CAREER: Towards Better Representations of the Nocturnal Low-Level Jets in New Generation Large-Eddy and Mesoscale Models

事业：在新一代大涡和中尺度模型中更好地表示夜间低空急流

• 批准号: 1122315
• 负责人: Sukanta Basu
• 金额: $ 29.88万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-11-10 至 2014-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1122315&HistoricalAwards=false
• 关键词: CAREER; Towards; Better; Representations; Nocturnal

This work will focus on a closely coordinated observational and numerical study of wind structure in the lowest layers of the atmosphere, with particular attention to mechanisms leading to development of a recurring wind pattern known as the "low level jet" (as in jetstream, aka LLJ, which frequently develops during nighttime hours over the U.S. central plains during spring/summer months). Particular attention will be directed toward identifying environmental controls on the degree to which this elevated source of momentum (and hence energy) is mixed down toward the earth's surface and its subsequent impacts on renewable energy production via wind turbines. The investigator's approach will embody a combination of: (1) development of an expanded observational database describing LLJ structure via an array of existing facilities operated by Texas Tech (including a 200 m tower mounted with sonic anemometers at 10 discrete levels) in conjunction with a newly acquired scintillometer--all of which are key to better understanding near-surface wind profile evolution under LLJ conditions; (2) numerical simulations to quantify turbulent controls on the intermittent vertical mixing of momentum from the level of the LLJ down to that of wind turbines during stably-stratified conditions typical of nighttime; (3) development of a new graduate-level course at Texas Tech University entitled "Wind Power Meteorology"; and (4) a broad K-12 outreach effort exposing teachers and students at local schools to a variety of classroom and field activities that will significantly enhance both primary and secondary science education.A particularly novel aspect of this project is inclusion of the "Large Eddy Simulation" (LES) approach in tandem with more traditional mesoscale simulations conducted via the Weather Forecasting Model (WRF). This effort, in tandem with above-mentioned special observations, will better describe the occurrence (and ultimately serve to achieve more accurate prediction) of episodes of turbulence in which stronger winds rooted aloft in the core of the LLJ mix downward toward the surface. The Broader Impacts of this work are substantial, and will include more accurate forecasts of changes in urban air quality and power generation capacity across large networks of turbine-powered electric generators ("wind farms") whose implementation is expanding rapidly in this era of mounting petroleum prices. Considerable enhancements to education at primary, secondary and university level will also occur as students are exposed to various aspects of the observation and numerical forecast of near-surface winds through suitable data visualization techniques (in the classroom) and field trips to become more familiar with renewable energy generation systems.

这项工作将侧重于对大气最低层风结构进行密切协调的观测和数值研究，特别关注导致称为“低空急流”的循环风模式发展的机制（如急流，又名LLJ，经常在春季/夏季的美国中部平原夜间发展）。 特别注意将被定向到识别环境控制的程度，这种升高的动量（因此能源）的来源是混合到地球表面和可再生能源生产通过风力涡轮机的后续影响。 研究者的方法将体现以下几个方面的结合：（1）通过德克萨斯理工大学运营的一系列现有设施，开发描述LLJ结构的扩展观测数据库（包括一座200米高的塔，在10个离散高度安装有声波风速计）以及新获得的闪烁仪--所有这些都是更好地了解LLJ条件下近地表风廓线演变的关键;（2）数值模拟，以量化湍流对夜间典型稳定分层条件下从LLJ水平到风力涡轮机水平的动量间歇性垂直混合的控制;（3）在得克萨斯理工大学开发一门新的研究生课程，名为“风力发电气象学”;（4）宽K-12外展工作，使当地学校的教师和学生接触到各种课堂和实地活动，这将大大提高小学和中学的科学教育。“大涡模拟”（LES）的方法与更传统的中尺度模拟通过天气预报模式（WRF）进行串联。这一努力与上述特殊观测相结合，将更好地描述湍流事件的发生（并最终用于实现更准确的预测），在这种湍流事件中，扎根于LLJ核心的强风向下混合到表面。这项工作的更广泛影响是巨大的，将包括更准确地预测城市空气质量和大型涡轮发电机网络（“风力发电场”）的发电能力的变化，其实施在这个石油价格上涨的时代迅速扩大。小学、中学和大学教育也将大大加强，因为学生通过适当的数据可视化技术（在课堂上）和实地考察接触到近地面风的观测和数值预报的各个方面，以更熟悉可再生能源发电系统。