At-sea testing and final development of the Hadal Water Column Profiler

对于深海水柱（即6500 m以上的水域）的混合、循环、化学性质和生物群落的了解甚少。已经进行的少量测量表明，hadal区的水不是静止的，与上面的海洋隔绝，而是在惊人的短时间内更新。需要更多的多学科观测来推进hadal水柱科学。为此，研究人员利用私人基金会的资金，开发了一个11公里深度的Hadal水柱剖面仪（能够到达海洋的最深点），它可以重复垂直剖面的温度，电导率，溶解氧，湍流混合，流速，声波反向散射和视频，它有一个小的11瓶水采样器。研究人员进行了为期两天的海上测试，测试结果表明，研制成功地生产出了一台功能正常的剖面仪，但Hadal水柱剖面仪还需要进行更多的海上测试，以发挥其作为海洋研究考察的尖端科学仪器的潜力。一旦投入使用，Hadal水柱剖面仪将提供一种手段，大大增加对全球海洋中采样最不足的地区之一的了解。它将能够首次直接测量深海海沟中的湍流混合，允许探索流动，海沟通风机制和中水生物群落，从而揭示生物连通性，并能够识别由浊度流产生的网状层，这些浊度流可能是海沟中常见且重要的生物地球化学和生物学。该项目将为这种独特仪器的最终开发提供额外的船舶时间。在为期4天的3次海上测试中，研究人员将承担从之前的海上测试中确定的6项任务。这些任务包括优化数据质量的“飞行”特性，同时使用传统的电导率-温度-深度和声学多普勒电流剖面仪测量来评估数据。在之前的海上测试中，使用了一个半尺寸的原型水采样器。这个项目将允许测试一个全尺寸的水采样器。最后，由于Hadal水柱剖面仪在深度评级和传感器套件方面的独特功能，未来的研究考察可能会严重依赖该仪器，因此建立可靠性，数据质量和操作效率方面的性能记录历史非常重要。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Very little is known about the mixing, circulation, chemical properties, and biological communities in the hadal water column, i.e., waters deeper than 6500 m. The handful of measurements that have been made show that rather than being quiescent and isolated from the ocean above, the water in the hadal zone is renewed on surprisingly short time scales. More multidisciplinary observations are needed to advance hadal water column science. To that end the researchers, using private foundation money, developed a 11 km depth rated (capable of getting to the deepest point in the ocean) Hadal Water Column Profiler which allows repeated vertical profiles of temperature, conductivity, dissolved oxygen, turbulent mixing, current velocity, acoustic backscatter, and video, and it has a small 11-bottle water sampler. The researchers conducted two days of at-sea testing which showed that the development had successfully produced a functioning profiler, but also that more at-sea testing is needed for the Hadal Water Column Profiler to reach its potential as a cutting-edge scientific instrument ready for oceanographic research expeditions. Once operational the Hadal Water Column Profiler will provide the means to substantially increase understanding of one of the most undersampled regions in the global ocean. It will enable the first direct measurements of turbulent mixing in the deep ocean trenches, allow for exploration of flow, trench ventilation mechanisms, and midwater biological communities shedding light on biological connectivity, and enable the identification of nepheloid layers created by turbidity flows that are likely common and important biogeochemically and biologically in trenches.This project will provide additional ship time for the final development of this unique instrument. During three 4-day periods of at-sea testing, the researchers will undertake six tasks identified from the prior at-sea testing. These tasks include optimizing the ‘flight’ characteristics for data quality and using contemporaneous traditional Conductivity-Temperature-Depth and Acoustic Doppler Current Profiler measurements to evaluate the data. During the previous at-sea testing a half size prototype water sampler was used. This project will allow a full-size water sampler to be tested. Finally, due to the unique capabilities of the Hadal Water Column Profiler, both in terms of depth rating and suite of sensors, future research expeditions are likely to rely heavily on this instrument so it is important to build up a documented history of performance in terms of reliability, data quality, and operational efficiency.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.