Submarine Estimates of Arctic Turbulence Spectra (SEATS)

北冰洋及其周边海域由季节性变化的冰覆盖和无冰的开阔海洋和大陆架沃茨组成，被认为是对全球变化过程最敏感的区域之一。目前估计的多年海冰损失率似乎超过了模型的预测。尽管与直接大气强迫隔绝，但通过重复的盐度和温度对通过冰孔部署的深度剖面以及最近部署的冰系剖面仪，已经清楚地观察到中尺度斜压不稳定涡旋（海洋内部的“风暴尺度”，10-100公里）。本文研究了海冰下湍流混合边界层的测量结果，确定了与冰速相关的摩擦阻力密切相关的混合层厚度。由于同样的原因，不同的过程导致建立一个湍流混合层冰下相比，开放的沃茨，我们预计，不同的机制将导致混合层再分层，因此，次中尺度（1-10公里）与中尺度涡和锋面边界的相互作用将在无冰和冰覆盖的地区之间的变化。本研究的目的是通过对大量已有数据资源的分析，更好地了解边缘或季节性变化的冰盖区域混合层变化的特征。皇家海军（RN）潜艇已经收集了北极和其他地方的温度和盐度数据很长一段时间。超过15年来，RN潜艇一直配备传感器套件，其中还包括许多生物化学仪器，特别是叶绿素（a）和“黄色物质”等色素。这些数据通常是高度机密的，无法用于国防部以外甚至主要是国防部内部的研究目的。这是因为传统的研究要求包括采集时间/日期和位置。然而，只有船只的速度，经过的时间（仪器采样间隔）和深度，在众所周知的公布的范围内，需要伴随的数据流，我们检查的物理和生物参数的空间互相关系数。这是一种机制，用于查看在空间和时间上收集的数据，这些数据包含在其中的固有可变性的时间和空间尺度上。具体来说，与我们的MOD合作者的讨论表明，在混合层和更深的层中都将提供大量的数据。波数谱与这些互相关系数的傅立叶变换成正比，并量化了在一系列长度尺度上特征（包括涡旋和细丝）对变异性的贡献。对于一般的航行船舶速度，观测者的“速度”是这样的，即穿越一个结构所需的时间远远小于其演变所需的时间，但最小的结构。O号船的扰动尺度（100米）将把我们的研究限制在次中尺度细丝和以上（~0.2-100公里）。我们可以解决的一个关键问题是，其他性质的光谱与物理光谱的关系有多密切。

The arctic ocean and it's peripheral seas comprise a seasonally variable mix of ice covered and ice-free open ocean and shelf waters that are considered to be one of the most sensitive regions to global change processes. Current estimated rates of multi-annual sea-ice loss appear to be exceeding model predictions. Despite the insulation from direct atmospheric forcing, mesoscale baroclinically unstable eddies (the oceanic's internal 'storm scale', 10-100 km) have been clearly observed through repeated salinity and temperature against depth profiles deployed through ice holes and more recently by the deployment of ice-tethered profiling instruments. Measurements of a turbulent well mixed boundary layer under sea-ice have been examined, establishing a mixed layer thickness closely coincident with an ice speed related frictional drag. For the same reason that different processes lead to the establishment of a turbulent mixed layer under ice compared to open waters, we expect that different mechanisms will lead to mixed layer re-stratification and therefore that the sub-mesoscale (1-10's km) interaction with mesoscale eddies and frontal boundaries will vary between ice-free and ice-covered regions. The aim of this study is an improved understanding of the characteristics of mixed layer variability in marginal or seasonally variable ice-covered regions, through the analysis of a large pre-existing data resource.Royal Navy (RN) submarines have collected temperature and salinity data in the Arctic, and elsewhere for a long time. For over 15 years RN submarines have been equipped with a sensor suite that also includes a number of biogeochemical instruments particularly for pigments such as chlorophyll(a) and 'yellow substance'. These data are normally highly classified and unavailable for research purposes outside and even largely within the MOD itself. This is because traditional research requirements include acquisition time/date and position. However, only vessel velocity, elapsed time (instrument sampling interval) and depth, within well known published ranges, are required to accompany the data-streams for us to examine the spatial cross correlation coefficients in the physical and biological parameters. This is a mechanism for looking at data collected spatially and temporally in terms of the time and space scales of the inherent variability contained within it. Specifically, discussions with our MOD collaborators indicate that significant amounts of data will be available both in the mixed layer and deeper. The wavenumber spectrum is simply proportional to the Fourier transform of these cross-correlation coefficients, and quantifies the contribution to variability from features at a range of length scales, including eddies and filaments. For general underway vessel velocities, the 'speed' of the observer is such that the time taken to traverse a structure is very much less than the time taken for its evolution for all but the smallest structures. The disturbance scale of the vessel O(100 m) will limit our study to sub-mesoscale filaments and above (~0.2-100 km). A key issue we can address is how closely related the spectra of other properties are to the physical spectra.