On the subsurface countercurrents in the Philippine Sea
On the subsurface countercurrents in the Philippine Sea
复制标题
关于菲律宾海的地下逆流
DOI：
10.1002/2013jc009690
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发表时间：
2015-01-01
影响因子：
3.6
通讯作者：
Hu, Dunxin
中科院分区：
文献类型：
--
作者：
Wang, Fan;Zang, Nan;Hu, Dunxin
菲律宾海次表层逆流及其在水团输送中的作用已在以往的研究中得到报道。它们的存在仍然存在争议，潜在的动力仍然不清楚。利用最近获得的水文和卫星测高资料，研究了棉兰老岛潜流(MUC)、吕宋潜流(LUC)和北赤道潜流(NEUC)三个次表层逆流的气候结构和相互关系。通过多段分析，确定了表层流下方和相反的三个次表层流。MUC在北纬6.5度至10.5度的纬向剖面上显示出两个向北的速度核，最大速度都大于10厘米S(-1)。LUC在北纬18度和北纬16.25度断面的黑潮下有一个不明显的核心，其南向速度大于2厘米S(-1)。向东流动的近地天体在东经128.2度和东经130度剖面上也有两个分离的核心，速度大于1厘米S(-1)。对-S关系的分析表明，东北涛动中心的南部由MUC输送南太平洋水和南/北太平洋水的混合输送，而北部则可能是LUC输送的北太平洋水的命运。次表层逆流与海面高度(SSH)和温跃层深度(DTC)之间的水平梯度相反，存在于连通带中，在温跃层下方的斜压调节克服了海面的正压强迫，这表明了3种次表层逆流之间的动力联系。
The subsurface countercurrents in the Philippine Sea and their roles in water mass transportation have been reported in previous studies. Their existence is still controversial, and the underlying dynamics remains unclear. This study investigates the climatological structures and relationships of three subsurface countercurrents, namely the Mindanao Undercurrent (MUC), the Luzon Undercurrent (LUC), and the North Equatorial Undercurrent (NEUC), using recently available hydrographic and satellite altimeter data. The three subsurface currents below and opposite to the surface currents are confirmed by multisections analysis. The MUC, as traced at zonal sections between 6.5 degrees N and 10.5 degrees N, shows two northward velocity cores, both with maximum speed larger than 10 cm s(-1). The LUC exhibits an obscure core with southward velocity larger than 2 cm s(-1) under the Kuroshio at 18 degrees N and 16.25 degrees N sections. The eastward flowing NEUC also has two separated cores at 128.2 degrees E and 130 degrees E sections with velocity larger than 1 cm s(-1). Analyses of -S relationship suggest that the southern part of NEUC is fed by the MUC with the South Pacific water and South/North Pacific water mixture, while the northern NEUC is likely a destiny of the North Pacific water carried by the LUC. Tightly associated with the opposite horizontal gradients between sea surface height (SSH) and the depth of thermocline (DTC), the subsurface countercurrents exist in connected zones where the baroclinic adjustment below the thermocline overcomes the barotropic forcing at the sea surface, which indicates the dynamical linkages among the three subsurface countercurrents.