MoorSPICE: Moorings for the Southwest Pacific Circulation Experiment

长期以来，所罗门海一直被认为是西热带太平洋西部边界流将南太平洋温跃层水从亚热带重新分配到赤道的主要途径。最近的证据表明，源自这些南太平洋温跃层水域的海洋异常是ENSO在年代际时间尺度上变化的原因。然而，所罗门海海洋环流的几个关键方面仍然没有得到很好的观测，模型也没有适当地描述。有多少水通过所罗门海被带到赤道，以及在多大的密度范围内，这些问题仍然存在。西南太平洋环流系泊实验（MoorSPICE）是一项国际合作实验，旨在测量这些边界流的流量，同时在连接所罗门海的主要通道：不可或缺海峡、Vitiaz海峡、圣乔治海峡和所罗门海峡进行系泊部署。这些测量从2011年8月开始，历时18个月。这个项目是MoorSPICE的美国组成部分。MoorSPICE的主要动机是获得通过所罗门海主要出口通道流向赤道太平洋的南太平洋西部边界流的平均值和变率的定量视图。每条路径可能意味着不同的水团组合，并意味着水到达赤道的不同时间尺度。通过各海峡的运输比例也可能随时间而变化。因此，海峡之间的分隔可能决定了温跃层水通往赤道的路线（它与赤道暗流交汇的经度），并可能对赤道对西南太平洋风和环流变化的响应产生潜在影响。知识价值：在所罗门海的每个主要通道上同时进行系泊部署，将为南太平洋西部边界流的划分以及它如何响应区域和远程风强迫而变化提供重要信息。由于通道狭窄和地形复杂，目前的数值模型对每条通道的流动指导作用很小，而且很少有可用的观测资料来约束模型。最终的MoorSPICE数据集将允许对通往赤道的各种温跃层水路径的模型模拟进行定量评估，包括其随时间的变化。了解亚热带海水向热带的输送和性质特征将有助于阐明热带外诱发ENSO变率的机制。更广泛的影响：作为促进发现和理解的教育组成部分的一部分，moospice将支持研究生的研究项目。研究结果将通过讲习班、海洋学会议和学校的报告以及一个网站在科学界内外广泛传播。MoorSPICE是一项协调的国际研究工作，将加强我们的研究基础设施。完整的MoorSPICE数据集将在实地工作结束两年后提供给社区。使用MoorSPICE数据验证模型将通过广泛的海洋、气候、管理和保护应用提供社会效益。

The Solomon Sea has long been recognized as a major pathway for the western boundary currents of the western tropical Pacific to redistribute South Pacific thermocline waters from the subtropics to the equator. Recent evidence suggests that oceanic anomalies originating in these South Pacific thermocline waters are responsible for the modulation of ENSO variability on decadal time scales. However, several key aspects of the oceanic circulation in the Solomon Sea remain poorly observed and are not properly depicted by models. Questions remain as to how much water is carried through the Solomon Sea to the equator and in what density range. The Moorings for the Southwest Pacific Circulation Experiment (MoorSPICE) is an international co-operative experiment designed to measure the flow in these boundary currents with simultaneous mooring deployments in the major passages that bound the Solomon Sea: Indispensible Strait, Vitiaz Strait, St. Georges Channel and Solomon Strait. The measurements span an 18-month period beginning in August 2011. This project is the U.S. component of MoorSPICE. The key motivation for MoorSPICE is to obtain a quantitative view of the mean and variability of the equatorward South Pacific western boundary current flow through the main exit channels of the Solomon Sea to the equatorial Pacific. Each pathway possibly means different water mass combinations, and implies a different time scale for water to reach the equator. The ratio of transport through each of the straits may also vary with time. The partition between the straits could thus be determinant for the thermocline water route to the equator (the longitude at which it joins the Equatorial Undercurrent) with potential consequences for the equatorial response to changes in the southwest Pacific winds and circulation.Intellectual merit: The simultaneous mooring deployments in each major passage of the Solomon Sea will provide vital information on the partitioning of the South Pacific western boundary flow and how it changes in response to regional and remote wind forcing. Because of the narrow passages and complex topography, at present the numerical models offer little guidance of the flow through each pathway and there are few available observations to constrain the models. The definitive MoorSPICE data set will allow for quantitative evaluation of model simulations of the various thermocline water pathways en route to the equator, including their time-dependent variability. Understanding the transport and property characteristics of the subtropical waters that are transmitted to the tropics will help elucidate the mechanisms that are responsible for the extra-tropical induced ENSO variability.Broader Impacts: As part of the educational component to advance discovery and understanding, MoorSPICE will support the research project of a graduate student. The results will be broadly disseminated within and beyond the scientific community through workshops, presentations at oceanographic meetings and schools, and a web site. MoorSPICE is a coordinated international research effort that will act to enhance our research infrastructure. The full MoorSPICE data set will be made available to the community two years after the finish of the fieldwork. Validation of models with the MoorSPICE data will provide societal benefit through a wide range of ocean, climate, management and conservation applications.