In this study, the inverse method is used to compute the Kuroshio in the East China Sea and southeast of Kyushu and the currents east of the Ryukyu Islands, on the basis of hydrographic data obtained during September-...In this study, the inverse method is used to compute the Kuroshio in the East China Sea and southeast of Kyushu and the currents east of the Ryukyu Islands, on the basis of hydrographic data obtained during September-October, 1987 by R/V Chofu Maru. The results show that: (1)A part of the Taiwan Warm Current has a tendency to converge to the shelf break; (2) the Kuroshio flows across the section C3 (PN) with a reduced current width, and the velocity of the Kuroshio at the section C3 increases and its maximum current speed is about 158 cm/s, and its volume transport here is about 26×106m3/s; (3) the Kuroshio has two current cores at the sections C3 (PN) and B2 (at the Tokara Strait); (4) the currents east of the Ryukyu Islands are found to flow northward over the Ryukyu Trench during September-October, 1987. The velocities of the currents are not strong throughout the depths. At the section C2 east of the Ryukyu Islands, the maximum current speed is at the 699 m levei and its magnitude is 25 cm/s, and its volume transport is about 21×06 m3/s; (5) the volume transports of the Kuroshio through the sections B2 (at the Tokara Strait) and C6 (southeast of Kyushu) are 23. 33, 67. 31×106 m3/s, respectively; (6) there are two meso-scale anticyclonic warm eddies between 135° E and the area east of the Ryukyu Islands, and their characters and hydrographic structure are discussed.展开更多
A modified inverse method is used to compute the circulations east of Taiwan and in the East China Sec and east of the Ryukyu Islands with hydrographic data obtained during early summer of 1985. The computational regi...A modified inverse method is used to compute the circulations east of Taiwan and in the East China Sec and east of the Ryukyu Islands with hydrographic data obtained during early summer of 1985. The computational region covers an area west of 129°E and from 21°45'N to 35°N. The computed results show that: (1 ) The net volume transport (VT ) of the Kuroshio through 21°45'N Section east of Ta Taiwan and west of 123°E is about 45 × 10￣6 m￣3/sduring early summer of 1985. The Kuroshio has. two current cores. One is located near Taiwan, and its velocity isvery large and its maximum velocity is 226 cm/s at the 100 m level, which is close to the maximum velocity of the beginning of the Kuroshio east of the Philippines. The other is located further to the east, and its maximum velocity is159 cm/s at the 100m level; (2) through a transect northwest Of Miyakojima Island and a transect southwest of Okinawa laaed the volume transports of the Kuroshio in the East China Sea both are about 25 × 10￣6 m￣3/s. The maximumvelocity of the Kuroshio at these two sections is 194 and 128 cm/s, respectively, and both are located on the shelfbreak; (3) beneath and east of the Kurohio there are the countercurrent (4) southeast of Okinawa Island there is anortheastward current, and its VT at Section HI is about 12. 6 × 10￣6 m￣3/s, and it comes from a westward flow at 129° This project was supported by the National Natural Science Foundation of China under contract No. 49476278.(Second Institute of Oceanography, State Oceanic Administration, Hongzhou310012, China) (Institute of Oceanography, Taiwan University, Taipei, China)E Section and the recirculating gyre, and does not originate from the Kuroshio east of Taiwan during early summer of 1985. There is a southwestward abyssal current east of Okinawa Islands (5) there are several different scale eddies in this computational region. For example, there is a meso-scale strong cyclonic eddy east of Miyakojima Island.展开更多
Based on the wind and hydrographic data obtained from the cruise of China - Japan Cooper- ative Research on Subtropical Gyre during December 1997, the Kuroshio east of Taiwan Island and the currents southeast of the R...Based on the wind and hydrographic data obtained from the cruise of China - Japan Cooper- ative Research on Subtropical Gyre during December 1997, the Kuroshio east of Taiwan Island and the currents southeast of the Ryukyu-gunto are computed by using three-dimensional diagnostic, semidiag- nostic and prognostic models in the a coordinate. The computed results show that: (1 ) The density and velocity fields have been adjusted when time is about 15 d, namely, the solution of semidiagnostic calcu- lation is obtained. The quasi-steady state solution has been reached after 300 d, thus and the results of prognostic calculation got. (2) From the diagnostic calculation, the following main results can be obtained-1) There is a stronger cyclonic eddy with tongue-shaped in the region south of Taiwan Island, and the Kuroshio is located east of this cyclonic eddy. Compared with the results in July 1997, the position of the main axis of the Kuroshio moves eastward. 2) There is an anticyclonic eddy south of Miyako- jima, and there is a cyclonic eddy near the middle of the southern computational boundary. 3) The upwelling dominates in an area of the Kuroshio near Taiwan Island. (3) Comparing the results of diagnostic calculation with those of semidiagnotic and prognostic calculations indicates that the hortizontal velocity fields agree qualitatively, and there is a little difference between them in quantity. For example, the maximun horizontal velocities of the Kuroshio at the sea surface at t = 0 d (diagnostic), 15 d (semiaiagnostic) and 300 d (prognostic) are 88. 6, 98. 0 and 97. 0 cm/s, respectively. As to the distributions of vertical components of velocity, there are some differences between them, which shows that the semidiagnostic and porognostic results can coincide with better the salinity and temperature distributions.展开更多
文摘In this study, the inverse method is used to compute the Kuroshio in the East China Sea and southeast of Kyushu and the currents east of the Ryukyu Islands, on the basis of hydrographic data obtained during September-October, 1987 by R/V Chofu Maru. The results show that: (1)A part of the Taiwan Warm Current has a tendency to converge to the shelf break; (2) the Kuroshio flows across the section C3 (PN) with a reduced current width, and the velocity of the Kuroshio at the section C3 increases and its maximum current speed is about 158 cm/s, and its volume transport here is about 26×106m3/s; (3) the Kuroshio has two current cores at the sections C3 (PN) and B2 (at the Tokara Strait); (4) the currents east of the Ryukyu Islands are found to flow northward over the Ryukyu Trench during September-October, 1987. The velocities of the currents are not strong throughout the depths. At the section C2 east of the Ryukyu Islands, the maximum current speed is at the 699 m levei and its magnitude is 25 cm/s, and its volume transport is about 21×06 m3/s; (5) the volume transports of the Kuroshio through the sections B2 (at the Tokara Strait) and C6 (southeast of Kyushu) are 23. 33, 67. 31×106 m3/s, respectively; (6) there are two meso-scale anticyclonic warm eddies between 135° E and the area east of the Ryukyu Islands, and their characters and hydrographic structure are discussed.
文摘A modified inverse method is used to compute the circulations east of Taiwan and in the East China Sec and east of the Ryukyu Islands with hydrographic data obtained during early summer of 1985. The computational region covers an area west of 129°E and from 21°45'N to 35°N. The computed results show that: (1 ) The net volume transport (VT ) of the Kuroshio through 21°45'N Section east of Ta Taiwan and west of 123°E is about 45 × 10￣6 m￣3/sduring early summer of 1985. The Kuroshio has. two current cores. One is located near Taiwan, and its velocity isvery large and its maximum velocity is 226 cm/s at the 100 m level, which is close to the maximum velocity of the beginning of the Kuroshio east of the Philippines. The other is located further to the east, and its maximum velocity is159 cm/s at the 100m level; (2) through a transect northwest Of Miyakojima Island and a transect southwest of Okinawa laaed the volume transports of the Kuroshio in the East China Sea both are about 25 × 10￣6 m￣3/s. The maximumvelocity of the Kuroshio at these two sections is 194 and 128 cm/s, respectively, and both are located on the shelfbreak; (3) beneath and east of the Kurohio there are the countercurrent (4) southeast of Okinawa Island there is anortheastward current, and its VT at Section HI is about 12. 6 × 10￣6 m￣3/s, and it comes from a westward flow at 129° This project was supported by the National Natural Science Foundation of China under contract No. 49476278.(Second Institute of Oceanography, State Oceanic Administration, Hongzhou310012, China) (Institute of Oceanography, Taiwan University, Taipei, China)E Section and the recirculating gyre, and does not originate from the Kuroshio east of Taiwan during early summer of 1985. There is a southwestward abyssal current east of Okinawa Islands (5) there are several different scale eddies in this computational region. For example, there is a meso-scale strong cyclonic eddy east of Miyakojima Island.
基金This project was supported by the National Natural Science Foundation of China under contract !Nos 49776287 and 49736200 the
文摘Based on the wind and hydrographic data obtained from the cruise of China - Japan Cooper- ative Research on Subtropical Gyre during December 1997, the Kuroshio east of Taiwan Island and the currents southeast of the Ryukyu-gunto are computed by using three-dimensional diagnostic, semidiag- nostic and prognostic models in the a coordinate. The computed results show that: (1 ) The density and velocity fields have been adjusted when time is about 15 d, namely, the solution of semidiagnostic calcu- lation is obtained. The quasi-steady state solution has been reached after 300 d, thus and the results of prognostic calculation got. (2) From the diagnostic calculation, the following main results can be obtained-1) There is a stronger cyclonic eddy with tongue-shaped in the region south of Taiwan Island, and the Kuroshio is located east of this cyclonic eddy. Compared with the results in July 1997, the position of the main axis of the Kuroshio moves eastward. 2) There is an anticyclonic eddy south of Miyako- jima, and there is a cyclonic eddy near the middle of the southern computational boundary. 3) The upwelling dominates in an area of the Kuroshio near Taiwan Island. (3) Comparing the results of diagnostic calculation with those of semidiagnotic and prognostic calculations indicates that the hortizontal velocity fields agree qualitatively, and there is a little difference between them in quantity. For example, the maximun horizontal velocities of the Kuroshio at the sea surface at t = 0 d (diagnostic), 15 d (semiaiagnostic) and 300 d (prognostic) are 88. 6, 98. 0 and 97. 0 cm/s, respectively. As to the distributions of vertical components of velocity, there are some differences between them, which shows that the semidiagnostic and porognostic results can coincide with better the salinity and temperature distributions.
