Study on oceanic thermocline structure in subtropical/subpolar gyres

副热带/副极地环流海洋温跃层结构研究

• 批准号: 10640414
• 负责人: KUBOKAWA Atsushi
• 金额: $ 1.54万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10640414/
• 关键词: Ocean circulation; Thermocline; Eastern boundary ventilation; Cross-gyre flow; Oceanic response; Planetary waves; Ventilated thermocline theory; Eastern Boundary Vantilation; 水温躍層構造; Ventilated Thermocline; Cross-gyre ventilation

Numerical experiments with idealized OGCM were carried out to investigate the oceanic eastern boundary structure and its effects on the thermocline structure. The experimental results indicate that the zonal flow in the vicinity of the eastern boundary is limited in the mixed-layer, which is realized by the density gap just above the thermocline. Diapycnal process does not act an important role at the eastern edge of the basin except in the mixed layer. Formulation for the eastern boundary structure is also presented. It was also shown that such eastern boundary structure strongly affects the thermocline in the interior region. On the shallow thermocline in the subtropics, eastern boundary ventilated region is emerged, which is identified as a region of high potential vorticity. In the deep thermocline, which does not outcrop in the subtropical, a cross-gyre ventilation occurs. This cross-gyre ventilation is caused by the density structure at the eastern boundary.In addition to the above work, we carried out theoretical studies on the response of oceanic thermocline to enhancement of Ekman pumping velocity, and on the planetary wave dynamics in 2.5-layer ventilated thermocline model.

通过理想化OGCM数值实验研究了大洋东部边界结构及其对温跃层结构的影响。实验结果表明，东部边界附近的纬向流受到混合层的限制，这是由温跃层正上方的密度间隙实现的。除混合层外，在盆地东缘，岩密过程并不起重要作用。还提出了东部边界结构的公式。研究还表明，这种东部边界结构强烈影响内部区域的温跃层。副热带浅温跃层上出现东部边界通风区，被确定为高位涡区。在副热带地区不露头的深层温跃层中，会发生交叉环流通风。这种交叉环流通风是由东部边界的密度结构引起的。除上述工作外，我们还开展了海洋温跃层对Ekman抽速增强的响应以及2.5层通风温跃层模型中的行星波动力学的理论研究。