A study of annual and inter-annual variability in the north Pacific ocean by the use of the satellite altimeter data

利用卫星高度计数据研究北太平洋的年际和年际变化

• 批准号: 07640578
• 负责人: WAKATA Yoshinobu
• 金额: $ 0.77万
• 依托单位: KYUSHU UNIVERSITY (1997)The University of Tokyo (1995-1996)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07640578/
• 关键词: satellite; TOPEX; POSEIDON; sea surface height; kelvin wave; Rossby wave; ケルピン波; 季節内振動; 太平洋; 季節変化; GEOSAT; 海洋大循環; データ同化

The property of wave propagation in the Pacific ocean was studied by the use of altimeter data obtained by the satellite TOPEX/POSEIDON.The eastward propagating Kelvin waves are detected in the equatorial area, and the westward baroclinic Rossby waves in the middle latitude. The presence of these waves suggests the possibility of the ocean prediction such as the weather prediction in the meteorology from the regularity of the waves. The first, the data assimilation with nudging method was carried out to investigate the possibility of the prediction. The numerical simulation could represent the generation process of the waves owing to the wind forcing, but does not the propagation speed. As time advances, the results deviates from the observation. However, the wave is continuing to be adjusted while propagating after the assimilation, the results are greatly improved.Secondly, the Kelvin wave excited by an intraseasonal wind forcing with a 40-day period over the western Pacific ocean wa … More s simulated using an ocean general circulation model, and was investigated by the use of spectral analysys. The amplitude of the temperature has two peaks north and south of the equator at the depth of the thermocline, and the amplitude of zonal velocity also has two peaks on the equator up and down the thermocline. Further, it was put in question why this wave, which appears to be transient rather than modelike, always propagates with a phase velocity having a special value of about 3m/s. The vertical one-dimensional forcing problem in the infinitely deep ocean was studies to focus on the transiency, where the external forcing of up and down motions moving eastward is imposed at the surface and the reflection from the bottom is inhibited. The wave response to the forcing with a speed of about 3m/s has a large amplitude, i.e. quasi-resonance occurs. In this case, the thermocline plays the role of a reflector, and the upper ocean between the sea surface and the thermocline behaves as a duct. Here, the special value of the wave velocity is interpreted as a resonance condition. It was found that the wave damps in consequence of leaking energy downward, and the damping rate depends on the period of the wave. Less

利用TOPEX/POSEIDON卫星测高资料研究了太平洋波浪的传播特性，在赤道地区探测到向东传播的Kelvin波，在中纬度地区探测到向西传播的斜压Rossby波。这些波浪的存在暗示了海洋预测的可能性，例如气象学中的天气预测。第一，利用nudging方法进行资料同化，以探讨预报的可能性。数值模拟可以反映风强迫作用下波浪的生成过程，但不能反映波浪的传播速度。随着时间的推移，结果会偏离观察结果。但是，同化后的Kelvin波在传播过程中继续被调整，结果得到了很大的改善。其次，西太平洋地区由一个40天周期的季节内风强迫激发的Kelvin波，在同化后的10天内，在西太平洋地区的10天周期内，在风强迫激发的Kelvin波中，有40天周期的Kelvin波，在同化后的10天内，有40天周期的Kelvin波，在同化后的10天内，有40天周期的Kelvin波，在同化后的10天内，有40天周期的Kelvin波，在同化后的10天内，有40天周期的Kelvin波 ...更多信息 用海洋环流模式模拟了1998年12月至1999年12月的南海夏季风，并用谱分析方法进行了研究。温跃层深度处的温度振幅在赤道南北有两个峰值，纬向速度振幅在温跃层上、下赤道也有两个峰值。此外，人们还提出了一个问题，为什么这种波，这似乎是瞬态的，而不是模似的，总是传播的相速度具有一个特殊的值约为3米/秒。研究了无限深海洋中的一维垂直强迫问题，着重讨论了向东运动的上、下运动的外部强迫作用在海面上而来自海底的反射被抑制的瞬变现象。当速度为3 m/s左右时，波浪响应的振幅较大，即出现准共振现象。在这种情况下，温跃层起着反射器的作用，而海面和温跃层之间的上层海洋则起着管道的作用。这里，波速的特殊值被解释为共振条件。结果表明，波浪的衰减是能量向下泄漏的结果，衰减率与波浪的周期有关。少