Decadal Upper Ocean Variability in the North Pacific: Mechanisms, Impact and Prediction

北太平洋上层海洋年代际变化：机制、影响和预测

• 批准号: 0926594
• 负责人: Bo Qiu
• 金额: $ 41.79万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0926594&HistoricalAwards=false
• 关键词: Decadal; Upper; Ocean; Variability; North

Decadal variability in the midlatitude North Pacific Ocean has received considerable attention in recent years because of its impact upon the marine ecosystems and the weather anomalies over the North America continent. While scattered evidence exists suggesting the ocean dynamics works to contribute to an increase in variance and persistence of the North Pacific midlatitude ocean-atmosphere system on decadal timescales, a detailed understanding of how the system works is still lacking. In order to improve our ability to predict the midlatitude Pacific climate variability, a better understanding of how the upper ocean dynamic and thermodynamic processes interact is of fundamental importance.The mid-latitude North Pacific Ocean is subject to both buoyancy and momentum flux forcing at the sea surface. Because of the planetary beta effect, the wind stress-induced upper ocean anomalies tend to propagate westward and accumulate in the Kuroshio Extension region. By transporting warmer tropical-origin water to the mid-latitudes, the Kuroshio Extension is also where the largest air-sea heat exchange and its variability take place. The non-linear nature of the western boundary current circulation variability can further complicate the time-varying upper ocean signals. In this study, Dr Qiu and colleagues examine the processes underlying the observed upper ocean variability based on available in-situ/satellite observations and a high-resolution OGCM hindcast output. The scientific goals of the proposal are (1) to provide a comprehensive description of the decadal variability in the midlatitude North Pacific from the perspective of the upper ocean dynamic and thermodynamic process interaction, (2) to develop testable hypotheses about the role of ocean dynamics in determining the sea surface temperature changes, and (3) to explore whether the long memory of the ocean dynamics can be utilized for improved prediction.The Kuroshio Extension system is an important component of the earth's climate system, particularly in the North Pacific basin. Its influence upon the intensity and tracks of the midlatitude storms and the North Pacific marine ecosystems, as well as its impact on the weather patterns of the U.S. northwest coast, are of important societal relevance. This study aims to gain a better understanding of the roles of ocean dynamics in determining the decadal and longer timescale variability in the North Pacific climate system. This improved understanding could potentially expand our capacity to predict the decadal oceanic state. While the focus of the study is on the KE system specifically, many of the scientific questions, such as the roles of the oceanic adjustment through baroclinic Rossby waves, the intrinsic recirculation gyre variations, the interaction between the western boundary outflow and the bottom topography, and the impact of the upper ocean circulation changes upon the regional SSTs, apply to the other western boundary current systems as well. A better understanding of the KE system variability could serve as a useful step in elucidating the ocean's roles in the midlatitude air-sea coupling in general.

近年来，北太平洋中纬度的衰老变异性受到了很大的关注，因为它对北美大陆的海洋生态系统和天气异常产生了影响。尽管存在分散的证据，表明海洋动力学有助于促进北太平洋中纬度海洋 - 大气系统在十年时间尺度上的差异和持久性，但仍然缺乏对系统如何工作的详细理解。为了提高我们预测太平洋气候变化的能力，更好地理解上海洋动力学和热力学过程的相互作用是至关重要的。北太平洋中纬度地区既受浮力和海洋表面上的动量磁通量。由于行星β的效应，风应力引起的上海异常倾向于向西传播并在黑鲁西奥延伸区域积聚。通过将温暖的热带原始水运送到中纬度地区，黑发延伸也是最大的空气热交换及其可变性的地方。西部边界电流循环变异性的非线性性质可能会使随时间变化的上海信号复杂化。在这项研究中，Qiu博士及其同事根据可用的原位/卫星观测值和高分辨率的OGCM Hindcast输出来检查观察到的上海变异性的过程。该提案的科学目标是（1）从上海上的动态和热力学过程相互作用的角度提供对北太平洋中纬度际变异性的全面描述，（2）开发可测试的假设，以探索海洋表面温度变化的长期迁移的海洋动力学的作用，以探索海洋动力学的发展。地球气候系统的重要组成部分，特别是在北太平洋盆地。它对中纬度风暴和北太平洋海洋生态系统的强度和轨道的影响及其对美国西北海岸天气模式的影响具有重要的社会意义。这项研究旨在更好地了解海洋动力学在确定北太平洋气候系统中年代际和较长时间尺度变异性方面的作用。这种改善的理解可能会扩大我们预测衰老海洋国家的能力。虽然该研究的重点是专门放在KE系统上，但许多科学问题，例如通过斜压rossby波，海洋调整的作用，固有的再循环循环变化，西部边界流出和底部超平面和底部循环之间的相互作用以及上海流循环对区域SSTS的影响，应用于其他西部边界的系统系统。更好地了解KE系统的变异性可以是阐明海洋在中纬度空气耦合中的作用的有用步骤。