Collaborative Research: Quantitative Investigation of Finestructure and Internal Waves in the Norwegian Sea from Simultaneous Temperature and Acoustic Reflectance Measurements

合作研究：通过同步温度和声反射测量对挪威海的精细结构和内波进行定量研究

• 批准号: 0452265
• 负责人: Raymond Schmitt
• 金额: $ 15.13万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0452265&HistoricalAwards=false
• 关键词: Collaborative; Research; Quantitative; Investigation; Finestructure

ABSTRACTOCE-0452744-0452265Oceanic finestructure can be imaged in great detail using low-frequency (10-150 Hz) seismic reflection profiling. In September 2003, a joint hydrographic/seismic imaging survey of oceanic finestructure was conducted, acquiring temperature and salinity data on 110 XBT.s and 12 XCTD.s as a low-cost piggyback to a previously scheduled seismic reflection study in the Norwegian Sea. Initial results showed that the reflection method (1) is sensitive to fine-scale temperature contrasts as small as 0.03 C; (2) can image finestructure from M2 internal tides and map the sites of M2 internal tide generation; (3) can map water-mass boundaries in great detail; (4) can produce quantitative internal wave spectra that reproduce the expected Garrett-Munk spectrum and deviations from it; and (5) can image disruptions in finestructure consistent with internal wave on critical continental slopes. This proposal will focus on analysis of the data, targeting the following questions: (1) How can we best extract quantitative information on internal wave displacement spectra and vertical coherence from acoustic images of finestructure? (2) What are the characteristics of the internal wave field in the thermocline of Norwegian Sea, and are there systematics with depth, distance from continental slope, and bottom topography? (3) Is high-wavenumber internal wave energy enhanced at sites near critical continental slopes? (4) Where are M2 internal tides generated on the Norwegian continental slope, and are there systematics with slope angle and tidal cycle? (5) What is the relationship of imaged reflectors to the geostrophic velocity field? (6) What is the shape of the deep water mass boundaries revealed in the various sections? This work is a logical next step in determining the capabilities and limitations of low-frequency acoustic imaging to study ocean structures and dynamics.

ABSTRACTOCE-0452744-0452265 使用低频 (10-150 Hz) 地震反射剖面可以对海洋精细结构进行详细成像。 2003年9月，对海洋精细结构进行了联合水文/地震成像调查，获取了110 XBT.s和12 XCTD.s的温度和盐度数据，作为先前计划的挪威海地震​​反射研究的低成本搭载。 初步结果表明，反射法 (1) 对小至 0.03 C 的精细温度差异敏感； (2) 可以对M2内潮汐的精细结构进行成像并绘制M2内潮汐产生地点； (3) 能够详细绘制水体边界； (4) 可以产生定量的内波谱，再现预期的 Garrett-Munk 谱及其偏差； (5) 可以对与关键大陆坡上的内波一致的精细结构破坏进行成像。 该提案将重点关注数据分析，针对以下问题：（1）如何从精细结构声学图像中最好地提取内波位移谱和垂直相干性的定量信息？ （2）挪威海温跃层内波场有什么特征，是否有深度、距大陆坡距离、海底地形的系统性？ (3) 临界大陆坡附近的高波数内波能量是否增强？ （4）挪威大陆坡M2内潮产生于何处，是否有坡角和潮汐周期的系统？ (5) 成像反射体与地转速度场有何关系？ (6) 各剖面揭示的深水团边界形状如何？ 这项工作是确定低频声学成像研究海洋结构和动力学的能力和局限性的合理下一步。