Spatial and temporal variability of the Kuroshio water based on a net work of the long-term repeat sections

基于长期重复剖面网络的黑潮水时空变化

• 批准号: 08640540
• 负责人: SUGA Toshio
• 金额: $ 0.96万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640540/
• 关键词: Kuroshio; Kuroshio recirculation; repeat sections; water masses; transport; isopycnal averaging; Subtropical Mode Water (STMW); North Pacific Intermediate Water (NPIW); 集中観測; 等密度平均

Downstream changes of the transport and water characteristics of the Kuroshio were investigated with the long-term repeat hydrographic sections. We also use the new climatological data constructed by our group and the high-resolution hydrograhic data obtained by our extensive survey of the Kuroshio by R/V Hakuho Maru, the cruise KH-96-4. The main results are as follows.1. Long-term mean geostrophic fluxes of the Kuroshio relative to 800 dbar or 1000 dbar were calculated by the potentrial density classes of 0.1 siguma_<theta> interval. Ii was shown that the downstream increase of the transport from the East China Sea to the south of Japan depends on the density classes. The increase in the density classes of North Pacific Subtropical Mode Water (NPSTMW) and North Pacific Intermediate Water (NPIW) is remarkable. The water of these classes shows downstream changes of the water characteristics, which indicates vigorous inflow of relatively new NPSTMW and NPIW into the Kuroshlo.2. Differences in the water characteristics of the density classes of NPSTMW and NPIW were detected, which is consistent with the previous hypothesis that the advection of these water masses from the east is severely reduced during the large-meander periods of the Kuroshio. The consistent differences in the water properties over the Kuroshio recirculation region were also detected based on our new climatological data.3. The spatial structures of the Kuroshio water, revealed by the repeat hydrographic sections described above, were confirmed and refined by the snapshot data obtained by our extensive survey, KH-96-4.

利用长期重复水文剖面研究了黑潮下游的输运和水特征的变化。我们还使用了我们小组建立的新的气候资料和我们在KH-96-4号考察船白凤丸对黑潮的广泛调查中获得的高分辨率水文资料。主要研究结果如下：1.用0.1 σ_间隔的位密度级计算了黑潮相对于800 dbar和1000 dbar的长期平均地转通量<theta>。结果表明，从东海到日本南部的输运的下游增加取决于密度级。北太平洋副热带模式水（NPSTMW）和北太平洋中层水（NPIW）的密度等级增加显着。这些类别的水显示了水特征的下游变化，这表明相对较新的NPSTMW和NPIW进入黑潮的强劲流入。NPSTMW和NPIW的密度类的水特性的差异进行了检测，这是与以前的假设，这些水团从东方的平流是严重减少在黑潮的大弯曲期间。根据新的气候资料，黑潮环流区的水性质也存在一致的差异。由上述重复水文剖面所揭示的黑潮水的空间结构，由我们广泛调查KH-96-4所获得的快照数据所证实和改进。