Collaborative Research: CEDAR: High-Resolution Imaging of Instability Dynamics and Breakdown

合作研究：CEDAR：不稳定动力学和击穿的高分辨率成像

• 批准号: 1445783
• 负责人: David Fritts
• 金额: $ 24万
• 依托单位: GLOBAL ATMOSPHERIC TECHNOLOGIES AND SCIENCES, INC.
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-15 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1445783&HistoricalAwards=false
• 关键词: Collaborative; Research; CEDAR; Resolution; Imaging

This is a 3-year collaborative investigation between The Aerospace Corporation and GATS Inc. to place a new airglow camera at the Andes Lidar Observatory (ALO) in Chile and use those data to study turbulent processes near the mesopause. Turbulent viscosity is a critical unknown parameter in numerical models of the 80 to 100 km altitude region. It is notoriously very difficult to measure. This project will provide a method of measuring this parameter in this important atmospheric region where turbulent viscosity may vary by 3 orders of magnitude. The results of this study will also contribute to a more general understanding of fluid dynamics accompanying flow instabilities. Specifically, this project will utilize the Aerospace Corporation?s new high-resolution infrared camera (AIC2) that uses fast optics and a 2048 x 2048 IR detector to image the OH airglow at 30 m pixel size with a 2 s image cadence. The ALO site also includes a Na wind-temperature lidar and a meteor radar. Data from the AIC2 and the other ALO instruments will be used to investigate the breakdown into turbulence of Kelvin-Helmholtz instabilities (KHIs) and to measure the turbulent viscosity. This new technique will allow characterization of the turbulent viscosity for a variety of background conditions and over daily and seasonal timescales. The measurements will be combined with high-resolution direct numerical simulations to produce the most complete picture to date of KHI breakdown and its evolution into turbulence.

这是航空航天公司和 GATS Inc. 之间为期 3 年的合作研究，目的是在智利安第斯山脉激光雷达天文台 (ALO) 放置一台新的气辉相机，并利用这些数据来研究中层顶附近的湍流过程。湍流粘度是 80 至 100 km 海拔区域数值模型中的一个关键未知参数。众所周知，它很难测量。该项目将提供一种在这个重要的大气区域测量该参数的方法，该区域的湍流粘度可能会变化 3 个数量级。这项研究的结果也将有助于更全面地理解伴随流动不稳定性的流体动力学。 具体来说，该项目将利用航空航天公司的新型高分辨率红外相机 (AIC2)，该相机使用快速光学器件和 2048 x 2048 红外探测器，以 30 m 像素大小和 2 s 图像节奏对 OH 气辉进行成像。 ALO站点还包括Na风温激光雷达和流星雷达。来自 AIC2 和其他 ALO 仪器的数据将用于研究开尔文-亥姆霍兹不稳定性 (KHI) 的湍流分解并测量湍流粘度。这项新技术将允许在各种背景条件以及每日和季节性时间尺度上表征湍流粘度。这些测量结果将与高分辨率直接数值模拟相结合，以生成迄今为止最完整的 KHI 分解及其演变为湍流的图像。