Wave-Wave Interactions and Upper Atmosphere Variability

行星波(PW)和潮汐波(TW)等大尺度垂直传播波是低层大气气象活动能量向高层大气传输的主要途径。这些波之间的耦合相互作用据信是作为二次波结构传输到上层大气和电离层的强可变性的一个来源，这可能会影响导航、通信和雷达跟踪系统。了解中间层和低热层(MLT)区域这种可变性的来源是空间物理学面临的主要挑战之一。这一奖项的重点将是研究这些大尺度波相互作用及其产生的次生波，办法是利用美国国家大气研究委员会大气环流模式(TIME-GCM)产生的为期一年的数据集，并结合使用全球尺度波模式(GSWM)，后者将模拟高层大气模式的低层大气输入。研究工作的更广泛影响将通过几种不同的方式实现：(A)通过与领导力与多样性(BOLD)中心的合作，与不同的学生群体接触；(B)通过发现学习学徒(DLA)计划，让本科生参与研究；(C)利用上述联系，教授研究生如何指导。对于出现非线性相互作用的个别情况，将使用非线性版本的GSWM模型进行数值实验，调查诸如两个主波的相位如何影响次波的产生等因素。这项工作的主要目标如下：1)描述和了解从低层大气向上传播的大气和潮汐之间相互作用的基本机制，2)量化这些相互作用对全球大气-电离层系统造成的变化，以及3)评估对地面和天基观测系统的影响。

Large-scale vertically-propagating waves such as planetary waves (PW) and tidal waves (TW) represent the primary means by which energy from lower atmosphere meteorological activity is transmitted into the upper atmosphere region. The coupling interaction between these waves is believed to be a source of strong variability that is transmitted into the upper atmosphere and ionosphere as secondary wave structures that could potentially affect navigation, communications and radar tracking systems. Understanding the origins of such variability in the mesosphere and lower thermosphere (MLT) region is one of the major challenges faced in space physics. This award would focus on studying these large-scale wave interactions and the secondary waves they produce by using a year-long dataset generated by the use of a NCAR general circulation model (TIME-GCM), coupled to the use of the Global Scale Wave Model (GSWM) that would provide simulations of the lower atmosphere inputs into the upper atmosphere model. The broader impacts of the research effort will be realized in several different ways: (a) engagement with a diverse population of students through partnership with the Broadening Opportunity through Leadership and Diversity (BOLD) Center; (b) engaging an undergraduate student in the research through the Discovery Learning Apprentice (DLA) Program; (c) leveraging the above connections to teach graduate students how to mentor. For individual cases where non-linear interactions are seen, a non-linear version of the GSWM model will be employed to perform numerical experiments, investigating factors such as how the phases of the two primary waves impact the generation of the secondary waves. The primary objectives of the work are as follows: 1) to delineate and understand the basic mechanisms underlying the interactions between PWs and tides propagating up from the lower atmosphere, 2) to quantify the variability imposed on the global atmosphere-ionosphere system by these interactions, and 3) to assess the implications for ground-based and space-based observing systems.