July 2006 to October 2007 in the Taiwan Strait, the species composition, community structure and spatio-temporal distribution of dinoflagellate were studied. A total of 131 dinoflagellates belonging to 18 genera were identified. The population was dominated by hyperthermal and hyperhaline species accounting for 72.52% of the total species. Eurythermal and euryhaline species were the second most common one accounting for 25.19% of the total species. It was only 2.29% for neritic species. The maximum species number occurred in summer, while the maximum cell density appeared in spring. The average dinoflagellate cell density was 404.96x104 cells/m3. It showed that the dinof]agellate cell density increased from the nearshore waters to the open sea and from the north to the south. Compared with the results during 1984-1985, the horizontal distribution pattern and seaeonal variation of the dinofiagellate have not changed significantly, but the dinoflagellate cell density increased by 3.01 times. Further analysis of the dinoflagellate abundance variations both in the spatial and temporal aspects, indicated that the abundance of dinoflagellate increased more significantly in cold seasons, and there was a larger increase in the north of the Taiwan Strait. Besides, the dinoflagellate community structure changed notably. It showed that the diversity and evenness index were relatively high, and the proportion of dinoflageliate cell density to the total phytoplankton increased.展开更多
An analysis of historical oxygen data provides evidence on the water exchange between theSouth China Sea (SCS) and the Pacific Ocean (PO). In the vicinity of the Luzon Strait (LS) , the dissolved oxygen concentration ...An analysis of historical oxygen data provides evidence on the water exchange between theSouth China Sea (SCS) and the Pacific Ocean (PO). In the vicinity of the Luzon Strait (LS) , the dissolved oxygen concentration of sea water is found to be lower on the Pacific side than on the SCS side at depths between 700 and 1500 m (intermediate layer) , while the situation is reversed above 700 m (upper layer) and below 1 500 m (deep layer). The evidence suggests that water exits the SCS in the intermediate layer but enters it from the Pacific in both the upper and the deep layers, supporting the earlier speculation that the Luzon Strait transport has a sandwiched structure in the vertical. Within the SCS basin, the oxygen distribution indicates widespread vertical movement, including the upwelling in the intermediate layer and the downwelling in the deep layer.展开更多
基金Supported by the National Key Research and Development Program of China(No.2021YFB3901304)the Shandong Provincial Natural Science Foundation(No.ZR2024QD054)+2 种基金the National Key Research and Development Program of China(No.2019YFA0606702)the National Natural Science Foundation of China(Nos.41906157,42306194,42306195)the Oceanographic Data Center,Chinese Academy of Sciences and the platform of Sino-Indonesian Joint Laboratory for Marine Sciences(SIMS)。
文摘Internal solitary waves(ISWs)are an essential dynamic process in the ocean due to their large amplitude and long propagation distance.Traditional satellite observations provide only twodimensional observations of ocean signatures induced by ISWs.The Surface Water and Ocean Topography(SWOT)satellite has drawn significant attention due to its high resolution and threedimensional observation capabilities.SWOT can generate high-precision three-dimensional sea surface topography,capture sea surface undulations,and reveal ISW-related surface oscillations,thus offering a new perspective for studying ISWs.We collected 43 SWOT observations with clear ISW signatures in the Lombok Strait from August 2023 to June 2024.Based on collected data,the ISW imaging characteristics and distributions were analyzed,and the ISW-related sea level anomaly(SLA)data were measured by the SWOT to calculate the ISW amplitude and reveal the amplitude variations during the propagation along the wave crest.The ISW amplitudes generally range between 10 and 100 m,with most ISW amplitudes between 20 and 40 m.By analyzing two consecutive generated ISW packets,we identified the spreading effect along ISW wave crests,which manifests as ISW amplitude decrease with increase in propagation distance,and the amplitude distribution is non-uniform along the wave crest.Further analysis of the propagation paths of the maximum amplitude of ISW moving northward through the Lombok Strait revealed that these maxima are predominantly oriented in northeast direction.Finally,the relationship between the amplitude of ISW and the resulting SLA was analyzed.The Pearson correlation coefficient between these two variables is as high as 0.90,which suggests a strong positive correlation between amplitude and SLA.Furthermore,this relationship is closely related to the water depth,indicating that the three-dimensional sea surface observations provided by SWOT offer crucial observational data for the inversion of amplitudes of ISW.
基金the National Natural Science Foundation of China(Nos.42206076,42476078)the National Program on Global Change and Air-Sea Interaction(No.GASI-02-SCSCJB01)the China-Malaysia Cooperation Project‘Effect on variability of seasonal monsoon on sedimentary process in Peninsular Malaysia waters’。
文摘The Malacca Strait(MS)is a vital conduit for the exchange of water and sediment between the Indian Ocean and the Pacific Ocean,serving as a critical‘gateway'for sediment transport.Here,we present the geochemical characteristics of surface sediments in the MS to elucidate the relationship between terrestrial material inputs and modern oceanic dynamic transport processes in the strait.The results reveal that the MS can be divided into three distinct geochemical provinces.ProvinceⅠ,located in the central region of the strait,is characterized by residual deposits.The preservation of these residual deposits can be attributed to the restricted sediment supply and the relatively weaker modern sedimentary hydrodynamic conditions.ProvinceⅡ,situated to the north of ProvinceⅠ,exhibits provenance differences between its southern and northern regions.The northern region is primarily supplied by sediments originating from the eastern shelf of the Andaman Sea,whereas sediments derived from Sumatra and the Sunda Shelf are predominantly deposited in the southern part of ProvinceⅡ.ProvinceⅢextends along the western coast of the Malaysian Peninsula,with sediments primarily sourced from the Malaysian Peninsula and the Sunda Shelf,while contributions from Sumatra and the eastern shelf of the Andaman Sea are negligible.River sediments from the Malaysian Peninsula and Sumatra are transported northwestward along their respective coasts by prevailing currents,which also facilitate the transportation of Sunda Shelf sediments within the strait,while sediments from the eastern shelf of the Andaman Sea are delivered to the MS via southward coastal currents during the southwest monsoon period.The southward currents and well-developed eddies potentially impede the northward transport of sediments from the Sunda Shelf and restrict the distribution of Andaman Sea sediments within the strait.This study substantially enhances the understanding of source-to-sink processes in the Indo-Pacific region.
基金The National Natural Science Foundation of China under contract No.42076003.
文摘The impacts of the Luzon Strait transport on shallow meridional overturning circulation(SMOC)in the South China Sea(SCS)have been pointed out by previous studies,but the issue whether the Luzon Strait transport dominates the SMOC formation still remains open.The Helmholtz decomposition is applied based on the ocean general circulation model for the earth simulator products to address this issue.Results show that the motion caused by the Luzon Strait transport is characterized as an obvious southward flow between 13°N and 20°N.After this motion being removed,the clockwise winter SMOC and the anticlockwise summer SMOC can still exist significantly.The SMOC existence and its seasonal variation are also reproduced in the numerical simulation with the Luzon Strait closed.Both results of the Helmholtz decomposition and numerical experiment suggest that the SMOC formation and its seasonal variation are not dominated by the Luzon Strait transport.The SCS monsoon is the primary driving factor for the SMOC,which is related to the physical processes within the SCS.
基金The Key R&D Project of Zhejiang Province under contract No.2023C03120the General Scientific Research Project of Zhejiang Province under contract No.Y202353957the National Natural Science Foundation of China under contract No.42106017.
文摘El Niño-Southern Oscillation(ENSO)affects the changes in ocean physical elements in Taiwan Strait(TWS)primarily by regulating the strength of the East Asian Winter Monsoon(EAWM)and the intrusion of the Kuroshio.Additionally,the fluctuating impact between nutrient-poor seawater with high dissolved inorganic carbon(DIC)that infiltrates owing to the Kuroshio during El Niño phases and nutrient-rich seawater with low DIC from the South China Sea(SCS)carried by the EAWM during La Niña phases determines the nutrient content in TWS,thereby sculpting appropriate or unsuitable biochemical environment.In this study,based on high-resolution sea-surface partial pressure of carbon dioxide(pCO_(2))data,we investigate the relationship between pCO_(2)level of TWS and ENSO events in winter.The physical mechanisms affecting the anomalous distribution of pCO_(2)level during ENSO are also explored.Stepwise regression was employed to identify the optimal influencing factors for modeling pCO_(2).Results indicate a significant positive correlation between Niño3.4 index and pCO_(2),which is significantly influenced by factors such as sea-surface temperature(SST),chlorophyll-a(Chl a),and DIC.These are related to the anomalously strong Kuroshio intrusion and weaker EAWM during El Niño years.It brings a large amount of high SST water with low nutrient concentration and high DIC,which is detrimental to CO_(2)dissolution and phytoplankton growth over the TWS,leading to an increase in pCO_(2).Conversely,pCO_(2)level is significantly low under the influence of SCS seawater during La Niña years.Based on the characterization of the pCO_(2)level response to ENSO,the carbon balance at TWS can be explored.
基金The Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)under contact No.SML2021SP309the National Natural Science Foundation of China under contract Nos 42276005,42430402,and 92158204.
文摘The Indonesian Throughflow(ITF),mainly through the Makassar Strait,transports amounts of water and salt from the tropical Pacific Ocean to the Indian Ocean,playing a crucial role in modulating heat and energy budget between two oceans.The South China Sea Throughflow(SCSTF)significantly contributes to the net transport of the ITF via Karimata Strait and Mindoro-Sibutu Passage.However,the specific proportion and variability of South China Sea(SCS)water joining the ITF are still unclear.Based on high-resolution reanalysis data and a Lagrangian particle tracking method-Connectivity Modelling System(CMS),we quantified the proportion and variability of SCS water joining the ITF in the Makassar Strait.The results show that about 16.41%of the particles released in the Makassar Strait could be back-tracked from the SCS and 42.45%from the western Pacific Ocean.The particles through Mindoro Strait and Karimata Strait are about 10.55%and 3.39%,respectively.About 14.56%and 15.42%particles are trapped in the Sulu and Sulawesi seas.The proportion of SCS water shows significant interannual variability,which is highly related to El Niño-Southern Oscillation(ENSO)events.The correlation coefficient between interannual change of SCS water volume proportion and the Niño 3.4 index is 0.75,with an increase of about 24%during El Niño years and a decrease of about−22%during La Niña years.The proportion also varies with the depth of particles released,showing two peaks at surface and subsurface depths of 5 m and 110 m,respectively.
基金supported by the National Natural Science Foundation of China under contract Nos. 40576015, 40810069004 and 40821063by the key research project of Fujian Province under contract No. 2004N203by the Fujian demonstrating region of the "863" Project of the Ministry of Science and Technology of China
文摘Diurnal and semi-diurnal tides in the Taiwan Strait and its adjacent areas are calculated by using a two-dimensional finite-difference model. Compared with data of more than 20 observation stations around the Taiwan Strait, the model-produced results agree quite well with those of previous researches using observational data from coastal tidal gauge stations. According to the results, the co-tidal and co-range charts are given. Furthermore, the characteristics of 8 major tidal constituents have been uminated respectively. The result shows that： （1） The tide motion can be attributed to the interaction between the degenerative rotary tidal system in the north and the progressive tidal system in the south. （2） The southward and northward tidal waves of semi-diurnal tide converge in the middle of the Taiwan Strait while the diurnal tidal waves propagate southwestward through the Taiwan Strait and the Luzon Strait. （3） The maximum amplitude of semi-diurnal tides exists at the area between the Meizhou Bay and Xinghua Bay, and that of diurnal tides appears in the region to the east of the Leizhou Peninsula, （4） The patterns of co-tidal and co-range charts of N2, K2 and P1, Q1 tidal constituents are similar to those of M2, S2 and K1 O1 tidat constituents, respectively
基金supported by the Marine Biological Sample Collection of the Chinese Offshore Investigation and Assessment (No. 908-ZC-II-02)the Ministry of Science and Technology for Commonweal Project of China (No. 200905009-3)
文摘Based on 4 cruise surveys from July 2006 to October 2007 in the Taiwan Strait, the species composition, community structure and spatio-temporal distribution of dinoflagellate were studied. A total of 131 dinoflagellates belonging to 18 genera were identified. The population was dominated by hyperthermal and hyperhaline species accounting for 72.52% of the total species. Eurythermal and euryhaline species were the second most common one accounting for 25.19% of the total species. It was only 2.29% for neritic species. The maximum species number occurred in summer, while the maximum cell density appeared in spring. The average dinoflagellate cell density was 404.96x104 cells/m3. It showed that the dinof]agellate cell density increased from the nearshore waters to the open sea and from the north to the south. Compared with the results during 1984-1985, the horizontal distribution pattern and seaeonal variation of the dinofiagellate have not changed significantly, but the dinoflagellate cell density increased by 3.01 times. Further analysis of the dinoflagellate abundance variations both in the spatial and temporal aspects, indicated that the abundance of dinoflagellate increased more significantly in cold seasons, and there was a larger increase in the north of the Taiwan Strait. Besides, the dinoflagellate community structure changed notably. It showed that the diversity and evenness index were relatively high, and the proportion of dinoflageliate cell density to the total phytoplankton increased.
基金This research was funded by Frontier Research System for Global Change through its sponsorship of the International Pacific Research Center (IPRC) and by the U. S. National Science Foundation under contract Grant No. OCEOO - 95906.
文摘An analysis of historical oxygen data provides evidence on the water exchange between theSouth China Sea (SCS) and the Pacific Ocean (PO). In the vicinity of the Luzon Strait (LS) , the dissolved oxygen concentration of sea water is found to be lower on the Pacific side than on the SCS side at depths between 700 and 1500 m (intermediate layer) , while the situation is reversed above 700 m (upper layer) and below 1 500 m (deep layer). The evidence suggests that water exits the SCS in the intermediate layer but enters it from the Pacific in both the upper and the deep layers, supporting the earlier speculation that the Luzon Strait transport has a sandwiched structure in the vertical. Within the SCS basin, the oxygen distribution indicates widespread vertical movement, including the upwelling in the intermediate layer and the downwelling in the deep layer.
