Collaborative Research: Ocean Horizontal Array Turbulence Study: An Investigation of Subfilter-Scale Fluxes in the Marine Surface Layer

OHATS（海洋水平阵列湍流研究）是一项新的实地研究计划，旨在研究海气相互作用，特别是海洋（大气）边界层中表层湍流与下垫面波的耦合。这些风浪影响海洋表层的动力学和海气动量和标量的通量。用大涡模拟（LES）可靠地模拟海洋表层的能力是未知的。LES，特别是它的子滤波尺度（SFS）参数化需要根据这种复杂流动的观测结果进行验证和指导。该项目的关键部分是专门针对海洋表层SFS变量测量的现场活动。这些观测结果将用于阐明波浪和大气稳定性对表层湍流的影响，并为验证和改进LES的SFS模型提供数据库。OHATS将于2004年夏天在玛莎葡萄园岛海岸附近新建的海气相互作用塔（ASIT）上进行。ASIT通过伍兹霍尔海洋研究所运营的玛莎葡萄园岛海岸天文台（MVCO）直接与海岸相连。OHATS将在一个类似于2000年在加利福尼亚完成的水平阵列湍流研究的两级设置中使用14个声速计。通过对测量的三维速度和温度场进行空间滤波，推导出SFS的速度和温度通量。为了建立与SFS变量的相关性，将对波场特性进行同步观测。OHATS将加强目前对海气相互作用过程的理解，为表面波和湍流之间的耦合提供见解，并为LES的SFS建模提供新的视角。该项目将为研究生和博士后提供实践经验和培训，以解决海气相互作用研究中的基本问题，即风浪耦合。这些数据将通过互联网提供给更广泛的社区。

OHATS (Ocean Horizontal Array Turbulence Study ) is a novel field program to examine air-sea interaction and in particular the coupling of surface-layer turbulence in the marine (atmospheric) boundary layer with the underlying surface waves. These wind-generated waves influence the dynamics of the marine surface layer and the air-sea fluxes of momentum and scalars. The ability to model the marine surface layer reliably with large-eddy simulation (LES) is unknown. LES and in particular its sub-filter-scale (SFS) parameterization require validation against and guidance from observations for this complex flow. The critical piece of the project is a field campaign specifically directed at the measurement of SFS variables in the marine surface layer. These observations will be used to elucidate the impact of waves and atmospheric stability on surface-layer turbulence and provide a database to validate and improve SFS models for LES. OHATS will be carried out in the summer of 2004 at the recently constructed Air-Sea Interaction Tower (ASIT) located off the coast of Martha's Vineyard. The ASIT is connected directly to shore via the Martha's Vineyard Coastal Observatory (MVCO) operated by Woods Hole Oceanographic Institution. OHATS will employ 14 sonic anemometers in a two-level setup similar to the Horizontal Array TurbulenceStudy done in California in 2000. SFS velocity and temperature fluxes will be deduced by spatially filtering the measured 3-D velocity and temperature fields. Simultaneous observations of the wave-field properties will be made in order to establish correlations with the SFS variables. OHATS will enhance the current understanding of air-sea interaction processes, provide insight into the couplings between surface waves and turbulence, and shed new light on SFS modeling for LES A graduate student will work on the project along a postdoctoral student from the Advanced Study Program at NCAR.. The project will provide hands-on experience and training with a fundamental problem in air-sea interaction research, i.e., the coupling of wind and waves to graduate student and post-doc. The data will be made available to the broader community via the internet.