Equatorial Pacific ocean horizontal velocity, divergence, and upwelling
Equatorial Pacific ocean horizontal velocity, divergence, and upwelling
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DOI：
10.1175/1520-0485(2001)031
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发表时间：
2001-01-01
影响因子：
3.5
通讯作者：
Firing, E
中科院分区：
文献类型：
--
作者：
Johnson, GC;McPhaden, MJ;Firing, E
根据1991年至1999年在赤道太平洋西经170度至西经95度之间进行的船上观测，估计了上层海洋的水平速度和散度。在断面的平均经度，136度西，估计了纬向流的平均输送。整个经度范围内的平均经向流包括南极面流向-0.09m S(-1)和北极面流向S(-1)，以及温跃层内近23℃(85m)的赤道流向S(-1)和-0.04m S(-1)。垂直速度的诊断是通过积分从地面向下整个区域估计的水平散度来诊断的。赤道上升流的峰值速度为1.9x10(-5)m S(-1)，在北纬3.6度-5.2度，西经170度-95度范围内的上升流输送在50m处为62(+/-18)×10(6)m(3)S(-1)。经向气流的不对称性表明，在10×10(6)m(3)量级上，来自南半球的温跃层水S(-1)在赤道被上涌，并作为地表水进入北半球。这条半球间的交换路径可能是南半球水供应印尼Throughflow的路线的一部分。
Upper-ocean horizontal velocity and divergence were estimated from shipboard observations taken from 1991 1999 in the equatorial Pacific between 170 degreesW and 95 degreesW. Mean transports were estimated for the zonal currents at the mean longitude of the sections, 136 degreesW. Mean meridional currents for the entire longitude range included poleward surface flows reaching -0.09 m s-(1) in the south and 0.13 m s(-1) in the north as well as equatorward flow within the thermocline reaching 0.05 m s(-1) in the south and -0.04 m s(-1) in the north near 23 degreesC (85 m). Vertical velocity was diagnosed by integrating horizontal divergence estimated for the entire region down from the surface. Equatorial upwelling velocities peaked at 1.9 (+/-0.9) x 10(-5) m s(-1) at 50 m. The upwelling transport in the area bounded by 3.6 degreesS-5.2 degreesN, 170 degreesW-95 degreesW was 62 (+/-18) x 10(6) m(3) s(-1) at 50 m. Strong downwelling was apparent within the North Equatorial Countercurrent. An asymmetry in the meridional flows suggested that on the order of 10 x 10(6) m(3) s(-1) of thermocline water from the Southern Hemisphere was upwelled at the equator and moved into the Northern Hemisphere as surface water. This interhemispheric exchange path could be part of the route for water from the Southern Hemisphere to supply the Indonesian Throughflow.