Near-inertial Wave Generation, Propagation and Mixing in the East Pacific Warm Pool

0424792知识成果：将利用东太平洋气候调查（EPIC 2001）密集实地调查期间收集的数据，研究与近惯性内波相关的生成、传播和上层海洋混合。这项工作将推进我们的近惯性波的产生，传播和衰减在低纬度地区的理解-过程是知之甚少，但可能很重要的近惯性波混合的贡献，全球混合预算的最新估计。混合层惯性运动的风通量图也表明东太平洋暖池（EPWP）可能是低纬惯性波生成的热点。初步研究结果表明，近惯性波产生的混合可能会影响夹带在混合层的基础和该地区的浅温跃层的结构和演变。EPIC 2001年调查的时间序列和空间数据都表明，温跃层内的剪切和湍流主要是由一个单一的，充满活力的，向下传播的近惯性内波。EPIC 2001数据集的丰富性，以及从若干平台对上层海洋和下层大气进行的时间和空间取样，为进行这种调查提供了独特的机会。以往对低纬近惯性波的研究缺乏空间数据，无法对近惯性波的传播和产生细节进行粗略的估计。量化和描述在时间和空间的近惯性波和混合它产生在10？N，95？W.2。确定波浪对混合层特性的影响.用线性波理论估计波的性质.量化波浪的能量通量并估计扩散和湍流耗散的损失。利用一个简单的混合层平板模式来研究风强迫的时空变化.利用风强迫原始方程数值模式研究波浪的产生和传播.比较我们的结果与过去的近惯性波研究和线性近惯性波theory.Broader的影响：这项研究将在密切的互动与其他EPIC 2001年的调查，并有助于更好地了解在EPWP和热带辐合带（ITCZ）的大气-海洋耦合EPIC的目标。研究结果还将为改进海洋模式中混合层湍流通量的参数化提供物理基础，这些模式用于预测关键气候区域的混合层深度和热含量。作为该项目的一部分，一名研究生将完成他的博士学位。使用现代分析和建模工具解释海洋湍流数据，作为上层海洋对大气强迫反应的一部分。

0424792Intellectual Merit: The generation, propagation and upper-ocean mixing associated with near inertial internal waves will be conducted using data collected during the Eastern Pacific Investigation of Climate(EPIC2001) intensive field survey. This work will advance our understanding of near-inertial wave generation, propagation and decay at low-latitudes-processes that are poorly understood though likely important in light of recent estimates of the contribution of near-inertial wave mixing to the global mixing budget. Maps of wind-flux into mixed-layer inertial motions also indicate that the Eastern pacific Warm Pool (EPWP) may be a hotspot for low-latitude inertial wave generation. Preliminary findings suggest that near-inertial wave-produced mixing may influence entrainment at the base of the mixed-layer and the structure and evolution of the region's shallow thermocline. Both time series and spatial data from the EPIC2001 survey show that shear and turbulence within the thermocline were dominated by a single, energetic, downward-propagating near-inertial internal wave. The richness of the EPIC2001 data set, with temporal and spatial sampling of the upper ocean and lower atmosphere from a number of platforms, presents the unique opportunity to conduct such an investigation. Previous studies of low-latitude near-inertial waves lacked spatial data to extend the propagation and generation details beyond rough estimation.The main scientific objectives of the project are to:1. Quantify and describe in time and space the near-inertial wave and mixing it produced at 10?N, 95?W.2. Determine the influence of the wave on mixed-layer properties.3. Estimate the wave's properties using linear wave theory.4. Quantify the wave's energy flux and estimate losses to spreading and turbulent dissipation.5. Use a simple mixed-layer slab model to investigate the temporal and spatial variability of wind forcing.6. Use a wind-forced primitive equation numerical model to investigate the wave's generation and propagation.7. Compare our results with those of past near-inertial wave research and linear near-inertial wave theory.Broader Impacts: This research will be done in close interaction with other EPIC2001 investigators and contribute to the EPIC goal of better understanding atmosphere-ocean coupling in the EPWP and Intertropical Convergence Zone (ITCZ). The results will also provide a physical basis for improving parameterizations of mixed-layer turbulent fluxes in ocean models utilized for making predictions of mixed-layer depth and heat-content in a key climatic region. As part of the project, a graduate student will complete his Ph.D. training in interpreting oceanic turbulence data as part of the upper ocean response to atmospheric forcing using modern analysis and modeling tools.