Subduction of North Pacific central mode water associated with subsurface mesoscale eddy
Subduction of North Pacific central mode water associated with subsurface mesoscale eddy
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DOI：
10.1029/2009gl037540
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发表时间：
2009-04
影响因子：
5.2
通讯作者：
E. Oka;K. Toyama;T. Suga
中科院分区：
文献类型：
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作者：
E. Oka;K. Toyama;T. Suga
2008年秋季在西北太平洋进行的一次船上高密度水文测量中，我们在北纬27.5°、东经145°500 dbar深度附近观测到一个厚度为150 dbar、直径40公里的反气旋性涡旋，该次表层中尺度涡旋包含北太平洋中心模水(CMW)，与同一地区的气候CMW特征相比，它具有异常低的位涡和高的溶解氧。剖面浮标测量探测到黑潮延伸区附近和南部的类似CMW斑块，以及黑潮延伸区以北的CMW形成区内的CMW向南迁移。这些观测事实表明，CMW不仅通过副热带涡旋北缘附近的大尺度东平流，而且通过与次表层中尺度涡旋的形成和迁移有关的向南的跨锋面平流，被俯冲到永久跃层中。
During a shipboard high‐density hydrographic survey carried out in the western North Pacific in fall 2008, we observed an anticyclonic eddy with a thickness of 150 dbar and a diameter of 40 km near 500 dbar depth at 27.5°N, 145°E. This subsurface mesoscale eddy contains the North Pacific central mode water (CMW), which has anomalously low potential vorticity and high dissolved oxygen compared to the climatological CMW properties in the same region. Profiling float measurements detect similar CMW patches near and south of the Kuroshio Extension as well as southward CMW migration within the CMW formation region north of the Kuroshio Extension. These observed facts suggest that CMW is subducted into the permanent pycnocline not only through large‐scale eastward advection near the northern edge of the subtropical gyre but also through southward cross‐frontal advection associated with the formation and migration of subsurface mesoscale eddies.