CEDAR Postdoc: Numerical Modeling of Mesospheric Bores, Nonlinear Ducted Waves, and Interpretation of Observations in the Middle Atmosphere

CEDAR 博士后：中层孔的数值模拟、非线性波导波以及中层大气观测的解释

• 批准号: 0924802
• 负责人: Brian Laughman
• 金额: $ 17.33万
• 依托单位: NorthWest Research Associates, Incorporated
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0924802&HistoricalAwards=false
• 关键词: CEDAR; Postdoc; Numerical; Modeling; Mesospheric

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)This project focuses on modeling studies of mesospheric bores. These wave features occur in the upper mesosphere and lower thermosphere and are identified as a sharp wave front with a large horizontal extent (on the order of 500 km) followed by a train of wave crests. Mesospheric bores were first observed in 1993. Since then, there have been many additional observations but limited detailed understanding. This project will quantitatively assess the dynamics and characteristics of mesospheric bores, including the environments that support them, the forcings that give rise to them, and their impacts on the atmosphere. The effort has two main components: (1) extend a current numerical model already developed to encompass more complicated forcings and environments typical of the mesosphere and lower thermosphere; (2) model observed airglow data for which concurrent lidar and radar measurements describe the thermal and wind environments. For task 1, the proposed model extensions will simulate more realistic background conditions for the bores along with the responses of various types of bore structures to these conditions. The second task will use airglow, radar, and lidar observations to provide information on the background thermal structure of the atmosphere and on how bores propagate through it. The numerical studies will improve quantitative understanding of bore dynamics and determine how the existing theories might be expanded or amended to apply in realistic environments. Applications to observations will also define how observations can best quantify the bore dynamics as well as related ducting phenomena. The broader impacts of the project concern the implications for better understanding and quantification of energy and momentum transport and deposition in the mesosphere and lower thermosphere, which impacts the mean flow and global circulation models. An improved understanding of the nonlinear dynamics of mesospheric bores is also relevant to other dynamically similar phenomena, both in the lower atmosphere and in various engineering applications. The project will support a new researcher in his first research effort after completion of the Ph.D.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。 这些波的特点发生在上层中间层和下层热层，被确定为一个尖锐的波前与一个大的水平范围（约500公里），其次是一列波峰。1993年首次观测到中间层孔。从那时起，有许多额外的意见，但有限的详细了解。 该项目将定量评估中间层孔的动态和特征，包括支持它们的环境、产生它们的作用力及其对大气层的影响。 这项工作有两个主要组成部分：（1）扩展目前已经开发的数值模式，以包括中间层和低热层典型的更复杂的强迫和环境;（2）模拟观测到的气辉数据，同时进行激光雷达和雷达测量，描述热和风环境。 对于任务1，所提出的模型扩展将模拟孔的更真实的背景条件沿着各种类型的孔结构对这些条件的响应。 第二项任务将利用气辉、雷达和激光雷达观测提供有关大气背景热结构和钻孔如何在大气中传播的信息。数值研究将提高对钻孔动力学的定量理解，并确定如何扩展或修正现有理论以应用于实际环境。应用观察也将定义如何观察可以最好地量化孔动态以及相关的管道现象。 该项目更广泛的影响涉及更好地了解和量化中间层和低热层的能量和动量输送和沉积的影响，这影响到平均流量和全球环流模型。更好地理解中间层孔的非线性动力学也与低层大气和各种工程应用中的其他动力学类似现象有关。 该项目将支持一个新的研究人员在他完成博士学位后的第一次研究工作。