Study on the effects of warm eddies induced by the Kuroshioon the physical process of continental shelf region.

黑潮引起的暖涡对大陆架地区物理过程的影响研究.

• 批准号: 60420014
• 负责人: KUNISHI Hideaki
• 金额: $ 13.76万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (A)
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-60420014/
• 关键词: Fluctuation of Kuroshio; Continental shelf region; Particle tracking; Eddies; Oceanic front; Discharge of coastal water; Satellite imargery; 数値実験; 黒潮フロントと渦; 暖水塊の東進現象; フェリーによる連続計測; 衛星画像の時系列解析; 暖水塊; 水温・塩分; フロント構造の伝播; 黒潮流路の変動; 淡水流出量; 土佐湾; 紀

Water motion in the continental shelf region induced by the fluctuation of the Kuroshio was studied by means of satellite picture analysis and numerical experiments. We calculated trajectories of a large number of labeled particles moving in velocity field produced by fluctuating Kuroshio in a numerical barotropic model. When the Kuroshio Flows near the Cape Ashizuri, a large counter-clockwise eddy is produced in the Tosa Bay and particles of the Kuroshio water flow away along the current axis, As it moves offshore form the Cape Ashizuri, those are trapped by the eddy and approach to the coast accompaning with a thermal front. These features in the numerical model were detected in NOAA AVHRR pictures.When and eddy appeares in the Kii-Channel approach, the coastal front in the channel becomes sharper and fluctuates to make a water exchange across the front, These phenomena depend on the density difference of two water masses bounded by the front.Another numerical experiment shows that a pair of eddies is produced by a baroclinic instability of the density front between coastal and oceanic waters on the shelf region, These eddies transport oceanic water toward the coast and coastal water toward the offshore direction across the shear flow such as the Kuroshio, This is the reason why a large parch of low-salinity water mass has been often found in the surface layer of the Kuroshio in summer season (IMASATO and QIU, 1987),

通过卫星云图分析和数值试验，研究了黑潮涨落引起的陆架区水体运动。利用正压数值模式计算了黑潮脉动产生的速度场中大量标记粒子的运动轨迹。当黑潮在芦栗角附近运动时，土佐湾内产生一个逆时针方向的大涡旋，黑潮粒子沿流轴沿着流走，当黑潮粒子从芦栗角离岸运动时，被涡旋捕获，并与热锋一起向海岸运动。数值模式中的这些特征在NOAA AVHRR图像上得到了很好的体现，当Kii海峡进口出现涡旋时，海峡内的海岸锋变得尖锐，并发生波动，使锋上发生水交换，另一个数值试验表明，在两个水团之间，由于密度锋的斜压不稳定性，陆架区的近岸和大洋沃茨，这些涡旋将大洋水向沿岸输送，沿岸水向近海方向输送，穿过剪切流，如黑潮，这就是为什么夏季黑潮表层经常出现大面积干燥的低盐度水团的原因（IMASATO和QIU，1987），

项目成果

Akitomo, Kazunori: "Numerical model of the generation of a shallow sea front." Proceedings of International Symposium on Physics of Shallow Bays, Estuarine and Continental Shelves.(1987)

Akitomo, Kazunori：“浅海前沿生成的数值模型。”

戸田孝: 1986年度日本海洋学会秋季大会講演要旨集. 219-220 (1986)

Takashi Toda：日本海洋学会 1986 年秋季会议摘要 219-220 (1986)。

秋友和典: 1987年度日本海洋学会春季大会講演要旨集. (1987)

Kazunori Akitomo：日本海洋学会 1987 年春季会议摘要（1987）。

Akitomo, Kazunori: Proceedings of International Symposium of Physics of Shallow Bays, Estuarine and Continental Shelves.(1987)

Akitomo, Kazunori：国际浅湾、河口和大陆架物理学研讨会论文集。(1987)

Amasato, Norihisa: Journal of Physical Oceanography. 17(7). 953-968 (1987)

天里德久：《物理海洋学杂志》。