2005 Vol. 24, No. 1
Display Method:
2005, (1): 1-13.
Abstract:
On the basis of the current measurements at 200,500 and 800 m from moored current meters with the time series data from March 17 to April 15 at the mooring station (20°49'57"N,120°48' 12"E) and the hydrographic data obtained in the Luzon Strait during the spring of 2002 cruise,the circulation in the investigated area is computed by using the modified inverse method.The major observed results are as follows:(1) the average velocity and the flow direction in the observing days are (47.4 cm/s,346°) at the 200 m level.The aver age velocity in the observing days is (20.3 cm/s,350°) at the 500 m level.These mean that the Kuroshio intrudes into the South Chin Sea to flow northwestward through the Luzon Strait at 200 and 500 m levels.(2) The average velocity in the observing days is (1.2cm/s,35°) at the 800 m level,I.E.,its direction is northeastward.This means that the flow condition at the 800 m level very differs from that at the 200 and 500 m levels.(3) There is the high density and cold water (HDCW) in the middle of western part of in the investigated region,and its center is located near the hydrological station 3 at Section A.(4) There is the lower density and warm water (LDWW) in the southeastern part of investigated region.(5) The currents in April 2002 are stronger than those in March 2002.The major computed results are as follows:(1) The northwestward and southeastward VTs through Section B are 32.48×106 m3/s (inclusive of VT ofanticyclonic eddy) and 3.34×106 m3/s,respectively.The net northwestward VT through Section B in the investigated area is about 29.14×106 m3/s.(2) The eastern and western VTs through Section A are about 16.71×106 and 8.57×106 m3/s,respectively.Thus,the net eastward VT through Section A is about 8.14×106 m3/s.(3) The net northward VT through Section M is about 24.68×106 m3/s.(4) After about 24.68×106 m3/s flows through Section M,most of it,about 16.54×106 m3/s,flows northward through the eastern part of Section C and then flows northward into the region east Taiwan Island.The other part of it,about 8.14×106 m3/s,branches out from the main Kuroshio and then flows meanderingly through the western part of Section C.Thus,the Kuroshio has the two cores of current at Section C.(5) The direction of the computed current near the mooring station M agrees with the direction of the current measurements at 200 and 500 m from moored current meters,i.e.,their directions both are northwestward.(6) About 3.34×106 m3/s of the South Chin Sea water probably flows slowly from the northwest to the southeast in the layer below 550 m at the western part of Section B.
On the basis of the current measurements at 200,500 and 800 m from moored current meters with the time series data from March 17 to April 15 at the mooring station (20°49'57"N,120°48' 12"E) and the hydrographic data obtained in the Luzon Strait during the spring of 2002 cruise,the circulation in the investigated area is computed by using the modified inverse method.The major observed results are as follows:(1) the average velocity and the flow direction in the observing days are (47.4 cm/s,346°) at the 200 m level.The aver age velocity in the observing days is (20.3 cm/s,350°) at the 500 m level.These mean that the Kuroshio intrudes into the South Chin Sea to flow northwestward through the Luzon Strait at 200 and 500 m levels.(2) The average velocity in the observing days is (1.2cm/s,35°) at the 800 m level,I.E.,its direction is northeastward.This means that the flow condition at the 800 m level very differs from that at the 200 and 500 m levels.(3) There is the high density and cold water (HDCW) in the middle of western part of in the investigated region,and its center is located near the hydrological station 3 at Section A.(4) There is the lower density and warm water (LDWW) in the southeastern part of investigated region.(5) The currents in April 2002 are stronger than those in March 2002.The major computed results are as follows:(1) The northwestward and southeastward VTs through Section B are 32.48×106 m3/s (inclusive of VT ofanticyclonic eddy) and 3.34×106 m3/s,respectively.The net northwestward VT through Section B in the investigated area is about 29.14×106 m3/s.(2) The eastern and western VTs through Section A are about 16.71×106 and 8.57×106 m3/s,respectively.Thus,the net eastward VT through Section A is about 8.14×106 m3/s.(3) The net northward VT through Section M is about 24.68×106 m3/s.(4) After about 24.68×106 m3/s flows through Section M,most of it,about 16.54×106 m3/s,flows northward through the eastern part of Section C and then flows northward into the region east Taiwan Island.The other part of it,about 8.14×106 m3/s,branches out from the main Kuroshio and then flows meanderingly through the western part of Section C.Thus,the Kuroshio has the two cores of current at Section C.(5) The direction of the computed current near the mooring station M agrees with the direction of the current measurements at 200 and 500 m from moored current meters,i.e.,their directions both are northwestward.(6) About 3.34×106 m3/s of the South Chin Sea water probably flows slowly from the northwest to the southeast in the layer below 550 m at the western part of Section B.
2005, (1): 14-30.
Abstract:
On the basis of hydrographic data obtained in August 2000 cruise,the circulation in the South China Sea (SCS) is computed by the modified inverse method in combination with SSH data from TOPEX/ERS-2 analysis.For study of the dynamical mechanism,which causes the pattern of summer circulation in the SCS,the diagnostic model (Yuan et al.1982.Acta Oceanologica Sinica,4(1):1~11;Yuan and Su.1992.Numerical Computation of Physical Oceanography.474~542) is used to simulate numerically the summer circulation in the SCS.The following results have been obtained.(1) The central and southwestern SCSs are dominated mainly by anticyclonic circulation systems.They are mainly as follows.1) There is strong anticyclonic eddy southeast of Vietnam (W1).Its horizontal scale is about 300 kin,and it extends vertically from the surface to the about 1 000 m level.2) There are a warm eddy W2 southeast of Zhongsha Islands and the anticyclonic circulation system W3 west off the Luzon Island.3) There is a stronger cyclonic eddy C1 between the anticyclonic eddies W1 and W2.4) A strong northward coastal jet is present near the coast of Vietnam,and separates from the coast of Vietnam at about 12°N to the northeast.(2)The northern SCS is dominated mainly by a cyclonic circulation system.There is a cyclonic circulation system near and north of Section N2.(3) The southeastern SCS is dominated mainly by the cyclonic circulation system.(4) Comparing the results of circulation in the SCS during the summer of 2000 with those during the summer of 1998,it is found that they agree qualitatively,but there is the some difference between them in quantity.This shows that the circulation in the SCShas obviously seasonal feature.(5) The dynamical mechanism which products the basic pattern of summer circulation is because the following two reasons:1) the joint effect of the baroclinity and relief (JEBAR) is essential dynamical cause; and 2) it is next important dynamical cause that the interaction between the wind stress and bottom topography under the southerly monsoon.(6) Comparing the hydrographic structure and distribution of stream functions with the SSH data from TOPEX/ERS-2 analysis in the SCS during August of 2000,they agree qualitatively.
On the basis of hydrographic data obtained in August 2000 cruise,the circulation in the South China Sea (SCS) is computed by the modified inverse method in combination with SSH data from TOPEX/ERS-2 analysis.For study of the dynamical mechanism,which causes the pattern of summer circulation in the SCS,the diagnostic model (Yuan et al.1982.Acta Oceanologica Sinica,4(1):1~11;Yuan and Su.1992.Numerical Computation of Physical Oceanography.474~542) is used to simulate numerically the summer circulation in the SCS.The following results have been obtained.(1) The central and southwestern SCSs are dominated mainly by anticyclonic circulation systems.They are mainly as follows.1) There is strong anticyclonic eddy southeast of Vietnam (W1).Its horizontal scale is about 300 kin,and it extends vertically from the surface to the about 1 000 m level.2) There are a warm eddy W2 southeast of Zhongsha Islands and the anticyclonic circulation system W3 west off the Luzon Island.3) There is a stronger cyclonic eddy C1 between the anticyclonic eddies W1 and W2.4) A strong northward coastal jet is present near the coast of Vietnam,and separates from the coast of Vietnam at about 12°N to the northeast.(2)The northern SCS is dominated mainly by a cyclonic circulation system.There is a cyclonic circulation system near and north of Section N2.(3) The southeastern SCS is dominated mainly by the cyclonic circulation system.(4) Comparing the results of circulation in the SCS during the summer of 2000 with those during the summer of 1998,it is found that they agree qualitatively,but there is the some difference between them in quantity.This shows that the circulation in the SCShas obviously seasonal feature.(5) The dynamical mechanism which products the basic pattern of summer circulation is because the following two reasons:1) the joint effect of the baroclinity and relief (JEBAR) is essential dynamical cause; and 2) it is next important dynamical cause that the interaction between the wind stress and bottom topography under the southerly monsoon.(6) Comparing the hydrographic structure and distribution of stream functions with the SSH data from TOPEX/ERS-2 analysis in the SCS during August of 2000,they agree qualitatively.
2005, (1): 31-38.
Abstract:
A coupled single-layer/two-layer model is employed to study the South China Sea (SCS) upper circulation and its response before and after the onset of summer monsoon.It is found that,in summer,due to the β effect and the first baroclinic mode of the wind-driven current,a northward western boundary jet current is formed along the Indo-China Peninsula coast,and it leaves the coast at about 13° N and diffuses towards northeast; next to the Indo-China Peninsula,a large anticyclonic gyre in the southern SCS and a cyclonic eddy to the north of this gyre are induced.There are two possible mechanisms for the generation of this anticyclonic gyre:first,it is induced by the summer wind stress curl; second,it is associated with the westward moving of two anticyclonic eddies,which are originally generated to the west of Palawan Island and over the Nansha Trough respectively,in winter.The cyclonic eddy north of this anticyclonic gyre may be induced by the summer wind stess curl or related to the southwestward moving of the cyclonic eddy/gyre induced by the Kuroshio branch in the northern SCS.
A coupled single-layer/two-layer model is employed to study the South China Sea (SCS) upper circulation and its response before and after the onset of summer monsoon.It is found that,in summer,due to the β effect and the first baroclinic mode of the wind-driven current,a northward western boundary jet current is formed along the Indo-China Peninsula coast,and it leaves the coast at about 13° N and diffuses towards northeast; next to the Indo-China Peninsula,a large anticyclonic gyre in the southern SCS and a cyclonic eddy to the north of this gyre are induced.There are two possible mechanisms for the generation of this anticyclonic gyre:first,it is induced by the summer wind stress curl; second,it is associated with the westward moving of two anticyclonic eddies,which are originally generated to the west of Palawan Island and over the Nansha Trough respectively,in winter.The cyclonic eddy north of this anticyclonic gyre may be induced by the summer wind stess curl or related to the southwestward moving of the cyclonic eddy/gyre induced by the Kuroshio branch in the northern SCS.
2005, (1): 39-45.
Abstract:
Some life history statistics of the mesoscale eddies of the South China Sea (SCS) derived from altimetry data will be further discussed according their different formation periods.A total of three ATLAS (autonomous temperature line acquisition system)mooring buoys data will be analyzed to discuss eddies' impact on temperature profiles.They identify that the intraseasonal variation of SCS thermocline is partly controlled by mesoscale eddies.
Some life history statistics of the mesoscale eddies of the South China Sea (SCS) derived from altimetry data will be further discussed according their different formation periods.A total of three ATLAS (autonomous temperature line acquisition system)mooring buoys data will be analyzed to discuss eddies' impact on temperature profiles.They identify that the intraseasonal variation of SCS thermocline is partly controlled by mesoscale eddies.
2005, (1): 46-59.
Abstract:
A simulation of suspended sediment movement relating to tidal and wave forcing during a winter monsoon in November 1983 in the Huanghai and East China Seas continental shelf is attempted by using the model describing the cohesive/non-cohesive sediment resuspension generated by interactions between currents and waves.model simulation showed that sediment concentrafon was increased by resuspension at shallow depths during the strong storm conditions due to high bottom stress interacted between currents and waves.This result is in general agreement with observations in horizontal distribution of suspended sediment distribution.At three current meter mooring positions off the southern Shandong Peninsula resusponsion occurred only at a depth of 22 m,nearest coastal position and at deeper parts at depths of 51 and 80 m wave-current interaction effects were not significant.It has shown that the present model simulation demonstrated the capability of reproduction of suspended sediment movement under wintertime extreme event reasonably well.
A simulation of suspended sediment movement relating to tidal and wave forcing during a winter monsoon in November 1983 in the Huanghai and East China Seas continental shelf is attempted by using the model describing the cohesive/non-cohesive sediment resuspension generated by interactions between currents and waves.model simulation showed that sediment concentrafon was increased by resuspension at shallow depths during the strong storm conditions due to high bottom stress interacted between currents and waves.This result is in general agreement with observations in horizontal distribution of suspended sediment distribution.At three current meter mooring positions off the southern Shandong Peninsula resusponsion occurred only at a depth of 22 m,nearest coastal position and at deeper parts at depths of 51 and 80 m wave-current interaction effects were not significant.It has shown that the present model simulation demonstrated the capability of reproduction of suspended sediment movement under wintertime extreme event reasonably well.
A three-dimensional model study on ocean dynamic response to traveling cyclone over the Huanghai Sea
2005, (1): 60-75.
Abstract:
On the basis of numerical simulation of the mean circulation and relevant thermal-salinity fields in June with a three-dimensional ocean model (ECOM-si),the model outputs are used as first guess of initial fields for numerical integration of the model equations and the numerical results are applied to investigating the dynamical responses of the Huanghai Sea and the East China Sea (HECS) in the course of a weak land-to-sea cyclone's passage over the Huanghai Sea on 15~16 June 1999.Predominance of the dynamic impact of cyclone over the thermal one in June in the HECS is justified using observations and model simulations.The cyclone and its surrounding weather system,i.e.,subtropical high ridge to its south could influence current and thermal fields in the Bohai Sea,the Huanghai Sea and the northern East China Sea even though the intensity of cyclone was rather weak.The response of oceanic currents to the wind stresses driven by the cyclone and its southern subtropical high were strongly characterized by the wind driit with its extent of equivalent scale of cyclone in the horizontal and of Ekman layer in the vertical.The sea response at a given site was closely related to the transient local wind speed and direction,especially was sensitive to the local wind direction,which is demonstrated at three points locating at the southern and western Huanghai Sea and the northern East China Sea.So the sea responses at locations differed considerably from one another.Current responded to the wind stress in a simple way:directly to the wind-driven current and subsequent gradient current and slope current,etc.,whereas sea temperature responded to the wind stress in two ways:directly to the cyclone-induced cooling and indirectly to water movements both in the horizontal and the vertical by the cyclone's wind stress.So the sea temperature variation under the influence of cyclone was more complicate than the current.The HECS in response to the cyclone and its ambient weather system was likely to be a fast process and such a response could last at least for more than 1 d.Current increased with the duration of wind stress exerted on the surface and decreased with the increasing depth.Affected by the cyclone,the maximum sea surface temperature decreased by almost 1.6℃ during the 24 h cyclone.
On the basis of numerical simulation of the mean circulation and relevant thermal-salinity fields in June with a three-dimensional ocean model (ECOM-si),the model outputs are used as first guess of initial fields for numerical integration of the model equations and the numerical results are applied to investigating the dynamical responses of the Huanghai Sea and the East China Sea (HECS) in the course of a weak land-to-sea cyclone's passage over the Huanghai Sea on 15~16 June 1999.Predominance of the dynamic impact of cyclone over the thermal one in June in the HECS is justified using observations and model simulations.The cyclone and its surrounding weather system,i.e.,subtropical high ridge to its south could influence current and thermal fields in the Bohai Sea,the Huanghai Sea and the northern East China Sea even though the intensity of cyclone was rather weak.The response of oceanic currents to the wind stresses driven by the cyclone and its southern subtropical high were strongly characterized by the wind driit with its extent of equivalent scale of cyclone in the horizontal and of Ekman layer in the vertical.The sea response at a given site was closely related to the transient local wind speed and direction,especially was sensitive to the local wind direction,which is demonstrated at three points locating at the southern and western Huanghai Sea and the northern East China Sea.So the sea responses at locations differed considerably from one another.Current responded to the wind stress in a simple way:directly to the wind-driven current and subsequent gradient current and slope current,etc.,whereas sea temperature responded to the wind stress in two ways:directly to the cyclone-induced cooling and indirectly to water movements both in the horizontal and the vertical by the cyclone's wind stress.So the sea temperature variation under the influence of cyclone was more complicate than the current.The HECS in response to the cyclone and its ambient weather system was likely to be a fast process and such a response could last at least for more than 1 d.Current increased with the duration of wind stress exerted on the surface and decreased with the increasing depth.Affected by the cyclone,the maximum sea surface temperature decreased by almost 1.6℃ during the 24 h cyclone.
2005, (1): 76-85.
Abstract:
Seasonal variation and topography of the mixed layer in the Sea of Japan are studied by comparison of results from long-term observation data analysis and from numerical simulation with the MHI oceanic model (Shapiro.1998.Marine Hydrophysical Journal,6:26~40).The data are retrieved from Oceanographic Atlas of the Bering Sea,Okhotsk Sea,and Japan/East Sea (Rostov,Rostov,Dmitrieva,et al.2003.Pacific Oceanography,1(1):70~72).The simulated and long-term patterns are compared.An impact of surface buoyancy flux,wind,and convergence/divergence of surface currents upon the mixed layer in the Sea of Japan is analyzed.
Seasonal variation and topography of the mixed layer in the Sea of Japan are studied by comparison of results from long-term observation data analysis and from numerical simulation with the MHI oceanic model (Shapiro.1998.Marine Hydrophysical Journal,6:26~40).The data are retrieved from Oceanographic Atlas of the Bering Sea,Okhotsk Sea,and Japan/East Sea (Rostov,Rostov,Dmitrieva,et al.2003.Pacific Oceanography,1(1):70~72).The simulated and long-term patterns are compared.An impact of surface buoyancy flux,wind,and convergence/divergence of surface currents upon the mixed layer in the Sea of Japan is analyzed.
2005, (1): 86-94.
Abstract:
Eight sets of coastal acoustic tomography (CAT) systems were deployed during November 29 to December 10,2002 at the coasts on both sides of Tokyo Bay to measure tidal current structures at 15-min interval.Sound transmission across the Tokyo Bay (between Yokohama and Chiba)was successfully traced,even under severe interference from ship generated wakes and bubbles.Tidal current fields changing from northward to southward flow are well reconstructed by the inverse analysis of travel-time difference data for a period with the best sound transmission condition.It is suggested that the CAT is the most powerful tool to continuously map tidal current fields in the coastal seas with heavy shipping traffic and fisheries activity.
Eight sets of coastal acoustic tomography (CAT) systems were deployed during November 29 to December 10,2002 at the coasts on both sides of Tokyo Bay to measure tidal current structures at 15-min interval.Sound transmission across the Tokyo Bay (between Yokohama and Chiba)was successfully traced,even under severe interference from ship generated wakes and bubbles.Tidal current fields changing from northward to southward flow are well reconstructed by the inverse analysis of travel-time difference data for a period with the best sound transmission condition.It is suggested that the CAT is the most powerful tool to continuously map tidal current fields in the coastal seas with heavy shipping traffic and fisheries activity.
2005, (1): 95-100.
Abstract:
Three kind of application of ADCP is reported for long-term monitoring in coastal sea.(1)The rourine monitoring of water qualities.The water quality and ADCP echo data (600 kHz) observed in the long-term are analgzed at MT (Marine Tower) Station of Kansai International Airport in the Osaka Bay,Japan.The correlation between the turbidity and echo intensity in the surface layer is not good because air bubbles generated by breaking wave are not detected by the turbidity meter,but detected well by ADCP.When estimating the turbidity consists of plankton population from echo intensity,the effect of bubbles have to be eliminated.(2) Monitoring stirring up of bottom sediment.The special observation was carded out by using following two ADCP in the Osaka Bay,One ADCP was installed upward on the sea.The other ADCP was hanged downward at the gate type stand about 3 m above from the bottom.At the spring tide,high echo intensities indicating the stirring up of bottom sediment were observed.(3) The monitoring for the boundary condition of water mixing at an estuary.In summer season,the ADCP was set at the mouth of Tanabe Bay in Wakayama Prefecture,Japan.During the observation,water temperature near the bottom showed remarkable falls with interval of about 5~7 d.When the bottom temperature fell,the inflow current with low echo intensity water appears at the bottom layer in the ADCP record.It is concluded that when occasional weak northeast wind makes weak coastal upwelling at the mouth of the bay,the combination of upwelling with internal tidal flow causes remarkable water exchange and dispels the red tide.
Three kind of application of ADCP is reported for long-term monitoring in coastal sea.(1)The rourine monitoring of water qualities.The water quality and ADCP echo data (600 kHz) observed in the long-term are analgzed at MT (Marine Tower) Station of Kansai International Airport in the Osaka Bay,Japan.The correlation between the turbidity and echo intensity in the surface layer is not good because air bubbles generated by breaking wave are not detected by the turbidity meter,but detected well by ADCP.When estimating the turbidity consists of plankton population from echo intensity,the effect of bubbles have to be eliminated.(2) Monitoring stirring up of bottom sediment.The special observation was carded out by using following two ADCP in the Osaka Bay,One ADCP was installed upward on the sea.The other ADCP was hanged downward at the gate type stand about 3 m above from the bottom.At the spring tide,high echo intensities indicating the stirring up of bottom sediment were observed.(3) The monitoring for the boundary condition of water mixing at an estuary.In summer season,the ADCP was set at the mouth of Tanabe Bay in Wakayama Prefecture,Japan.During the observation,water temperature near the bottom showed remarkable falls with interval of about 5~7 d.When the bottom temperature fell,the inflow current with low echo intensity water appears at the bottom layer in the ADCP record.It is concluded that when occasional weak northeast wind makes weak coastal upwelling at the mouth of the bay,the combination of upwelling with internal tidal flow causes remarkable water exchange and dispels the red tide.
2005, (1): 101-106.
Abstract:
HAB (harmful algal bloom) is a serious marine ecological disaster.Up to now there is no definite conclusion about its mechanism of occurrence.The observation results show that the HAB breakout in the Xiangshan Bay was mainly caused by physical convergence capacity,and the breakout process had no direct relation to eutrophication.As a new idea it is thought that the process of the HAB breakout is mainly a physical convergence or accumulation process in some areas.A hypothesis about dynamic mechanism of the HAB appearing in the area off the Changjiang Estuary is put forward according to hydrology and topography and the past work,and a breakthrough is expected to be made for doing further research.
HAB (harmful algal bloom) is a serious marine ecological disaster.Up to now there is no definite conclusion about its mechanism of occurrence.The observation results show that the HAB breakout in the Xiangshan Bay was mainly caused by physical convergence capacity,and the breakout process had no direct relation to eutrophication.As a new idea it is thought that the process of the HAB breakout is mainly a physical convergence or accumulation process in some areas.A hypothesis about dynamic mechanism of the HAB appearing in the area off the Changjiang Estuary is put forward according to hydrology and topography and the past work,and a breakthrough is expected to be made for doing further research.
2005, (1): 107-114.
Abstract:
Sea surface wind stress variabilities near and off the east coast of Korea,are examined using 7 kinds of wind datasets from measurements at 2 coastal (land) stations and 2 ocean buoys,satellite scatterometer (QuikSCAT),and global reanalyzed products (ECMWF,NOGAPS,and NCEP/NCAR).Temporal variabilities are analyzed at 3 frequency bands; synoptic (2~20 d),intra-seasonal (20~90 d),and seasonal (>90 d).Synoptic and intra-seasonal variations are predominant near and off the Donghae City due to the passage of the mesoscale weather system.Seasonal variation is caused by southeastward wind stress during Asian winter monsoon.The sea surface wind stress from reanalyzed datasets,QuikSCAT and KMA-B measurements off the coast show good agreement in the magnitude and direction,which are strongly aligned with the alongshore direction.At the land-based sites,wind stresses are much weaker by factors of 3~10 due to the mountainous landmass on the east parts of Korea Peninsula.The first EOF modes(67%~70%) of wind stresses from reanalyzed and QuikSCAT data have similar structures of the strong southeastward wind stress in winter along the coast but show different curl structures at scales less than 200 kn due to the orographic effects.The second EOF modes (23%~25%)show southwestward wind stress in every September along the east coast of the North Korea.
Sea surface wind stress variabilities near and off the east coast of Korea,are examined using 7 kinds of wind datasets from measurements at 2 coastal (land) stations and 2 ocean buoys,satellite scatterometer (QuikSCAT),and global reanalyzed products (ECMWF,NOGAPS,and NCEP/NCAR).Temporal variabilities are analyzed at 3 frequency bands; synoptic (2~20 d),intra-seasonal (20~90 d),and seasonal (>90 d).Synoptic and intra-seasonal variations are predominant near and off the Donghae City due to the passage of the mesoscale weather system.Seasonal variation is caused by southeastward wind stress during Asian winter monsoon.The sea surface wind stress from reanalyzed datasets,QuikSCAT and KMA-B measurements off the coast show good agreement in the magnitude and direction,which are strongly aligned with the alongshore direction.At the land-based sites,wind stresses are much weaker by factors of 3~10 due to the mountainous landmass on the east parts of Korea Peninsula.The first EOF modes(67%~70%) of wind stresses from reanalyzed and QuikSCAT data have similar structures of the strong southeastward wind stress in winter along the coast but show different curl structures at scales less than 200 kn due to the orographic effects.The second EOF modes (23%~25%)show southwestward wind stress in every September along the east coast of the North Korea.
2005, (1): 115-124.
Abstract:
In order to determine the relative aging status ofupwelled or vertically mixed water in the northern Taiwan Strait,a recently developed method of calcularing the degree of nutrient consumption (DNC) was employed.Upwelling was detected at a water depth of about 75 m in summer.Bottom waters in the aphoric zone and newly-upwelled waters in the euphoric zone were found to be low in terms of their DNC.In general,a low DNC was noted alongside the other traditional upwelling indicators,such as lower temperature and degree of oxygen saturation,but higher salinity,apparent oxygen utilization,nutrient contents and chlorophyll-a.Enhanced vertical mixing,but without an apparent upwelling signal,was detected near the same location in winter.
In order to determine the relative aging status ofupwelled or vertically mixed water in the northern Taiwan Strait,a recently developed method of calcularing the degree of nutrient consumption (DNC) was employed.Upwelling was detected at a water depth of about 75 m in summer.Bottom waters in the aphoric zone and newly-upwelled waters in the euphoric zone were found to be low in terms of their DNC.In general,a low DNC was noted alongside the other traditional upwelling indicators,such as lower temperature and degree of oxygen saturation,but higher salinity,apparent oxygen utilization,nutrient contents and chlorophyll-a.Enhanced vertical mixing,but without an apparent upwelling signal,was detected near the same location in winter.
2005, (1): 125-133.
Abstract:
Kueishan Tao (24°51'N,121°55'E) is located at a tectonic junction of the fault system extension of Taiwan and the southern rifting end of the Okinawa Trough.A cluster of over 30 vents,at a water depth of about 10~20 m off the eastern tip of the tao emits hydrothermal fluids and volcanic gases such as H2S.A sulfur chimney or mound,formed by condensation of the sulfur contained in the hydrothermal fluid,can usually be seen around the vents.The tallest chimney reaches 6 m.Vents discharging a yellowish fluid have temperatures between 92 and 116℃ and flow rates as high as 158 t/h; vents discharging a whitish fluid have lower temperatures of between 48 and 62℃ and lower flow rates of about 7.0 t/h.These world-record,breaking low pH (as low as 1.52) fluids are totally different from those found in the black and white-chimneys of the mid-ocean ridges.Magnesium and SiO2 data indicate that these hydrothermal fluids probably originate from a depth of 915~1 350 m below the surface.While the ratios of major ions relative to the sodium of these hydrothermal fluids are quite similar to open ocean water,the ratios of SO4 and chloride to sodium seem to be higher for some of the vents.It is suggested that the volcanic gases contribute SO4 and ohlorine to the fluids,hence increasing their ratios relative to sodium.Some hydrothermal fluids,however,are found to be depleted of the major elements which can have been caused by phase separation.The concentrations of iron and manganese in the fluids are much lower than those found in the mid-ocean ridges,while the aluminium content is higher.Four species of benthos (Xenograpsus testudinatus,a snail,a sea anemone,and a Sipuncala),1 species of algae (Corallinaceae),and 1 species of fish (Siganus fusescens) were recorded near the hydrothermal vents.A mitoehondria DNA sequence comparison of Xenograpsus testudinatus with 6 other decapod species shows the greatest number of nitrogen base differences in the DNA fragments from 225 to 270.The gene diversity in this DNAregion possibly results from the unusual habitat.A sediment core was collected at a pond near the eastern side of the tao.No volcanic ash could be detected in the core sample spanning 3 620 a.
Kueishan Tao (24°51'N,121°55'E) is located at a tectonic junction of the fault system extension of Taiwan and the southern rifting end of the Okinawa Trough.A cluster of over 30 vents,at a water depth of about 10~20 m off the eastern tip of the tao emits hydrothermal fluids and volcanic gases such as H2S.A sulfur chimney or mound,formed by condensation of the sulfur contained in the hydrothermal fluid,can usually be seen around the vents.The tallest chimney reaches 6 m.Vents discharging a yellowish fluid have temperatures between 92 and 116℃ and flow rates as high as 158 t/h; vents discharging a whitish fluid have lower temperatures of between 48 and 62℃ and lower flow rates of about 7.0 t/h.These world-record,breaking low pH (as low as 1.52) fluids are totally different from those found in the black and white-chimneys of the mid-ocean ridges.Magnesium and SiO2 data indicate that these hydrothermal fluids probably originate from a depth of 915~1 350 m below the surface.While the ratios of major ions relative to the sodium of these hydrothermal fluids are quite similar to open ocean water,the ratios of SO4 and chloride to sodium seem to be higher for some of the vents.It is suggested that the volcanic gases contribute SO4 and ohlorine to the fluids,hence increasing their ratios relative to sodium.Some hydrothermal fluids,however,are found to be depleted of the major elements which can have been caused by phase separation.The concentrations of iron and manganese in the fluids are much lower than those found in the mid-ocean ridges,while the aluminium content is higher.Four species of benthos (Xenograpsus testudinatus,a snail,a sea anemone,and a Sipuncala),1 species of algae (Corallinaceae),and 1 species of fish (Siganus fusescens) were recorded near the hydrothermal vents.A mitoehondria DNA sequence comparison of Xenograpsus testudinatus with 6 other decapod species shows the greatest number of nitrogen base differences in the DNA fragments from 225 to 270.The gene diversity in this DNAregion possibly results from the unusual habitat.A sediment core was collected at a pond near the eastern side of the tao.No volcanic ash could be detected in the core sample spanning 3 620 a.
2005, (1): 134-145.
Abstract:
The long-term adjustment processes of atmosphere and ocean in response to gradually increased atmospheric CO2 concentration have been analyzed in 70 and 140 a integrations with NCAR fully-coupled climate system model (CSM).In these experiments the CO2 concentration has been increased to double and quadruples the initial concentration,respectively.After 70 a,at the time of CO2 doubling,the model predicts surface air temperature rises by 1.2 and 1.5 K for the globe and the northwestern Pacific Ocean,respectively.The behavior of the quadrupling run is similar:each global and regional mean surface air temperatures increase by 2.8 and 3.0 K at the time of CO2 quadrupling.From the experiments,surface air temperature changes in the northwestern Pacific Ocean will be more distinctive compared with the global average,mainly due to exceptionally large warming and sea level change near the entrance of the Kuroshio extension.
The long-term adjustment processes of atmosphere and ocean in response to gradually increased atmospheric CO2 concentration have been analyzed in 70 and 140 a integrations with NCAR fully-coupled climate system model (CSM).In these experiments the CO2 concentration has been increased to double and quadruples the initial concentration,respectively.After 70 a,at the time of CO2 doubling,the model predicts surface air temperature rises by 1.2 and 1.5 K for the globe and the northwestern Pacific Ocean,respectively.The behavior of the quadrupling run is similar:each global and regional mean surface air temperatures increase by 2.8 and 3.0 K at the time of CO2 quadrupling.From the experiments,surface air temperature changes in the northwestern Pacific Ocean will be more distinctive compared with the global average,mainly due to exceptionally large warming and sea level change near the entrance of the Kuroshio extension.
