Collaborative Research: RAPID: Pilot observations of enhanced near-bottom equatorial turbulence

合作研究：RAPID：增强近底赤道湍流的试点观测

• 批准号: 2309410
• 负责人: Caitlin Whalen
• 金额: $ 0.12万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-15 至 2024-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2309410&HistoricalAwards=false
• 关键词: Collaborative; Research; RAPID; Pilot; observations

The low-latitude deep Pacific is known to be the locus of a critical abyssal upwelling branch of the overturning circulation. This upwelling requires diapycnal mixing of buoyancy downward from the less dense upper ocean. However, the diapycnal mechanisms driving this process are currently poorly understood and relatively poorly sampled. This project will leverage a funded mooring array at 140°W (part of the NSF project OCE-2048660 “Evaluating mechanisms for enhanced mixing below tropical instability waves”) to make the first full year, high-resolution equatorial observations of abyssal mixing. The funded moorings are scheduled to be deployed at the end of 2023. Instrumentation will be added to the mooring planned for 0.5 and 3°N latitutde to observe the bottom boundary layer, using point and profiling current meters and a dense positioning of temperature sensors.This pilot project will inform understanding of the low-latitude diffusive upwelling branch of the global circulation, a fundamental component of climate. The observations will be used to test several hypothesized abyssal equatorial turbulence mechanisms including: near-bottom wave trapping driven by the horizontal component of the Earth's rotation, topographic lee-wave- driven mixing, and inertial instability generated through wave-driven displacement of fluid away from the equator. The project will advance knowledge of deep equatorial dynamics and the overturning circulation to inform future observations of mixing in the deep equatorial Pacific.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.

众所周知，低纬度深太平洋是倾覆循环的临界深渊上升流分支的所在地。这种上升的需要从密度较少的上大洋向下浮力的浮力混合。然而，目前对驱动此过程的二比机制的理解不足，采样相对较差。该项目将利用140°W的资助系泊阵列（NSF项目OCE-2048660的一部分“评估在热带不稳定性波浪以下的混合机制”）使第一年，高分辨率的高分辨率等效性观察到了Abyssal混合。资金的系泊设备计划在2023年底部署。将使用点和分析电流仪表以及温度传感器的密集定位，将仪器添加到计划的0.5和3°N Latitutde计划中，以观察底部边界层。该试点项目将告知人们对全球循环的低纬度扩散上升分支，这是气候的基本组成部分。该观察结果将用于测试几种假设的深渊等效性湍流机制，包括：由地球旋转的水平成分，Lee-Wave驱动的地形驱动的混合以及通过从等效率流动的波动流离失所产生的惯性不稳定。该项目将促进对等效性动态和推翻圈子的知识，以告知未来对深层公平太平洋中混合的观察结果。该奖项反映了NSF的法定任务，并通过评估该基金会的知识分子优点和更广泛的影响来审查标准。