Collaborative Research: Cold Tongue Mixing

该项目将通过对温度变化耗散的多年时间序列测量，以及对高时空分辨率海洋模式的后期分析，研究大西洋和太平洋海洋冷舌内热的纵向混合的时空变异性。温度方差耗散是用ChiPods测量的，ChiPods是由俄勒冈州立大学PI实验室开发的仪器，可以进行高频湍流测量，得出海洋混合的关键参数。Chipods将被部署在赤道太平洋和大西洋的系泊处，在那里他们将在四年的时间里持续测量湍流。该项目包括两名早期职业科学家和本科生水平的教育组成部分，包括基础工程建设，以及通过一个旨在通过针对美国和西非本科生的体验式学习活动增加海洋科学中种族和民族多样性的新项目。赤道大西洋和太平洋的冷舌作为热带海洋表面温度较低的地区，吸收了异常大量的热量。剪切驱动的湍流将热量转移到混合层下方并远离地表。非热传热速率由混合决定，可以使用部署在系泊处的ChiPods直接测量。提出的工作重点是解决赤道冷舌的长期混合信号。这将有助于评估混合在年际至十年尺度过程中的作用，有助于确定混合在变暖中断期间对太平洋冷舌热吸收的影响程度，量化有多少热量流入更深的海洋，并量化相关的模式偏差。ChiPods将部署在三个赤道系泊点，两个在大西洋，一个在太平洋。分析的目的是更好地了解湍流的间歇性及其对垂直湍流热通量的季节性、年际和长期变化的影响，特别是与热带不稳定波有关的影响。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。

This project will examine temporal and spatial variability of diapycnal mixing of heat within the oceanic cold tongues of the Atlantic and Pacific oceans through multi-year time series measurements of dissipation of temperature variance, and through post-analysis of high temporal and spatial resolution ocean models. Temperature variance dissipation is measured using ChiPods, instruments developed by PI's lab at OSU that make high-frequency turbulence measurements to derive key parameters of ocean mixing. The Chipods will be deployed on moorings in the equatorial Pacific and Atlantic oceans where they will make continuous measurements of turbulence over four years. The project includes two early career scientists and educational components at the undergraduate student level both in basic engineering construction and through a new program aimed at increasing racial and ethnic diversity in ocean sciences through an experiential learning activity targeting US and West African undergraduates.The cold tongues of the equatorial Atlantic and Pacific Oceans stand out as regions of cool tropical sea surface temperatures that take up anomalously large amounts of heat. Shear-driven turbulence moves heat well below the mixed layer and away from the surface. The rate of diathermal heat transport is determined by mixing, which can be measured directly using ChiPods deployed on moorings. The proposed work focuses on resolving long-term mixing signals in the equatorial cold tongues. This will allow evaluation of the role of mixing in interannual to decadal-scale processes, help determine the extent to which mixing influenced the Pacific cold tongue’s heat uptake during the warming hiatus, quantify how much heat is fluxed down to the deeper ocean, and quantify related model biases. ChiPods will be deployed at three equatorial mooring sites, two in the Atlantic and one in the Pacific. Analyses will be aimed at better understand intermittency of turbulence and its effect on seasonal, interannual and longer-term variations in vertical turbulent heat flux, particularly associated with tropical instability waves.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.