A morphology-based edge detection method has been used to study sea surface temperature (SST) fronts in the Taiwan Strait and its adjacent area. The method is based on mathematical morphology with multi-dimensional an...A morphology-based edge detection method has been used to study sea surface temperature (SST) fronts in the Taiwan Strait and its adjacent area. The method is based on mathematical morphology with multi-dimensional and multi-structural elements. Using six years’ SST data from September 2002 to August 2008, we distinguished the large SST front like Kuroshio Front as well as the smaller ones: namely Taiwan Bank Front, Zhe-Min Coastal Front and Zhang-Yun Ridge Front. The seasonal and monthly variations of these fronts were also studied. Generally, the SST fronts are stronger in winter but weaker in summer. And the fronts are at their active stage during the period from January to May but at their declining stage during the period from July to October.展开更多
The present paper uses planktonic foraminifera and their stableisotopes to study the changes in the depth of thermocline (DOT) in the Okinawa Trough since the last 10000 a based on the analysis of Core B-3GC in the no...The present paper uses planktonic foraminifera and their stableisotopes to study the changes in the depth of thermocline (DOT) in the Okinawa Trough since the last 10000 a based on the analysis of Core B-3GC in the northern Okinawa Trough, together with that of the core in the southern Okinawa Trough. As results show, the thermocline was shallow before 6400 aBP, and deepened afterward, then became shallow again from 4000 to 2000 aBP. The DOT fluctuations display a positive correlation with those of sea surface temperature (SST). In addition, the changes in the northern Okinawa Trough are similar to those in the southern trough, implying a possible connection with the variation of the Kuroshio Current. The changes of SST and DOT suggest that the Kuroshio Current changed its intensity or main axis from 4000 to 2000 aBP and around about 6400 aBP respectively. Moreover, the changes of DOT from 8200 to 6400 aBP may indicate a gradual intensification of the Kuroshio Current.展开更多
Sea surface temperature(SST)in the Yellow Sea Warm Current(YSWC)pathway is sensitive to the East Asian Winter Monsoon(EAWM)and YSWC.However,the role of the YSWC in the evolution of regional SST remains unclear.Here,we...Sea surface temperature(SST)in the Yellow Sea Warm Current(YSWC)pathway is sensitive to the East Asian Winter Monsoon(EAWM)and YSWC.However,the role of the YSWC in the evolution of regional SST remains unclear.Here,we present new U 37 k′based SST and grain size sequences spanning the last 6092 years in the sediment core Z1,which was retrieved from the central Yellow Sea muddy area.Overall,U 37 k′-SST gradually increased since 6.1 ka BP,with a series of centennial-scale fl uctuations.Its variation was mainly caused by EAWM when YSWC was weak between 6.1 and~3.9 ka BP,as shown by the end-member content of grain size.However,after YSWC was fully developed,i.e.,since~3.9 ka BP,it exerted critical eff ects on SST evolution in its pathway.The 1010-and 538-year cycles of the SST sequence indicated a basic control of solar activity on the oceanic conditions in the Yellow Sea.It is suggested that the variation of total solar irradiance was amplifi ed by thermohaline circulation and then transmitted to the Yellow Sea through the EAWM.Meanwhile,the tropical Pacifi c signal of El Niño was transmitted to the YSWC through the Kuroshio Current.The dual properties of warm water transported by YSWC to compensate the EAWM and driving by Kuroshio Current closely linked the variation of SST in the YSWC pathway to the Northern Hemisphere high latitude climate and the tropical Pacifi c.These fi ndings highlight the signifi cance of YSWC on regional SST evolution and its teleconnection to high and low latitude forcing,which grains a better understanding of the long-term evolution of SST in the middle latitude Yellow Sea.展开更多
By Using the P-σ five-layer primitive equation model,three sets of numerical experiments are performed with normal zonal mean SST(the control case),the positive SST anomalies in the Kuroshio current and east-of-Japan...By Using the P-σ five-layer primitive equation model,three sets of numerical experiments are performed with normal zonal mean SST(the control case),the positive SST anomalies in the Kuroshio current and east-of-Japan Ocean(the midlatitude western Pacific),and positive SST anomalies over both the midlatitude and the equatorial western Pacific.The experimental results show that the positive SST anomalies over the midlatitude western Pacific have great influence on the Asian summer monsoon:the Indian monsoon is weak- ened and the East Asian monsoon is intensified.This happens just reverse to the effects of positive SST anomalies over the equatorial westero Pacific on the Asian summer monsoon.Further,the influence mechanism of the SST anomalies over the midlatitude westcrn Pacific on the Asian summer monsoon is discussed.展开更多
One thousand and forty-nine sea surface isotherm maps during 1990 - 2000 were used to detect the Kuroshio axis off the coast of Japan. The current axis on the surface cannot be identified by just one indicative isothe...One thousand and forty-nine sea surface isotherm maps during 1990 - 2000 were used to detect the Kuroshio axis off the coast of Japan. The current axis on the surface cannot be identified by just one indicative isotherm as is commonly done in deep water, but still there are complicated isotherms indicatives of the Kuroshio axis. Three types of isotherms indicatives of the surface axis of the Kuroshio are identified, which are nesti indicator, warm-tongue-isotherm-indicator, and isotherm-indicator. The ocourrence frequency of NWTI-type is 72%, that of WTII-type is 19.1% and that of Ⅱ-type is 8.9%. The vector-based and raster-based methods were introduced and used to retrieve automatically the Kumshio paths from SST data. The total retrieving percentage is 74% by the three methods, 52.3% by the vector method, 56.8% by one raster method and 49.6% by another raster method. For the NWTI - type, the total retrieving percentage is 91.3% by the three methods, 64.4% by the vector method, 75. 9% by one raster method and 65% by another raster method. Using retrieving results of the Kumshio axis from SST data,the Kuroshio path detour is analyzed during 1990 - 2000.展开更多
Based on several images taken by. the NOAA -11 and - 12 advanced very high resolution radiometer (AVHRR/2) during 1989-1993, and combined with a larger-scale of oceanographic investigation during 8-27 March 1992, som...Based on several images taken by. the NOAA -11 and - 12 advanced very high resolution radiometer (AVHRR/2) during 1989-1993, and combined with a larger-scale of oceanographic investigation during 8-27 March 1992, some related questions of the physical oceanography in the South China As have been discussed. The results show that there were a more complementary action for the investigation and study on the physical oceanographic phenomena in the South China As using the satellite imageries and in-situ data, and the distribution and variation of the satellite-derived sea surface tempera- ture field in the northeast South China Sea basically mirrored the results obtained from in-situ investigation. Some of the large-scale and meso-scale marine phenomena varied with the long and medium periods, for instance, an anticyclonic meandering of the Kuroshio path when it flowed through the Bashi Channel, the win water with high temperature along the west coastline of Lain Island, the western and northern warmer water tongues off the southwest of Taiwan Island, China, as well as the thermal front along the continental shelf off Guangdong, were well presented in both the satellite imageries and in-situ data. Then, there the can be revealed some marine phenomena with a short period, or in the further large area using the satellite imageries, which will provide scientific basis for planning and carrying out the effective marine investigation. Finally, a map of surface circulation pattern in the northeast South China Sea in winter is sketched according to the comprehensive analysis of the satellite and in-situ data.展开更多
长链二醇(LCDs)是一类微藻生物标志物,在海洋沉积物中除了能够指示其生物来源,近年来的工作还表明它们能够很好地用于示踪表层海水温度(SST)和营养盐。本文对冲绳海槽北部OTK-6站位的1根中晚全新世柱状沉积物(长度468 cm)进行了长链二...长链二醇(LCDs)是一类微藻生物标志物,在海洋沉积物中除了能够指示其生物来源,近年来的工作还表明它们能够很好地用于示踪表层海水温度(SST)和营养盐。本文对冲绳海槽北部OTK-6站位的1根中晚全新世柱状沉积物(长度468 cm)进行了长链二醇的提取分析,重建了7 ka B.P.以来的表层海水温度和营养盐变化历史,并与前人的黑潮指标变化进行对比。结果显示,在本研究区基于长链二醇的SST指标可能反映的是年均但略偏暖季的温度,其变化曲线与营养盐指标的变化曲线呈反向变化。而且上述温度和营养盐变化历史与前人给出的黑潮强弱变化历史对应较好,表现出黑潮增强时,SST温度升高,营养盐含量降低,与黑潮水的高温寡营养的特点一致。本文结果显示,在6.0~5.2 ka B.P.、4.2~3.5 ka B.P.、2.5~2.1 ka B.P.、1.8~1.4 ka B.P.以及1.1~0.8 ka B.P.前后黑潮对研究区域的影响加强。因此,认为基于长链二醇的温度和营养盐指标有潜力成为重建古黑潮演变的新型代用指标。展开更多
El Nio Modoki,similar to but different from canonical El Nio,has been observed since the late1970s.In this paper,using HadISST and NCEP/NCAR wind data,we analyze the relationship between El Nio Modoki and Sea Su...El Nio Modoki,similar to but different from canonical El Nio,has been observed since the late1970s.In this paper,using HadISST and NCEP/NCAR wind data,we analyze the relationship between El Nio Modoki and Sea Surface Temperature(SST)in the offshore area of China and its adjacent waters for different seasons.Our results show a significant negative correlation between El Nio Modoki in summer and SST in autumn in the offshore area of China and its adjacent waters,particularly for regions located in the east of the Kuroshio.It is also found that during El Nio Modoki period,anomalous northerlies prevail over the regions from the northern part of the Philippines to the offshore area of China,indicating that the northerlies are unfavorable for the transport of warm water from the western tropical Pacific to the mid-latitude area.Consequently,El Nio Modoki in summer may play a substantial role in cold SST anomalies in the offshore area of China and its adjacent waters in autumn through the influence of the Kuroshio,with a lagged response of the ocean to the atmospheric wind field.展开更多
基金supported by National Basic Research Program of China (Grant Nos. 2007CB411803 and 2009CB421208)National Natural Science Foundation of China (Grant Nos. 40576015, 40821063 and 40810069004)
文摘A morphology-based edge detection method has been used to study sea surface temperature (SST) fronts in the Taiwan Strait and its adjacent area. The method is based on mathematical morphology with multi-dimensional and multi-structural elements. Using six years’ SST data from September 2002 to August 2008, we distinguished the large SST front like Kuroshio Front as well as the smaller ones: namely Taiwan Bank Front, Zhe-Min Coastal Front and Zhang-Yun Ridge Front. The seasonal and monthly variations of these fronts were also studied. Generally, the SST fronts are stronger in winter but weaker in summer. And the fronts are at their active stage during the period from January to May but at their declining stage during the period from July to October.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 49999560, 49776289) the Program for the Young Scientific and Technological Stars of Shanghai (Grant No. 98QG14043).
文摘The present paper uses planktonic foraminifera and their stableisotopes to study the changes in the depth of thermocline (DOT) in the Okinawa Trough since the last 10000 a based on the analysis of Core B-3GC in the northern Okinawa Trough, together with that of the core in the southern Okinawa Trough. As results show, the thermocline was shallow before 6400 aBP, and deepened afterward, then became shallow again from 4000 to 2000 aBP. The DOT fluctuations display a positive correlation with those of sea surface temperature (SST). In addition, the changes in the northern Okinawa Trough are similar to those in the southern trough, implying a possible connection with the variation of the Kuroshio Current. The changes of SST and DOT suggest that the Kuroshio Current changed its intensity or main axis from 4000 to 2000 aBP and around about 6400 aBP respectively. Moreover, the changes of DOT from 8200 to 6400 aBP may indicate a gradual intensification of the Kuroshio Current.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB42000000)the National Natural Science Foundation of China(Nos.41830539,42076051)the Open Fund Project of the Key Laboratory of Marine Sedimentology and Environmental Geology,Ministry of Natural Resources(No.MASEG201901),and the Taishan Scholar Project。
文摘Sea surface temperature(SST)in the Yellow Sea Warm Current(YSWC)pathway is sensitive to the East Asian Winter Monsoon(EAWM)and YSWC.However,the role of the YSWC in the evolution of regional SST remains unclear.Here,we present new U 37 k′based SST and grain size sequences spanning the last 6092 years in the sediment core Z1,which was retrieved from the central Yellow Sea muddy area.Overall,U 37 k′-SST gradually increased since 6.1 ka BP,with a series of centennial-scale fl uctuations.Its variation was mainly caused by EAWM when YSWC was weak between 6.1 and~3.9 ka BP,as shown by the end-member content of grain size.However,after YSWC was fully developed,i.e.,since~3.9 ka BP,it exerted critical eff ects on SST evolution in its pathway.The 1010-and 538-year cycles of the SST sequence indicated a basic control of solar activity on the oceanic conditions in the Yellow Sea.It is suggested that the variation of total solar irradiance was amplifi ed by thermohaline circulation and then transmitted to the Yellow Sea through the EAWM.Meanwhile,the tropical Pacifi c signal of El Niño was transmitted to the YSWC through the Kuroshio Current.The dual properties of warm water transported by YSWC to compensate the EAWM and driving by Kuroshio Current closely linked the variation of SST in the YSWC pathway to the Northern Hemisphere high latitude climate and the tropical Pacifi c.These fi ndings highlight the signifi cance of YSWC on regional SST evolution and its teleconnection to high and low latitude forcing,which grains a better understanding of the long-term evolution of SST in the middle latitude Yellow Sea.
文摘By Using the P-σ five-layer primitive equation model,three sets of numerical experiments are performed with normal zonal mean SST(the control case),the positive SST anomalies in the Kuroshio current and east-of-Japan Ocean(the midlatitude western Pacific),and positive SST anomalies over both the midlatitude and the equatorial western Pacific.The experimental results show that the positive SST anomalies over the midlatitude western Pacific have great influence on the Asian summer monsoon:the Indian monsoon is weak- ened and the East Asian monsoon is intensified.This happens just reverse to the effects of positive SST anomalies over the equatorial westero Pacific on the Asian summer monsoon.Further,the influence mechanism of the SST anomalies over the midlatitude westcrn Pacific on the Asian summer monsoon is discussed.
基金This work was supported by the National Natural Science Foundation of China.
文摘One thousand and forty-nine sea surface isotherm maps during 1990 - 2000 were used to detect the Kuroshio axis off the coast of Japan. The current axis on the surface cannot be identified by just one indicative isotherm as is commonly done in deep water, but still there are complicated isotherms indicatives of the Kuroshio axis. Three types of isotherms indicatives of the surface axis of the Kuroshio are identified, which are nesti indicator, warm-tongue-isotherm-indicator, and isotherm-indicator. The ocourrence frequency of NWTI-type is 72%, that of WTII-type is 19.1% and that of Ⅱ-type is 8.9%. The vector-based and raster-based methods were introduced and used to retrieve automatically the Kumshio paths from SST data. The total retrieving percentage is 74% by the three methods, 52.3% by the vector method, 56.8% by one raster method and 49.6% by another raster method. For the NWTI - type, the total retrieving percentage is 91.3% by the three methods, 64.4% by the vector method, 75. 9% by one raster method and 65% by another raster method. Using retrieving results of the Kumshio axis from SST data,the Kuroshio path detour is analyzed during 1990 - 2000.
基金This project was supported by the National Key Programme for Developing Basic Sciences-Research on the China Seashore Circulatio
文摘Based on several images taken by. the NOAA -11 and - 12 advanced very high resolution radiometer (AVHRR/2) during 1989-1993, and combined with a larger-scale of oceanographic investigation during 8-27 March 1992, some related questions of the physical oceanography in the South China As have been discussed. The results show that there were a more complementary action for the investigation and study on the physical oceanographic phenomena in the South China As using the satellite imageries and in-situ data, and the distribution and variation of the satellite-derived sea surface tempera- ture field in the northeast South China Sea basically mirrored the results obtained from in-situ investigation. Some of the large-scale and meso-scale marine phenomena varied with the long and medium periods, for instance, an anticyclonic meandering of the Kuroshio path when it flowed through the Bashi Channel, the win water with high temperature along the west coastline of Lain Island, the western and northern warmer water tongues off the southwest of Taiwan Island, China, as well as the thermal front along the continental shelf off Guangdong, were well presented in both the satellite imageries and in-situ data. Then, there the can be revealed some marine phenomena with a short period, or in the further large area using the satellite imageries, which will provide scientific basis for planning and carrying out the effective marine investigation. Finally, a map of surface circulation pattern in the northeast South China Sea in winter is sketched according to the comprehensive analysis of the satellite and in-situ data.
文摘长链二醇(LCDs)是一类微藻生物标志物,在海洋沉积物中除了能够指示其生物来源,近年来的工作还表明它们能够很好地用于示踪表层海水温度(SST)和营养盐。本文对冲绳海槽北部OTK-6站位的1根中晚全新世柱状沉积物(长度468 cm)进行了长链二醇的提取分析,重建了7 ka B.P.以来的表层海水温度和营养盐变化历史,并与前人的黑潮指标变化进行对比。结果显示,在本研究区基于长链二醇的SST指标可能反映的是年均但略偏暖季的温度,其变化曲线与营养盐指标的变化曲线呈反向变化。而且上述温度和营养盐变化历史与前人给出的黑潮强弱变化历史对应较好,表现出黑潮增强时,SST温度升高,营养盐含量降低,与黑潮水的高温寡营养的特点一致。本文结果显示,在6.0~5.2 ka B.P.、4.2~3.5 ka B.P.、2.5~2.1 ka B.P.、1.8~1.4 ka B.P.以及1.1~0.8 ka B.P.前后黑潮对研究区域的影响加强。因此,认为基于长链二醇的温度和营养盐指标有潜力成为重建古黑潮演变的新型代用指标。
基金Special Scientific Research Project for Public Welfare(201006021,201005019)Youth Foundation of Chinese State Oceanic Administration(2013257)+2 种基金Scientific Research Foundation of Third Institute of Oceanography,SOA(TIO2013002TIO2013003)National Special Project:Chinese Offshore Investigation and Assessment(908-02-01-02)
文摘El Nio Modoki,similar to but different from canonical El Nio,has been observed since the late1970s.In this paper,using HadISST and NCEP/NCAR wind data,we analyze the relationship between El Nio Modoki and Sea Surface Temperature(SST)in the offshore area of China and its adjacent waters for different seasons.Our results show a significant negative correlation between El Nio Modoki in summer and SST in autumn in the offshore area of China and its adjacent waters,particularly for regions located in the east of the Kuroshio.It is also found that during El Nio Modoki period,anomalous northerlies prevail over the regions from the northern part of the Philippines to the offshore area of China,indicating that the northerlies are unfavorable for the transport of warm water from the western tropical Pacific to the mid-latitude area.Consequently,El Nio Modoki in summer may play a substantial role in cold SST anomalies in the offshore area of China and its adjacent waters in autumn through the influence of the Kuroshio,with a lagged response of the ocean to the atmospheric wind field.
