Collaborative Research: Downstream Impacts of the South Pacific Tropical Water

合作研究：南太平洋热带水的下游影响

• 批准号: 1129793
• 负责人: Rana Fine
• 金额: $ 39.78万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1129793&HistoricalAwards=false
• 关键词: Collaborative; Research; Downstream; Impacts; South

Observations of South Pacific Tropical Water (SPTW) have revealed variability on interannual time scales and a trend of increasing salinity over several decades. SPTW identified by a shallow salinity maximum forms in the eastern South Pacific and is transported in the subtropical gyre and along the equator. Variability of SPTW may affect the circulation and water properties in the equatorial region, in particular if the salinity and temperature anomalies are not density compensated. SPTW has a significant interior equatorward pathway, and thus a relatively short (5-15 years) residence time and high formation rate. As a consequence, the contribution of SPTW to the equatorial Pacific is expected to be faster and stronger than its North Pacific counterpart. This project will initiate a more complete understanding of how the equatorial ocean is ventilated through the subduction of South Pacific waters and how variability in this ventilation contributes to climate variability. The overall research objectives of the project are: to identify variability in SPTW, and to assess downstream impacts of this variability. The relationship of SPTW variability to interannual and longer term atmospheric forcing will be investigated. Depending on the extent and magnitude of the SPTW variability, it is hypothesized that there will be a dynamical signature in the downstream circulation and thermal structure of the tropical South Pacific. The research includes the analysis of available Argo floating profiles and WOCE/CLIVAR tracer (salinity, potential vorticity, oxygen, CFC, SF6, tritium, helium-3, 14C, etc.) data, as well as results from the OGCM for the Earth Simulator (OFES), and simulated passive and adjoint tracers from the Estimating the Circulation and Climate of the Ocean (ECCO).Intellectual merit: The project will utilize all available hydrographic (mainly Argo) and tracer observations to identify the variability of SPTW. The combined use of observations with results from high-resolution GCMs will allow for a comprehensive, physically consistent interpretation of this variability and its downstream impacts on the tropical Pacific Ocean circulation and thermal structure. In addition, the simulated passive tracer and its adjoint will provide unambiguous means to identify the SPTW pathways and in particular to assess the influence of meso-scale eddies and small scale processes. The SPTW contributes to the Equatorial Undercurrent and water upwelled in the eastern equatorial Pacific, both having direct relevance to ENSO. The derived assessment of the SPTW downstream impacts will enhance the understanding of ocean?s role in climate variability, and provide new information for the predictability and prediction of interannual and longer time scale variability such as ENSO and PDO in the Pacific. Broader impacts: The project will lead to improved skills for use with ENSO and climate prediction; advance science while promoting education by the training of a postdoctoral fellow and a graduate student in the analysis of observational data and model outputs; enhance infrastructure for research and education by establishing collaborations between different disciplines and different institutions; and benefit the society by the use of existing observations and results from high-resolution GCMs to assess climate change. One of the PIs participates in the program Mentoring Physical Oceanography Women to Increase Retention, and is on the implementation committee of an NSF Advance grant to the University of Miami.

对南太平洋热带水（SPTW）的观察结果揭示了几十年来盐度量表的变化和盐度增加的趋势。 SPTW在南太平洋东部的浅盐度最大形式鉴定出来，并在亚热带回旋中和赤道中运输。 SPTW的可变性可能会影响赤道区域的循环和水性质，特别是如果盐度和温度异常未补偿密度。 SPTW具有明显的内部赤道途径，因此相对较短（5 - 15年）的停留时间和高层速率。 因此，SPTW对赤道太平洋的贡献预计将比北太平洋同行更快，更强大。 该项目将通过南太平洋水域的俯冲以及该通风的可变性如何促进气候变异性，对赤道海洋的通风方式有了更全面的了解。 该项目的总体研究目标是：确定SPTW中的可变性，并评估该变异性的下游影响。 将研究SPTW变异性与年际和长期大气强迫的关系。 根据SPTW变异性的程度和大小，假设在热带南太平洋的下游循环和热结构中将有一个动力学特征。 这项研究包括分析可用的Argo浮动轮廓和WOCE/Clivar Tracer（盐度，潜在涡度，氧气，氧气，CFC，SF6，SF6，Tritium，Tritium，Tritium，3，14C等），以及来自地球（OFES）的OGCM以及OGCM产生的（OFES），以及模拟的无源和相邻（估算的循环）（循环），并估算了循环的循环（循环）。优点：该项目将利用所有可用的水文学（主要是ARGO）和示踪剂观测来确定SPTW的可变性。 观测值与高分辨率GCM的结果的综合使用将允许对这种变异性进行全面的，物理上一致的解释及其对热带太平洋循环和热结构的下游影响。 此外，模拟的被动示踪剂及其伴随将提供明确的手段来识别SPTW途径，尤其是评估中尺度涡流和小规模过程的影响。 SPTW有助于赤道潜流和在赤道太平洋上升的水，都与ENSO直接相关。 对SPTW下游影响的派生评估将增强对海洋在气候变异性中的作用的理解，并为太平洋中ENSO和PDO等年度和更长的时间尺度变异性提供新信息。 更广泛的影响：该项目将提高ENSO和气候预测的技能；通过培训博士后研究员和研究生，在观察数据和模型输出分析中，通过培训了教育；通过建立不同学科与不同机构之间的合作来增强研究和教育的基础设施；并通过使用现有观察结果和高分辨率GCMS评估气候变化的结果来使社会受益。 其中一位PI参加了指导物理海洋学妇女的计划，以增加保留率，并参加了迈阿密大学的NSF预付款授予的实施委员会。