Meridional Circulation Cells and the Source Waters of the Pacific Equatorial Undercurrent

Origins and Pathways of the Pacific Equatorial Undercurrent Identified by a Simulated Adjoint Tracer

“…The tropical water feeds the EUC mainly via the TCs in the central Pacific, with a larger portion originated from the northern side than from the southern side of the equator. This is in accordance with former model results that show a main‐run solution of 3.63 Sv for the northern TC and 3.16 for the southern TC (Lu et al, ). However, an observational study done by Johnson et al () revealed an opposite result, which showed that the equatorward thermocline flow was greater in the southside of the equator.…”

“…Besides these subtropical source waters, the tropical surface water provides about 22% of the EUC water with a transit time of around 2 years. This is in consistent with Lu et al () who had a similar result of 26%, and slightly smaller than the result achieved by Goodman et al () who suggested that 30% of the EUC water is ventilated within the tropical region. The reasons for these discrepancies could be various, and the use of different velocity field could be a major cause.…”

Origins and Pathways of the Pacific Equatorial Undercurrent Identified by a Simulated Adjoint Tracer

“…The tropical water feeds the EUC mainly via the TCs in the central Pacific, with a larger portion originated from the northern side than from the southern side of the equator. This is in accordance with former model results that show a main‐run solution of 3.63 Sv for the northern TC and 3.16 for the southern TC (Lu et al, ). However, an observational study done by Johnson et al () revealed an opposite result, which showed that the equatorward thermocline flow was greater in the southside of the equator.…”

“…Besides these subtropical source waters, the tropical surface water provides about 22% of the EUC water with a transit time of around 2 years. This is in consistent with Lu et al () who had a similar result of 26%, and slightly smaller than the result achieved by Goodman et al () who suggested that 30% of the EUC water is ventilated within the tropical region. The reasons for these discrepancies could be various, and the use of different velocity field could be a major cause.…”

The three-dimensional structure and seasonal variation of the North Pacific meridional overturning circulation

“…1). Obviously, the NPMOC has a multi-cell structure, somewhat consistent with the results of Lu et al (1998) except that the central position of the STC is a little southward and there is the DTC. Since the subpolar cell is very weak and even disappears in summer, it is not discussed in this study.…”

Pathways into the Pacific Equatorial Undercurrent: A Trajectory Analysis*

“…The spatial patterns and quantitative results presented here are consistent with previous studies. The 3 1 ⁄2 layer model used by Lu et al (1998) indicated about 2/3 of the EUC water originated south of the equator, the same ratio found here. Huang and Liu (1999) in the National Centers for Environmental Prediction (NCEP) Ocean Model had a greater percentage of northern water in the EUC, but their model has no Indonesian Throughflow, which preferentially draws water from the north relative to the south.…”

Origins and Pathways of the Pacific Equatorial Undercurrent Identified by a Simulated Adjoint Tracer

“…The tropical water feeds the EUC mainly via the TCs in the central Pacific, with a larger portion originated from the northern side than from the southern side of the equator. This is in accordance with former model results that show a main‐run solution of 3.63 Sv for the northern TC and 3.16 for the southern TC (Lu et al, ). However, an observational study done by Johnson et al () revealed an opposite result, which showed that the equatorward thermocline flow was greater in the southside of the equator.…”

“…Besides these subtropical source waters, the tropical surface water provides about 22% of the EUC water with a transit time of around 2 years. This is in consistent with Lu et al () who had a similar result of 26%, and slightly smaller than the result achieved by Goodman et al () who suggested that 30% of the EUC water is ventilated within the tropical region. The reasons for these discrepancies could be various, and the use of different velocity field could be a major cause.…”

The three-dimensional structure and seasonal variation of the North Pacific meridional overturning circulation

“…1). Obviously, the NPMOC has a multi-cell structure, somewhat consistent with the results of Lu et al (1998) except that the central position of the STC is a little southward and there is the DTC. Since the subpolar cell is very weak and even disappears in summer, it is not discussed in this study.…”

Pathways into the Pacific Equatorial Undercurrent: A Trajectory Analysis*

“…The spatial patterns and quantitative results presented here are consistent with previous studies. The 3 1 ⁄2 layer model used by Lu et al (1998) indicated about 2/3 of the EUC water originated south of the equator, the same ratio found here. Huang and Liu (1999) in the National Centers for Environmental Prediction (NCEP) Ocean Model had a greater percentage of northern water in the EUC, but their model has no Indonesian Throughflow, which preferentially draws water from the north relative to the south.…”

Origins and Pathways of the Pacific Equatorial Undercurrent Identified by a Simulated Adjoint Tracer

“…The tropical water feeds the EUC mainly via the TCs in the central Pacific, with a larger portion originated from the northern side than from the southern side of the equator. This is in accordance with former model results that show a main‐run solution of 3.63 Sv for the northern TC and 3.16 for the southern TC (Lu et al, ). However, an observational study done by Johnson et al () revealed an opposite result, which showed that the equatorward thermocline flow was greater in the southside of the equator.…”

“…Besides these subtropical source waters, the tropical surface water provides about 22% of the EUC water with a transit time of around 2 years. This is in consistent with Lu et al () who had a similar result of 26%, and slightly smaller than the result achieved by Goodman et al () who suggested that 30% of the EUC water is ventilated within the tropical region. The reasons for these discrepancies could be various, and the use of different velocity field could be a major cause.…”

The three-dimensional structure and seasonal variation of the North Pacific meridional overturning circulation

“…1). Obviously, the NPMOC has a multi-cell structure, somewhat consistent with the results of Lu et al (1998) except that the central position of the STC is a little southward and there is the DTC. Since the subpolar cell is very weak and even disappears in summer, it is not discussed in this study.…”

Pathways into the Pacific Equatorial Undercurrent: A Trajectory Analysis*

“…The spatial patterns and quantitative results presented here are consistent with previous studies. The 3 1 ⁄2 layer model used by Lu et al (1998) indicated about 2/3 of the EUC water originated south of the equator, the same ratio found here. Huang and Liu (1999) in the National Centers for Environmental Prediction (NCEP) Ocean Model had a greater percentage of northern water in the EUC, but their model has no Indonesian Throughflow, which preferentially draws water from the north relative to the south.…”