Boundary Layer Structure and Evolution During Terrain-induced Rotor EXperiment (T-REX)

地形诱导转子实验 (T-REX) 期间的边界层结构和演化

• 批准号: 0522004
• 负责人: Rod Frehlich
• 金额: --
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0522004&HistoricalAwards=false
• 关键词: Boundary; Layer; Structure; Evolution; During

The Principal Investigator (PI) will study the evolution of the first few km of the lower atmosphere during the Terrain-Induced Rotor Experiment (T-REX). The T-REX is a multi-investigator focused on the study of mountain rotors and other lee wave phenomena. In his research, the PI will use state-of-the-art high-resolution Doppler lidar and high-resolution profiles of velocity, temperature, turbulence, ozone, and aerosol particle concentration. The PI also will deploy a Tethered Lifting System (TLS). The focus of this effort is the evolution of small-scale turbulence, wave-turbulence interactions, and variations of the boundary layer height and dynamics during the rotor events. In addition, new lidar algorithms will be modified to provide real-time profiles of turbulence and wind information to guide the deployment of field instruments, particularly aircraft and tethered systems, when conditions of high turbulence are present and pose a possible hazard. The Doppler lidar analyses will focus on extracting reliable small-scale turbulence information by correcting the effects of the spatial averaging by the lidar pulse volume. This development will permit more accurate comparisons between the lidar results and the in situ turbulence measurements provided by the TLS profiles. Comparable developments in the TLS technique will enable concurrent, high-resolution profiling of winds, temperatures, and turbulent properties from the surface to heights of a few km. A newly developed temperature sensor chain flown from the TLS will also be deployed to provide more accurate temperature gradients for measurements of thermal stability in the boundary layer. The primary focus of the in situ measurements will be the stable boundary layer (SBL) and the nighttime remnants of the daytime convective processes that define the residual layer (RL). Daytime conditions will also be considered depending on the logistical constraints of the field program and the importance of the daytime measurements for the various stages of the rotor evolution. The intellectual merit of the research includes an improved understanding of boundary layer processes from the unprecedented high-resolution in situ data and the three dimensional measurements of wind fields and turbulence with Doppler lidar. The simultaneous measurements will also provide the first validation of accurate turbulence estimates with an operational Doppler lidar as well as verification of new model derived estimates of small scale turbulence which are critical for next generation optimal data assimilation and numerical weather prediction models. The broader impacts include improved methods for model parameterization especially correct calculations of the boundary layer height, improved forecasts of terrain induced turbulence for aviation safety, and new input to optimal data assimilation for the challenging conditions of complex terrain and stable boundary layers. The value of real-time wind speed and turbulence profiles will be demonstrated to guide future field campaigns.

首席研究员将在地形诱导转子实验（T-REX）期间研究低层大气最初几公里的演变。 T-REX是一个多研究者，专注于研究山脉转子和其他背风波现象。 在他的研究中，PI将使用最先进的高分辨率多普勒激光雷达和高分辨率的速度，温度，湍流，臭氧和气溶胶颗粒浓度的剖面。 PI还将部署系留提升系统（TLS）。 这项工作的重点是小尺度湍流的演变，波湍流相互作用，以及在转子事件的边界层高度和动态的变化。 此外，将修改新的激光雷达算法，以提供湍流和风信息的实时分布图，以便在出现高度湍流并可能造成危险时指导现场仪器的部署，特别是飞机和系留系统。多普勒激光雷达分析将侧重于通过校正激光雷达脉冲体积的空间平均效应来提取可靠的小尺度湍流信息。 这一发展将允许激光雷达结果和TLS剖面提供的原位湍流测量结果之间进行更准确的比较。 TLS技术的可比发展将使从地面到几公里高度的风、温度和湍流特性的并行、高分辨率廓线成为可能。 还将部署一个新开发的从TLS飞行的温度传感器链，以提供更准确的温度梯度，用于测量边界层的热稳定性。 现场测量的主要重点将是稳定边界层（SBL）和白天对流过程的夜间残留物，定义残留层（RL）。 白天的条件也将根据现场计划的后勤限制和白天测量对转子演变的各个阶段的重要性来考虑。 这项研究的智力价值包括从前所未有的高分辨率现场数据和多普勒激光雷达对风场和湍流的三维测量中加深对边界层过程的理解。 同步测量还将首次验证使用多普勒激光雷达进行的准确湍流估计，并验证新模型推导的小尺度湍流估计，这对下一代最佳数据同化和数值天气预报模型至关重要。更广泛的影响包括改进模型参数化方法，特别是边界层高度的正确计算，改进对地形引起的湍流的预测以确保航空安全，以及为复杂地形和稳定边界层的挑战性条件下的最佳数据同化提供新的投入。 将展示实时风速和湍流廓线的价值，以指导今后的实地活动。